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1,911,518 | What are your favourite tools? | Vote for your favourites from the list below, and if you have a go-to tool that's missing, be sure to... | 0 | 2024-07-04T17:00:36 | https://dev.to/solitary-polymath/what-are-your-favourite-tools-2hk0 | webdev, beginners, survey | Vote for your favourites from the list below, and if you have a go-to tool that's missing, be sure to share it in the last section of the survey or you can share it in the comment section of this post.<br><br>
{% codepen https://codepen.io/solitary-polymath/pen/rNEByzJ %}
<br><br>
 | solitary-polymath |
1,911,799 | Advanced Digital Marketing Services | Title: Unleashing the Power of Advanced Digital Marketing Services In today’s hyper-connected world,... | 0 | 2024-07-04T17:00:31 | https://dev.to/amna_khan_63f1f5d464c3e2c/advanced-digital-marketing-services-5295 | **Title: Unleashing the Power of Advanced Digital Marketing Services**
In today’s hyper-connected world, businesses must evolve to stay relevant and competitive. Traditional marketing techniques, while still valuable, no longer suffice in an era where digital platforms dominate consumer interaction. This shift has led to the rise of advanced digital marketing services, which leverage cutting-edge technologies and strategies to reach, engage, and convert audiences more effectively than ever before.
## The Evolution of Digital Marketing
Digital marketing has come a long way since the early days of banner ads and basic email campaigns. Today, it encompasses a wide range of services, each designed to target specific aspects of consumer behavior and preferences. <a href="https://genetechagency.com/advanced-digital-marketing-services/">Advanced Digital Marketing Services</a> go beyond the basics, utilizing sophisticated tools and data-driven strategies to deliver personalized, high-impact campaigns.
## Key Components of Advanced Digital Marketing Services
1. **Search Engine Optimization (SEO):** SEO remains a cornerstone of digital marketing. However, advanced SEO goes beyond keyword optimization. It involves a deep understanding of search algorithms, user intent, and technical aspects like site architecture and page speed. Advanced SEO services also incorporate AI and machine learning to predict trends and optimize content dynamically.
2. **Content Marketing:** High-quality, relevant content is crucial for engaging and retaining customers. Advanced content marketing services use data analytics to understand audience preferences and create personalized content. This can include blog posts, videos, infographics, and interactive media that not only attract but also engage and convert visitors.
3. **Social Media Marketing:** Social media platforms are powerful tools for building brand awareness and loyalty. Advanced social media marketing involves more than just posting updates. It includes sophisticated strategies like influencer marketing, social listening, and hyper-targeted advertising. Using advanced analytics, businesses can measure the effectiveness of their campaigns and adjust in real-time.
4. **Email Marketing Automation:** While email marketing is a tried-and-true method, automation takes it to the next level. Advanced email marketing services utilize AI to segment audiences, personalize content, and trigger emails based on user behavior. This ensures that messages are timely, relevant, and more likely to drive action.
5. **Pay-Per-Click (PPC) Advertising:** PPC campaigns are a staple in digital marketing, but advanced services optimize every aspect of them. This includes precise keyword targeting, dynamic ad creation, and real-time bidding adjustments. AI-driven analytics help refine campaigns continually, ensuring maximum ROI.
6. **Data Analytics and AI:** Data is the backbone of advanced digital marketing. By leveraging big data and AI, businesses can gain deep insights into consumer behavior, campaign performance, and market trends. Predictive analytics help in anticipating future trends and making proactive adjustments to marketing strategies.
## The Role of AI and Machine Learning
Artificial intelligence (AI) and machine learning are revolutionizing digital marketing. These technologies enable more accurate targeting, personalized content, and efficient use of resources. For instance, AI algorithms can analyze vast amounts of data to identify patterns and trends that humans might miss. This leads to more effective segmentation, better customer experiences, and higher conversion rates.
Machine learning, a subset of AI, allows systems to learn and improve over time. In digital marketing, this means that campaigns can adapt dynamically based on real-time data. For example, a machine learning algorithm might adjust ad placements and budgets automatically to optimize performance continually.
## The Importance of a Multi-Channel Approach
Consumers interact with brands across multiple channels, including social media, email, search engines, and more. An advanced digital marketing strategy integrates these channels to provide a seamless and consistent customer experience. This multi-channel approach ensures that marketing efforts are cohesive and that customers receive a unified message, regardless of how they interact with the brand.
## The Future of Digital Marketing
As technology continues to evolve, so too will digital marketing. Emerging technologies like augmented reality (AR), virtual reality (VR), and the Internet of Things (IoT) are set to create new opportunities for engaging consumers in immersive and interactive ways. Additionally, the growing emphasis on data privacy and security will shape how marketers collect and use consumer information.
Businesses that embrace these advanced digital marketing services will be well-positioned to thrive in an increasingly digital world. By leveraging the latest technologies and strategies, they can create more effective, personalized, and impactful marketing campaigns.
In conclusion, the landscape of digital marketing is ever-changing, with new tools and techniques emerging regularly. Advanced digital marketing services are essential for businesses looking to stay ahead of the curve. By harnessing the power of SEO, content marketing, social media, email automation, PPC, and data analytics, companies can reach their target audiences more effectively and drive sustainable growth. | amna_khan_63f1f5d464c3e2c |
|
1,911,798 | Innovative JavaScript Features in 2024: Enhancing Developer Experience and Codebase Quality | The JavaScript language continues to evolve, and 2024 brings some exciting new features that will... | 0 | 2024-07-04T16:54:55 | https://dev.to/fido1hn/innovative-javascript-features-in-2024-enhancing-developer-experience-and-codebase-quality-5ah4 | javascript, ecma2024, node | The JavaScript language continues to evolve, and 2024 brings some exciting new features that will improve the developer experience and codebase quality. Let's explore some of these features and how they will benefit developers.
1)** Temporal**
Temporal is a proposal to introduce a new global object that replaces the existing Date object in JavaScript. This new object offers a more modern and intuitive API for working with dates, times, and time zones. With Temporal, developers can easily handle complex date and time-related tasks, ensuring accurate and reliable results. This feature will reduce the need for external libraries and minimize potential errors in date-related code.
2) **Pipe Operator**
The pipe operator (|>) is a new addition that enables developers to write more readable and maintainable code. This operator allows for chaining function calls in a left-to-right sequence, similar to the pipe operator in functional programming languages like F# and Elixir. By adopting the pipe operator, developers can eliminate complex nesting and create a clearer, more straightforward code flow.
3) **Records and Tuples**
Records and Tuples bring a more structured and immutable way of working with data in JavaScript. Records are immutable objects with a fixed set of properties, while Tuples are fixed-size arrays with named elements. These features allow developers to create complex data structures and ensure data integrity, promoting functional programming techniques and facilitating code maintainability.
4) **RegExp /v flag**
The RegExp /v flag introduces a more concise and maintainable syntax for regular expressions in JavaScript. This flag allows developers to define regular expressions with a verbose syntax that includes whitespace and comments, making it easier to read and understand complex regular expressions. The /v flag will help developers create more maintainable code and reduce the likelihood of errors when working with regular expressions.
5) **Decorators**
Decorators are a powerful feature that enables developers to modify or extend the behavior of functions, classes, and properties. With Decorators, developers can create reusable, higher-order abstractions that encapsulate common logic and patterns. This feature will improve code reusability and maintainability, making codebases more modular and easier to work with.
The new JavaScript features in 2024 offer developers a variety of tools and capabilities to enhance their coding experience and improve the overall quality of their codebases. By adopting these features, developers can create more maintainable, readable, and reliable code, ultimately resulting in better applications and a more productive development process.
Happy Coding ❤️ | fido1hn |
1,911,796 | Item 38: Emule enums extensíveis por meio de interfaces | Enums em Java: Enums são preferíveis aos padrões enum typesafe (descritos na primeira edição do... | 0 | 2024-07-04T16:49:07 | https://dev.to/giselecoder/item-38-emule-enums-extensiveis-por-meio-de-interfaces-38bc | java, javaefetivo | **Enums em Java:**
- Enums são preferíveis aos padrões enum typesafe (descritos na primeira edição do livro).
- A exceção é a extensibilidade, que era possível no padrão original, mas não é suportada pelas enums em Java.
**Extensibilidade de Enums:**
- Extensibilidade de enums geralmente é uma má ideia:
- Confusão entre elementos de tipos estendidos e tipos base.
- Dificuldade em enumerar todos os elementos de tipos base e suas extensões.
- Complica o design e implementação.
**Uso de Enums Extensíveis:**
- Útil em casos como códigos de operação (opcodes).
- Permite que usuários da API forneçam suas próprias operações.
**Solução com Interfaces:**
- Enums podem implementar interfaces arbitrárias.
- Defina uma interface para o tipo de opcode e um enum que implemente essa interface.
**Exemplo:**
- Operation (interface) e BasicOperation (enum) do Item 34.
- Criação de um enum que implemente a interface Operation.
**Uso na API:**
- Utilize o tipo da interface (Operation) nas APIs.
- Pode definir e usar enums estendidos que implementem a interface.
**Implementação:**
- Passar o literal de classe (ExtendedOperation.class) ou uma Collection<? extends Operation>.
**Limitações e Soluções:**
- Implementações não podem ser herdadas de um tipo enum para outro.
- Pode duplicar código ou usar métodos auxiliares estáticos para evitar duplicação.
**Exemplo na Biblioteca Java:**
- Tipo enum java.nio.file.LinkOption implementa as interfaces CopyOption e OpenOption.
**Resumo:**
- Emule enums extensíveis escrevendo uma interface para acompanhar um tipo enum base que implemente a interface.
- Clientes podem escrever seus próprios enums ou tipos que implementem a interface.
- Instâncias desses tipos podem ser usadas onde as instâncias do tipo enum base são usadas, desde que as APIs sejam escritas em termos da interface.
| giselecoder |
1,911,795 | What is the reason for the high number of full stack developers? | The rise in the number of full-stack developers is influenced by several factors related to the... | 0 | 2024-07-04T16:44:34 | https://dev.to/ndiaga/what-is-the-reason-for-the-high-number-of-full-stack-developers-5214 | The rise in the number of full-stack developers is influenced by several factors related to the demands of the tech industry, the benefits of full-stack development skills, and trends in software development practices. Here’s a detailed look at the reasons behind this trend:
**1. Broad Skill Set Requirements
A. Versatility in Skill Sets
Demand for Versatility: Full-stack developers are proficient in both front-end and back-end technologies, which allows them to work on all aspects of a project. This versatility makes them valuable to employers and startups looking for developers who can handle diverse tasks.
Wide Range of Technologies: Full-stack developers are skilled in various programming languages, frameworks, and tools, including HTML, CSS, JavaScript, and server-side languages like Node.js, Python, or PHP. This broad skill set enables them to tackle a variety of development challenges.
Examples:
Front-End: HTML, CSS, JavaScript, React, Angular
Back-End: Node.js, Python, PHP, Ruby on Rails, Java
**2. Increased Demand for Efficient Development
A. Need for Efficient Development Processes
Cost-Effectiveness: Companies prefer hiring full-stack developers because they can perform multiple roles, reducing the need for separate front-end and back-end developers. This leads to cost savings and more streamlined development processes.
Faster Development: Full-stack developers can manage the complete development process from start to finish, which speeds up project timelines and reduces the need for extensive coordination between different developers.
Examples:
Startup Teams: Small startups or teams often hire full-stack developers to manage end-to-end development.
Agile Environments: Full-stack developers fit well in agile development environments where flexibility and quick iterations are essential.
**3. Growth of Web and Mobile Application Development
A. Expansion of Web and Mobile Applications
Surge in Online Services: The rise of web and mobile applications has led to a higher demand for developers who can build and maintain these applications.
Cross-Platform Development: Full-stack developers can handle both web and mobile development, which is increasingly important as businesses look for cross-platform solutions.
Examples:
Web Apps: E-commerce platforms, content management systems
Mobile Apps: Social media apps, on-demand services
**4. Educational Opportunities and Learning Resources
A. Availability of Learning Resources
Accessible Education: The availability of online courses, bootcamps, and tutorials has made it easier for individuals to learn full-stack development skills.
Community Support: Strong developer communities and forums provide support for aspiring full-stack developers.
Examples:
Online Courses: Coursera, Udemy, Pluralsight
Bootcamps: General Assembly, Flatiron School, Codecademy
**5. Career Flexibility and Opportunities
A. Attractive Career Prospects
Job Opportunities: Full-stack development skills open up a wide range of job opportunities, from web development roles to positions in software engineering and project management.
Career Advancement: Full-stack developers have the flexibility to shift between different roles and technologies, which can lead to career growth and advancement.
Examples:
Job Titles: Full-Stack Developer, Software Engineer, Technical Lead
Career Paths: Development, Project Management, Technical Consulting
**6. Growth of Tech Startups and Small Businesses
A. Increase in Startups and Small Businesses
Startup Ecosystem: The growth of tech startups and small businesses has increased the demand for full-stack developers who can build and scale applications with limited resources.
Versatile Skills: Startups often require developers who can handle various tasks, making full-stack developers a preferred choice.
Examples:
Tech Startups: New ventures in fintech, healthtech, and edtech
Small Businesses: Local businesses expanding into online services
**7. Advancements in Development Frameworks and Tools
A. Evolution of Development Frameworks
Modern Frameworks: The development of robust full-stack frameworks and tools has made it easier for developers to become proficient in both front-end and back-end development.
Integration Tools: Tools for integration and deployment have simplified the process of managing full-stack applications.
Examples:
Frameworks: MERN Stack (MongoDB, Express.js, React, Node.js), MEAN Stack (MongoDB, Express.js, Angular, Node.js)
Deployment Tools: Docker, Kubernetes, CI/CD pipelines
**8. Increased Emphasis on Comprehensive Understanding
A. Importance of a Holistic Approach
Comprehensive View: A full-stack developer's ability to understand and manage both front-end and back-end components offers a comprehensive view of the entire application lifecycle.
Problem-Solving: Having a broad skill set allows developers to identify and solve issues across different parts of the development process.
Examples:
Problem-Solving: Debugging issues that span both the client and server sides
Holistic Understanding: Overseeing the entire development workflow from design to deployment
Conclusion
The high number of full-stack developers is driven by the demand for versatile, cost-effective, and efficient development solutions. Full-stack developers offer a broad skill set that covers both front-end and back-end development, which aligns well with the needs of modern businesses and startups.
If you’re interested in building a powerful e-commerce site, you might want to explore PrestaShop, an open-source platform that offers extensive features and customization options for creating your online store. You can also check out our MarketPlace Module at PrestaTuts.com for tools to help you build a successful e-commerce marketplace.
Additional Resources
What is a Full-Stack Developer?
The Benefits of Being a Full-Stack Developer
How to Become a Full-Stack Developer
Understanding these factors can help you appreciate why full-stack development is so popular and how you can leverage these skills for career growth or project success. | ndiaga |
|
1,911,735 | Building an AI-Powered Web Application with Next.js and TensorFlow.js | This tutorial is designed to guide you through building an AI-powered web application and showcase... | 0 | 2024-07-04T16:44:11 | https://dev.to/ivansing/building-an-ai-powered-web-application-with-nextjs-and-tensorflowjs-nf1 | nextjs, tensorflow, programming, ai | This tutorial is designed to guide you through building an AI-powered web application and showcase the potential of AI in everyday web development. Artificial Intelligence (AI) is revolutionizing modern web technology, making it more innovative and responsive. By incorporating AI, developers can enhance user experiences through features like real-time data analysis, personalized content recommendations, and advanced image recognition.
Next.js is a robust Reach framework that enables developers to quickly build server-side rendered and static web applications. It offers excellent performance, scalability, and a seamless developer experience. TensorFlow.js, on the other hand, TensorFlow.js is a Javascript library that allows you to train and run machine learning models directly in the browser. By combining Next.js and TensorFlow.js, you can create sophisticated web applications that leverage the power of AI without needing extensive backend infrastructure.
By the end of this tutorial, you will have built a fully functional AI-powered web application capable of performing image recognition tasks. You'll gain hands-on experience with Next.js and TensorFlow.js, learning how to integrate machine learning models into a modern web framework. This tutorial will equip you with the skills to start incorporating AI features into your projects, opening up new possibilities for innovation and user engagement.
## Setting Up the Environment
### Prerequisites:
- Basic JavaScript
- Node.js
- Code Editor
## Step 1: Setting Up the Project
First, ensure you have Node.js installed on your system. If you haven't already, you can download it from [nodejs.org](https://nodejs.org/en).
## Step 2: Installing Next.js
If you haven't installed Next.js yet, you can create a new Next.js project using the following command:
### Installing Next.js:
```bash
npx create-next-app ai-web-app
```
Test that the app is working as for now:
```bash
npm run dev
```
You will see the Next.js app on the page `http://localhost:3000`. If it works, we can proceed.
### Installing TensorFlow.js:
```bash
npm install @tensorflow/tfjs @tensorflow-models/mobilenet
```
### Project Structure
```bash
ai-web-app/
├── node_modules/
├── public/
├── src/
│ ├── pages/
│ │ ├── api/
│ │ │ └── hello.js
│ │ ├── _app.js
│ │ ├── _document.js
│ │ ├── index.js
│ ├── styles/
│ │ ├── globals.css
│ │ ├── Home.module.css
│ ├── utils/
│ │ └── imageProcessing.js
├── .gitignore
├── package.json
├── README.md
```
So, we have to add the following file:
- imageProcessing.js
- Edit src/pages/index.js:
Erase all the code and add the following ones:
## Part 1: Imports and State Initialization
1. Imports
- `Head` from `next/head`: Used to modify the `<head>` section of the HTML.
- `styles` from `../styles/Home.module.css`: Imports the CSS module for styling.
- `useState` from `react`: React hook for state management.
- `loadModel` and `loadImage` from `@/utils/imageProcessing`: Utility functions for loading the model and image.
2. State Initialization
- `model`: State to store the loaded TensorFlow model.
- `predictions`: State to store the predictions made by the model.
```javascript
import Head from "next/head";
import styles from "../styles/Home.module.css";
import { useState } from "react";
import { loadModel, loadImage } from "@/utils/imageProcessing";
export default function Home() {
const [model, setModel] = useState(null);
const [predictions, setPredictions] = useState([]);
```
## Part 2: Handling Image Analysis
3. handleAnalyzeClick Function:
- Retrieves the uploaded image file.
- Loads the image and passes it to the model for classification.
- Sets the predictions state with the results.
```javascript
const handleAnalyzeClick = async () => {
const fileInput = document.getElementById("image-upload");
const imageFile = fileInput.files[0];
if (!imageFile) {
alert("Please upload an image file.");
return;
}
try {
const image = await loadImage(imageFile);
const predictions = await model.classify(image);
setPredictions(predictions);
} catch (error) {
console.error('Error analyzing the image:', error);
}
};
```
1. Retrieving the Uploaded Image File:
```javascript
const fileInput = document.getElementById("image-upload");
const imageFile = fileInput.files[0];
```
- `document.getElementById("image-upload");`: This retrieves the file input element from the DOM. This element is where users upload their images.
- `const imageFile = fileInput.files[0];`: This gets the first file from the file input. The `files` property is an array-like object, so we select the first file uploaded.
2. Checking if an Image File is Uploaded:
```javascript
if (!imageFile) {
alert("Please upload an image file.");
return;
}
```
- `if (!imageFile)`: This checks if an image file is selected. If no file is selected, `imageFile` will be `null` or `undefined`.
- `alert("Please upload an image file.");`: If no file is selected, an alert message is displayed to the user.
- `return;`: The Function exits early if no file is selected, preventing further execution.
3. Loading the Image and Classifying It:
```javascript
try {
const image = await loadImage(imageFile);
const predictions = await model.classify(image);
setPredictions(predictions);
} catch (error) {
console.error('Error analyzing the image:', error);
}
```
- `try { ... } catch (error) { ... }`: The `try-catch` The block handles any errors during the image loading and classification process.
- Loading the Image:
```javascript
const image = await loadImage(imageFile);
```
- `loadImage(imageFile)`: This function is a utility that converts the image file into a format suitable for processing TensorFlow.js. It likely involves reading the file and creating an HTML image element or a TensorFlow.js tensor.
- `await`: This keyword ensures that the Function waits for the image loading to complete before moving to the next step.
- `const image =`: The loaded image is stored in the image Variable.
### Classifying the Image:
```javascript
const predictions = await model.classify(image);
```
- `model.classify(image)`: This method uses the TensorFlow.js model to classify the input image. It returns predictions about what the image contains.
- `await`: This ensures the Function waits for the classification process to complete.
- `const predictions =`: The classification results are stored in the predictions Variable.
### Setting Predictions State:
```javascript
setPredictions(predictions);
```
`setPredictions(predictions)`: This updates the predictions State with the new classification results. This triggers a re-render of the component, displaying the predictions to the user.
4. Handling Errors:
```javascript
catch (error) {
console.error('Error analyzing the image:', error);
}
```
catch (error) { ... }: This block catches any errors that occur during the try block.
console.error('Error analyzing the image:', error);: If an error occurs, it logs the error message to the console for debugging purposes.
## Part 3: Loading the TensorFlow Model
4. Model Loading:
- Uses a `useState` Hook to load the model when the component mounts.
- Sets the loaded model into the state.
```javascript
useState(() => {
(async () => {
try {
const loadedModel = await loadModel();
setModel(loadedModel);
} catch (error) {
console.error('Error loading the model:', error);
}
})();
}, []);
```
- Defines a React `useState` Hook that initializes and loads the TensorFlow.js model when the component mounts.
- It uses an immediately invoked asynchronous function to call the `loadModel` Function, which loads the model and sets it in the component's state using the `setModel` Function.
- If an error occurs during the model loading process, it catches the error and logs it to the console.
- The empty dependency array `[]` ensures this effect runs only once when the component is first rendered.
### Basic Layout
To begin building our AI-powered web application with Next.js and TensorFlow.js, we'll set up a basic layout using Next.js components. This initial structure will be the foundation for our application's user interface.
## Part 4: Rendering the UI
###5. Rendering:
- Renders the main layout of the application.
- Provides input for image upload and button for analysis.
- Displays the predictions if available.
## JSX Return Statement
### 1. Fragment Wrapper
```javascript
return (
<>
...
</>
```
`<> ... </>`: This React Fragment allows multiple elements to be grouped without adding extra nodes to the DOM.
### 2. Container Div
```javascript
<div className={styles.container}>
...
</div>
```
`<div className={styles.container}> ... </div>`: This div wraps the main content of the page and applies styling from the `styles.container` Class.
### 3. Head Component
```javascript
<Head>
<title>AI-Powered Web App</title>
</Head>
```
### 4. Main Content
```javascript
<main className={styles.main}>
...
</main>
```
`<main className={styles.main}> ... </main>`: This main element contains the primary content of the page and applies styling from the `styles.main` class
### 5. Title and Description
```javascript
<h1 className={styles.title}>AI-Powered Web Application</h1>
<p className={styles.description}>
Using Next.js and TensorFlow.js to show some AI model.
</p>
```
- `<h1 className={styles.title}> ... </h1>`: This heading displays the main title of the page with styling from the `styles.title` Class.
- `<p className={styles.description}> ... </p>`: This paragraph provides a brief description and is styled using the `styles.description` Class.
### 6. Input Area
```javascript
<div id="input-area">
<input type="file" className={styles.input} id="image-upload" />
<button className={styles.button} onClick={handleAnalyzeClick}>
Analyze Image
</button>
</div>
```
- `<div id="input-area"> ... </div>`: This div wraps the input elements for uploading and analyzing an image.
- `<input type="file" className={styles.input} id="image-upload" />`: This input element allows users to upload an image file. It uses the `styles.input` class for styling and has an ID of `image-upload`.
- `<button className={styles.button} onClick={handleAnalyzeClick}>Analyze Image</button>`: This button triggers the `handleAnalyzeClick function` when clicked. It is styled using the `styles.button` Class.
### 7. Ouput Area
```javascript
<div id="output-area">
{predictions.length > 0 && (
<ul>
{predictions.map((pred, index) => (
<li key={index}>
{pred.className}: {(pred.probability * 100).toFixed(2)}%
</li>
))}
</ul>
)}
</div>
```
- `<div id="output-area"> ... </div>`: This div contains the output area where predictions are displayed.
- `{predictions.length > 0 && ( ... )}`: This conditional rendering checks for predictions and renders the list of predictions if there are any.
- `<ul> ... </ul>`: An unordered list that will contain the prediction items.
- `predictions.map((pred, index) => ( ... ))`: This maps over the predictions Array and render each prediction as a list item.
- `<li key={index}> ... </li>`: Each list item displays the class name and probability of the prediction, formatted to two decimal places. The `key` attribute helps React identify which items have changed
Edit the Styles for the index.js file in Home.module.css erase all the code, and add the following one:
```css
.container {
min-height: 100vh;
padding: 0 0.5rem;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
}
.main {
padding: 5rem 0;
flex: 1;
display: flex;
flex-direction: column;
justify-content: center;
align-items: center;
}
.title {
margin: 0;
line-height: 1.15;
font-size: 4rem;
text-align: center;
}
.description {
margin: 4rem 0;
line-height: 1.5;
font-size: 1.5rem;
text-align: center;
}
#ouput-area {
margin-top: 2rem;
}
.li {
margin-top: 10px;
font-size: 20px;
}
.button {
margin-top: 1rem;
padding: 0.5rem 1rem;
font-size: 1rem;
cursor:pointer;
background-color: #0070f3;
color: white;
border: none;
border-radius: 5px;
}
.button:hover {
background-color: #005bb5;
}
```
Once you have done the previous steps, check to see something like this:
Now, let's work with the brain of the app. imageProcessing.js File:
## Part 1: Loading the Model
### Function: loadModel
```javascript
import * as tf from "@tensorflow/tfjs";
import * as mobilenet from "@tensorflow-models/mobilenet";
export async function loadModel() {
try {
const model = await mobilenet.load();
return model;
} catch (error) {
console.error("Error loading the model:", error);
throw error;
}
}
```
This Function loads the MobileNet model using TensorFlow.js. Here's a step-by-step explanation:
- Imports: The Function imports TensorFlow.js (`tf`) and the MobileNet model (`mobilenet`).
- Function Definition: The `loadModel` function is defined as an asynchronous function.
- Try-Catch Block: Within a try-catch block, the Function loads the MobileNet model asynchronously with `await mobilenet.load()`.
- Return Model: If successful, it returns the loaded model.
- Error Handling: If an error occurs, it logs the error to the console and throws it, allowing the calling function to handle it.
## Part 2: Preprocessing the Image
### Function: preprocesImage
```javascript
export function preprocesImage(image) {
const tensor = tf.browser
.fromPixels(image)
.resizeNearestNeighbor([224, 224]) // MobileNet input size
.toFloat()
.expandDims();
return tensor.div(127.5).sub(1); // Normalize to [-1, 1] range
}
```
This function preprocesses an image in the format required by MobileNet. Here's a step-by-step explanation:
- Function Definition: The `preprocesImage function` is defined to take an image as an argument.
- Tensor Conversion: The Function converts the image to a tensor using `tf.browser.fromPixels(image)`.
- Resize: It resizes the image tensor to `[224, 224]`, which is the required input size for MobileNet.
- Float Conversion: The tensor is then converted to a float using `.toFloat()`.
- Add Dimension: The tensor is expanded to include a batch dimension using `.expandDims()`.
- Normalization: Finally, the tensor is normalized to a range of `[-1, 1]` by dividing by `127.5` and subtracting `1`.
## Part 3: Loading the Image
### Function: loadImage
```javascript
export function loadImage(file) {
return new Promise((resolve, reject) => {
const reader = new FileReader();
reader.onload = (event) => {
const img = new Image();
img.src = event.target.result;
img.onload = () => resolve(img);
};
reader.onerror = (error) => reject(error);
reader.readAsDataURL(file);
});
}
```
This Function loads an image file and returns an HTML Image element. Here's a step-by-step explanation:
- Function Definition: The `loadImage function` is defined to take a file as an argument.
- Promise Creation: The Function returns a new Promise, which resolves with the loaded image or rejects with an error.
- FileReader: A `FileReader` Object is created to read the file.
- Reader onLoad: The `onload` event handler of the reader is defined. It creates a new Image Object sets its source to the file reader's result and resolves the promise with the image once it is loaded.
- Reader onError: The `onerror` event handler of the reader is defined to reject the promise with an error if one occurs.
Read File: The file reader reads the file as a data URL using `reader.readAsDataURL(file)`.
Now you can test this final project by uploading images to the project's page and seeing the final results; if you have any problems, please check the provided link to clone the project from Github:
[Github repository project](https://github.com/ivansing/ai-web-app)
## Conclusion
This tutorial taught you how to build an AI-powered web application using Next.js and TensorFlow.js. We covered:
1. **Setting Up the Environment**: You installed Next.js and TensorFlow.js and set up your development environment.
2. **Creating the User Interface**: You made a simple UI for uploading images and displaying predictions.
3. **Integrating TensorFlow.js**: You integrated the MobileNet model to perform image classification directly in the browser.
By combining Next.js and TensorFlow.js, you can create sophisticated web applications that leverage the power of AI, enhancing user experiences with features like image recognition.
## Next Steps
To further improve your application, consider exploring these additional features:
- **Enhanced UI**: Improve the user interface with more advanced styling or additional features.
- **Additional Models**: Integrate other pre-trained models from TensorFlow.js or train your custom models.
- **Real-Time Data**: Implement real-time data processing and display for dynamic user interactions.
## Additional Resources
- [Next.js Documentation](https://nextjs.org/docs)
- [TensorFlow.js Documentation](https://www.tensorflow.org/api_docs)
- [MobileNet Model Documentation](https://github.com/tensorflow/tfjs-models/tree/master/mobilenet)
- [Vercel Documentation](https://vercel.com/docs)
## About the Author
Ivan Duarte is a backend developer with experience working freelance. He is passionate about web development and artificial intelligence and enjoys sharing their knowledge through tutorials and articles. Follow me on [X](https://x.com/ldway27), [Github](https://github.com/ivansing), and [LinkedIn ](https://www.linkedin.com/in/lance-dev/)for more insights and updates.
| ivansing |
1,911,793 | Create a Node Server using Hono | Hono, as per the docs, was originally built for Cloudflare Workers. It's an application framework... | 0 | 2024-07-04T16:44:02 | https://syntackle.com/blog/node-http-server-using-hono/ | javascript, webdev, beginners, node |
Hono, as per the docs, was originally built for [Cloudflare Workers](https://hono.dev/docs/concepts/motivation). It's an application framework designed to work the best for cloudflare pages and workers as well as javascript runtimes Deno and Bun. Although not built specifically for Node, an adapter can be used to run it in Node.
In this tutorial, you will get to know how you can create a simple HTTP server in Node using Hono in less than 10 lines of code.
## Prerequisites
Create a bare bones node environment using `npm init -y`.
## Setting Up Hono
Install hono from `npm` along with its nodejs adapter.
```bash
npm i hono @hono/node-server
```
## Creating A Server
1. Create a file named `index.mjs` and then, import Hono and its nodejs adapter.
```js
import { Hono } from "hono"
import { serve } from "@hono/node-server"
```
2. Initialize a new Hono app.
```js
const app = new Hono()
```
3. Handle a simple GET route.
```js
app.get("/", (context) => context.json({ "hello": "world" }))
```
4. Serve the app using the nodejs adapter.
```js
serve({ port: 3000, fetch: app.fetch }, (i) => console.log(`listening on port ${i.port}...`))
```
Here's a snippet of all the code combined:
```js
import { Hono } from "hono"
import { serve } from "@hono/node-server"
const app = new Hono()
app.get("/", (context) => context.json({ "hello": "world" }))
serve({ port: 3000, fetch: app.fetch }, (i) => console.log(`listening on port ${i.port}...`))
```
## Conclusion
One highlight of Hono is its [Regexp router](https://hono.dev/docs/api/routing#regexp). It allows you to define routes which match a regex pattern. Apart from that, it also offers multiple built-in authentication modules for implementing various authentication methods such as [basic](https://hono.dev/docs/middleware/builtin/basic-auth), [bearer](https://hono.dev/docs/middleware/builtin/bearer-auth), and [jwt](https://hono.dev/docs/middleware/builtin/jwt). | murtuzaalisurti |
1,911,792 | I created an npm package! Introducing React Native Social PostCard: A Key Component for Social Media Apps | Imagine you’re building a new social media app and you want to add a polished, customizable post... | 0 | 2024-07-04T16:43:41 | https://dev.to/covenantcodes__/i-created-an-npm-package-introducing-react-native-social-postcard-a-key-component-for-social-media-apps-26od | Imagine you’re building a new social media app and you want to add a polished, customizable post component to enhance user engagement. This is where [React Native Social PostCard](https://www.npmjs.com/package/react-native-social-postcard) comes into play, offering a sleek and interactive solution to showcase posts within your app.
## The Birth of an Idea
The journey of React Native Social PostCard began with a simple problem. I was creating a social app and then I discovered that there isn’t any useable postcard package available in the npm library so I decide to make one. To my surprise, in less than a week of zero marketing or publicizing I had over a hundred downloads already. This simple idea will provide developers with an easy-to-use component that can seamlessly integrate into any social media application built with React Native. The goal was to encapsulate all the essential features of a social media post, from displaying the author’s information and post content to enabling user interactions like liking, commenting, and bookmarking.
Check out the documentation [here](https://www.npmjs.com/package/react-native-social-postcard)
## Here is a Demo of the Component :
## Installation: Setting Up the Scene
Before diving into the features, let’s get the package set up in your project. Installation is straightforward with npm or yarn:
```
npm install react-native-vector-icons
# or
yarn add react-native-vector-icons
```
Next, install the React Native Social PostCard package:
```
npm install react-native-social-postcard
# or
npm install react-native-social-postcard
```
With these simple commands, you’re ready to start incorporating the PostCard component into your application.
## A Closer Look at the PostCard Component
The PostCard component is the heart of this package, designed to display a complete social media post. It comes with several customizable props that give you control over its appearance and behavior.
**- post (object):** This prop is crucial as it holds the post details, such as the author’s name, timestamp, avatar, images, and the full text of the post. It also includes the number of likes.
**- colors (object):** Allows customization of the colors for like, comment, and bookmark icons, making it easy to match the component to your app’s theme.
**- commentCount (number):** Displays the number of comments on the post.
**- onCommentPress (function):** A function triggered when the comment button is pressed.
**- onBookmarkPress (function):**A function triggered when the bookmark icon is pressed.
**- onPicturePress (function):** A function triggered when an image in the post is pressed.
Each prop is designed to ensure that the component is both functional and flexible, fitting seamlessly into various use cases.
Unpacking the Post Object
The `post `object is the backbone of the PostCard component. It has a specific structure:
```
{
author: PropTypes.string.isRequired,
timestamp: PropTypes.string.isRequired,
avatar: PropTypes.oneOfType([PropTypes.string, PropTypes.object]).isRequired,
images: PropTypes.arrayOf(PropTypes.oneOfType([PropTypes.string, PropTypes.object])).isRequired,
fullText: PropTypes.string.isRequired,
likeCount: PropTypes.number
}
```
This structure ensures that all necessary information about the post is provided, allowing the component to render it accurately.
## Customizing Colors for Better UX
To align the PostCard with your app’s design, the colors object lets you specify the colors for various icons:
**- likeOutlineColor:** Color for the outline of the like icon (default: “#403C9A”).
**- likeFilledColor:** Color for the filled like icon (default: “#FF0000”).
**- commentColor:** Color for the comment icon (default: “#403C9A”).
**- bookmarkOutlineColor:** Color for the outline of the bookmark icon (default: “#403C9A”).
**- bookmarkFilledColor:** Color for the filled bookmark icon (default: “#0000FF”).
These settings ensure that the component not only functions well but also looks great within your app’s user interface.
## Breaking Down the Components
The package includes several subcomponents, each designed to handle a specific part of the post:
**1. PostHeader:** Displays the author’s name, post timestamp, and avatar.
Props: author (string), timestamp (string), avatar (object)
**2. PostContent: **Renders the main content of the post, including text and images.
Props: fullText (string), images (array), onPicturePress (function)
**3. PostActions:** Manages the action buttons for liking, commenting, and bookmarking.
Props: liked (bool), likeCount (number), toogleLike (function), onCommentPress (function), handleBookMark (function), commentCount (number), bookmark (bool), colors (object)
These components work together to create a cohesive and interactive post experience for users.
## The Road Ahead
React Native Social PostCard is more than just a component; it’s a tool designed to enhance user interaction and engagement within your social media app. By integrating this package, you can focus on building out other features while ensuring that your posts look and feel great.
In conclusion, the journey of creating a social media app involves many steps, and having reliable, customizable components like React Native Social PostCard can significantly ease the process. Whether you’re building a new app from scratch or enhancing an existing one, this package provides the versatility and functionality needed to create a compelling user experience.
Ready to give it a try? Install [React Native Social PostCard](https://www.npmjs.com/package/react-native-social-postcard) today and take the first step towards a more interactive and engaging social media application. | covenantcodes__ |
|
1,911,790 | Mastering Cypher Query Language for Neo4j Graph NoSQL Databases | Introduction The Cypher Query Language (CQL) is a powerful tool designed for querying... | 0 | 2024-07-04T16:42:03 | https://blog.spithacode.com/posts/8f153562-1269-443a-a87d-7681711d0cbf | webdev, javascript, nosql, beginners | ## Introduction
The Cypher Query Language (CQL) is a powerful tool designed for querying graph databases. Unlike traditional relational databases, graph databases excel in managing heavily connected data with undefined relationships. CQL provides a syntax that is both intuitive and powerful, making it easier to create, read, update, and delete data stored in graph databases. In this comprehensive guide, we'll explore the features, constraints, terminologies, and commands of CQL, along with practical examples to help you harness its full potential.
## Features of Cypher Query Language (CQL)
### Suitable for Heavily Connected Data
One of the standout features of CQL is its suitability for data that is heavily connected. Unlike relational databases, where relationships are often complex and cumbersome to manage, graph databases thrive on connections. CQL allows for intuitive and efficient querying of these relationships, making it an ideal choice for social networks, recommendation engines, and more.
### Multiple Labels for Nodes
In CQL, a node can be associated with multiple labels. This flexibility allows for better organization and categorization of data. For instance, a node representing a person can have labels such as Person, Employee, and Customer, each representing different aspects of the individual's identity.
## Constraints of CQL
### Fragmentation Limitations
While CQL is powerful, it does have some constraints. Fragmentation is only possible for certain domains. This means that, in some cases, data may need to be traversed in its entirety to retrieve a definitive answer.
### Full Graph Traversal for Definitive Answers
For some queries, especially those involving complex relationships, the entire graph may need to be traversed to ensure that the returned data is accurate and complete. This can be resource-intensive and time-consuming, depending on the size and complexity of the graph.
## Terminologies in CQL
### Node
A node represents an entity in the graph. Nodes can have properties that store information about the entity, such as name, age, or any other relevant attribute.
### Label
Labels allow for the grouping of nodes. They replace the concept of tables in SQL. For example, a node with a label Person groups all nodes that represent people.
### Relation
A relation is a materialized link between two nodes. This replaces the notion of relationships in SQL, enabling direct connections between entities.
### Attributes
Attributes are properties that a node or a relation can have. For instance, a Person node may have attributes such as name and age, while a LIKES relationship may have attributes like since.
## Basic Commands in CQL
### CREATE
The CREATE command is used to create nodes and relationships. This is fundamental for building the graph structure.
### MATCH
The MATCH command is used to search for patterns in the graph. It is the cornerstone of querying in CQL, allowing you to retrieve nodes and relationships based on specified criteria.
## Creating Nodes
### Basic Node Creation
Creating nodes in CQL is straightforward. Use the CREATE command followed by the node details.
```
CREATE (:Person {name:\"John\", age:30})
CREATE (:Food {name:\"Pizza\"})
```
### Creating Nodes with Properties
Nodes can be created with properties, which are key-value pairs that store information about the node.
```
CREATE (:Person {name:\"Jane\", age:25, occupation:\"Engineer\"})
CREATE (:Food {name:\"Burger\", calories:500})
```
## Searching Nodes
### Basic Node Search
The MATCH command allows you to search for nodes in the graph.
```
MATCH (p:Person) RETURN p
```
### Advanced Search with WHERE Clause
For more specific searches, use the WHERE clause to filter nodes based on their properties.
```
MATCH (p:Person)
WHERE p.age > 20
RETURN p.name, p.age
```
## Creating Relationships
### Creating Relationships While Creating Nodes
You can create relationships between nodes as you create them.
```
CREATE (p:Person {name:\"John\", age:30})-[:LIKES]->(f:Food {name:\"Pizza\"})
```
### Creating Relationships Between Existing Nodes
Relationships can also be created between existing nodes using the MATCH command.
```
MATCH (p:Person {name:\"John\"})
MATCH (f:Food {name:\"Pizza\"})
CREATE (p)-[r:LIKES]->(f)
RETURN r
```
## Modifying Nodes and Relationships
### Adding Attributes
Attributes can be added to existing nodes using the SET command.
```
MATCH (p:Person {name:\"John\"})
SET p.occupation = \"Developer\"
RETURN p
```
### Deleting Attributes
To delete an attribute, set its value to NULL.
```
MATCH (p:Person {name:\"John\"})
SET p.age = NULL
RETURN p
```
### Modifying Attributes
Attributes can be modified by setting them to new values.
```
MATCH (p:Person {name:\"John\"})
SET p.age = 35
RETURN p
```
## Using Aggregate Functions in CQL
### COUNT
The COUNT function returns the number of nodes or relationships.
```
MATCH (n) RETURN count(n)
```
### AVG
The AVG function calculates the average value of a numeric property.
```
MATCH (n) RETURN avg(n.age)
```
### SUM
The SUM function calculates the total sum of a numeric property.
```
MATCH (n) RETURN sum(n.age)
```
## Advanced Queries in CQL
### Number of Relations by Type
To get the count of each type of relationship in the graph, use the type function.
```
MATCH ()-[r]->() RETURN type(r), count(*)
```
### Collecting Values into Lists
The COLLECT function creates a list of all values for a given property.
```
MATCH (p:Product)-[:BELONGS_TO]->(o:Order)
RETURN id(o) as orderId, collect(p)
```
## Database Maintenance in CQL
### Deleting Nodes and Relationships
To delete all nodes and relationships, use the DELETE command.
```
MATCH (a)-[r]->(b) DELETE a, r, b
```
### Visualizing Database Schema
Visualize the database schema to understand the structure of your graph.
```
CALL db.schema.visualization YIELD nodes, relationships
```
## Practical Tricks and Tips
### Finding Specific Nodes
Here are three ways to find a node representing a person named Lana Wachowski.
```
// Solution 1
MATCH (p:Person {name: \"Lana Wachowski\"})
RETURN p
// Solution 2
MATCH (p:Person)
WHERE p.name = \"Lana Wachowski\"
RETURN p
// Solution 3
MATCH (p:Person)
WHERE p.name =~ \".*Lana Wachowski.*\"
RETURN p
```
### Complex Query Examples
Display the name and role of people born after 1960 who acted in movies released in the 1980s.
```
MATCH (p:Person)-[a:ACTED_IN]->(m:Movie)
WHERE p.born > 1960 AND m.released >= 1980 AND m.released < 1990
RETURN p.name, a.roles
```
Add the label Actor to people who have acted in at least one movie.
```
MATCH (p:Person)-[:ACTED_IN]->(:Movie)
WHERE NOT (p:Actor)
SET p:Actor
```
## Application Examples
### Real-World Use Cases
Consider a database for an online store where you need to manage products, clients, orders, and shipping addresses. Here's how you might model this in CQL.
### Example Queries
Let's create some example nodes and relationships for an online store scenario:
```
CREATE (p1:Product {id: 1, name: \"Laptop\", price: 1000})
CREATE (p2:Product {id: 2, name: \"Phone\", price: 500})
CREATE (c:Client {id: 1, name: \"John Doe\"})
CREATE (o:Order {id: 1, date: \"2023-06-01\"})
CREATE (adr:Address {id: 1, street: \"123 Main St\", city: \"Anytown\", country: \"USA\"})
```
Now, let's create the relationships between these nodes:
```
CREATE (p1)-[:BELONGS_TO]->(o)
CREATE (p2)-[:BELONGS_TO]->(o)
CREATE (c)-[:MADE]->(o)
CREATE (o)-[:SHIPPED_TO]->(adr)
```
### Querying Products Ordered in Each Order
To find out the products ordered in each order, including their quantity and unit price, use the following query:
```
MATCH (p:Product)-[:BELONGS_TO]->(o:Order)
RETURN id(o) as orderId, collect(p)
```
### Querying Clients and Shipping Addresses
To determine which client made each order and where each order was shipped, use this query:
```
MATCH (c:Client)-[:MADE]->(o:Order)-[:SHIPPED_TO]->(adr:Address)
RETURN c.name as client, id(o) as orderId, adr.street, adr.city, adr.country
```
## FAQ
What is Cypher Query Language (CQL)?
Cypher Query Language (CQL) is a powerful query language designed specifically for querying and updating graph databases. It allows you to interact with data in a way that emphasizes the relationships between data points.
How does CQL differ from SQL?
While SQL is designed for querying relational databases, CQL is designed for graph databases. This means that CQL excels at handling complex, highly connected data, whereas SQL is better suited for tabular data structures.
Can I use CQL with any database?
CQL is primarily used with Neo4j, a popular graph database management system. However, other graph databases may have their own query languages with similar capabilities.
What are the benefits of using CQL?
CQL allows for intuitive querying of graph databases, making it easier to manage and analyze data with complex relationships. It supports a rich set of commands for creating, updating, and deleting nodes and relationships, as well as powerful query capabilities.
Is CQL difficult to learn?
CQL is designed to be user-friendly and intuitive. If you are familiar with SQL, you will find many similarities in CQL. The main difference lies in how data relationships are handled.
How can I optimize my CQL queries?
Optimizing CQL queries involves understanding your graph's structure and using efficient query patterns. Indexing frequently searched properties and avoiding unnecessary full graph traversals can significantly improve performance.
## Conclusion
Cypher Query Language (CQL) is a robust tool for managing graph databases, offering powerful capabilities for querying and updating complex, highly connected data. By mastering CQL, you can leverage the full potential of graph databases, making it easier to handle intricate data relationships and perform sophisticated analyses. | stormsidali2001 |
1,911,789 | How long did it take for the Shopify team to develop their e-commerce platform from the ground up? | Shopify’s journey from a small startup to a major e-commerce platform is quite fascinating. Here’s an... | 0 | 2024-07-04T16:39:11 | https://dev.to/ndiaga/how-long-did-it-take-for-the-shopify-team-to-develop-their-e-commerce-platform-from-the-ground-up-2npi | Shopify’s journey from a small startup to a major e-commerce platform is quite fascinating. Here’s an overview of their development timeline and the availability of their source code:
Development Timeline of Shopify
**1. Initial Development (2004 - 2006)
Founding: Shopify was founded in 2004 by Tobias Lütke, Daniel Weinand, and Scott Lake. Initially, the platform was created to address challenges the founders faced while building their own online store.
First Release: The platform was launched in 2006. The team initially focused on building a simple, user-friendly e-commerce solution for small businesses.
**2. Early Growth and Expansion (2006 - 2010)
Feature Expansion: In the years following its launch, Shopify added more features, improved the platform’s stability, and began to expand its customer base.
Funding and Growth: Shopify received its first significant round of funding in 2010, which allowed them to further develop the platform and grow their team.
**3. Continued Development and Major Updates (2010 - Present)
Platform Evolution: Over the years, Shopify has continued to evolve, adding features such as mobile commerce, advanced analytics, and third-party app integrations.
Acquisitions: The company has made several strategic acquisitions to enhance its capabilities, including acquiring companies specializing in e-commerce solutions and technology.
Summary:
Initial Development to Launch: Approximately 2 years (2004 - 2006).
Ongoing Development: Continuous over the years with major updates and feature expansions.
Is There Any Open Source Code Available for Shopify’s Platform?
No, Shopify’s Code is Not Open Source
Proprietary Software: Shopify is a proprietary platform, and its core source code is not available as open source.
Shopify API: While the core code is proprietary, Shopify provides a robust API that allows developers to build apps, integrations, and custom features on top of the platform.
Shopify Themes and Apps: There are many themes and apps available through the Shopify Theme Store and Shopify App Store, but these are also managed under Shopify’s commercial licensing agreements.
Alternative: PrestaShop for Your E-Commerce Needs
If you’re looking for a powerful and flexible e-commerce platform, consider using PrestaShop. PrestaShop is an open-source platform with a wide range of features and a large community of developers.
Why Choose PrestaShop?
Open Source Code: Unlike Shopify, PrestaShop’s source code is open for modification. You can customize the platform to fit your specific needs.
Feature-Rich Platform: PrestaShop offers robust features out-of-the-box, including advanced product management, SEO tools, and multi-language support.
Flexible and Scalable: The platform can be tailored to both small businesses and large enterprises.
MarketPlace Module: For building a multi-vendor marketplace, you can use our MarketPlace Module from PrestaTuts.com. This module allows you to create a platform where multiple sellers can list their products, similar to eBay or Amazon.
Explore PrestaShop and Our MarketPlace Module
PrestaShop Official Website: PrestaShop
MarketPlace Module: NS Help Desk on PrestaTuts.com
Benefits of Using PrestaShop Over Shopify:
Customization: Full access to the codebase allows for extensive customization.
Cost-Effective: Lower costs compared to Shopify’s subscription plans and transaction fees.
Community Support: A large community for support and development.
Conclusion
Shopify’s Development Timeline: Shopify took around 2 years from its founding to launch, and its development has been ongoing with continuous updates and improvements since then.
Source Code: Shopify’s core code is proprietary, but you can utilize their API for integrations and customizations.
Alternative Solution: If you’re interested in an open-source platform with extensive features and customization options, PrestaShop is a strong alternative. For building a multi-vendor marketplace, you can leverage our MarketPlace Module from PrestaTuts.com.
Feel free to reach out if you have more questions or need further assistance with PrestaShop!
Additional Resources
PrestaShop vs. Shopify: Which is Better for Your Business?
How to Build a Multi-Vendor Marketplace with PrestaShop
PrestaTuts Blog: E-Commerce Tips and Tools
This detailed breakdown provides a comprehensive view of Shopify’s development and offers a solid alternative with PrestaShop for your e-commerce needs. | ndiaga |
|
1,911,788 | Linux users creation with Bash script | Introduction In a growing organization, managing user accounts efficiently is crucial.... | 0 | 2024-07-04T16:38:58 | https://dev.to/adesokan_israel_109436759/linux-users-creation-with-bash-script-4733 | ##Introduction
In a growing organization, managing user accounts efficiently is crucial. Automating the process can save significant time and reduce errors. This article explains a Bash script designed to read a list of users and groups from a text file, create the users and groups, set up home directories, generate passwords, and log all actions. This script is particularly useful for SysOps engineers responsible for maintaining system user accounts.
The purpose of this blog is to provide solution for the creation of Linux users using bash script in an automated and reliable way. Below is the scenario for the problem statement.
Your company has employed many new developers. As a SysOps engineer, write a bash script called create_users.sh that reads a text file containing the employee’s usernames and group names, where each line is formatted as user;groups.
The script creates users and groups as specified, set up home directories with appropriate permissions and ownership, generate random passwords for the users, and log all actions to /var/log/user_management.log. Additionally, store the generated passwords securely in /var/secure/user_passwords.txt.
## **Script Overview**
The create_users.sh script reads a text file where each line is formatted as user;groups, creates the users and groups, sets up home directories, and generates random passwords. Actions are logged to /var/log/user_management.log, and passwords are securely stored in /var/secure/user_passwords.csv.
## Detailed Breakdown
Log and Secure Password File Setup:
The script begins by setting up the log file and secure password file. It ensures that the directories exist and sets appropriate permissions for the password file.
```
LOG_FILE="/var/log/user_management.log"
PASSWORD_FILE="/var/secure/user_passwords.csv"
mkdir -p /var/log
touch $LOG_FILE
mkdir -p /var/secure
touch $PASSWORD_FILE
chmod 600 $PASSWORD_FILE
```
Logging Function:
A function is defined to log messages with timestamps.
```sh
log_message() {
echo "$(date +'%Y-%m-%d %H:%M:%S') - $1" >> $LOG_FILE
}
```
Password Generation
A helper function generates random passwords.
```sh
generate_password() {
tr -dc A-Za-z0-9 </dev/urandom | head -c 12
}
```
- Input File Check
The script checks if an input file is provided and exits if not.
```sh
if [ -z "$1" ]; then
echo "Usage: $0 <user-file>"
exit 1
fi
USER_FILE="$1"
```
- Processing the Input File
The script reads the input file line by line, ignoring whitespace and empty lines, and processes each user.
```sh
while IFS=';' read -r username groups; do
username=$(echo $username | xargs)
groups=$(echo $groups | xargs)
[ -z "$username" ] && continue
```
- Creating Users and Groups
For each user, the script checks if the user already exists, creates the primary group (same as the username), creates the user, sets up home directory permissions, and generates a password.
```sh
if id -u "$username" >/dev/null 2>&1; then
log_message "User $username already exists"
else
groupadd "$username"
log_message "Group $username created"
useradd -m -g "$username" -s /bin/bash "$username"
log_message "User $username created with home directory /home/$username"
chmod 700 "/home/$username"
log_message "Set permissions for /home/$username"
password=$(generate_password)
echo "$username:$password" | chpasswd
log_message "Password set for user $username"
echo "$username,$password" >> $PASSWORD_FILE
fi
```
- Adding Users to Additional Groups
The script then adds the user to any additional groups specified in the input file.
```sh
if [ -n "$groups" ]; then
IFS=',' read -ra GROUP_ARRAY <<< "$groups"
for group in "${GROUP_ARRAY[@]}"; do
group=$(echo $group | xargs)
if ! getent group "$group" >/dev/null; then
groupadd "$group"
log_message "Group $group created"
fi
usermod -aG "$group" "$username"
log_message "User $username added to group $group"
done
fi
```
#### Completion
Finally, the script logs the completion of the user creation process.
"log_message "User creation process completed"
echo "User creation process completed. Check the log file at $LOG_FILE for details."
To run and test the create_users.sh script, follow these steps:
Step 1:
#### Prepare Your Environment
Ensure you have the necessary permissions to create users, groups, and modify system files. Running the script might require superuser privileges.
Step 2:
#### Create the Input File
Create a text file with the usernames and groups. For example, create a file named users.txt with the following content:
```sh
isreal;sudo,dev,www-data
isreal2;sudo
isreal3;dev,www-data
```
Step 3:
#### Ensure Necessary Directories Exist
Ensure that the directories /var/log and /var/secure exist and have the appropriate permissions. You might need to create them if they don't exist:
```sh
sudo mkdir -p /var/log /var/secure
sudo touch /var/log/user_management.log /var/secure/user_passwords.csv
sudo chmod 600 /var/secure/user_passwords.csv
```
Step 4:
#### Run the Script
To execute the script, use the following command, passing the name of the input file as an argument:
```sh
sudo bash create_users.sh users.txt
```
Step 5:
#### Verify the Script's Actions
Check the Log File: Verify the actions logged in /var/log/user_management.log.
```sh
sudo cat /var/log/user_management.log
```
Check the Passwords File: Verify the securely stored passwords in /var/secure/user_passwords.csv.
```sh
sudo cat /var/secure/user_passwords.csv
```
Verify User and Group Creation: Check if the users and groups were created correctly.
List users and groups
```sh
getent passwd | grep -E 'isreal|isreal2|isreal3'
getent group | grep -E 'isreal|sudo|dev|www-data'
```
Check Home Directory Permissions:
Ensure the home directories were created with the correct permissions.
```sh
ls -ld /home/isreal /home/isreal2 /home/isreal3
```
## Conclusion
With this, we have successfully automated user creation with a Bash script which could help to reduce errorand ensure reliability, from defining user details in users.txt to execution, the project has transitioned from execution to completion.
To be part of the program that provided this task scenario, visit their official websites to gain more insights
https://hng.tech/internship
https://hng.tech/hire
Thanks for reading | adesokan_israel_109436759 |
|
1,911,949 | How to Split Files using Winrar in Windows 11? | Splitting a single large file is crucial when trying to upload and transfer it to someone. Most... | 0 | 2024-07-05T03:15:52 | https://winsides.com/how-to-split-files-using-winrar-in-windows-11/ | beginners, windows11, tips, tutorials | ---
title: How to Split Files using Winrar in Windows 11?
published: true
date: 2024-07-04 16:38:38 UTC
tags: beginners,Windows11,Tips,Tutorials
canonical_url: https://winsides.com/how-to-split-files-using-winrar-in-windows-11/
cover_image: https://winsides.com/wp-content/uploads/2024/07/How-to-Split-Files-using-WinRar-in-Windows-11.png
---
**Splitting a single large file** is crucial when trying to **upload and transfer it to someone**. Most online platforms restrict the **uploading of large files** to save on their **server bandwidth costs**. While **input bandwidth is often free** , **output bandwidth** , especially for **downloading large files** , can be expensive. Many **online file transfer websites** limit single file uploads to **less than 500MB**. If you want to transfer a **movie that is 4GB in size** , it becomes impossible to do so via an online portal. To overcome this issue, you can use **WinRAR** to **split your movie into multiple 400MB files** and create final **ZIP files**. This way, you can upload all the **ZIP files to the transfer portal without any problems**.
**Splitting files** might be difficult or completely new to many users, so I have detailed steps and instructions to perform **file splitting using WinRAR in Windows 11**. Let’s get into the tutorial.
## Installing WinRar Application:
- Installing WinRAR is the first step in splitting large files.
- You can download the latest version of WinRAR from their official website: [https://www.win-rar.com/download.html](https://www.win-rar.com/download.html).
- Once you have downloaded the WinRAR.exe file, proceed with the installation process.
- You can verify that the installation process has been completed successfully by searching for “WinRAR” in the Start Menu. The application will be displayed as shown in the image below.
_WinRar application installed successfully_
## Splitting Files using WinRar:
- Now, you need to go to the directory where the large file you want to split is located.
_Files Directory_
- Now, you need to hold the “ **Shift** ” key on the keyboard and right-click the file that needs to be split to view the expanded right-click options directly!
- In the expanded options, choose the “ **Add to archive** ” option. This will launch the WinRAR application.
_Add to Archive option in WinRar_
- Now, you need to rename your file if needed; otherwise, you can leave it as is. It is recommended to choose the **.zip** format instead of the **.rar** format.
- Then, you need to set the size in the “ **Split into volumes, size** ” option. By default, it is set to **5MB** replace it with your own values. Currently, it supports **Bytes (B)**, **Kilobytes (KB)**, **Megabytes (MB)**, and **Gigabytes (GB)**.
- I have set it to **1MB in the option** , and finally, click the **OK** button to create the archive file.
_Splitting Files based on Size_
- Once you click the **OK** button, WinRAR will create archive files by splitting the ZIP file into multiple 1MB files, as shown in the image below.
_Files Splitted using Winrar_
That’s it. Now the single large file has been split into multiple 1MB files. You can now easily upload these files to online portals without any barriers and easily transfer them.
## Re-assembling the Splitted Files:
- Make sure all the files are located along with the main ZIP file in the directory!
- Right-click on the main ZIP file and click the “ **Extract All** ” option.
_Extract All option using WinRar_
- Choose the **destination directory** and click the **Extract** button.
- Now, the WinRAR application will extract the ZIP file by combining all the split files into one merged output single large file.
_One Merged file has been extracted on Desired Directory._
## Splitting Files using Winrar- Uses:
- **Large files can be tough to transfer over the internet or other media.** Splitting them into smaller parts makes it easier to email, upload, or transfer them.
- **Many email services and online platforms have file size limits.** By splitting files, I can bypass these limits by sending or uploading smaller, individual parts.
- **Downloading a large file can often run into errors and interruptions.** Smaller split files are less likely to have issues, and if one part fails, I only need to re-download that part.
- **Splitting files helps me manage storage space on devices with limited capacity.** I can store parts on different storage media or locations.
- **It’s also useful for creating backups and archives,** especially if I need to fit them onto multiple CDs, DVDs, or other storage devices with limited capacity.
- **I can choose the size of each split part,** giving me the flexibility to customize the file sizes based on my needs. | vigneshwaran_vijayakumar |
1,911,787 | emojis | draw somthing that is in the stack | 0 | 2024-07-04T16:38:18 | https://dev.to/leah_voight_f3a51968941b9/emojis-2hp9 | draw somthing that is in the stack
| leah_voight_f3a51968941b9 |
|
1,911,786 | ⚡ MyFirstApp - React Native with Expo (P24) - Code Layout Register Screen | ⚡ MyFirstApp - React Native with Expo (P24) - Code Layout Register Screen | 27,894 | 2024-07-04T16:36:21 | https://dev.to/skipperhoa/myfirstapp-react-native-with-expo-p24-code-layout-register-screen-2iid | react, reactnative, webdev, tutorial | ⚡ MyFirstApp - React Native with Expo (P24) - Code Layout Register Screen
{% youtube xTA9q1e5J7I %} | skipperhoa |
1,911,785 | Buy Verified Cash App Accounts | Buy Verified Cash App Accounts In today’s digital era, the ability to transfer money from one place... | 0 | 2024-07-04T16:35:28 | https://dev.to/oehdnf_fdjd_63f42adac16fa/buy-verified-cash-app-accounts-aa5 | webdev, javascript, programming, beginners | Buy Verified Cash App Accounts
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Our Cash App Account Features-
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SSN, ID card
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Passport and visa card attachment
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If You Need More Information Please Contact Us
24/7 Customer Support/ Contact
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live:.cid.1dbfb5499a7b86c3
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Why More Popular Cash App Accounts?
Cash App started its journey in 2014 under the company name Square Cash. At that time, it became more popular for peer-to-peer transaction capabilities. 4 years later, The Cash App company expanded its business in the UK market and introduced every user to bitcoin trading functionality. This evolution was significantly increased by high-profile advertising campaigns. That’s why the Cash App increased 212 percent profit from 2019 to 2020.
Key Factors of Cash App’s Popularity
There are a lot of key factors for getting more popularity of cash app accounts. But there are a few features like multipurpose financial operation, bitcoin trading, simple and user-friendly interface, peer-to-peer payment, etc which allow every user to use the cash app account. We can discuss this
Multipurpose Financial Operation: The Cash app offers a peer-to-peer payment service which is most popular for every user. These include direct Money transfer and a free Visa debit card which is linked to the user’s cash App balance. Every cash app user pays online or in person at the selected merchants. Cash app users enjoy many more discounts and fee-free direct deposit.
Investment and Bitcoin Trading: Investment and cryptocurrency trading are other best features of Cash App accounts. The verified Cash App accounts users can buy and sell stocks ETFs directly through their accounts without paying any extra fees.
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How to buy Cash App Account?
When you think that you need to **[buy verified Cash App accounts](https://best5stareviews.com/product/buy-verified-cash-app-accounts/)** then you have to prioritize the security and authenticity to ensure the safe transaction. Several reputable companies or platforms give new and old verified cash app accounts. But we always committed to our customers about authenticity and high-quality customer service. We give these services for 3-4 years. We always highlight the reliability as a source for purchasing verified cash app accounts.
How to verify Cash App Bitcoin?
To verify your Cash App Bitcoin account for Bitcoin transactions first, open the Cash app on your device. On the Bitcoin section, by tapping the “Banking” tab you will get the “Enable Withdrawals and Deposits” to initiate the verification. You have to provide all kinds of information such as full name, Date of birth, and Last four digits of SSN. After providing these pieces of information, you have to upload your selfie which needs government-issued documents like passports, driver’s licenses, or Government national ID cards, etc. Once submitted, it will take a few days to confirm your identity.
The Benefits of Verified Cash App Accounts
To ensure a seamless and secure financial experience, the Cash app always verifies the identity for giving full access and higher-limit transactions. For the verification process, every user need to provide their full name, date of birth, address, the last four digits of SSN, and the other documents too. Again, users must be at least 18 years old to use the verified cash app accounts. If you face any problems for creating any account, then we will recommend to buy a verified cash app account from us.
Increase Transaction Limit: one of the primary benefits of verification is to increase the transaction limit. Verified users can send and received larger amount of money than unverified users accounts. Verification unlock the access of extra features of Cash App accounts such as ordering Cash Card.
Increase Security Level: By completing the verification, you will get an extra security layer of your accounts and protect your unauthorized transactions from unknown persons or by unknown persons.
Business Tools: Verified Cash account users can transfer money instantly and also can receive funds without waiting time. Cash App provides business users additional features such as the ability to accept payment online, track sales, generate invoices, and any other financial operations.
Offer And Rewards: The verified cash app owner get many exclusive offers, discounts, rewards which is not available for unverified users. Verified users also offer a secure way to access funds on the app. They can invest or buy crypto from their account which makes it more profitable.
Verified vs. Non-Verified Cash App Accounts
Verified and non-verified cash App accounts offer different levels of access and functionality. A verified Cash app users always get more benefits than unverified accounts. Both types of accounts allow users to send and receive money.
Feature Verified Account Non-Verified Account
Creation and Verification Cost Free Free
Transaction Limits (Sending) Up to $7,500 per week Up to $250 per week
Transaction Limits (Receiving) Unlimited Up to $1,000 per month
Security Measures Enhanced (e.g., two-factor authentication) Standard
Access to Additional Services Yes (e.g., Bitcoin transactions, Cash Card) Limited
Verified Cash App Accounts for Sale
Verified Cash app accounts for sale offer users the opportunity to give access a lot of benefits and features that come with verified accounts. Buyers enjoy the advantages of verified Cash app accounts in a short time such as higher transaction limits, security, and additional features. Verified Cash App Accounts users get full access to improving and hiding privacy.
Different Types of Verified Cash App Accounts
Cash App offers different types of accounts for getting real experience and to get the capabilities of the features. Each type of account is designed uniquely. Cash apps give features for multifaceted financial platforms.
Standard Cash App Account
It allows users to send and receive money from other Cash App users without any effort. Users can apply for Cash cards for customized debit cards. They can link directly to their Cash App balance to get easy access to funds and payments.
Cash App Plus Account
Previously, this account was known as Cash App Premium. The Cash App account develops the user experience by offering access to exclusive boosts. These Boosts provide discounts and cashback offers when the card is used to purchase any product. In this type of accounts, users invest in stocks and buy bitcoin directly.
Cash App Business Account
It provides businesses with the necessary tools for smooth transactions. This type of account supports various types of business structures including sole proprietors, single-members LLCs, non-profit organizations, etc.
Cash App Investing Account
The Cash App investing account focuses on stock and bitcoin investing. It enables users to buy and sell stocks and bitcoin directly through their account app. This type of account is for those users who looking to diversify their financial portfolio within a single platform.
Cash App Bitcoin Account
The cash app Bitcoin account offers a dedicated platform for those users who are interested in Bitcoin. This type of account allows for buying, selling, and transferring Bitcoin from one wallet to another wallet. It’s a reliable and secure environment for catering to the needs of cryptocurrency.
Why is Cash App Not letting me Verify my Identity?
If Cash App is not allowing to verify your identity then there several factors that work. Firstly, to ensure that you provide all types of correct information. When uploading your verification documents you need to clear and meet the specified requirements to avoid rejection. Make sure your age must be above 18 years. If you fail to complete verification, try again and also make sure and recheck the information correctly. Multiple unsuccessful verifications then try to contact their support before getting a temporary restriction. If you don’t want to face the issue then you can buy a verified cash app account by clicking on our website and avoid the boring step.
Verified Cash App Accounts for Sale
Verified Cash app accounts for sale offer users the opportunity to give access a lot of benefits and features that come with verified accounts. Buyers enjoy the advantages of verified Cash app accounts in a short time such as higher transaction limits, security, and additional features. Verified Cash App Accounts users get full access to improving and hiding privacy.
Frequently Ask Question
What is a verified Cash App account?
A verified Cash App account is one which passes the verification process by confirming the user’s identity such as full name, Date of birth, SSN, etc. Once verified, the users gain all additional access.
How do I know if my Cash App account is verified?
You can check by opening the app and navigating to your account settings. Find out the verification badge or status indicator which displayed near your profile information. If your account is verified, you should see a confirmation message or indicate verification completed.
How long does it take to verify a Cash App account?
The verification process takes a few minutes to complete but in some cases, it will take up to 24-48 hours. If your verification is taking longer, contact cash app support for assistance.
Can I have multiple verified Cash App accounts?
No, Can App only allows one verified account. If you create multiple accounts then it may suspension or closure of your accounts. If you need more accounts then you can create business accounts.
Can I buy and sell Bitcoin with a verified Cash App account?
Yes. You can buy and sell Bitcoin with a verified Cash App account. You can convert the Bitcoin into cash. Cash App gives cryptocurrency trading functionality.
Can I still use Cash App if my account is not verified?
Yes. you can still use Cash App if not your account is verified. However, there are some limitations to using unverified accounts such as buying and selling Bitcoin, Access the Cash Card, etc.
| oehdnf_fdjd_63f42adac16fa |
1,911,784 | ⚡ MyFirstApp - React Native with Expo (P23) - Update Layout Splash Screen | ⚡ MyFirstApp - React Native with Expo (P23) - Update Layout Splash Screen | 27,894 | 2024-07-04T16:34:27 | https://dev.to/skipperhoa/myfirstapp-react-native-with-expo-p23-update-layout-splash-screen-1hc6 | react, reactnative, webdev, tutorial | ⚡ MyFirstApp - React Native with Expo (P23) - Update Layout Splash Screen
{% youtube i1hk7n1oaxw %} | skipperhoa |
1,911,783 | Documentando uma API com Go Swagger | Passos para documentar uma RESTful API em Go com Swagger Instalar o Swagger Tools go get -u... | 0 | 2024-07-04T16:34:26 | https://dev.to/marialuizaleitao/documentando-uma-api-com-go-swagger-587 | Passos para documentar uma RESTful API em Go com Swagger
1. **Instalar o Swagger Tools**
`go get -u github.com/swaggo/swag/cmd/swag`
2. **Adicionar Swagger Annotations para descrever endpoints, parâmetros e respostas**
### **Swagger Info Annotation:**
No topo do arquivo `main.go` ou em um arquivo específico, adicione informações como versão, título e descrição.
```go
// @title My API
// @version 1.0
// @description This is a RESTful API in Go using Swagger
// @contact.name API Support
// @contact.email [email protected]
// @host localhost:8000
// @BasePath /v1
```
### **Operation Annotations:**
Para cada endpoint, anote a function com os detalhes da requisição HTTP, path, e um resumo básico.
```go
// @Summary Get a list of movies
// @Description Retrieves a list of movies
// @Tags movies
// @Accept json
// @Produce json
// @Success 200 {array} Movie
// @Router /movies [get]
func getMovies(w http.ResponseWriter, r *http.Request) {
// code ...
}
```
### **Parameter Annotations:**
Descreva o path, a query, e o body da requisição.
```go
// previous Operation Annotations...
// @Param id path string true "Movie ID"
// @Success 200 {object} Movie
// @Failure 404 {object} ErrorResponse
// @Router /movies/{id} [get]
func getMovie(w http.ResponseWriter, r *http.Request) {
// code ...
}
```
### **Response Annotations:**
Defina a estrutura de responses retornadas pelos endpoints da API.
```go
// Movie struct
// @Description structure of Movie
type Movie struct {
ID string `json:"id"`
Name string `json:"name"`
}
// ErrorResponse struct
// @Description structure of ErrorResponse
type ErrorResponse struct {
Code int `json:"code"`
Message string `json:"message"`
}
```
## **Gerar a Documentação do Swagger:**
Rode o comando `swag init` no diretório do projeto pra gerar o Swagger JSON e YAML baseados nas anotações. **Se houverem mudanças nas anotações, esse comando deve ser rodado novamente.**
```csharp
swag init
```
Suba a aplicação e entrar na Swagger UI (`http://localhost:8000/swagger/index.html`) pra interagir com a documentação.
# Boas práticas de documentação:
- Use linguagem descritiva e sucinta pra ajudar no entendimento da API.
- Organize a ordem das anotações de forma lógica pra seguir um fluxo claro e padronizado, facilitando a manutenção. | marialuizaleitao |
|
1,911,760 | Navigating Comfort with a Skilled HVAC Installation Contractor | Maintaining the ideal temperature and air quality in your home or business is crucial for comfort and... | 0 | 2024-07-04T15:54:10 | https://dev.to/comfortcontrol/navigating-comfort-with-a-skilled-hvac-installation-contractor-3m4a |
Maintaining the ideal temperature and air quality in your home or business is crucial for comfort and health, making the choice of an HVAC installation contractor a significant decision. This article explores the key factors to consider when selecting a contractor for HVAC installation and preventive maintenance.
1: What Makes a Reliable HVAC Installation Contractor?
When it comes to heating, ventilation, and air conditioning systems, the expertise of an HVAC installation contractor is indispensable. A reliable contractor possesses a blend of experience, skill, and knowledge that facilitates efficient and correct installation of HVAC systems. Their understanding of various models and building types ensures that your system is not only installed but also optimized for performance according to your specific needs.
2: Importance of Preventative Maintenance Services
Preventative maintenance is vital in extending the lifespan of your HVAC system. Regular checks by a seasoned HVAC installation contractor can prevent minor issues from escalating into major problems that could lead to costly repairs or even complete system failure. With preventative maintenance services, contractors assess and tune-up essential components of your system to ensure everything functions smoothly.
3: Choosing Your Contractor Wisely
Selecting an HVAC installation contractor should be done with careful consideration. Look for contractors who are licensed and insured, providing you with peace of mind regarding their qualifications and protection against potential liabilities. Additionally, consider contractors who are willing to conduct thorough inspections before suggesting solutions tailored to your space's requirements.
4: The Role of Customer Service in HVAC Installation
The interaction you have with your HVAC installation contractor should be professional and informative. Excellent customer service involves clear communication about what services will be provided, how long the process will take, and any recommendations for maintaining your system post-installation.
5: Questions To Ask Your Potential Contractor
Before committing to an **[hvac installation contractor king](http://tinyurl.com/HVAC-Company-King-NC)**, ask pertinent questions that will give you insight into their work ethic and quality of service. Inquire about their experience with installations similar to yours, whether they offer detailed quotes upfront, how they handle unexpected challenges during installations, and what kind just follow-up support is provided after the completion of the project.
6: The Value Added by Hiring Professionals
A professional HVAC installation contractor brings value beyond just installing a new system. They have keen insights on energy efficiency which can help reduce utility bills through proper selection and setup of equipment designed to conserve energy while still maintaining optimal indoor climate control.
The role of an experienced HVAC installation contractor cannot be overstated in ensuring that heating and cooling systems are effectively implemented within residential or commercial spaces. Their technical proficiency combined with preventative maintenance services contribute significantly towards achieving long-term functionality of these essential units. By carefully selecting a knowledgeable contractor who provides excellent customer service and upholds industry standards, property owners can enjoy sustained comfort year-round without undue concern over their system's reliability or efficiency.
**[Comfort Control Systems NC
](https://comfortcontrolsystemsnc.com/)**336-800-3483
234 S Main St, King, North Carolina, 27021 | comfortcontrol |
|
1,911,782 | Welcome to my very first post. | Hi everyone. My name is Paulina Udeh. I am a software Engineer. I will be sharing my thoughts and... | 0 | 2024-07-04T16:30:08 | https://dev.to/paulina_udeh/welcome-to-my-very-first-post-1d3n | Hi everyone. My name is Paulina Udeh. I am a software Engineer. I will be sharing my thoughts and writing about on technology, system design. database design and programming languages.
Come along with me and lets learn together. | paulina_udeh |
|
1,911,781 | Complete Guide for Server-Side Rendering (SSR) in Angular | This comprehensive post includes a quick introduction to SSR, a detailed setup guide and several best... | 0 | 2024-07-04T16:27:24 | https://www.angulararchitects.io/blog/complete-guide-for-server-side-rendering-ssr-in-angular/ | This comprehensive post includes a quick introduction to SSR, a detailed setup guide and several best practices with _Angular 17 or even 18_ ([released on May 22nd, 2024](https://blog.angular.dev/angular-v18-is-now-available-e79d5ac0affe)), enhancing the **initial load performance** and thus the **user experience** of modern **Angular applications**. While we do not recommend updating production apps to _V18_ at the time of writing this post, most of the presented SSR features are already stable in _Angular 17_. The new Event Replay feature of _V18_ can easily be added later on. Nevertheless, if you want to use _Material_ and/or _CDK_ with SSR, you might want to upgrade to _V18_ as soon as possible.
In any case, make sure you have already updated to _V17_. If not, follow [my _Angular 17_ upgrade guide](https://www.angulararchitects.io/blog/angular-17-update-control-flow-app-builder-migration/), including the recommended migrations.
The _Angular team_ has recently (well actually for quite some time) been putting in [a huge effort](https://angular.dev/roadmap#fast-by-default) and doing a fantastic job to help us improve the initial load time. SSR plays a significant role in achieving that goal for our framework of choice. Read my post from last July to learn [why initial load performance is so crucial](https://www.angulararchitects.io/blog/why-is-initial-load-performance-so-important/) for your _Angular_ apps.
## Essentials
Let's start with the basics. You can, of course, skip this section if you're already familiar with SSR, and continue with the next section about [building](#build).
### Server-Side Rendering (SSR)
Server-Side Rendering (SSR) is a web development technique where the (in our case node) server generates **the HTML content** of a web page (in our case with JavaScript), providing faster initial load time. This results in a smoother user experience, especially for those on slower networks (e.g. onboard a train in 🇩🇪 or 🇦🇹 – which I happen to be a lot recently 😏) or low-budget devices. Additionally, it improves SEO and crawlability for Social Media and other bots like the infamous ChatGPT.
New _Angular CLI_ projects will automatically prompt SSR (since _Angular 17_):
```bash
ng new your-fancy-app-name
```
For existing projects simply run the `ng add` command (since _Angular 17_):
```bash
ng add @angular/ssr
```
**Warning**: You might have to fix stuff manually (like adding imports of CommonJsDependencies) after adding SSR to your project 😬
Follow the [angular.dev guide](https://angular.dev/guide/ssr#configure-server-side-rendering) for detailed configuration. However, I'd recommend switching to the new Application Builder, which has SSR and SSG baked in. Let's first clarify what SSG does.
### Static Site Generation (SSG)
Static Site Generation (SSG) or Prerendering (like the Angular framework likes to call it), is the technique where HTML pages are prerendered **at build time** and served as static HTML files. Instead of executing on demand, SSG generates the HTML once and serves the same pre-built HTML to all users. This provides even faster load times and further improves the user experience. However, since the HTML is being stored on the server this approach is limited whenever live data is needed.
### Hydration (since NG 16)
Hydration is the process where the prerendered static HTML, generated by SSR or SSG, is enhanced with interactivity on the client side. After the initial HTML is delivered and rendered in the browser, _Angular's JavaScript_ takes over to "hydrate" the static content, attaching **event listeners** and thus making the page fully interactive. This approach combines the fast initial load times of SSR/SSG with the dynamic capabilities of a SPA, again leading to a better overall user experience.
Before _Angular's Hydration_ feature, the prerendered static DOM would have been destroyed and replaced with the client-side-rendered interactive version, potentially resulting in a layout shift or a full browser window flash aka content flicker – both leading to bad results in performance tools like [**Lighthouse** and **WebPageTest**](https://www.angulararchitects.io/blog/how-to-measure-initial-load-performance/). In my opinion, _Angular SSR_ was not production-ready until supporting Non-Destructive Hydration. This has changed in 2023 since this feature has already become stable in _Angular 17_.
BTW, it's super easy to enable Hydration in _Angular_ 💧
```typescript
export const appConfig: ApplicationConfig = {
providers: [
provideClientHydration(), // use NG 16 hydration
],
};
```
If you're still using _NgModules_ (for reasons), it becomes:
```typescript
@NgModule({
providers: [provideClientHydration()],
})
export class AppModule {}
```
### Event Replay (in Developer Preview since NG 18)
This example was taken from the official [_Angular blog_](https://blog.angular.dev/event-dispatch-in-angular-89d868d2351c). Consider an app that contains a click button like this:
```html
<button type="button" (click)="onClick()">Click</button>
```
Previously, the event handler `(click)="onClick()"` would only be called once your application has finished Hydration in the client. With Event Replay enabled, **[JSAction](https://github.com/google/jsaction)** is listening at the root element of the app. The library will capture events that (natively) bubble up to the root and replay them once Hydration is complete.
If implemented, _Angular_ apps will stop ignoring events before Hydration is complete and allow users to **interact with the page while it's still loading**. There is no need for developers to do anything special beyond enabling this feature.
And again, it's super comfy to enable Event Replay in your app 🤩
```typescript
export const appConfig: ApplicationConfig = {
providers: [
provideClientHydration(
withEventReplay(), // use hydration with NG 18 event replay
),
],
};
```
**Note**: At the time of writing this feature is still in Developer Preview, please use it with caution.
## Build
Since _Angular 17_ we have two options for building our _Angular app_.
### Angular's new Application Builder (all-in-one)
As mentioned, I'd recommend switching to the new Application Builder using [**esbuild**](https://esbuild.github.io/) and [**Vite**](https://vitejs.dev/). The advantage of using esbuild over Webpack is that it offers faster build times and more efficient and fine-grained bundling. The significantly smaller bundle also leads to better initial load performance – with or without SSR! Vite is a faster development server supporting extremely fast Hot Module Replacement (HMR).
Additionally, both **SSR** and **Prerendering (SSG)** are enabled by default as mentioned in this screenshot from the _Angular Docs_ showing a table of the _Angular Builders_ (note that the `@angular-devkit/build-angular:server` is missing here):
Simply run `ng b` to trigger a `browser` and `server` build in one step. _Angular_ will automatically process the Router configuration(s) to find all unparameterized routes and prerender them for you. If you want, you can add parameterized routes via [a txt file](https://angular.dev/guide/prerendering#prerendering-parameterized-routes). To migrate, read my [automated App Builder migration guide](https://www.angulararchitects.io/blog/angular-17-update-control-flow-app-builder-migration/).
### If still using Webpack (for reasons)
If – for any reason – you're still committed to using **Webpack** to build your web app, you need the browser builder to be configured in your `angular.json` (might be in `project.json` if you're using Nx). This will, of course, be added automatically once you run `ng add @angular/ssr`.
```json
{
"server": {
"builder": "@angular-devkit/build-angular:server",
"options": {
"outputPath": "dist/your-fancy-app-name/server",
"main": "server.ts",
"tsConfig": "tsconfig.server.json"
}
}
}
```
Note: The referenced `server.ts` lies in the project's root and is the entry point of your server application. With this dedicated server builder, there is also a dedicated `tsconfig.server.json` (whereas the new Application Builder recommended previously merges the two tsconfig files for more convenience) 🤓
Now let's quickly have a look at the build scripts:
**Important note**: If you haven't started using `pnpm`, you're missing out. However, of course, both `npm run ...` and `yarn ...` will also work instead of `pnpm ...`.
```bash
pnpm dev:ssr
ng run your-fancy-app-name:serve-ssr
```
Similar to `ng s`, which offers live reload during development, but uses server-side rendering. Altogether, it's a bit slower than `ng s` and won't be used a lot apart from quickly testing SSR on `localhost`.
```bash
pnpm build:ssr
ng build && ng run your-fancy-app-name:server
```
Builds both the `browser` application and the `server` script in production mode into the `dist` folder. Use this command when you want to build the project for deployment or run performance tests. For the latter, you could use [serve](https://www.npmjs.com/package/serve) or a similar tool to serve the application on your `localhost`.
## Deploy
You have two options for deployment. While both are technically possible, I'd recommend using the second one.
### Using on-demand rendering mode via node server
Starts the server for serving the application with node using SSR.
```bash
pnpm serve:ssr
node dist/your-fancy-app-name/server/main.js
```
I've shown a detailed [example Docker container here](https://www.angulararchitects.io/blog/how-to-use-angular-ssr-with-hydration/).
**Caution**: _Angular_ requires a certain _Node.js_ version to run, for details see the [Angular version compatibility matrix](https://angular.dev/reference/versions#actively-supported-versions).
### Using build time SSR with SSG (recommended)
This option doesn't need a node environment on the server and is also way faster than the other one.
```bash
pnpm prerender
ng run your-fancy-app-name:prerender
```
Used to generate an application's prerendered routes. The static HTML files of the prerendered routes will be attached to the `browser` build, not the `server`. Now you can deploy your `browser` build to whatever host you want (e.g. [**nginx**](https://nginx.org/en/)). You're doing the same thing as without SSR with some extra directories (and `index.html` files).
**Important note**: If you're using the new (and recommended) Application Builder, you can skip these steps for building and prerendering since they're already included in `ng b`. In other words, you have zero extra work for building including SSR & SSG – pretty great, huh? 😎
## Debug
The first step in debugging is looking for misconfigurations in your `angular.json` (`project.json`) or some errors in your `server.ts`. If both look good, there is no definite way to debug SSR and SSG issues. Feel free to [**contact me**](mailto:[email protected]) if you're experiencing any troubles.
### How to avoid the most common issue
Browser-specific objects like **document**, **window**, **localStorage**, etc., do **NOT** exist on the `server` app. Since these objects are not available in a Node.js environment, trying to access them results in errors. This can be avoided by using the document injector or by running code explicitly in the browser:
```typescript
import { Component, inject, PLATFORM_ID } from "@angular/core";
import { DOCUMENT, isPlatformBrowser, isPlatformServer } from "@angular/common";
export class AppComponent {
private readonly platform = inject(PLATFORM_ID);
private readonly document = inject(DOCUMENT);
constructor() {
if (isPlatformBrowser(this.platform)) {
console.warn("browser");
// Safe to use document, window, localStorage, etc. :-)
console.log(document);
}
if (isPlatformServer(this.platform)) {
console.warn("server");
// Not smart to use document here, however, we can inject it ;-)
console.log(this.document);
}
}
}
```
### Browser-Exclusive Render Hooks
An alternative to injecting `isPlatformBrowser` are the two render hooks `afterNextRender` and `afterRender`, which can only be used within the [**injection context**](https://angular.dev/guide/di/dependency-injection-context) (basically field initializers or the constructor of a component):
The `afterNextRender` hook, takes a callback function that runs **once** after the **next** change detection – a bit similar to the init lifecycle hooks. It's used for performing one-time initializations, such as integrating 3party libs or utilizing browser APIs:
```typescript
export class MyBrowserComponent {
constructor() {
afterNextRender(() => {
console.log("hello my friend!");
});
}
}
```
If you want to use this outside of the injection context, you'll have to add the injector:
```typescript
export class MyBrowserComponent {
private readonly injector = inject(Injector);
onClick(): void {
afterNextRender(
() => {
console.log("you've just clicked!");
},
{ injector: this.injector },
);
}
}
```
The `afterRender` hook, instead, is executed after **every upcoming** change detection. So use it with extra **caution** – same as you would do with the `ngDoCheck` and `ng[Content|View]Checked` hooks because we know that Change Detection will be triggered a lot in our _Angular_ app – at least until we go **zoneless**, but that story that will be presented in yet another blog post 😎
```typescript
export class MyBrowserComponent {
constructor() {
afterRender(() => {
console.log("cd just finished work!");
});
}
}
```
If you'd like to deep dive into these hooks, I recommend reading this [blog post](https://netbasal.com/exploring-angulars-afterrender-and-afternextrender-hooks-7133612a0287) by Netanel Basal.
### Angular Hydration in DevTools
The awesome _Angular_ collaborator [Matthieu Riegler](https://x.com/Jean__Meche) has recently added **hydration debugging** support to the _Angular's DevTools_! Which are, besides all Chromium derivatives, also available for Firefox, but then why would somebody still use that Boomer browser? 😏
Note the 💧 for hydrated components. Even though this feature was announced in the _Angular 18_ update, it also works in past versions.
### Other SSR Debugging Best Practices
Here is a collection of some more opinionated debugging recommendations:
- **DevTools**: Besides the updated _Angular DevTools_ tab, inspect your HTML with the **Elements** tab and your API requests with the **Network** tab. BTW, you should also simulate a slow connection here when performance testing your app.
- **Console**: I personally like to log everything into my **Console**. Not interested in a logger lib since I'm fine with console.log() and maybe some other levels. Any console logs will be printed into the terminal where `ng b` or `pnpm dev:ssr` or `pnpm serve:ssr` has been run. We don't need to talk about logging into the browser's console on production, or do we?
- **Node.js**: Start your SSR server with the --inspect flag to get more information: `node --inspect dist/server/main.js`
- **Fetching**: Ensure all necessary data is available at render time. Use _[Angular's TransferState](https://angular.dev/api/core/TransferState?tab=description)_ to transfer data from the server to the client.
- **Routing**: Make sure all routes are correctly configured and match on both the `browser` and `server` builds.
- **Environments**: Ensure environment variables are correctly set up for both `browser` and `server` builds.
- **3rd-party Libs**: As always, be very careful about what you include in your project. Some libraries might not be implemented correctly and thus not work in an SSR context. Use conditional imports or platform checks to handle these cases or, even better, get rid of those libs in the first place.
That's all I have got so far. If you've got anything to add, feel super free to [**contact me**](mailto:[email protected])!
## Advanced
### Disable Hydration for Components
Some components may not work properly with hydration enabled due to some issues, like DOM Manipulation. As a workaround, you can add the `ngSkipHydration` attribute to a component's tag to skip hydrating the entire component.
```html
<app-example ngSkipHydration />
```
Alternatively, you can set `ngSkipHydration` as a host binding.
```typescript
@Component({
host: { ngSkipHydration: "true" },
})
class DryComponent {}
```
Please use this carefully and thoughtfully. It is intended as a last-resort workaround. Components that have to skip hydration should be considered bugs that need to be fixed.
### Use Fetch API instead of XHR
The **[Fetch API](https://web.dev/articles/introduction-to-fetch)** offers a modern, promise-based approach to making HTTP requests, providing a cleaner and more readable syntax compared to the well-aged `XMLHttpRequest`. Additionally, it provides better error handling and more powerful features such as support for streaming responses and configurable request options. It's also recommended to be used with SSR by the _[Angular team](https://stackoverflow.com/questions/77512654/angular-detected-that-httpclient-is-not-configured-to-use-fetch-apis-angul/77512684#77512684)_.
To enable it, simply add `withFetch()` to your `provideHttpClient()`:
```typescript
export const appConfig: ApplicationConfig = {
providers: [provideHttpClient(withFetch())],
};
```
If you're still using _NgModules_ (for reasons), this becomes:
```typescript
@NgModule({
providers: [provideHttpClient(withFetch())],
})
export class AppModule {}
```
### Configure SSR API Request Cache
The _Angular HttpClient_ will cache all outgoing network requests when running on the server. The responses are serialized and transferred to the browser as part of the server-side HTML. In the browser, _HttpClient_ checks whether it has data in the cache and if so, reuses that instead of making a new HTTP request during the initial load. _HttpClient_ stops using the cache once an application becomes stable in the browser.
By default, HttpClient caches all `HEAD` and `GET` requests that don't contain **Authorization** or **Proxy-Authorization** headers. You can override those settings by using `withHttpTransferCacheOptions` when providing hydration:
```typescript
export const appConfig: ApplicationConfig = {
providers: [
provideClientHydration(
withEventReplay(),
withHttpTransferCacheOptions({
filter: (req: HttpRequest<unknown>) => true, // to filter
includeHeaders: [], // to include headers
includePostRequests: true, // to include POST
includeRequestsWithAuthHeaders: false, // to include with auth
}),
),
],
};
```
### Use Hydration support in Material 18 and CDK 18 💧
Starting with _Angular Material 18_, all components and primitives are fully SSR and Hydration compatible. For information, read this [blog post](https://blog.angular.dev/material-3-experimental-support-in-angular-17-2-8e681dde650e). On how to upgrade your _Angular Material_ app, consult the docs on [migrate from Material 2 to Material 3](https://material.angular.io/guide/material-2-theming#how-to-migrate-an-app-from-material-2-to-material-3).
### Combine SSR for static & CSR for user content 🤯
The future is here! With _**Angular 17 Deferrable Views**_ you can easily mix SSR/SSG with CSR 🎉
The usage is pretty straightforward: Currently, all `@defer` components will render their `@placeholder` on the server and the real content will be loaded and rendered once they have been triggered (by _on_ or _when_) in the browser. Learn more about [how to use and trigger Deferrable Views](https://www.angulararchitects.io/blog/how-to-improve-initial-load-performance-with-angular-17s-deferrable-views/).
Here are some primitive **examples** of how to combine SSR and CSR:
- Static pages: Use SSR
- Static content with live updates: Use deferred components for the live content and SSR for the rest
- Product list with prices depending on the user: Defer price components and use SSR for the rest
- List with items depending on the user: Defer the list component and use SSR for the rest
So basically, everywhere you need CSR (e.g. for user-dependent content), you need to `@defer` those parts. Use the `@placeholder` (and `@loading`) to show spinners or equivalents to inform the user that something is still being loaded. Also, make sure to reserve the right amount of space for the deferred components – avoid layout shifts at all costs!
### SEO and Social Media Crawling 🔍
If you want to look good on Google and/or social media platforms, make sure to implement all the necessary **meta tags** in SSR. For a comprehensive list, including some tools and tips, [jump here](https://moz.com/blog/meta-data-templates-123).
```typescript
export class SeoComponent {
private readonly title = inject(Title);
private readonly meta = inject(Meta);
constructor() {
// set SEO metadata
this.title.setTitle("My fancy page/route title. Ideal length 60-70 chars");
this.meta.addTag({ name: "description", content: "My fancy meta description. Ideal length 120-150 characters." });
}
}
```
### Use SSR & SSG within AnalogJS 🚀
[AnalogJS](https://analogjs.org/) is _the_ meta-framework built on top of _Angular_ – like [Next.js](https://nextjs.org/) (React), [Nuxt](https://nuxt.com/) (VueJS), [SolidStart](https://start.solidjs.com/) (Solid). Analog supports SSR during development and building for production. If you want to know more, read the announcement of [version 1.0](https://dev.to/analogjs/announcing-analogjs-10-19an) by [Brandon Roberts](https://x.com/brandontroberts) or wait for my **upcoming blog post** 😏
### Angular SSR & SSG featuring I18n
Since the _Angular I18n_ only works during built-time, it's fairly limited. Therefore, we recommend using [Transloco](https://jsverse.github.io/transloco/) (or [NGX-Translate](https://github.com/ngx-translate/core)). When adding Transloco by running `ng add @jsverse/transloco`, you'll be prompted for SSR usage. However, you can also manually add the necessary changes for SSR (see [Transloco Docs](https://jsverse.github.io/transloco/docs/ssr-support)):
```typescript
@Injectable({ providedIn: "root" })
export class TranslocoHttpLoader implements TranslocoLoader {
private readonly http = inject(HttpClient);
getTranslation(lang: string) {
return this.http.get<Translation>(`${environment.baseUrl}/assets/i18n/${lang}.json`);
}
}
```
```typescript
export const environment = {
production: false,
baseUrl: "http://localhost:4200", // <== provide base URL for each env
};
```
This will SSR everything in the default language and then switch to the user's language (if different) in the browser. While this generally works, **it's definitely not ideal to see the text being swapped**. Furthermore, we need to ensure there are **no layout shifts** upon switching! If you come up with any ideas on how to improve this, please [**contact me**](mailto:[email protected])!
### Caution with Module / Native Federation
At the time of writing this post, the **Angular Architects'** federation packages do not support SSR:
- [**Module Federation**](https://github.com/angular-architects/module-federation-plugin/blob/main/libs/mf/README.md) using custom Webpack configurations under the hood and
- [**Native Federation**](https://github.com/angular-architects/module-federation-plugin/blob/main/libs/native-federation/README.md) same API – but using browser-native [Import Maps](https://www.angulararchitects.io/blog/import-maps-the-next-evolution-step-for-micro-frontends-article/) and thus also working with `esbuild`
You **won't be able to use SSR** out of the box when you set up a federated Angular app. While there are plans to support that, we currently cannot provide a date when this will be possible.
For the time being _the master of module federation **Manfred Steyer**_ introduced an interesting approach, combining SSR with **native federation**. If the microfrontends are integrated via the _Angular Router_, then a server-side and a client-side variant can be offered per **routes** definition:
```typescript
function isServer(): boolean {
return isPlatformServer(inject(PLATFORM_ID));
}
function isBrowser(): boolean {
return isPlatformBrowser(inject(PLATFORM_ID));
}
const appRoutes = [
{
path: "flights",
canMatch: [isBrowser],
loadChildren: () => loadRemoteModule("mfe1", "./Module").then((m) => m.FlightsModule),
},
{
matcher: startsWith("flights"),
canMatch: [isServer],
component: SsrProxyComponent,
data: {
remote: "mfe1",
url: "flights-search",
tag: "app-flights-search",
} as SsrProxyOptions,
},
];
```
Learn more about this approach in [this article on devm.io](https://devm.io/angular/microfrontend-module-federation-ssr-hydration) or check out the `ssr-islands` branch of [Manfred's example on GitHub](https://github.com/manfredsteyer/module-federation-plugin-example/) to see an implemented example. While this setup reduces conflicts by isolating microfrontends, it introduces complexity in maintaining separate infrastructure code for both the client and server sides, making it challenging. Therefore, it's crucial to assess if this **trade-off** suits your specific project needs and meets your **architecture and performance goals**.
### Caution with PWA
Be careful if you are using _Angular SSR_ in combination with the _Angular PWA_ service worker because the behavior deviates from default SSR. The initial request will be server-side rendered as expected. However, subsequent requests are handled by the service worker and thus client-side rendered.
Most of the time that's what you want. Nevertheless, if you want a fresh request you can use the `freshness` option as _Angular PWA_ `navigationRequestStrategy`. This approach will try a network request and fall back to the cached version of `index.html` when offline. For more information, consult the _[Angular Docs](https://angular.dev/ecosystem/service-workers/config#navigationrequeststrategy)_ and read this [response on Stack Overflow](https://stackoverflow.com/questions/56383569/how-to-make-angular-universal-and-pwa-work-together/56400078#56400078).
## Workshops
If you want to deep dive into Angular, we offer a variety of workshops – both in English and German.
- [**Performance Workshop**](https://www.angulararchitects.io/en/training/angular-performance-optimization-workshop/) 🚀
- [**Accessibility Workshop**](https://www.angulararchitects.io/en/training/angular-accessibility-workshop/) ♿
- [**Styling Workshop**](https://www.angulararchitects.io/en/training/angular-styling-workshop/) 🎨
## Outlook
### Partial Hydration (NG 19 or 20)
Partial hydration, announced at [ng-conf](https://ng-conf.org/) and [Google I/O](https://io.google/2024/explore/7deddebc-3cae-4285-b2a9-affb5296102e/) 2024, is a technique that allows incremental hydration of an app after server-side rendering, improving performance by loading less JavaScript upfront.
```html
@defer (render on server; on viewport) {
<app-deferred-hydration />
}
```
The prototype block above will render the calendar component on the server. Once it reaches the client, _Angular_ will download the corresponding JavaScript and hydrate the calendar, making it interactive only after it enters the viewport. This is in contrast to full hydration, where all the components on the page are rendered at once.
It builds upon `@defer`, enabling _Angular_ to render main content on the server and hydrate deferred blocks on the client after being triggered. The _Angular team_ is actively prototyping this feature, with an early access program available for Devs building performance-critical applications.
## Conclusion
In summary, implementing Server-Side Rendering (SSR) in _Angular_, along with Static Site Generation (SSG), Hydration and Event Replay, significantly improves the initial load performance of your _Angular_ apps. This leads to a better user experience, especially on slower networks or low-budget devices, and enhances SEO and crawlability of your web app.
By following the steps and best practices outlined in this guide, you can achieve better load performance for your apps with minimal effort. The new Application Builder makes building and deploying very smooth.
Feel free to [**contact me**](mailto:[email protected]) for further questions or join our [**Performance Workshop 🚀**](https://www.angulararchitects.io/en/training/angular-performance-optimization-workshop/) to learn more about performance optimization for _Angular_ apps.
## References
- [Why is Initial Load Performance so Important?](https://www.angulararchitects.io/blog/why-is-initial-load-performance-so-important/) by Alexander Thalhammer
- [Angular 16 - official blog post](https://blog.angular.dev/angular-v16-is-here-4d7a28ec680d) by Minko Gechev
- [Angular Update Guide to V17 incl. migrations](https://www.angulararchitects.io/blog/angular-17-update-control-flow-app-builder-migration/) by Alexander Thalhammer
- [Angular 17’s Deferrable Views](https://www.angulararchitects.io/blog/how-to-improve-initial-load-performance-with-angular-17s-deferrable-views/) by Alexander Thalhammer
- [Angular 18 - official blog post](https://blog.angular.dev/angular-v18-is-now-available-e79d5ac0affe) by Minko Gechev
- [Angular’s after(Next)Render hooks](https://netbasal.com/exploring-angulars-afterrender-and-afternextrender-hooks-7133612a0287) by Netanel Basal
- [Angular Event Replay blog post](https://blog.angular.dev/event-dispatch-in-angular-89d868d2351c) by Jatin Ramanathan, Tom Wilkinson
- [Angular SSR Docker example](https://www.angulararchitects.io/blog/how-to-use-angular-ssr-with-hydration/) by Alexander Thalhammer
This blog post was written by [Alex Thalhammer](https://alex.thalhammer.name/). Follow me on [GitHub](https://github.com/L-X-T), [X](https://twitter.com/LX_T) or [LinkedIn](https://at.linkedin.com/in/thalhammer).
| lxt |
|
1,910,831 | Mastering Asynchronous Programming in JavaScript | Introduction Asynchronous programming is a core concept in JavaScript that enables developers to... | 0 | 2024-07-04T16:25:53 | https://dev.to/dev_habib_nuhu/mastering-asynchronous-programming-in-javascript-4dh7 | **Introduction**
Asynchronous programming is a core concept in JavaScript that enables developers to write non-blocking code, allowing applications to perform multiple tasks simultaneously. Understanding asynchronous programming is crucial for building efficient and responsive web applications. In this article, we'll explore the fundamentals of asynchronous programming in JavaScript, including callbacks, promises, and async/await.
**What is Asynchronous Programming?**
Asynchronous programming allows a program to initiate a potentially time-consuming operation and move on to other tasks before that operation completes. This approach is essential for tasks like network requests, file I/O, and timers, ensuring that an application remains responsive.
**Callbacks**
Callbacks are the simplest form of asynchronous programming in JavaScript. A callback is a function passed as an argument to another function, which is then executed after the completion of an operation.
```
function fetchData(callback) {
setTimeout(() => {
callback('Data fetched');
}, 2000);
}
function handleData(data) {
console.log(data);
}
fetchData(handleData);
```
Pros:
- Simple to implement and understand.
- Useful for small, straightforward tasks.
Cons:
- Can lead to "callback hell" or "pyramid of doom" with nested callbacks, making code difficult to read and maintain.
**Promises**
Promises provide a more robust way to handle asynchronous operations. A promise represents a value that may be available now, in the future, or never. Promises have three states: pending, fulfilled, and rejected.
```
function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve('Data fetched');
}, 2000);
});
}
fetchData()
.then(data => console.log(data))
.catch(error => console.error(error));
```
Pros:
- Improves readability and maintainability.
- Chainable, allowing for sequential asynchronous operations.
Cons:
- Requires understanding of promise chaining and error handling.
**Async/Await**
Async/await is syntactic sugar built on top of promises, providing a more readable and concise way to handle asynchronous code. Functions declared with async return a promise, and await is used to pause execution until the promise is resolved.
```
async function fetchData() {
return new Promise((resolve, reject) => {
setTimeout(() => {
resolve('Data fetched');
}, 2000);
});
}
async function handleData() {
try {
const data = await fetchData();
console.log(data);
} catch (error) {
console.error(error);
}
}
handleData();
```
Pros:
- Enhances code readability and maintainability.
- Simplifies error handling with try/catch blocks.
Cons:
- Requires understanding of promises.
- Not all asynchronous operations may benefit from async/await.
**Conclusion**
Asynchronous programming is a fundamental skill for JavaScript developers, enabling them to build responsive and efficient applications. By understanding callbacks, promises, and async/await, you can write clean, maintainable, and effective asynchronous code. Practice these concepts to master asynchronous programming and enhance your development skills. | dev_habib_nuhu |
|
1,911,780 | Video Playlist html, css and JS | Hi, I’m doing a little project to add to my portfolio. What I would like to do is create a playlist... | 0 | 2024-07-04T16:25:16 | https://dev.to/raz41/video-playlist-html-css-and-js-a18 | html, css, javascript | Hi, I’m doing a little project to add to my portfolio. What I would like to do is create a playlist video like in picture 1
but I have several other events in which I would also like to put images so that each when clicking on an event as in image 2 opens a page which is image 1 with its different fightCard, where there is a problem is how I can add video links so that it is different for each event (img2) as for example on streaming sites (img3) to illustrate clearly what I mean here is a small video.
NB: I use an api for all the information you see on the image
Code source:
https://pastebin.com/GW3HY7bE
Où
https://codepen.io/Raz41/pen/mdZbWNV
img1:
img2:
img3:
video:
https://ufile.io/cut0gzwt | raz41 |
1,911,765 | AWS Lambda in Deno or Bun | The article describes creating the AWS Lambda using purely Deno or Bun Javascript runtimes with zero... | 0 | 2024-07-04T16:22:41 | https://dev.to/begoon/aws-lambda-in-deno-or-bun-2l65 | deno, bunjs, aws, awslambda | The article describes creating the AWS Lambda using purely Deno or Bun Javascript runtimes with zero external dependencies. We will use Deno by default, but the switch to Bun can be made via the `RUNTIME` variable (see `Makefile`).
Usually, to create an AWS lambda in Typescript, the code must be compiled in Javascript because AWS Lambda does not natively support Deno and Bun, only Node.
Some projects offer the flexibility of using Typescript directly in AWS Lambda, such as [Deno Lambda](https://github.com/denoland/deno-lambda).
However, we will implement our own custom AWS Lambda runtime to run Typescript by Deno or Bun and use AWS Lambda API directly.
The project comprises a Makefile for automation and clarity, Dockerfiles for containerization, and the `lambda.ts` file for the AWS Lambda function. That's all you need.
We will be building Docker images-based AWS Lambda deployment.
We start by explaining how to prepare AWS resources (image repository, role and policies, and lambda deployment).
We will use AWS CLI.
## Part 1
You can skip this part of the article entirely if you are comfortable creating an AWS Elastic Container Repository named `$(FUNCTION_NAME)` (refer to Makefile) to prepare the lambda function named `$(FUNCTION_NAME)` to be created from the image, which we will build later.
You need to have `.env` file:
```
AWS_PROFILE=<YOU AWS PROFILE NAME>
AWS_ACCOUNT=<YOU AWS ACCOUNT>
AWS_REGION=<YOU AWS REGION>
```
The profile name allows AWS CLI to find your AWS_ACCESS_KEY_ID
and AWS_SECRET_ACCESS_KEY.
The `.env` file is included at the beginning of `Makefile`:
```
include .env
export
FUNCTION_NAME=lambda-ts-container
REPO = $(AWS_ACCOUNT).dkr.ecr.$(AWS_REGION).amazonaws.com
```
Once again, instead of using the Makefile file below, you can create the repository and manually prepare the AWS Lambda creation via AWS Console.
Create the depository:
```Makeflle
create-repo:
aws ecr create-repository \
--profile $(AWS_PROFILE) \
--repository-name $(FUNCTION_NAME)
```
`make create-repo`
Login docker to the repository:
```Makefile
ecr-login:
aws ecr get-login-password --region $(AWS_REGION) \
--profile $(AWS_PROFILE) \
| docker login --username AWS --password-stdin $(REPO)
```
`make ecr-login`
Build, tag and push the image:
```Makefile
build-tag-push: build tag-push
build:
docker build -t $(FUNCTION_NAME) \
--platform linux/amd64 \
-f Dockerfile-$(RUNTIME) .
tag-push:
docker tag $(FUNCTION_NAME):latest \
$(REPO)/$(FUNCTION_NAME):latest \
docker push $(REPO)/$(FUNCTION_NAME):latest
```
`make build-tag-push`
Before creating the AWS Lambda, we need to create a role:
```Makefile
create-lambda-role:
aws iam create-role \
--profile $(AWS_PROFILE) \
--role-name $(FUNCTION_NAME)-role \
--assume-role-policy-document \
'{"Version": "2012-10-17","Statement": [{ "Effect": "Allow", "Principal": {"Service": "lambda.amazonaws.com"}, "Action": "sts:AssumeRole"}]}'
aws iam attach-role-policy \
--profile $(AWS_PROFILE)
--role-name $(FUNCTION_NAME)-role \
--policy-arn arn:aws:iam::aws:policy/service-role/AWSLambdaBasicExecutionRole
```
`make create-lambda-role`
The role uses the `AWSLambdaBasicExecutionRole` policy, which allows the lambda to write logs for CloudWatch.
Finally, we create the lambda function:
```Makefile
create-lambda:
aws lambda create-function \
--function-name $(FUNCTION_NAME) \
--role arn:aws:iam::$(AWS_ACCOUNT):role/$(FUNCTION_NAME)-role \
--package-type Image \
--code ImageUri=$(REPO)/$(FUNCTION_NAME):latest \
--architectures x86_64 \
--profile $(AWS_PROFILE) | cat
```
`make create-lambda`
We must create the AWS lambda URL and allow unauthenticated access to complete the lambda creation.
```Makefile
create-lambda-url:
aws lambda create-function-url-config \
--profile $(AWS_PROFILE) \
--function-name $(FUNCTION_NAME) \
--auth-type NONE
create-lambda-invoke-permission:
aws lambda add-permission \
--profile $(AWS_PROFILE) \
--function-name $(FUNCTION_NAME) \
--action lambda:InvokeFunctionUrl \
--statement-id FunctionURLAllowPublicAccess \
--principal "*" \
--function-url-auth-type NONE
```
`make create-lambda-url create-lambda-invoke-permission`
At this point, the AWS should be successfully created and deployed.
If you change the lambda source and want to deploy the update, you call:
```Makefile
deploy: build-tag-push update-image wait
update-image:
SHA=$(shell make last-tag) && \
echo "SHA=$(WHITE)$$SHA$(NC)" && \
aws lambda update-function-code \
--profile $(AWS_PROFILE) \
--function-name $(FUNCTION_NAME) \
--image $(REPO)/$(FUNCTION_NAME)@$$SHA \
| jq -r '.CodeSha256'
status:
@aws lambda get-function \
--function-name $(FUNCTION_NAME) \
--profile $(AWS_PROFILE) \
| jq -r .Configuration.LastUpdateStatus
wait:
@while [ "$$(make status)" != "Successful" ]; do \
echo "wait a moment for AWS to update the function..."; \
sleep 10; \
done
@echo "lambda function update complete"
```
`make deploy`
This command builds, tags and deploys a new image.
Let's invoke the function:
```Makefile
lambda-url:
@aws lambda get-function-url-config \
--function-name $(FUNCTION_NAME) \
| jq -r '.FunctionUrl | rtrimstr("/")'
get:
@HOST=$(shell make lambda-url) && \
http GET "$$HOST/call?a=1"
```
`make get`
This command calls the lambda function via its public URL. The URL path is `/call` but can be anything with some query parameters. The path and query parameters will be provided to the function code and other standard HTTP-related information.
Other examples in `Makefile` invoke the function in different ways. For example, `put-` calls the data function in the request body.
```Makefile
put-json:
@HOST=$(shell make lambda-url) && \
http -b PUT "$$HOST/call?q=1" a=1 b="message"
put-text:
@HOST=$(shell make lambda-url) && \
http -b PUT "$$HOST/call?q=1" --raw='plain data'
get-418:
@HOST=$(shell make lambda-url) && \
http GET "$$HOST/call?a=1&status=418"
```
The code uses the `http` command from `httpie`.
## Part 2
Let's look at the most exciting part -- the function's source code.
As I promised, we do not use any libraries. Instead, we use AWS Lambda API directly.
The AWS lambda lifecycle is a simple loop. The code below fetches the next function invocation event from the AWS API, passes it to the handler, and then sends the response to the AWS Lambda API response endpoint. That is it!
```Typescript
import process from "node:process";
const env = process.env;
const AWS_LAMBDA_RUNTIME_API = env.AWS_LAMBDA_RUNTIME_API || "?";
console.log("AWS_LAMBDA_RUNTIME_API", AWS_LAMBDA_RUNTIME_API);
const API = `http://${AWS_LAMBDA_RUNTIME_API}/2018-06-01/runtime/invocation`;
while (true) {
const event = await fetch(API + "/next");
const REQUEST_ID = event.headers.get("Lambda-Runtime-Aws-Request-Id");
console.log("REQUEST_ID", REQUEST_ID);
const response = await handler(await event.json());
await fetch(API + `/${REQUEST_ID}/response`, {
method: "POST",
body: JSON.stringify(response),
});
}
// This is a simplified version of the AWS Lambda runtime API.
// The full specification can be found at:
// https://docs.aws.amazon.com/lambda/latest/dg/services-apigateway.html
type APIGatewayProxyEvent = {
queryStringParameters?: Record<string, string>;
requestContext: { http: { method: string; path: string } };
body?: string;
};
async function handler(event: APIGatewayProxyEvent) {
const { method, path } = event.requestContext.http;
const echo = {
method,
path,
status: "200",
queryStringParameters: {},
runtime: runtime(),
env: {
...env,
AWS_SESSION_TOKEN: "REDACTED",
AWS_SECRET_ACCESS_KEY: "REDACTED",
},
format: "",
body: "",
};
if (event.queryStringParameters) {
echo.queryStringParameters = event.queryStringParameters;
echo.status = event.queryStringParameters.status || "200";
}
if (event.body) {
try {
echo.body = JSON.parse(event.body);
echo.format = "json";
} catch {
echo.body = event.body;
echo.format = "text";
}
}
return {
statusCode: echo.status,
headers: { "Content-Type": "application/json" },
body: JSON.stringify(echo),
};
}
function runtime() {
return typeof Deno !== "undefined"
? "deno " + Deno.version.deno
: typeof Bun !== "undefined"
? "bun " + Bun.version
: "maybe node";
}
```
For demonstration purposes, the handler returns the input data as the response.
NOTE: There are essential moments in the Dockerfile where we must configure the location for temporary files. The AWS Lambda container execution environment file system is read-only, and only the `/tmp` directory can be used for writing.
Let's discuss Dockerfiles to build the image.
```Dockerfile
FROM denoland/deno as deno
FROM public.ecr.aws/lambda/provided:al2
COPY --from=deno /usr/bin/deno /usr/bin/deno
# We need to set the DENO_DIR to /tmp because the AWS lambda filesystem
# is read-only except for /tmp. Deno may need to write to its cache.
ENV DENO_DIR=/tmp
COPY lambda.ts /var/task/
ENTRYPOINT [ "/usr/bin/deno" ]
CMD [ "run", "-A", "--no-lock", "/var/task/lambda.ts"]
```
Dockerfile uses the official AWS base image `public.ecr.aws/lambda/provided:al2`.
This image comes with the AWS Lambda Runtime Client preinstalled. This client runs in the background and proxies the requests from the lambda function loop to AWS endpoints. The `AWS_LAMBDA_RUNTIME_API` variable points to `localhost` with a port on which the Lambda Runtime Client listens.
This concludes the article.
By default, `Makefile` uses Deno (RUNTIME=deno). The RUNTIME variable can be set to `bun` as a drop-in change, so no other changes are required.
For convenience, the handler reports what runtime it is running on in the `runtime` field.
## Resources
The links to the sources of the files from this article:
- [Makefile](https://gist.github.com/begoon/993e29f5cf9a384b9e0e96e70a71b491#file-makefile)
- [lambda.ts](https://gist.github.com/begoon/993e29f5cf9a384b9e0e96e70a71b491#lambda-ts)
- [Dockefile-deno](https://gist.github.com/begoon/993e29f5cf9a384b9e0e96e70a71b491#Dockefile-deno)
- [Dockerfile-bun](https://gist.github.com/begoon/993e29f5cf9a384b9e0e96e70a71b491#Dockerfile-bun)
| begoon |
1,911,779 | How does Shopify compare to other e-commerce platforms in terms of features, pricing, and ease of use? | When comparing Shopify to other e-commerce platforms, it’s important to look at various aspects such... | 0 | 2024-07-04T16:21:53 | https://dev.to/ndiaga/how-does-shopify-compare-to-other-e-commerce-platforms-in-terms-of-features-pricing-and-ease-of-use-502j | When comparing Shopify to other e-commerce platforms, it’s important to look at various aspects such as features, pricing, ease of use, and more. Here’s a detailed overview that avoids comparison tables and provides a thorough look at what Shopify offers compared to other popular platforms.
1. Features
A. Shopify’s Key Features
Ease of Setup: Shopify offers a straightforward setup process with an easy-to-use interface for building and managing your store.
Store Customization: It provides a range of themes (both free and paid) that you can customize using its drag-and-drop builder.
Product Management: Features for adding products, managing inventory, and creating variations are robust. It supports digital, physical, and subscription products.
Payment Gateways: Built-in integration with various payment gateways and Shopify Payments for easy transactions.
Marketing Tools: Includes features like discount codes, gift cards, SEO settings, email marketing integrations, and social media tools.
Analytics: Offers comprehensive analytics and reporting tools to track sales, customer behavior, and store performance.
Mobile Optimization: All themes are responsive and optimized for mobile devices.
App Store: Access to a vast library of apps and plugins to extend functionality, including apps for SEO, marketing, and customer support.
Customer Support: 24/7 support via chat, email, and phone.
B. Other Platforms’ Features
WooCommerce: As a WordPress plugin, WooCommerce offers extensive customization options and a range of features through plugins. It’s highly flexible but requires more manual setup and maintenance.
Magento: A powerful platform for large-scale stores with advanced features and customization options, but it’s complex and more suited for larger businesses.
BigCommerce: Similar to Shopify in terms of features but with some advanced features built-in, like advanced SEO tools and multi-currency support.
PrestaShop: Offers a lot of features out of the box, with extensive customization options and a range of modules for additional functionality.
Wix eCommerce: Known for its drag-and-drop website builder, it’s user-friendly but less feature-rich compared to Shopify for e-commerce.
2. Pricing
A. Shopify’s Pricing Plans
Basic Shopify: $39/month – Includes basic features for starting an e-commerce store.
Shopify: $105/month – Offers additional features like professional reports and better shipping rates.
Advanced Shopify: $399/month – Includes advanced reporting, third-party calculated shipping rates, and more.
Additional Costs:
Transaction Fees: Shopify charges a fee for transactions if you don’t use Shopify Payments.
Themes: Premium themes cost between $140-$180, though there are also free themes available.
Apps: Many apps in the Shopify App Store have their own fees.
B. Other Platforms’ Pricing
WooCommerce: Free as a plugin, but you’ll need to pay for hosting, domain registration, and any premium plugins or themes.
Magento: Open-source version is free, but you’ll need to pay for hosting and possibly extensions. Magento Commerce, a premium version, has a high price point.
BigCommerce: Pricing starts at $39/month with similar features to Shopify. Higher plans offer advanced features.
PrestaShop: Free to use, but you may need to pay for hosting, themes, and modules.
Wix eCommerce: Pricing starts at around $23/month for e-commerce features. It also has a free plan, but it’s limited in features.
3. Ease of Use
A. Shopify’s Ease of Use
User-Friendly Interface: Designed for users with little technical knowledge. The dashboard is intuitive, and setting up a store is relatively straightforward.
Built-In Features: Many essential e-commerce features are built into the platform, reducing the need for third-party tools.
Support and Documentation: Extensive documentation, tutorials, and a supportive community help users navigate any issues.
B. Other Platforms’ Ease of Use
WooCommerce: Requires a basic understanding of WordPress. More complex to set up due to the need for separate hosting and potentially more plugins.
Magento: Complex and best suited for developers. Requires significant time and expertise to set up and maintain.
BigCommerce: Similar ease of use to Shopify but may have a steeper learning curve for advanced features.
PrestaShop: Offers many features but can be more complex to set up and manage. Some knowledge of PHP and web development may be required.
Wix eCommerce: Very user-friendly with a drag-and-drop builder, but less robust for large or complex e-commerce needs.
4. Scalability
A. Shopify’s Scalability
Growth-Friendly: Shopify scales well from small businesses to large enterprises with plans that cater to various business sizes.
Performance: The platform handles high traffic and large catalogs efficiently.
B. Other Platforms’ Scalability
WooCommerce: Can scale, but performance and management can become challenging as your store grows.
Magento: Highly scalable but best for businesses with significant resources.
BigCommerce: Also designed for growth, with features that support expanding businesses.
PrestaShop: Scalable with the right hosting and configurations but may require more manual adjustments.
Wix eCommerce: More suited for small to medium-sized stores and less scalable for large enterprises.
5. Security
A. Shopify’s Security Features
SSL Certificates: Included in all plans for secure transactions.
PCI Compliance: Shopify is PCI DSS compliant to ensure secure payment processing.
Regular Updates: Shopify handles updates and security patches automatically.
B. Other Platforms’ Security
WooCommerce: Security depends on your hosting provider and plugins. Regular updates and security measures are necessary.
Magento: Offers robust security features but requires regular maintenance and updates.
BigCommerce: PCI compliant with built-in security features.
PrestaShop: Security can vary based on modules and hosting. Regular updates and security practices are needed.
Wix eCommerce: Basic security features included, but less advanced compared to Shopify for large-scale needs.
6. Customer Support
A. Shopify’s Support
24/7 Support: Available through chat, email, and phone.
Help Center: Extensive documentation and community forums.
B. Other Platforms’ Support
WooCommerce: Support through forums, community help, and paid support options.
Magento: Support varies based on the version. Magento Commerce offers dedicated support.
BigCommerce: 24/7 support through chat, email, and phone.
PrestaShop: Community support and professional services available through third-party agencies.
Wix eCommerce: 24/7 support through chat and email.
Conclusion
Shopify is a robust e-commerce platform known for its ease of use, comprehensive features, and scalability. It’s a great choice for both beginners and established businesses looking for a reliable solution. Here’s a summary of why it might be the best choice for your e-commerce needs:
Ease of Use: Intuitive setup with a user-friendly interface.
Comprehensive Features: Built-in tools for marketing, payments, and analytics.
Scalability: Suitable for businesses of all sizes.
Security: High-level security features included.
Support: Excellent customer support and extensive resources.
If you’re considering Shopify or other platforms, think about what specific needs your e-commerce store has. For a cost-effective and feature-rich e-commerce solution, PrestaShop is also a great option, especially for those looking for more flexibility and out-of-the-box features.
For more information or to explore tools and support for PrestaShop, visit PrestaTuts.
Additional Resources
Shopify Pricing and Plans
PrestaTuts for PrestaShop Modules and Support
BigCommerce vs. Shopify
WooCommerce Features
Magento Solutions
Feel free to reach out if you have more questions or need further assistance!
| ndiaga |
|
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Contact Us / 24 Hours Reply
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| jipeni1861 |
1,911,770 | How can app developers implement a secure and user-friendly cryptocurrency payment gateway in their applications? | Implementing a secure and user-friendly cryptocurrency payment gateway in an application involves a... | 0 | 2024-07-04T16:13:06 | https://dev.to/ndiaga/how-can-app-developers-implement-a-secure-and-user-friendly-cryptocurrency-payment-gateway-in-their-applications-20lj | Implementing a secure and user-friendly cryptocurrency payment gateway in an application involves a combination of technical integration, security measures, and user experience design. Here’s a comprehensive guide on how app developers can achieve this:
1. Choose the Right Cryptocurrency Payment Gateway
Selecting the right payment gateway is crucial for both security and user experience. Consider the following popular options:
Coinbase Commerce: Offers support for multiple cryptocurrencies and is user-friendly.
BitPay: Known for its robust security features and ease of integration.
CoinGate: Provides a variety of payment options and an easy setup process.
NOWPayments: Supports a wide range of cryptocurrencies with simple integration.
Blockchain.com Merchant Solutions: A trusted platform for secure transactions and multiple crypto options.
2. Integrate the Payment Gateway
A. Obtain API Keys
Sign Up: Create an account with the chosen payment gateway.
Get API Keys: Access the API keys from the dashboard. These keys are necessary for integrating the gateway into your application.
B. Integration Methods
Use Official SDKs: Many gateways offer official SDKs for various programming languages, which can simplify integration.
Coinbase Commerce API
BitPay API Documentation
CoinGate API Documentation
NOWPayments API Documentation
Blockchain.com API Documentation
Direct API Calls: If there is no SDK, you can directly call the API endpoints using libraries like cURL in PHP, axios in JavaScript, or requests in Python.
Example in PHP:
php
Copier le code
`$apiKey = 'YOUR_API_KEY';
$url = 'https://api.paymentgateway.com/v1/transactions';
$data = array(
'amount' => 0.1,
'currency' => 'BTC',
'callback_url' => 'https://yourapp.com/callback'
);
$options = array(
'http' => array(
'header' => "Authorization: Bearer $apiKey\r\n" .
"Content-Type: application/json\r\n",
'method' => 'POST',
'content' => json_encode($data),
),
);
$context = stream_context_create($options);
$result = file_get_contents($url, false, $context);`
Example in JavaScript:
javascript
Copier le code
const axios = require('axios');
const apiKey = 'YOUR_API_KEY';
axios.post('https://api.paymentgateway.com/v1/transactions', {
amount: 0.1,
currency: 'BTC',
callback_url: 'https://yourapp.com/callback'
}, {
headers: {
'Authorization': `Bearer ${apiKey}`,
'Content-Type': 'application/json'
}
})
.then(response => console.log(response.data))
.catch(error => console.error(error));
C. Test Your Integration
Use Test Environments: Most gateways provide a sandbox or test environment for you to test transactions without real money.
Perform Transactions: Test various scenarios including successful payments, failed transactions, and refunds.
3. Ensure Security
A. Use HTTPS
SSL/TLS Certificates: Ensure that your application uses HTTPS to secure data transmission between users and your server.
B. Secure API Keys
Environment Variables: Store API keys in environment variables instead of hardcoding them into your application.
Restricted Access: Limit API key permissions to only the necessary actions (read/write).
C. Implement Webhooks for Payment Confirmation
Configure Webhooks: Set up webhooks to receive real-time updates on payment status.
Validate Webhooks: Verify that the webhook requests are genuinely from the payment gateway and not from a malicious source.
Example Validation in PHP:
php
Copier le code
$webhookSecret = 'YOUR_WEBHOOK_SECRET';
$receivedSignature = $_SERVER['HTTP_X_SIGNATURE'];
$computedSignature = hash_hmac('sha256', file_get_contents('php://input'), $webhookSecret);
if (hash_equals($computedSignature, $receivedSignature)) {
// Handle the webhook event
}
D. Follow Security Best Practices
Keep Software Updated: Regularly update your application, libraries, and dependencies.
Perform Security Audits: Regularly review your security measures and conduct vulnerability assessments.
4. Design a User-Friendly Experience
A. Simplify the Checkout Process
Clear Instructions: Provide clear instructions for users on how to complete their payments.
Show Real-Time Status: Display real-time updates on the payment process, such as transaction progress and confirmations.
B. Offer Multiple Payment Options
Multiple Cryptocurrencies: Support various cryptocurrencies to cater to different user preferences.
Alternative Payment Methods: Provide alternative payment methods like credit/debit cards for users who may not use cryptocurrencies.
C. Provide Support
Help Resources: Offer resources such as FAQs, tutorials, and support contact options.
Customer Support: Provide responsive customer support for issues related to cryptocurrency transactions.
5. Legal and Compliance Considerations
A. Follow Legal Regulations
Regulatory Requirements: Comply with local regulations regarding cryptocurrency transactions, which can vary by country.
Tax Implications: Understand and manage tax obligations related to cryptocurrency payments.
B. Privacy Policies
Privacy Statements: Update your privacy policy to include information about handling cryptocurrency transactions and data protection.
Example of Implementing a Payment Gateway
Here’s a simple example of integrating the Coinbase Commerce payment gateway into your application:
A. Setting Up
Sign Up for Coinbase Commerce and get your API key.
Install the Coinbase Commerce SDK:
bash
Copier le code
npm install @coinbase/coinbase-commerce-node
B. Code Example
javascript
Copier le code
const CoinbaseCommerce = require('@coinbase/coinbase-commerce-node');
const { Client, Resources } = CoinbaseCommerce;
Client.init('YOUR_API_KEY');
const chargeData = {
name: 'Sample Charge',
description: 'Payment for a sample product',
local_price: {
amount: '10.00',
currency: 'USD'
},
pricing_type: 'fixed_price',
metadata: {
customer_id: '12345',
customer_name: 'John Doe'
}
};
const charge = await Resources.Charge.create(chargeData);
console.log(charge.hosted_url); // Redirect users to this URL to complete the payment
Additional Resources
PrestaTuts for PrestaShop Modules and Support
Coinbase Commerce Integration Guide
BitPay API Documentation
CoinGate API Documentation
NOWPayments API Documentation
Blockchain.com API Documentation
Summary
To implement a secure and user-friendly cryptocurrency payment gateway:
Choose a Gateway: Select a gateway that fits your needs.
Integrate the Gateway: Obtain API keys and use SDKs or direct API calls for integration.
Ensure Security: Use HTTPS, secure API keys, and validate webhooks.
Design User Experience: Simplify checkout, offer multiple payment options, and provide support.
Follow Legal Requirements: Ensure regulatory compliance and update privacy policies.
If you have any more questions or need further assistance, feel free to ask or visit PrestaTuts for PrestaShop-related needs and support! | ndiaga |
|
1,911,767 | 2181. Merge Nodes in Between Zeros | 2181. Merge Nodes in Between Zeros Medium You are given the head of a linked list, which contains a... | 27,523 | 2024-07-04T16:08:34 | https://dev.to/mdarifulhaque/2181-merge-nodes-in-between-zeros-ghp | php, leetcode, algorithms, programming | 2181\. Merge Nodes in Between Zeros
Medium
You are given the `head` of a linked list, which contains a series of integers **separated** by `0`'s. The **beginning** and **end** of the linked list will have `Node.val == 0`.
For **every** two consecutive `0`'s, **merge** all the nodes lying in between them into a single node whose value is the **sum** of all the merged nodes. The modified list should not contain any `0`'s.
Return _the `head` of the modified linked list._
**Example 1:**
- **Input:** head = [0,3,1,0,4,5,2,0]
- **Output:** [4,11]
- **Explanation:** The above figure represents the given linked list. The modified list contains
- The sum of the nodes marked in green: 3 + 1 = 4.
- The sum of the nodes marked in red: 4 + 5 + 2 = 11.
**Example 2:**
- **Input:** head = [0,1,0,3,0,2,2,0]
- **Output:** [1,3,4]
- **Explanation:** The above figure represents the given linked list. The modified list contains
- The sum of the nodes marked in green: 1 = 1.
- The sum of the nodes marked in red: 3 = 3.
- The sum of the nodes marked in yellow: 2 + 2 = 4.
**Constraints:**
- The number of nodes in the list is in the range <code>[3, 2 * 10<sup>5</sup>]</code>.
- `0 <= Node.val <= 1000`
- There are no two consecutive nodes with `Node.val == 0`.
- The beginning and end of the linked list have `Node.val == 0`.
**Solution:**
```
/**
* Definition for a singly-linked list.
* class ListNode {
* public $val = 0;
* public $next = null;
* function __construct($val = 0, $next = null) {
* $this->val = $val;
* $this->next = $next;
* }
* }
*/
class Solution {
/**
* @param ListNode $head
* @return ListNode
*/
function mergeNodes($head) {
$dummy = new ListNode(0);
$current = $dummy;
$sum = 0;
// Skip the first zero node
$head = $head->next;
while ($head !== null) {
if ($head->val == 0) {
$current->next = new ListNode($sum);
$current = $current->next;
$sum = 0;
} else {
$sum += $head->val;
}
$head = $head->next;
}
return $dummy->next;
}
}
```
- **[LinkedIn](https://www.linkedin.com/in/arifulhaque/)**
- **[GitHub](https://github.com/mah-shamim)**
| mdarifulhaque |
1,911,766 | Frankfurt’s Financial Flair: Exploring the Intersection of Gaming and Fintech for Secure In-Game Economies | Frankfurt, in the centre of Europe’s financial sector, is becoming a major hub for the convergence... | 0 | 2024-07-04T16:07:17 | https://dev.to/gamecloud/frankfurts-financial-flair-exploring-the-intersection-of-gaming-and-fintech-for-secure-in-game-economies-26oe | fintech, economies | 
Frankfurt, in the centre of Europe’s financial sector, is becoming a major hub for the convergence of two rapidly growing industries: fintech and gaming. The way we view safe transactions, in-game economics, and the future of digital entertainment is changing as a result of this unusual convergence.
## The Rise of Frankfurt Fintech in Gaming
Frankfurt has a long-standing reputation as a financial centre, but its recent entry into the gaming sector has drawn attention. Fintech solutions that are specifically designed for the gambling industry can be easily implemented because of the city’s strong financial infrastructure. Businesses based in Frankfurt are leading the way in creating safe and effective methods for in-game transactions, from payment gateways to blockchain technology.
## Securing In-Game Economies
As virtual worlds become increasingly complex, the need for secure in-game economies has never been more critical. [Frankfurt fintech firms](https://frankfurt-main-finance.com/en/category/fintech-frankfurt-am-main/) are using their expertise to create sophisticated systems that protect both gamers and developers. These solutions address common concerns such as fraud prevention, secure storage of virtual currencies, and transparent transaction histories.
Blockchain technology, in particular, is making waves in this space. By providing an immutable ledger of transactions, blockchain offers unprecedented security and transparency for in-game economies. Frankfurt-based startups are exploring ways to integrate this technology seamlessly into gaming platforms, ensuring that every trade, purchase, or sale within a game is recorded and verifiable.
## The German Gaming Industry: A Fertile Ground for Innovation
Germany’s robust gaming industry makes an excellent testing ground for various finance ideas. With such a huge and active player base, German game makers are increasingly aiming to include innovative finance systems into their offerings. This collaboration between game designers and fintech specialists is accelerating the development of more immersive and financially sustainable virtual environments.
## Navigating EU Gaming Regulations
For entrepreneurs in the gaming and financial services industries, the strict rules imposed by the European Union offer both opportunities and problems. Thanks to their in-depth knowledge of financial rules and the constantly changing [EU gaming laws](https://www.nortonrosefulbright.com/en/knowledge/publications/531ca8fd/gaming-and-law-what-businesses-need-to-know), Frankfurt’s fintech companies are well-positioned to negotiate these complications. This knowledge is essential for creating conforming products that can be used in the whole European market.
## The Frankfurt Stock Exchange: A Model for In-Game Asset Trading
Some progressive companies are investigating the idea of formalised trading systems for in-game assets, taking inspiration from the Frankfurt Stock Exchange. Through these platforms, gamers will be able to exchange rare goods, virtual real estate, and other digital assets with confidence, bringing the sophistication and security of real-world financial markets to virtual economies.
## The Future of Fintech in European Gaming
The future holds interesting advancements thanks to the collaboration between the gaming industry and Frankfurt’s fintech sector. It is anticipated that games will increasingly seamlessly include financial services, that virtual transactions will be safer, and that producers and gamers would profit from creative monetization techniques.
## LolzSoft’s Expertise for Secure and Engaging In-Game Economies
LolzSoft, a subsidiary of [GameCloud](https://gamecloud-ltd.com/) Technologies, specializes in video game development and offers rapid prototyping and modular development solutions that could be highly beneficial for creating secure and engaging in-game economies. With our expertise in programming, designing, and developing video game software, we could help integrate robust and flexible in-game economies that align with Frankfurt’s thriving fintech ecosystem. By utilising our services, game developers can create immersive gaming experiences with well-balanced economies that enhance player engagement and monetization while ensuring security and transparency.
## Conclusion
The special location of Frankfurt at the nexus of technology and finance is bringing gaming economics into a new era. The city is contributing to the development of more safe, transparent, and interesting in-game economies by utilising cutting-edge financial solutions. As this trend continues to expand, Frankfurt will play a critical role in influencing the future of digital entertainment and virtual finance in Europe and beyond.
Know more about [Frankfurt’s Financial Flair](https://gamecloud-ltd.com/frankfurt-fintech-in-game-economies/) on GameCloud Technologies
| gamecloud |
1,911,813 | How to Migrate Amazon Redshift to a Different Account and Region: Step-by-Step Guide | Introduction Moving Amazon Redshift to a new account and region might seem difficult, but... | 0 | 2024-07-04T17:19:21 | https://dev.to/thulasirajkomminar/how-to-migrate-amazon-redshift-to-a-different-account-and-region-step-by-step-guide-2c38 | snapshot, migration, redshift, aws | ---
title: How to Migrate Amazon Redshift to a Different Account and Region: Step-by-Step Guide
published: true
date: 2024-07-04 16:01:33 UTC
tags: snapshot,migration,redshift,aws
canonical_url:
---
### Introduction
Moving Amazon Redshift to a new account and region might seem difficult, but it doesn’t have to be. You might need to follow regulations or reorganize your teams. In this guide, we will show you step by step how to move your Redshift data to a different account and region. After reading this guide, you will know how to do Redshift migrations easily, with minimal downtime and secure data. Let’s start and make your Redshift move simple!
### Prerequisites
For the migration process, choose a maintenance window with minimal write activity, ensuring alignment with the organization’s RTO and RPO requirements.
### Step 1: Configure cross-region snapshot
To move the cluster to a different region in a different account, you first need to configure the cross-region snapshot for the cluster in the source account where the cluster resides.
1. Go to your cluster and click **Actions**.
2. Select **Configure cross-region snapshot**.
3. In the **Destination AWS Region** drop-down menu, choose the region where you want to move the cluster in the target account.
4. Click **Save**.
### Step 2: Create a manual snapshot
To share a cluster snapshot with another AWS account, you need a manual snapshot.
1. Go to your cluster and click **Actions**.
2. Choose **Create Snapshot**.
3. Give the snapshot a name and click **Create Snapshot**.
Since we configured the cross-region snapshot in the previous step, creating a snapshot now will also copy it to the destination region.
### Step 3: Grant Access to KMS Key in the Target Account
When you share an encrypted snapshot, you also need to share the KMS key that was used to encrypt it. To do this, add the following policy to the KMS key. In this policy example, replace `123456789123` with the identifier of the TargetAccount.
```json
{
"Id": "key-policy-1",
"Version": "2012-10-17",
"Statement": [
{
"Sid": "Allow use of the key in TargetAccount",
"Effect": "Allow",
"Principal": {
"AWS": [
"arn:aws:iam::123456789123:root"
]
},
"Action": [
"kms:Decrypt"
],
"Resource": "*"
}
]
}
```
### Step 4: Share snapshot
Navigate to Snapshots, find the manual snapshot you created, and click on it. Under Snapshot access, click on edit. Enter the TargetAccount ID and click Add account. Once you’re done, click Save. Now, the snapshot will be accessible in the TargetAccount and the destination region..
### Step 5: Restoring a Cluster from Snapshot in the Target Account
Navigate to the TargetAccount and the destination region in Redshift. Under snapshots, you will find the shared snapshot. Click on Restore snapshot and configure options like Nodes, Networking, and more as needed.
### Conclusion
In this guide, we’ve covered the essential steps to migrate Amazon Redshift to a new account and region smoothly. By following these steps carefully, you can ensure minimal downtime and maintain data integrity throughout the migration process. I hope this guide has provided clarity and confidence for your Redshift migration journey!
### References:
- [Managing snapshots using the console](https://docs.aws.amazon.com/redshift/latest/mgmt/managing-snapshots-console.html#snapshot-create)
- [Managing snapshots using the console](https://docs.aws.amazon.com/redshift/latest/mgmt/managing-snapshots-console.html#snapshot-share)
- [Managing snapshots using the console](https://docs.aws.amazon.com/redshift/latest/mgmt/managing-snapshots-console.html#snapshot-restore) | thulasirajkomminar |
1,911,763 | Mastering Kubernetes: Understanding Cron Jobs and DaemonSets | Welcome back to our Kubernetes Mastery series! This is the 12th installment in the CK 2024 series and... | 0 | 2024-07-04T16:01:01 | https://dev.to/jensen1806/mastering-kubernetes-understanding-cron-jobs-and-daemonsets-1c3p | kubernetes, devops, docker, containers | Welcome back to our Kubernetes Mastery series! This is the 12th installment in the CK 2024 series and today we'll dive into CronJobs and DaemonSets in Kubernetes. Let's get started!
### The Importance of DaemonSets
In our previous posts, we explored ReplicaSets and Deployments, detailing how they deploy pods across multiple nodes. When we specify a replicas field in the manifest, Kubernetes creates multiple pods distributed across nodes. For example, if we set replicas: 3, Kubernetes might create three NGINX pods, each on different nodes.
DaemonSets function similarly but with a key difference: they ensure that a copy of a pod runs on all nodes in the cluster. If a new node is added to the cluster, the DaemonSet controller automatically adds a pod to it. Conversely, if a node is removed, the corresponding pod is also deleted. This behavior is useful for tasks such as running monitoring or logging agents on every node.
### Use Cases for DaemonSets:
1. **Monitoring Agents**: Collect metrics from each node.
2. **Logging Agents**: Stream logs from each node to a central system.
3. **Network Plugins**: Components like kube-proxy, Weave, Flannel, or Calico often run as DaemonSets.
### Creating a DaemonSet:
Here’s a simplified YAML manifest for a DaemonSet:
```
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: sample-agent
spec:
selector:
matchLabels:
name: sample-agent
template:
metadata:
labels:
name: sample-agent
spec:
containers:
- name: sample-agent
image: nginx
```
This manifest ensures that an NGINX pod runs on all nodes in the cluster.
To apply this configuration:
```
kubectl apply -f daemonset.yaml
kubectl get pods
```
You’ll notice that a pod is created on each node except the master node due to taints.
### CronJobs in Kubernetes
CronJobs are a type of job that runs on a scheduled basis, similar to cron jobs in Unix/Linux systems. They are not directly relevant to the CKA exam but are essential for automating repetitive tasks.
#### CronJob Syntax:
The cron syntax includes five fields:
- Minute (0-59)
- Hour (0-23)
- Day of Month (1-31)
- Month (1-12)
- Day of Week (0-6) starting with Sunday
Examples:
Run at 11:00 PM every Saturday: 0 23 * * 6
Run every 5 minutes: */5 * * * *
Creating a CronJob:
Here’s a simple example to print the date and a message every minute:
```
apiVersion: batch/v1beta1
kind: CronJob
metadata:
name: hello-cron
spec:
schedule: "* * * * *"
jobTemplate:
spec:
template:
spec:
containers:
- name: hello
image: busybox
args:
- /bin/sh
- -c
- date; echo Hello from the Kubernetes cluster
restartPolicy: OnFailure
```
To apply this configuration:
```
kubectl apply -f cronjob.yaml
kubectl get cronjobs
```
This CronJob runs every minute, prints the date, and outputs a hello message.
### Understanding Jobs
Jobs in Kubernetes run a pod to completion. Unlike CronJobs, they are typically used for one-time tasks like data processing or batch operations.
Here’s a simple Job manifest:
```
apiVersion: batch/v1
kind: Job
metadata:
name: simple-job
spec:
template:
spec:
containers:
- name: pi
image: perl
command: ["perl", "-Mbignum=bpi", "-wle", "print bpi(2000)"]
restartPolicy: Never
```
To apply this configuration:
```
kubectl apply -f job.yaml
kubectl get jobs
```
This job calculates pi to 2000 decimal places and completes.
### Conclusion:
In this post, we covered the fundamentals of DaemonSets, CronJobs, and Jobs in Kubernetes. DaemonSets ensure that critical pods run on every node, while CronJobs automate tasks on a schedule, and Jobs execute one-time tasks to completion. Understanding these components is crucial for managing Kubernetes clusters effectively.
Stay tuned for our next post where we’ll dive deeper into Kubernetes networking components and their deployment strategies.
For further reference, check out the detailed YouTube video here:
{% embed https://www.youtube.com/watch?v=kvITrySpy_k&list=WL&index=18 %}
| jensen1806 |
1,911,762 | 🐍 Answer the phone! with Python | Python is a powerful language that can do many things; most use it for machine learning or web... | 0 | 2024-07-04T15:59:25 | https://kevincoder.co.za/answer-the-phone-with-python | webdev, programming, python, tutorial | Python is a powerful language that can do many things; most use it for machine learning or web development, but did you know that Python can also interact with hardware and other services like SIP?
## What is SIP Anyway?
Similar to how we have HTTP for the web, voice-over-internet systems usually run on a protocol named SIP, which provides guidelines on how to establish, modify, and terminate sessions over the network.
A SIP session can then carry voice, text, or even video. In the case of our application, SIP is just a signaling protocol and, therefore is responsible for connecting and disconnecting the call to our Python script.
Once the call is answered and established, we then use the "RTP" or Real-time Transport Protocol to handle the audio stream.
Thankfully with PyVoIP, the library takes care of all the SIP and streaming mechanics, thus we don't have to worry too much about how SIP works or RTP for that matter.
## Let's build something cool!?
In this guide, I will show you how to build a simple phone answering service with Python.
The script will do the following:
1) Register as a SIP VOIP phone and wait for calls.
2) Accept incoming calls.
3) Transcribe the audio using OpenAI's Whisper.
## Installing pip packages
We going to need a few PIP packages as follows:
```bash
pip install pyVoIP
pip install pywav
pip install openai
```
Be sure to also add your OpenAI key to your environment, in bash you can easily do this by doing the following:
```bash
nano ~/.bashrc
# Add to the end of the file
export OPENAI_API_KEY="sk-xxx"
```
You will need to restart your terminal for this to take effect.
## Setting up a VOIP virtual phone
PyVoIP is a nifty little library that can easily help you set up a virtual phone with just a few lines of code.
> ℹ️ You probably want to use something like Twilio instead for a real-world application. PyVoIP audio quality isn't the best and needs quite a bit of modification to work correctly.
To get started, let's set up a basic phone:
```python
from pyVoIP.VoIP import VoIPPhone, CallState
def answer(call):
try:
call.answer()
except Exception as e:
print(e)
finally:
call.hangup()
vp = VoIPPhone(
'sip domain', 5060, 'sipuser',
'sippassword', callCallback=answer
)
vp.start()
print(vp._status)
input("Press any key to exit the VOIP phone session.")
vp.stop()
```
In this example, we create a virtual phone using the "VoiPPhone" class. This class takes in a few arguments as follows:
- **SIP Credentials**: When you purchase a SIP account from a VOIP provider, you should have received a username, password, and an IP or domain name that will be connected to a phone number. (3Cx.com is an example of a SIP provider).
- **callCallback**: This is the function that will handle answering the phone call.
The callback function will receive one argument, i.e. the "call" object which will contain all the relevant information relating to the caller and provide various methods for you to accept and receive or send audio back to the caller.
> ℹ️ Did you know that you can build your own VOIP server as well? Asterisk is a powerful open-source VOIP server that you can use to set up your own SIP accounts, phone numbers, extensions, and so forth.
## Transcribing audio
To convert audio into text we can use OpenAI's Whisper service, here's a simple example of how to convert our audio into text:
```python
from openai import OpenAI
import pywav
def convert_to_wav(audio, tmpFileName):
data_bytes = b"".join(audio)
wave_write = pywav.WavWrite(tmpFileName, 1, 8000, 8, 7)
wave_write.write(data_bytes)
wave_write.close()
return open(tmpFileName, "rb")
def transcribe_to_text(audio_file):
tmpFileName = f"/tmp/audio/_audio_buffer_{uuid.uuid4()}.wav"
client = OpenAI()
transcription = client.audio.transcriptions.create(
model="whisper-1",
file=convert_to_wav(audio_file, tmpFileName)
)
try:
return transcription.text
except Exception as ex:
print(ex)
return ""
```
The "transcribe_to_text" function takes in a list of raw audio byte samples, we then need to convert those samples into an actual audio file because the OpenAI SDK is expecting a file object, not raw audio bytes.
We therefore use "pywav" in our "convert_to_wav" function to convert the raw audio bytes into a ".wav" audio file.
> ⚠️ This logic is simplified so that it's easier to understand, but essentially it can be optimized to remove the need for saving to a temp file since disk IO on a slow drive might cause issues.
## Updating our answer method to chunk the audio
In our "answer" method we receive the audio as a continuous stream of bytes, therefore each chunk of audio is 20ms. We cannot send a 20ms chunk of audio to Whisper because the minimum length is 100ms.
Thus, we need to append the audio to a buffer and we'll only send the audio to Whisper once we reach 1000ms (or 1 second).
Here is the updated "answer" function:
```python
def answer(call):
try:
call.answer()
buffer = []
buff_length = 0
while call.state == CallState.ANSWERED:
audio = call.read_audio()
# We divide by 8 because the audio sample rate is 8000 Hz
buff_length += len(audio) / 8 # or simply 20
if buff_length <= 1000:
buffer.append(audio)
else:
print(transcribe_to_text(buffer))
buffer = []
buff_length = 0
except Exception as e:
print(e)
finally:
call.hangup()
```
> 💡 You can also send back audio to the caller by calling "call.write_audio(raw_audio_bytes_here)"
## The full code
```python
from pyVoIP.VoIP import VoIPPhone, CallState
import uuid
from openai import OpenAI
import os
import pywav
def convert_to_wav(audio, tmpFileName):
data_bytes = b"".join(audio)
wave_write = pywav.WavWrite(tmpFileName, 1, 8000, 8, 7)
wave_write.write(data_bytes)
wave_write.close()
return open(tmpFileName, "rb")
def transcribe_to_text(audio_file):
tmpFileName = f"/tmp/audio/_audio_buffer_{uuid.uuid4()}.wav"
client = OpenAI()
transcription = client.audio.transcriptions.create(
model="whisper-1",
file=convert_to_wav(audio_file)
)
try:
return transcription.text
except Exception as ex:
print(ex)
return ""
def answer(call):
try:
call.answer()
buffer = []
buff_length = 0
while call.state == CallState.ANSWERED:
audio = call.read_audio()
buff_length += len(audio) / 8
if buff_length <= 1000:
buffer.append(audio)
else:
print(transcribe_to_text(buffer))
buffer = []
buff_length = 0
except Exception as e:
print(e)
finally:
call.hangup()
vp = VoIPPhone('xxx', 5060, 'xxx', 'xxx', callCallback=answer)
vp.start()
print(vp._status)
input("Press any key to exist")
vp.stop()
```
## Conclusion
There you have it! A simple phone answering system that can stream live audio and transcribe that audio into text.
Now PyVoIP as mentioned earlier is not the best tool for the job since it doesn't handle background noise and static very well. You would need to write some kind of logic to strip out the bad audio samples first before transcribing for an actual real-world application, but hopefully, this is a good start.
| kwnaidoo |
1,911,466 | Don't Be a Victim: The Ultimate Guide to Defending Against Cybersecurity Threats | In today's hyper-connected world, cybersecurity is more crucial than ever. From personal data... | 0 | 2024-07-04T15:59:24 | https://dev.to/verifyvault/dont-be-a-victim-the-ultimate-guide-to-defending-against-cybersecurity-threats-20kl | opensource, cybersecurity, security, github | In today's hyper-connected world, cybersecurity is more crucial than ever. From personal data breaches to corporate espionage, the threats are real and ever-evolving. Imagine waking up one day to find your bank account emptied or your identity stolen—all because of a cyber attack that could have been prevented.
### <u>**Common Cybersecurity Threats**</u>
1. **Phishing Attacks:** These deceptive emails or messages lure you into revealing sensitive information. Always verify the source before clicking any links.
2. **Malware:** Viruses, worms, and ransomware can wreak havoc on your devices. Keep your antivirus software updated and avoid downloading from suspicious sources.
3. **Weak Passwords:** Easily guessable passwords are an open invitation to hackers. Use strong, unique passwords for each account and consider using a password manager.
4. **Man-in-the-Middle (MitM) Attacks:** Hackers intercept communications between two parties, potentially stealing sensitive data. Use encrypted connections (HTTPS) whenever possible.
5. **Insider Threats:** Sometimes the biggest threats come from within. Limit access to sensitive information and educate employees about cybersecurity best practices.
### <u>**How to Guard Against Them:**</u>
- **Use Two-Factor Authentication (2FA):** Add an extra layer of security to your accounts with 2FA. VerifyVault offers a free, open-source 2FA application for Windows and soon Linux, ensuring your accounts stay protected even if your password is compromised.
- **Keep Software Updated:** Patching vulnerabilities is crucial. Enable automatic updates on all devices and applications.
- **Backup Regularly:** In case of ransomware or hardware failure, regular backups can save your data. VerifyVault offers automatic backups, making it easier to secure your accounts.
- **Educate Yourself:** Stay informed about the latest threats and educate yourself and your team on cybersecurity practices.
Cybersecurity is a shared responsibility. By taking proactive steps to safeguard your data and privacy, you not only protect yourself but also contribute to a safer digital environment for everyone. Don't wait until it's too late—start implementing these strategies today and make cybersecurity a priority.
Ready to enhance your online security? Download [VerifyVault](https://github.com/VerifyVault), the free and open-source 2FA application for desktop. Protect your accounts with encrypted, offline access and automatic backups. Secure your digital life now!
[VerifyVault Beta v0.3 Download](https://github.com/VerifyVault/VerifyVault/releases/tag/Beta-v0.3) | verifyvault |
1,911,761 | Crafting Custom Methods in JavaScript with Prototypes | JavaScript's prototype system is a powerful feature that allows developers to extend the capabilities... | 0 | 2024-07-04T15:56:59 | https://dev.to/geraldhamiltonwicks/crafting-custom-methods-in-javascript-with-prototypes-5c41 | javascript, node | JavaScript's prototype system is a powerful feature that allows developers to extend the capabilities of built-in objects such as arrays, strings, and objects. By adding custom methods to these prototypes, we can create more expressive and reusable code. In this tutorial, we'll walk through how to create and use custom prototype methods in JavaScript.
## Why Use Prototypes?
Prototypes allow you to add methods to existing objects, arrays, and strings in JavaScript, making it easy to create reusable and extendable code. This approach can help you avoid repetitive code and enhance the functionality of built-in JavaScript objects, arrays, and strings.
## Example Custom Methods
We'll create three custom methods as examples:
1. `toUpperCase` for arrays
2. `capitalizeFirstLetter` for strings
3. `deepCopy` for objects
### 1. Array Method: `toUpperCase`
The `toUpperCase` method will convert all elements in an array of strings to uppercase.
**File: `arrayExtensions.js`**
```javascript
Array.prototype.toUpperCase = function() {
return this.map(element => element.toUpperCase());
};
// Export a dummy object just to ensure the module is loaded
export { };
```
### 2. String Method: `capitalizeFirstLetter`
The `capitalizeFirstLetter` method will capitalize the first letter of a string.
**File: `stringExtensions.js`**
```javascript
String.prototype.capitalizeFirstLetter = function () {
const capitalizedLetter = this[0].toUpperCase();
const othersLetters = this.slice(1, this.length);
return capitalizedLetter + othersLetters;
}
// Export a dummy object just to ensure the module is loaded
export {};
```
### 3. Object Method: `deepCopy`
The `deepCopy` method will create a deep copy of an object. This is useful because JavaScript objects are copied by reference, not by value. This means that changes to a copied object will affect the original object. A deep copy ensures that the original object remains unchanged.
**File: `objectExtensions.js`**
```javascript
Object.prototype.deepCopy = function() {
return JSON.parse(JSON.stringify(this));
}
// Export a dummy object just to ensure the module is loaded
export {};
```
## Using Custom Methods in Your Project
To use these custom methods in your project, you need to import the files where these methods are defined. This will ensure that the methods are added to the prototypes of the respective objects.
**File: `main.js`**
```javascript
import './arrayExtensions.js';
import './stringExtensions.js';
var fruits = ["Banana", "Orange", "Apple", "Mango"];
console.log(fruits.toUpperCase()); // Output: ["BANANA", "ORANGE", "APPLE", "MANGO"]
const data = "gerald";
console.log(data.capitalizeFirstLetter()); // "Gerald";
const firstPerson = { name: "Gerald", age: 25 };
const secondPerson = firstPerson.deepCopy();
secondPerson.name = 'Jefferson';
console.log(firstPerson); // { name: "Gerald", age: 25 }
console.log(secondPerson); // { name: "Jefferson", age: 25 }
```
## Benefits of Custom Prototype Methods
- **Reusability**: Custom methods can be reused across your project, reducing code duplication.
- **Readability**: Using well-named methods can make your code more readable and easier to understand.
- **Maintainability**: Changes to a prototype method are reflected wherever the method is used, making it easier to maintain.
## Use with Caution
But be cautious. Adding custom methods to built-in objects can be dangerous if used incorrectly. Use with caution, and stay tuned for a future article where I'll explore safer ways to add methods!
## Conclusion
By leveraging JavaScript's prototype system, you can add custom methods to built-in objects, arrays, and strings, and enhance their functionality. This approach can help you write cleaner, more efficient, and more maintainable code. Try creating your own custom prototype methods to see how they can improve your projects! | geraldhamiltonwicks |
1,911,759 | The Silent Crisis in Open Source: When Maintainers Walk Away | Maintainer transitions can create a lot of challenges. That's why open source support through proactive measures like knowledge transfer and community engagement is so important. | 0 | 2024-07-04T15:50:11 | https://opensauced.pizza/blog/when-open-source-maintainers-leave | opensource, community, burnout | ---
title: The Silent Crisis in Open Source: When Maintainers Walk Away
published: true
description: Maintainer transitions can create a lot of challenges. That's why open source support through proactive measures like knowledge transfer and community engagement is so important.
tags: opensource, community, burnout
cover_image: https://dev-to-uploads.s3.amazonaws.com/uploads/articles/52q4hyv61kfmnps2yme4.png
# Use a ratio of 100:42 for best results.
# published_at: 2024-07-04 15:46 +0000
canonical_url: https://opensauced.pizza/blog/when-open-source-maintainers-leave
---
In May 2022, [Dane Springmeyer](https://app.opensauced.pizza/u/springmeyer), the primary maintainer of [node-pre-gyp](https://app.opensauced.pizza/s/mapbox/node-pre-gyp?range=360), a critical tool in the Node.js ecosystem, [announced his decision to step down](https://github.com/mapbox/node-pre-gyp/issues/657). This wasn't just another developer moving on; for nearly a decade he had been maintaining the project.
Despite outlining the urgency and the need for community involvement to keep the project maintained, proposing several options for the future of the project, and emphasizing the importance of maintaining or gracefully deprecating `node-pre-gyp` to avoid disruptions, it wasn't resolved until very recently.
This situation is just one that captures the challenges of maintainer transitions in open source projects. The departure of a key maintainer can have far-reaching implications, affecting the project's sustainability, security, and overall health.
## The Impact of a Maintainer's Departure
Unaddressed pull requests and unresolved issues start piling up, creating a backlog and uncertainty for the contributor community. The lack of regular updates can expose the project to security vulnerabilities, quickly decreasing trust among users and contributors. For `node-pre-gyp`, this scenario unfolded as community members scrambled to find a way forward. **Single points of failure can have widespread repercussions.**
There's another type of loss that we forget about: the loss of institutional knowledge and context. Maintainers often possess critical insights into the project's history, design decisions, and future roadmap. Without this knowledge, new maintainers may struggle to navigate the project effectively. This loss of continuity can disrupt the project's development and direction, impacting its long-term viability.
This is one of the reasons, we make the [lottery factor](https://opensauced.pizza/docs/welcome/glossary/#lottery-factor) visible on repository pages on OpenSauced.
> The Lottery Factor is a metric that identifies how at risk a project is if a key contributor leaves. It is calculated by the percentage of pull request (PR) contributions made by the top contributors. If 50% of the PR contributions come from two or fewer contributors, the lottery factor is high.
Understanding how at risk a project is if a key contributor leaves can help contributors and maintainers prepare for potential transitions and ensure the project's sustainability.
### The Invisible Maintainer: A Hidden Threat
One often overlooked aspect of the maintainer crisis is the difficulty in identifying who actually maintains a project. This lack of transparency can lead to communication breakdowns, unclear decision-making processes, hidden lottery factor, and accountability issues.
Understanding who the maintainers are is key to project health. If you take a look at the [node-pre-gyp contributors dashboard](https://app.opensauced.pizza/s/mapbox/node-pre-gyp/contributors), you'll see that they were able to make the transition to a new maintainer.
This isn't just about giving credit where it's due. It's about supporting the community with necessary intelligence.
When we know who the maintainers are, we:
- Know who's behind our dependencies.
- Can target our open source support. Find the overworked maintainers and back them up.
- Can actively support the next generation of project leaders.
It's one step in the right direction, but it's not enough. We need to make maintainer transitions more transparent, predictable, and manageable.
## The Ticking Time Bomb of Maintainer Burnout
Springmeyer's case is far from unique. Across the open source ecosystem, projects are vulnerable to maintainer abandonment for a variety of reasons, including [burnout](https://opensauced.pizza/blog/stop-burning-out-maintainers:-an-empathetic-guide-for-contributors), [lonliness](https://opensauced.pizza/blog/the-lonely-journey-of-open-source-maintainers), or lack of support. In the case of springmeyer, he cited personal and professional shifts, such as parental leave and changing priorities at Mapbox. Marak, the Faker.js creator, intentionally deleted Faker.js to highlight the pressures and lack of open source support maintainers often face. These situations emphasize the need for a supportive infrastructure that recognizes and alleviates the burden on maintainers.
This current unsustainable model is a ticking time bomb. When key maintainers leave, projects can quickly become outdated, insecure, or completely non-functional. The ripple effects can be catastrophic, potentially impacting thousands of dependent projects and millions of users.
## The Trust Paradox: The Hidden Challenge of Maintainer Succession
Finding new maintainers isn't just about identifying skilled developers. It's about trust. Handing over the keys to a project with millions of downloads to someone else can be risky. This trust paradox creates a dilemma:
> "[If] you are maintaining a project, you're kind of a gatekeeper. If you oftentimes you don't want to be, but also you don't have the time to onboard some random people, because you're afraid that like the millions of downloads this package has will fall into the hands of someone you don't know, and they could really cause damage, right? So how to do that?" - Gregor Martynus on [The Secret Sauce](https://www.youtube.com/watch?v=Gu_jWAjviLs&list=PLHyZ0Wz_A44VR4BXl_JOWSecQeWcZ-kS3&index=10)
This quote identifies a critical dilemma:
- Maintainers may find themselves reluctant guardians of widely-used projects.
- The time investment required to properly vet and onboard new maintainers is substantial.
- Giving someone maintainer access to a project can carry enormous risk.
This creates a vicious cycle: overworked maintainers struggle to find time to onboard help, leading to further burnout and increasing the risk of sudden project abandonment.
### Quantifying the Risk: New Metrics for Project Health
To address this problem, we need better ways to assess the health and sustainability of open source projects. Two emerging metrics offer valuable insights:
1. **Lottery Factor**: This metric highlights the dependency on key contributors. A project is considered vulnerable if 2 or fewer contributors account for 50% or more of the project's contributions. It's essentially measuring the "bus factor" - how many people could the project lose before it's in serious trouble?
2. **Contributor Confidence**: This metric predicts the likelihood that users who star or fork a repository will return to make contributions. A higher score (typically 30-40%) indicates a healthy, active project where contributions are valued.
These metrics offer a data-driven approach to assessing project health. A high Lottery Factor combined with low Contributor Confidence could be a red flag, indicating a project overly reliant on a small number of contributors and struggling to attract new ones.
### Preventing the Exodus: A Call to Action
1. **Sustainable Funding Models**: We need to move beyond the "free labor" mindset. Companies benefiting from open source projects should contribute financially, either through direct sponsorship or by allocating paid developer time to maintenance to prove open source support.
2. **Succession Planning**: Projects should actively cultivate a bench of potential maintainers. This means documenting processes, sharing knowledge, and actively supporting new contributors. Aim to lower that Lottery Factor!
3. **Community Health Metrics**: Regularly track metrics like Contributor Confidence. If it starts to dip, it may be time to invest in community outreach or simplify the contribution process. Healthy communities attract and retain contributors.
These approaches don't just make maintainer succession safer—they make it more achievable. By reducing the cognitive load of vetting new maintainers, we lower the barrier to expanding the maintainer pool.
## Redefining Open Source Insights
The departure of Dane Springmeyer from `node-pre-gyp` wasn't just a personal decision — it was a reminder of the hidden fragility of our digital infrastructure.
We need to move into a new era in open source; one where gut feelings and GitHub stars aren't seen as metrics of project health. One where the true pulse of a project — its maintainer dedication, community activity, and sustainability — can be quantified and understood.
We should strive to:
- See beyond commit counts to understand the real dynamics of contributor engagement and open source support
- Identify the unsung heroes holding projects together
- Predict potential maintainer burnout before it happens
- Understand the true lottery factor of your essential dependencies
This should be the reality of open source intelligence. When we adopt this mindset, we can:
- Make informed decisions about which projects to rely on and support
- Focus contributor efforts where they'll have the most impact
- Proactively address project vulnerabilities
- Rally around projects in need before they reach crisis point
This vision requires a shift in mindset. We have to move beyond simple metrics and anecdotal evidence and embrace data-driven insights that reveal the true health of our open source ecosystem. It's time to truly see the human element that drives open source forward.
It's about making the invisible visible. It's about transforming raw data into actionable intelligence that ensures open source software support and sustainability.
| bekahhw |
1,911,758 | Managing Users in PraisePHS Microsystems Ltd with a Bash Script | In any corporate environment, managing users efficiently and securely is paramount. PraisePHS... | 0 | 2024-07-04T15:49:45 | https://dev.to/praisephs/managing-users-in-praisephs-microsystems-ltd-with-a-bash-script-26jo | cloudcomputing, devops, bash, ubuntu | In any corporate environment, managing users efficiently and securely is paramount. PraisePHS Microsystems Ltd. employs a systematic approach to user management using a Bash script. This article will explain how the provided Bash script functions, ensuring smooth and secure user creation and management.
**Overview**
The script takes a file containing user and group information as input, creates users, assigns them to specified groups, sets passwords, and logs the process. The users.txt file, for example, provides the necessary user and group details in a semicolon-separated format.
**Bash Script Breakdown**
Here's a step-by-step explanation of the script:
1. The script starts by defining the necessary files: the input file containing user information, the log file for logging actions, and the password file for storing generated passwords.
2. This function generates a random password using OpenSSL's rand function, ensuring a strong and unique password for each user.
3. This section ensures the existence and correct permissions of the log and password files. If these files or directories do not exist, the script creates them and sets appropriate permissions to ensure security
4. The script reads each line of the input file, removes any carriage returns, trims whitespace, and skips empty lines to ensure clean data processing.
- User Existence Check: The script checks if a user already exists. If they do, it logs this information.
- User Creation: If the user does not exist, the script generates a password, creates the user with a home directory, sets the password, and logs these actions.
- Group Management: The script adds the user to specified groups. If a group does not exist, it creates the group before adding the user.
- Permissions and Ownership: Finally, the script sets the permissions and ownership
for the user's home directory to ensure security.
Example Input File: users.txt
The users.txt file contains user information in the format username; group1,group2
For more information about the HNG internship, visit the [HNG Internship page](https://hng.tech/internship)
If you are looking to hire talented interns, check out the [HNG Hire page](https://hng.tech/hire) | praisephs |
1,911,757 | OpenAI (LLM) Function Call Schema Generator from Swagger (OpenAPI) Document | Outline https://github.com/wrtnio/openai-function-schema Made an OpenAI function schema... | 22,751 | 2024-07-04T15:48:30 | https://dev.to/samchon/openai-llm-function-call-schema-generator-from-swagger-openapi-document-3g4n | openai, opensource, typescript, swagger | <!--
OpenAI (LLM) Function Call Schema Generator from Swagger (OpenAPI) Document
-->
## Outline
https://github.com/wrtnio/openai-function-schema
Made an OpenAI function schema library, `@wrtnio/openai-function-schema`.
It supports OpenAI function call schema definitions, and converter from Swagger (OpenAPI) document to the OpenAI function call schema definitions. Also, `@wrtnio/openai-function-schema` provides function call executor from the schema definitions, so that you can easily execute the remote Restful API operation with OpenAI composed arguments.
The best use case of `@wrtnio/openai-function-schema` what I imagine is, you hang up every API operations of your backend server by converting Swagger document to `@wrtnio/openai-function-schema`, so that make it possible to to call your server operations in the chat session through the OpenAI function calling feature.
For reference, `@wrtnio/openai-function-schema` supports every versions of Swagger (OpenAPI) specifications.
- Swagger v2.0
- OpenAPI v3.0
- OpenAPI v3.1
Now, let's setup `@wrtnio/openai-function-schema`, and take advantages of it.
```bash
npm install @wrtnio/openai-function-schema
```
```typescript
import {
IOpenAiDocument,
IOpenAiFunction,
OpenAiComposer,
OpenAiFetcher,
} from "@wrtnio/openai-function-schema";
import fs from "fs";
import typia from "typia";
import { v4 } from "uuid";
import { IBbsArticle } from "../../../api/structures/IBbsArticle";
const main = async (): Promise<void> => {
// COMPOSE OPENAI FUNCTION CALL SCHEMAS
const swagger = JSON.parse(
await fs.promises.readFile("swagger.json", "utf8"),
);
const document: IOpenAiDocument = OpenAiComposer.document({
swagger
});
// EXECUTE OPENAI FUNCTION CALL
const func: IOpenAiFunction = document.functions.find(
(f) => f.method === "put" && f.path === "/bbs/articles",
)!;
const article: IBbsArticle = await OpenAiFetcher.execute({
document,
function: func,
connection: { host: "http://localhost:3000" },
arguments: [
// imagine that arguments are composed by OpenAI
v4(),
typia.random<IBbsArticle.ICreate>(),
],
});
typia.assert(article);
};
main().catch(console.error);
```
## Command Line Interface
```bash
########
# LAUNCH CLI
########
# PRIOR TO NODE V20
$ npm install -g @wrtnio/openai-function-schema
$ npx wofs
# SINCE NODE V20
$ npx @wrtnio/openai-function-schema
########
# PROMPT
########
--------------------------------------------------------
Swagger to OpenAI Function Call Schema Converter
--------------------------------------------------------
? Swagger file path: test/swagger.json
? OpenAI Function Call Schema file path: test/plain.json
? Whether to wrap parameters into an object with keyword or not: No
```
You can easily convert Swagger (OpenAPI) documents to OpenAI function schemas just by CLI command.
When you run npx @wrtnio/openai-function-schema (or npx wofs after global setup), the CLI (Command Line Interface) will inquiry those arguments. After you fill all of them, the OpenAI fuction call schema file of [`IOpenAiDocument`](https://github.com/wrtnio/openai-function-schema/blob/main/src/structures/IOpenAiDocument.ts) type would be created to the target location.
If you want to specify arguments without prompting, you can fill them like below:
```bash
# PRIOR TO NODE V20
$ npm install -g @wrtnio/openai-function-schema
$ npx wofs --input swagger.json --output openai.json --keyword false
# SINCE NODE V20
$ npx @wrtnio/openai-function-schema
--input swagger.json
--output openai.json
--keyword false
```
Here is the list of [`IOpenAiDocument`](https://github.com/wrtnio/openai-function-schema/blob/main/src/structures/IOpenAiDocument.ts) files generated by CLI command.
Project | Swagger | Positional | Keyworded
--------------|---------|--------|-----------
BBS | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/bbs.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/bbs.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/bbs.json)
Clickhouse | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/clickhouse.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/clickhouse.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/clickhouse.json)
Fireblocks | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/fireblocks.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/fireblocks.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/fireblocks.json)
Iamport | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/iamport.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/iamport.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/iamport.json)
PetStore | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/petstore.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/petstore.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/petstore.json)
Shopping Mall | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/shopping.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/shopping.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/shopping.json)
Toss Payments | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/toss.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/toss.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/toss.json)
Uber | [swagger.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/swagger/uber.json) | [positional.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/positional/uber.json) | [keyworded.json](https://github.com/wrtnio/openai-function-schema/blob/main/examples/keyword/uber.json)
## Features
Here is the schema definitions and functions of `@wrtnio/openai-function-schema`.
- Schema Definitions
- [`IOpenAiDocument`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiDocument.ts): OpenAI function metadata collection with options
- [`IOpenAiFunction`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiFunction.ts): OpenAI's function metadata
- [`IOpenAiSchema`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiSchema.ts): Type schema info escaped `$ref`.
- Functions
- [`OpenAiComposer`](https://github.com/wrtnio/openai-function-schema/blob/master/src/OpenAiComposer.ts): Compose `IOpenAiDocument` from Swagger (OpenAPI) document
- [`OpenAiFetcher`](https://github.com/wrtnio/openai-function-schema/blob/master/src/OpenAiFetcher.ts): Function call executor with `IOpenAiFunction`
- [`OpenAiDataCombiner`](https://github.com/wrtnio/openai-function-schema/blob/master/src/OpenAiDataCombiner.ts): Data combiner for LLM function call with human composed data
- [`OpenAiTypeChecker`](https://github.com/wrtnio/openai-function-schema/blob/master/src/OpenAiTypeChecker.ts): Type checker for `IOpenAiSchema`
If you want to utilize `@wrtnio/openai-function-schema` in the API level, you should start from composing [`IOpenAiDocument`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiDocument.ts) through `OpenAiComposer.document()` method.
After composing the [`IOpenAiDocument`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiDocument.ts) data, you may provide the nested [`IOpenAiFunction`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiFunction.ts) instances to the OpenAI, and the OpenAI may compose the arguments by its function calling feature. With the OpenAI automatically composed arguments, you can execute the function call by `OpenAiFetcher.execute()` method.
Here is the example code composing and executing the [`IOpenAiFunction`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiFunction.ts).
- Test Function: [test_fetcher_positional_bbs_article_update.ts](https://github.com/wrtnio/openai-function-schema/blob/main/test/features/fetcher/positional/test_fetcher_positional_bbs_article_update.ts)
- Backend Server Code: [BbsArticlesController.ts](https://github.com/wrtnio/openai-function-schema/blob/main/test/controllers/BbsArticlesController.ts)
```typescript
import {
IOpenAiDocument,
IOpenAiFunction,
OpenAiComposer,
OpenAiFetcher,
} from "@wrtnio/openai-function-schema";
import fs from "fs";
import typia from "typia";
import { v4 } from "uuid";
import { IBbsArticle } from "../../../api/structures/IBbsArticle";
const main = async (): Promise<void> => {
// COMPOSE OPENAI FUNCTION CALL SCHEMAS
const swagger = JSON.parse(
await fs.promises.readFile("swagger.json", "utf8"),
);
const document: IOpenAiDocument = OpenAiComposer.document({
swagger
});
// EXECUTE OPENAI FUNCTION CALL
const func: IOpenAiFunction = document.functions.find(
(f) => f.method === "put" && f.path === "/bbs/articles",
)!;
const article: IBbsArticle = await OpenAiFetcher.execute({
document,
function: func,
connection: { host: "http://localhost:3000" },
arguments: [
// imagine that arguments are composed by OpenAI
v4(),
typia.random<IBbsArticle.ICreate>(),
],
});
typia.assert(article);
};
main().catch(console.error);
```
By the way, above example code's target operation function has multiple parameters. You know what? If you configure a function to have only one parameter by wrapping into one object type, OpenAI function calling feature constructs arguments a little bit efficiently than multiple parameters case.
Such only one object typed parameter is called `keyword parameter`, and `@wrtnio/openai-function-schema` supports such keyword parameterized function schemas. When composing [`IOpenAiDocument`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiDocument.ts) by `OpenAiComposer.document()` method, configures `option.keyword` to be `true`, then every [`IOpenAiFunction`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiFunction.ts) instances would be keyword parameterized. Also, `OpenAiFetcher` understands the keyword parameterized function specification, so that performs proper execution by automatic decomposing the arguments.
Here is the example code of keyword parameterizing.
- Test Function: [test_fetcher_keyword_bbs_article_update.ts](https://github.com/wrtnio/openai-function-schema/blob/main/test/features/fetcher/keyword/test_fetcher_keyword_bbs_article_update.ts)
- Backend Server Code: [BbsArticlesController.ts](https://github.com/wrtnio/openai-function-schema/blob/main/test/controllers/BbsArticlesController.ts)
```typescript
import {
IOpenAiDocument,
IOpenAiFunction,
OpenAiComposer,
OpenAiFetcher,
} from "@wrtnio/openai-function-schema";
import fs from "fs";
import typia from "typia";
import { v4 } from "uuid";
import { IBbsArticle } from "../../../api/structures/IBbsArticle";
const main = async (): Promise<void> => {
// COMPOSE OPENAI FUNCTION CALL SCHEMAS
const swagger = JSON.parse(
await fs.promises.readFile("swagger.json", "utf8"),
);
const document: IOpenAiDocument = OpenAiComposer.document({
swagger,
options: {
keyword: true, // keyword parameterizing
}
});
// EXECUTE OPENAI FUNCTION CALL
const func: IOpenAiFunction = document.functions.find(
(f) => f.method === "put" && f.path === "/bbs/articles",
)!;
const article: IBbsArticle = await OpenAiFetcher.execute({
document,
function: func,
connection: { host: "http://localhost:3000" },
arguments: [
// imagine that argument is composed by OpenAI
{
id: v4(),
body: typia.random<IBbsArticle.ICreate>(),
},
],
});
typia.assert(article);
};
main().catch(console.error);
```
At last, there can be some special API operation that some arguments must be composed by user, not by LLM (Large Language Model). For example, if an API operation requires file uploading or secret key identifier, it must be composed by user manually in the frontend application side.
For such case, `@wrtnio/openai-function-schema` supports special option [`IOpenAiDocument.IOptions.separate`](https://github.com/wrtnio/openai-function-schema/blob/master/src/structures/IOpenAiDocument.ts). If you configure the callback function, it would be utilized for determining whether the value must be composed by user or not. When the arguments are composed by both user and LLM sides, you can combine them into one through `OpenAiDataComposer.parameters()` method, so that you can still execute the function calling with `OpenAiFetcher.execute()` method.
Here is the example code of such special case:
- Test Function: [test_combiner_keyword_parameters_query.ts](https://github.com/wrtnio/openai-function-schema/blob/main/test/features/combiner/test_combiner_keyword_parameters_query.ts)
- Backend Server Code: [MembershipController.ts](https://github.com/wrtnio/openai-function-schema/blob/main/test/controllers/MembershipController.ts)
```typescript
import {
IOpenAiDocument,
IOpenAiFunction,
IOpenAiSchema,
OpenAiComposer,
OpenAiDataCombiner,
OpenAiFetcher,
OpenAiTypeChecker,
} from "@wrtnio/openai-function-schema";
import fs from "fs";
import typia from "typia";
import { IMembership } from "../../api/structures/IMembership";
const main = async (): Promise<void> => {
// COMPOSE OPENAI FUNCTION CALL SCHEMAS
const swagger = JSON.parse(
await fs.promises.readFile("swagger.json", "utf8"),
);
const document: IOpenAiDocument = OpenAiComposer.document({
swagger,
options: {
keyword: true,
separate: (schema: IOpenAiSchema) =>
OpenAiTypeChecker.isString(schema) &&
(schema["x-wrtn-secret-key"] !== undefined ||
schema["contentMediaType"] !== undefined),
},
});
// EXECUTE OPENAI FUNCTION CALL
const func: IOpenAiFunction = document.functions.find(
(f) => f.method === "patch" && f.path === "/membership/change",
)!;
const membership: IMembership = await OpenAiFetcher.execute({
document,
function: func,
connection: { host: "http://localhost:3000" },
arguments: OpenAiDataCombiner.parameters({
function: func,
llm: [
// imagine that below argument is composed by OpenAI
{
body: {
name: "Wrtn Technologies",
email: "[email protected]",
password: "1234",
age: 20,
gender: 1,
},
},
],
human: [
// imagine that below argument is composed by human
{
query: {
secret: "something",
},
body: {
secretKey: "something",
picture: "https://wrtn.io/logo.png",
},
},
],
}),
});
typia.assert(membership);
};
main().catch(console.error);
```
| samchon |
1,911,756 | Best practices in programming: Clean code for you and your team 🚀 | Discover coding best practices! Learn how to write readable, maintainable and clean code that is not... | 0 | 2024-07-04T15:47:17 | https://blog.disane.dev/en/best-practices-in-programming-clean-code-for-you-and-your-team/ | programming, bestpractices, softskills, javascript | Discover coding best practices! Learn how to write readable, maintainable and clean code that is not only understandable for you, but also for your team. 🚀
---
In software development, it is crucial to write code that not only works, but is also well-structured, readable and maintainable. This applies not only to team collaboration, but also in the event that you come back to your own code months later. In this article, I will introduce you to the best practices and principles you should follow when programming.
Using JavaScript examples, I'll show you how to turn bad code into readable code and the benefits of functional programming.
I also go into the most important soft skills that are essential for a developer. Programming is a craft and just as much love should be put into the code ❤️
There is a very good book on this topic by Robert C. Martin:
[Clean Code: A Handbook of Agile Software Craftsmanship - Robert C. Martin: 9780132350884 - AbeBooksClean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin - ISBN 10: 0132350882 - ISBN 13: 9780132350884 - Pearson - 2008 - Softcover](https://www.abebooks.com/9780132350884/Clean-Code-Handbook-Agile-Software-0132350882/plp)
## Why good code is important 🤔
### Readability
Readable code allows you and other developers to quickly understand and use the code. When you look at your own code again after a few months, you don't want to have to think for hours about what this or that part of the code does. Readable code saves time and nerves. Readable code also helps to find and fix bugs faster, as the logic and structure are clearly visible.
### Maintainability
Maintainable code is crucial for fixing bugs and adding new features. Unstructured and unclear code makes maintenance more difficult and increases the likelihood of bugs being introduced when new features are added. Maintainable code should be modular so that changes in one module do not have unforeseen effects on other parts of the code.
### Collaboration
In most projects, you are not working alone. Clear and well-structured code facilitates team collaboration. Other developers can read, understand and further develop your code. A uniform code base with consistent naming conventions and formatting makes it easier to familiarize new team members and promotes a productive working environment.
### Reusability
Well-written code is often reusable. By applying principles such as DRY (Don't Repeat Yourself) and KISS (Keep It Simple, Stupid), you can ensure that your code blocks can be reused in different parts of your project or even in other projects.
### Code for less experienced developers
A good developer writes code in such a way that it is also understandable for developers with a lower level of knowledge. This means that the code is well documented, clearly structured and free of unnecessary complexity.
## Principles of good code 🛠️
### Clarity before cleverness
It is tempting to write clever and complicated code that looks impressive at first glance. But clarity should always take precedence. Simple and clear code is often the better way to go. Code that is easy to understand makes debugging and further development easier.
```js
// Clever, but possibly difficult to understand
const isValid = (str) => !/[^\w]/.test(str);
// Clear and understandable
const isValid = (str) => {
const regex = /[^\w]/;
return !regex.test(str);
};
```
Always put yourself in the shoes of another programmer and ask yourself three questions:
* Would a beginner understand my code?
* Will I still understand my code in 6 months?
* Can I train someone in the code without having to train them?
If you can answer one of these questions with no, then your code is probably too complicated.
### Consistency
A consistent style makes the code easier to read. Use consistent naming conventions, indentation and formatting. This makes it easier to understand and maintain the code. Tools such as ESLint or Prettier can help to format the code automatically and keep it consistent.
```js
// Inconsistent
const userName = "John";
const UserAge = 30;
// Consistent
const userName = "John";
const userAge = 30;
```
### DRY (Don't Repeat Yourself) 🔂
Avoid redundancies in code. Repeated code should be outsourced to functions or classes. This reduces errors and makes changes easier. If there is a change in the code, it only needs to be made in one place.
```js
// Redundant code
function getUserName(user) {
return user.firstName + ' ' + user.lastName;
}
function getUserAddress(user) {
return user.street + ', ' + user.city;
}
// DRY principle applied
function getFullName(user) {
return `${user.firstName} ${user.lastName}`;
}
function getAddress(user) {
return `${user.street}, ${user.city}`;
}
```
### KISS (Keep It Simple, Stupid) 🤯
Keep your code as simple as possible. Complexity increases the susceptibility to errors and makes it more difficult to understand. Simple code is often more robust and efficient code. Use simple and clear logic instead of complex and nested structures.
```js
// Complex and difficult to understand
function getDiscount(price, isMember) {
return isMember ? (price > 100 ? price * 0.9 : price * 0.95) : price;
}
// Simple and clear
function getDiscount(price, isMember) {
if (isMember) {
if (price > 100) {
return price * 0.9;
} else {
return price * 0.95;
}
}
return price;
}
```
### YAGNI (You Aren't Gonna Need It) ❌
Implement only the functionalities that you currently need. Superfluous features increase complexity and maintenance costs. This principle helps to keep the code lean and focused.
```js
// Overengineering
function calculatePrice(price, tax, discount, isMember) {
let finalPrice = price + (price * tax);
if (isMember) {
finalPrice -= discount;
}
return finalPrice;
}
// YAGNI principle applied
function calculatePrice(price, tax) {
return price + (price * tax);
}
```
## Code is like a good book 📚
The correct naming of variables, functions and classes is essential for the readability and comprehensibility of the code, similar to a well-written book. Clear and precise names reflect the intention of the code block and facilitate maintenance and team collaboration. For example, a function that calculates the square of a number should be called `calculateSquare`, not `doSomething`.
A class for calculating squares could be called `SquareCalculator`. Well-named and structured code saves time and nerves and makes working in a team more pleasant and productive. By writing your code in such a way that it is understandable even for less experienced developers, you avoid technical debt and improve the quality of your project in the long term.
Names often follow the rules of language, similar to adjectives, nouns and verbs, which makes them more intuitive and easier to understand.
### Adjectives
Adjectives describe properties or states. In programming, they are often used to name variables that store certain states or properties.
```js
let isActive = true;
let userName = "JohnDoe";
```
In this example, `isActive` describes the state of an object (whether it is active or not) and `userName` stores a property of a user.
### Verbs
Verbs describe actions or processes. In programming, verbs are often used to name functions that perform certain actions.
```js
function calculateArea(width, height) {
return width * height;
}
function fetchData(url) {
// Retrieve data from a URL
}
```
Here, `calculateArea` and `fetchData` describe the actions that the respective functions perform (calculating an area and retrieving data respectively).
### Nouns
Nouns denote people, places or things. In programming, nouns are often used to name classes and objects that represent certain entities or concepts.
```js
class User {
constructor(name, email) {
this.name = name;
this.email = email;
}
}
class Product {
constructor(id, price) {
this.id = id;
this.price = price;
}
}
```
In this example, `User` and `Product` denote concrete entities in a system, similar to nouns in language.
### Adverbs
Adverbs modify verbs and describe how an action is performed. In programming, adverbs can help to specify function names and clarify how an action is performed.
```js
function calculateAreaQuickly(width, height) {
// Quickly calculate the area
return width * height;
}
function fetchDataSafely(url) {
// Fetch data safely from a URL
}
```
Here, `quickly` and `safely` modify the actions and provide additional information about how the actions should be performed.
## Bad vs. good code in JavaScript 💻
### Example of bad code
```js
function processData(input) {
let output = [];
for (let i = 0; i < input.length; i++) {
let processedData = input[i] * 2;
output.push(processedData);
}
console.log(output);
return output;
}
```
### **Example of good code**
```js
function processData(input) {
return input.map(item => item * 2);
}
const input = [1, 2, 3, 4, 5];
const output = processData(input);
console.log(output); // [2, 4, 6, 8, 10]
```
In this example, the code has been simplified by using `Array.prototype.map`, which increases readability and maintainability.
## Technical debt 🏦
Technical debt occurs when short-term solutions or compromises are made in programming to achieve quick results instead of implementing long-term, sustainable solutions. This can be caused by time pressure, lack of resources or lack of planning. Like financial debt, technical debt must also be "paid back", which takes the form of additional work for maintenance and refactoring. Technical debt can affect code quality, slow down development and make it difficult to introduce new features. Therefore, it is important to make conscious decisions and, where possible, favor long-term and clean solutions to avoid accumulating technical debt.
### Hardcoded values
Bad solution
```js
function calculateTotalPrice(quantity) {
return quantity * 9.99;
}
```
In this example, the price of the product is hardcoded in the code. This is a quick solution, but it leads to technical debt because any change to the price requires a change in the code.
### Sustainable solution
```js
const PRODUCT_PRICE = 9.99;
function calculateTotalPrice(quantity) {
return quantity * PRODUCT_PRICE;
}
```
By using a constant for the product price, the code becomes more flexible and easier to maintain. Changes to the price only need to be made in one place, which reduces technical debt.
### Duplicated code
Technical debt
```js
function calculateRectangleArea(width, height) {
return width * height;
}
function calculateTriangleArea(base, height) {
return (base * height) / 2;
}
```
There is duplicated code here that contains the calculation of the area. This repetition leads to technical debt, as changes to the logic have to be made in several places.
```js
function calculateArea(shape, ...dimensions) {
switch (shape) {
case 'rectangle':
return dimensions[0] * dimensions[1];
case 'triangle':
return (dimensions[0] * dimensions[1]) / 2;
default:
throw new Error('Unknown shape');
}
}
```
By merging the calculation logic into a single function, the code becomes DRY (Don't Repeat Yourself). This reduces technical debt and makes the code easier to maintain and extend.
## Disadvantages of kilometer-long one-liners 🚫
Kilometer-long one-liners can be difficult to read and debug. They tend to become complex and opaque, making maintenance difficult.
### Example of a bad one-liner
```js
const result = array.map(x => x * 2).filter(x => x > 10).reduce((acc, x) => acc + x, 0);
```
### Split-and-readable-code
```js
const doubled = array.map(x => x * 2);
const filtered = doubled.filter(x => x > 10);
const result = filtered.reduce((acc, x) => acc + x, 0);
```
By splitting the code into multiple lines, it becomes much more readable and easier to debug.
## Functional programming 🧑💻
Functional programming can help to write clean and efficient code. It encourages the use of immutable data and pure functions.
### Functional programming in JavaScript
```js
const numbers = [1, 2, 3, 4, 5];
const doubled = numbers.map(num => num * 2);
const even = doubled.filter(num => num % 2 === 0);
console.log(even); // [4, 8]
```
In this example, the original data is not changed and the operations are clear and comprehensible.
## Advantages of functional programming
### Invariability
Invariability means that data is no longer changed after it has been created. Instead, new data structures are created. This reduces errors and makes the code more predictable.
### Pure functions
Pure functions are functions that have no side effects and always return the same result for the same input. This makes the code easier to test and debug. The expected mode of operation is deterministic.
**Negative example ❌**
Here the value of the global variable `counter` is changed, which does not make the function pure, as the state outside the function is affected and the result differs for the same calls.
```js
let counter = 0;
function incrementCounter() {
// This function increases the value of counter and returns the new value
counter++;
return counter;
}
// Testing the function with side effect
console.log(incrementCounter()); // Output: 1
console.log(incrementCounter()); // Output: 2 (not the same result with the same calls)
```
**Positive example ✅**
```js
function add(a, b) {
// This function returns the sum of a and b
return a + b;
}
// Testing the pure function
console.log(add(2, 3)); // Output: 5
console.log(add(2, 3)); // Output: 5 (always the same result)
```
### Higher-order functions
Higher-order functions are functions that take other functions as arguments or return functions. This enables flexible and reusable code blocks.
```js
const add = (a) => (b) => a + b;
const add5 = add(5);
console.log(add5(10)); // 15
```
## Soft skills for developers 🤝
### Communication
Good communication is essential. You need to be able to convey your ideas and solutions clearly and precisely. This applies to working with other developers as well as communicating with non-technical people.
### Teamwork
The ability to work effectively as part of a team is crucial. This includes sharing knowledge, supporting colleagues and solving problems together. Teamwork also encourages development and learning within the team.
### Problem solving
Problem solving skills are central to the work of a developer. You need to be able to analyze complex problems, break them down and find effective solutions. A structured approach to problem solving helps you work more efficiently.
### Adaptability
Technology is constantly evolving. As a developer, you must be willing to learn new technologies and methods and adapt to change. Adaptability allows you to respond flexibly to new challenges.
## Code-Reviews and pair programming 🧑🤝🧑
### Code reviews
Code reviews are an important part of software development. They make it possible to detect errors at an early stage and improve the code. Regular code reviews increase code quality and knowledge is shared within the team.
### Pair programming
Pair programming is a technique in which two developers work together on one computer. One writes the code while the other reviews it. This method promotes knowledge sharing and collaboration within the team.
## Test-Driven Development (TDD) 🧪
### Advantages of TDD
Test-Driven Development (TDD) is a method in which tests are written before the actual code is developed. This helps to define clear requirements and ensure that the code delivers the expected results.
### Example of TDD in JavaScript
```js
//write test
const assert = require('assert');
function add(a, b) {
return a + b;
}
assert.strictEqual(add(1, 2), 3);
assert.strictEqual(add(-1, 1), 0);
// Implement code
function add(a, b) {
return a + b;
}
```
TDD leads to more robust and less error-prone code, as every functionality is covered by tests.
## More-helpful-principles-and-techniques
### Modularity
Modularity means dividing the code into small, independent modules. Each module should have a clearly defined task. This makes it easier to test, maintain and reuse code.
```js
// Unmodular code
function processData(data) {
// Data validation
if (!Array.isArray(data)) {
throw new Error('Invalid data');
}
// Data processing
const processed = data.map(item => item * 2);
// Data output
console.log(processed);
return processed;
}
// Modular code
function validateData(data) {
if (!Array.isArray(data)) {
throw new Error('Invalid data');
}
}
function processData(data) {
return data.map(item => item * 2);
}
function logData(data) {
console.log(data);
}
const inputData = [1, 2, 3, 4, 5];
validateData(inputData);
const processedData = processData(inputData);
logData(processedData);
```
### Automated testing
Automated testing is essential to ensure that the code works correctly and that new changes do not break existing functionalities. Unit tests, integration tests and end-to-end tests are common types of tests.
```js
const { expect } = require('chai');
// Function for testing
function add(a, b) {
return a + b;
}
// unit test
describe('add', () => {
it('should return the sum of two numbers', () => {
expect(add(1, 2)).to.equal(3);
expect(add(-1, 1)).to.equal(0);
});
});
```
### Documentation
Good documentation is crucial to help other developers (and your future self) understand the code. This includes both comments in the code (e.g. for JavaScript JSDoc) and external documentation such as README files.
```js
/**
* Adds two numbers.
*
* @param {number} a - The first number.
* @param {number} b - The second number.
* @return {number} The sum of the two numbers.
*/
function add(a, b) {
return a + b;
}
```
[Documentation - JSDoc ReferenceWhat JSDoc does TypeScript-powered JavaScript support?](https://www.typescriptlang.org/docs/handbook/jsdoc-supported-types.html)
## Conclusion 🎉
Good code is clear, readable and maintainable. It enables efficient collaboration and facilitates the maintenance and further development of projects.
You can significantly improve the quality of your code by applying best practices and principles such as clarity over cleverness, consistency and DRY. Functional programming and the development of important soft skills will also help you become a successful developer.
Remember that you are not only writing code for yourself, but also for other developers and for your future self.
---
If you like my posts, it would be nice if you follow my [Blog](https://blog.disane.dev) for more tech stuff. | disane |
1,911,755 | Best Practices beim Programmieren: Sauberer Code für Dich und Dein Team 🚀 | Entdecke die besten Praktiken beim Programmieren! Lerne, wie Du lesbaren, wartbaren und sauberen Code... | 0 | 2024-07-04T15:44:53 | https://blog.disane.dev/best-practices-beim-programmieren-sauberer-code-fur-dich-und-dein-team/ | programmierung, bestpractises, softskills, javascript | Entdecke die besten Praktiken beim Programmieren! Lerne, wie Du lesbaren, wartbaren und sauberen Code schreibst, der nicht nur für Dich, sondern auch für Dein Team verständlich ist. 🚀
---
In der Softwareentwicklung ist es entscheidend, Code zu schreiben, der nicht nur funktioniert, sondern auch gut strukturiert, leserlich und wartbar ist. Dies gilt nicht nur für die Zusammenarbeit im Team, sondern auch für den Fall, dass Du Monate später auf Deinen eigenen Code zurückkommst. In diesem Artikel werde ich Dir die besten Praktiken und Prinzipien vorstellen, die Du beim Programmieren beachten solltest.
Anhand von JavaScript-Beispielen zeige ich Dir, wie man schlechten Code in lesbaren Code umwandelt und welche Vorteile funktionale Programmierung hier bieten.
Außerdem gehe ich auf die wichtigsten Soft Skills ein, die für einen Entwickler unerlässlich sind. Programmieren ist ein Handwerk und genauso viel Liebe sollte auch in den Code gesteckt werden ❤️
Zu dem Thema gibt es ein sehr gutes Buch von Robert C. Martin:
[Clean Code: A Handbook of Agile Software Craftsmanship - Robert C. Martin: 9780132350884 - AbeBooksClean Code: A Handbook of Agile Software Craftsmanship by Robert C. Martin - ISBN 10: 0132350882 - ISBN 13: 9780132350884 - Pearson - 2008 - Softcover](https://www.abebooks.com/9780132350884/Clean-Code-Handbook-Agile-Software-0132350882/plp)
## Warum guter Code wichtig ist 🤔
### Lesbarkeit
Lesbarer Code ermöglicht es Dir und anderen Entwicklern, den Code schnell zu verstehen und zu nutzen. Wenn Du nach einigen Monaten Deinen eigenen Code wieder anschaust, möchtest Du nicht stundenlang überlegen müssen, was dieser oder jener Teil des Codes tut. Lesbarer Code spart Zeit und Nerven. Ein gut lesbarer Code hilft auch dabei, Fehler schneller zu finden und zu beheben, da die Logik und Struktur klar ersichtlich sind.
### Wartbarkeit
Wartbarer Code ist entscheidend, um Fehler zu beheben und neue Funktionen hinzuzufügen. Unstrukturierter und unklarer Code erschwert die Wartung und erhöht die Wahrscheinlichkeit, dass beim Hinzufügen neuer Features Bugs entstehen. Wartbarer Code sollte modular aufgebaut sein, sodass Änderungen in einem Modul keine unvorhergesehenen Auswirkungen auf andere Teile des Codes haben.
### Zusammenarbeit
In den meisten Projekten arbeitest Du nicht allein. Klarer und gut strukturierter Code erleichtert die Zusammenarbeit im Team. Andere Entwickler können Deinen Code lesen, verstehen und weiterentwickeln. Eine einheitliche Codebasis mit konsistenten Namenskonventionen und Formatierungen erleichtert die Einarbeitung neuer Teammitglieder und fördert eine produktive Arbeitsumgebung.
### Wiederverwendbarkeit
Gut geschriebener Code ist oft wiederverwendbar. Durch die Anwendung von Prinzipien wie DRY (Don't Repeat Yourself) und KISS (Keep It Simple, Stupid) kannst Du sicherstellen, dass Deine Codebausteine in verschiedenen Teilen Deines Projekts oder sogar in anderen Projekten wiederverwendet werden können.
### Code für weniger erfahrene Entwickler
Ein guter Entwickler schreibt Code so, dass er auch für Entwickler mit geringerem Kenntnisstand verständlich ist. Dies bedeutet, dass der Code gut dokumentiert, klar strukturiert und frei von unnötiger Komplexität ist.
## Prinzipien guten Codes 🛠️
### Klarheit vor Cleverness
Es ist verlockend, cleveren und komplizierten Code zu schreiben, der auf den ersten Blick beeindruckend wirkt. Doch Klarheit sollte immer Vorrang haben. Einfacher und klarer Code ist oft der bessere Weg. Ein gut verständlicher Code erleichtert das Debugging und die Weiterentwicklung.
```js
// Clever, aber möglicherweise schwer verständlich
const isValid = (str) => !/[^\w]/.test(str);
// Klar und verständlich
const isValid = (str) => {
const regex = /[^\w]/;
return !regex.test(str);
};
```
Versetze dich immer in die Lage eines anderen Programmierers und stelle dir drei Fragen:
* Würde ein Anfänger mein Code verstehen?
* Verstehe ich meinen Code in 6 Monaten noch?
* Kann ich jemanden in den Code einarbeiten ohne in schulen zu müssen?
Kannst du davon eine Frage mit nein beantworten, dann ist dein Code vermutlich zu kompliziert.
### Konsistenz
Ein konsistenter Stil macht den Code lesbarer. Verwende einheitliche Namenskonventionen, Einrückungen und Formatierungen. Dies erleichtert das Verständnis und die Wartung des Codes. Tools wie ESLint oder Prettier können helfen, den Code automatisch zu formatieren und konsistent zu halten.
```js
// Inkonsistent
const userName = "John";
const UserAge = 30;
// Konsistent
const userName = "John";
const userAge = 30;
```
### DRY (Don't Repeat Yourself) 🔂
Vermeide Redundanzen im Code. Wiederholter Code sollte in Funktionen oder Klassen ausgelagert werden. Dies reduziert Fehler und erleichtert Änderungen. Wenn sich eine Änderung im Code ergibt, muss diese nur an einer Stelle vorgenommen werden.
```js
// Redundanter Code
function getUserName(user) {
return user.firstName + ' ' + user.lastName;
}
function getUserAddress(user) {
return user.street + ', ' + user.city;
}
// DRY Prinzip angewendet
function getFullName(user) {
return `${user.firstName} ${user.lastName}`;
}
function getAddress(user) {
return `${user.street}, ${user.city}`;
}
```
### KISS (Keep It Simple, Stupid) 🤯
Halte Deinen Code so einfach wie möglich. Komplexität erhöht die Fehleranfälligkeit und erschwert das Verständnis. Einfacher Code ist oft der robustere und effizientere Code. Verwende einfache und klare Logiken anstatt komplexer und verschachtelter Strukturen.
```js
// Komplex und schwer verständlich
function getDiscount(price, isMember) {
return isMember ? (price > 100 ? price * 0.9 : price * 0.95) : price;
}
// Einfach und klar
function getDiscount(price, isMember) {
if (isMember) {
if (price > 100) {
return price * 0.9;
} else {
return price * 0.95;
}
}
return price;
}
```
### YAGNI (You Aren't Gonna Need It) ❌
Implementiere nur die Funktionalitäten, die Du aktuell benötigst. Überflüssige Features erhöhen die Komplexität und Wartungskosten. Dieser Grundsatz hilft, den Code schlank und fokussiert zu halten.
```js
// Overengineering
function calculatePrice(price, tax, discount, isMember) {
let finalPrice = price + (price * tax);
if (isMember) {
finalPrice -= discount;
}
return finalPrice;
}
// YAGNI Prinzip angewendet
function calculatePrice(price, tax) {
return price + (price * tax);
}
```
## Code ist wie ein gutes Buch 📚
Die richtige Benennung von Variablen, Funktionen und Klassen ist essenziell für die Lesbarkeit und Verständlichkeit des Codes, ähnlich wie bei einem gut geschriebenen Buch. Klare und präzise Namen spiegeln die Absicht des Codebausteins wider und erleichtern Wartung und Zusammenarbeit im Team. Zum Beispiel sollte eine Funktion, die das Quadrat einer Zahl berechnet, `calculateSquare` heißen, nicht `doSomething`.
Eine Klasse für die Berechnung von Quadraten könnte `SquareCalculator` heißen. Gut benannter und strukturierter Code spart Zeit und Nerven und macht die Arbeit im Team angenehmer und produktiver. Indem Du Deinen Code so schreibst, dass er auch für weniger erfahrene Entwickler verständlich ist, vermeidest Du technische Schulden und verbesserst nachhaltig die Qualität Deines Projekts.
Benennungen folgen oft den Regeln der Sprache, ähnlich wie Adjektive, Substantive und Verben, was sie intuitiver und verständlicher macht.
### Adjektive
Adjektive beschreiben Eigenschaften oder Zustände. In der Programmierung werden sie oft verwendet, um Variablen zu benennen, die bestimmte Zustände oder Eigenschaften speichern.
```js
let isActive = true;
let userName = "JohnDoe";
```
In diesem Beispiel beschreibt `isActive` den Zustand eines Objekts (ob es aktiv ist oder nicht) und `userName` speichert eine Eigenschaft eines Benutzers.
### Verben
Verben beschreiben Aktionen oder Vorgänge. In der Programmierung werden Verben häufig verwendet, um Funktionen zu benennen, die bestimmte Aktionen ausführen.
```js
function calculateArea(width, height) {
return width * height;
}
function fetchData(url) {
// Daten von einer URL abrufen
}
```
Hier beschreiben `calculateArea` und `fetchData` die Aktionen, die die jeweiligen Funktionen ausführen (Berechnung einer Fläche bzw. Abrufen von Daten).
### Substantive
Substantive bezeichnen Personen, Orte oder Dinge. In der Programmierung werden Substantive oft verwendet, um Klassen und Objekte zu benennen, die bestimmte Entitäten oder Konzepte darstellen.
```js
class User {
constructor(name, email) {
this.name = name;
this.email = email;
}
}
class Product {
constructor(id, price) {
this.id = id;
this.price = price;
}
}
```
In diesem Beispiel bezeichnen `User` und `Product` konkrete Entitäten in einem System, ähnlich wie Substantive in der Sprache.
### Adverbien
Adverbien modifizieren Verben und beschreiben, wie eine Aktion ausgeführt wird. In der Programmierung können Adverbien dazu beitragen, Funktionsnamen zu spezifizieren und zu verdeutlichen, wie eine Aktion ausgeführt wird.
```js
function calculateAreaQuickly(width, height) {
// Schnelle Berechnung der Fläche
return width * height;
}
function fetchDataSafely(url) {
// Sichere Datenabruf von einer URL
}
```
Hier modifizieren `quickly` und `safely` die Aktionen und geben zusätzliche Informationen darüber, wie die Aktionen ausgeführt werden sollen.
## Schlechter vs. Guter Code in JavaScript 💻
### Beispiel für schlechten Code
```js
function processData(input) {
let output = [];
for (let i = 0; i < input.length; i++) {
let processedData = input[i] * 2;
output.push(processedData);
}
console.log(output);
return output;
}
```
### **Beispiel für guten Code**
```js
function processData(input) {
return input.map(item => item * 2);
}
const input = [1, 2, 3, 4, 5];
const output = processData(input);
console.log(output); // [2, 4, 6, 8, 10]
```
In diesem Beispiel wurde der Code durch die Verwendung von `Array.prototype.map` vereinfacht, was die Lesbarkeit und Wartbarkeit erhöht.
## Technische Schulden 🏦
Technische Schulden entstehen, wenn kurzfristige Lösungen oder Kompromisse beim Programmieren eingegangen werden, um schnelle Ergebnisse zu erzielen, anstatt langfristige, nachhaltige Lösungen zu implementieren. Dies kann durch Zeitdruck, fehlende Ressourcen oder mangelnde Planung verursacht werden. Wie finanzielle Schulden müssen auch technische Schulden "zurückgezahlt" werden, was in Form von zusätzlicher Arbeit für Wartung und Refaktorierung geschieht. Technische Schulden können die Codequalität beeinträchtigen, die Entwicklung verlangsamen und die Einführung neuer Features erschweren. Daher ist es wichtig, bewusste Entscheidungen zu treffen und, wenn möglich, langfristige und saubere Lösungen zu bevorzugen, um die Ansammlung technischer Schulden zu vermeiden.
### Hardcodierte Werte
Schlechte Lösung
```js
function calculateTotalPrice(quantity) {
return quantity * 9.99;
}
```
In diesem Beispiel ist der Preis des Produkts im Code hardcodiert. Dies ist eine schnelle Lösung, aber sie führt zu technischen Schulden, weil jede Änderung des Preises eine Änderung im Code erfordert.
### Nachhaltige Lösung
```js
const PRODUCT_PRICE = 9.99;
function calculateTotalPrice(quantity) {
return quantity * PRODUCT_PRICE;
}
```
Durch die Verwendung einer Konstanten für den Produktpreis wird der Code flexibler und leichter zu warten. Änderungen am Preis müssen nur an einer Stelle vorgenommen werden, was die technische Schuld reduziert.
### Duplizierter Code
Technische Schulden
```js
function calculateRectangleArea(width, height) {
return width * height;
}
function calculateTriangleArea(base, height) {
return (base * height) / 2;
}
```
Hier gibt es duplizierten Code, der die Berechnung der Fläche beinhaltet. Diese Wiederholung führt zu technischen Schulden, da Änderungen an der Logik an mehreren Stellen vorgenommen werden müssen.
```js
function calculateArea(shape, ...dimensions) {
switch (shape) {
case 'rectangle':
return dimensions[0] * dimensions[1];
case 'triangle':
return (dimensions[0] * dimensions[1]) / 2;
default:
throw new Error('Unknown shape');
}
}
```
Durch die Zusammenführung der Berechnungslogik in eine einzige Funktion wird der Code DRY (Don't Repeat Yourself). Dies reduziert die technische Schuld und macht den Code einfacher zu warten und zu erweitern.
## Nachteile von kilometerlangen Einzeilern 🚫
Kilometerlange Einzeiler können schwer zu lesen und zu debuggen sein. Sie neigen dazu, komplex und undurchsichtig zu werden, was die Wartung erschwert.
### Beispiel für einen schlechten Einzeiler
```js
const result = array.map(x => x * 2).filter(x => x > 10).reduce((acc, x) => acc + x, 0);
```
### Aufgespaltener und lesbarer Code
```js
const doubled = array.map(x => x * 2);
const filtered = doubled.filter(x => x > 10);
const result = filtered.reduce((acc, x) => acc + x, 0);
```
Durch das Aufteilen des Codes in mehrere Zeilen wird er wesentlich lesbarer und einfacher zu debuggen.
## Funktionale Programmierung 🧑💻
Funktionale Programmierung kann helfen, sauberen und effizienten Code zu schreiben. Sie fördert die Verwendung von unveränderlichen Daten und reinen Funktionen.
### Funktionale Programmierung in JavaScript
```js
const numbers = [1, 2, 3, 4, 5];
const doubled = numbers.map(num => num * 2);
const even = doubled.filter(num => num % 2 === 0);
console.log(even); // [4, 8]
```
In diesem Beispiel werden die ursprünglichen Daten nicht verändert, und die Operationen sind klar und nachvollziehbar.
## Vorteile der funktionalen Programmierung
### Unveränderlichkeit
Unveränderlichkeit bedeutet, dass Daten nach ihrer Erstellung nicht mehr verändert werden. Stattdessen werden neue Datenstrukturen erstellt. Dies reduziert Fehler und macht den Code vorhersehbarer.
### Reine Funktionen
Reine Funktionen sind Funktionen, die keine Seiteneffekte haben und immer das gleiche Ergebnis für die gleichen Eingaben liefern. Dies macht den Code einfacher zu testen und zu debuggen. Die erwartete Funktionsweise ist deterministisch.
**Negatives Beispiel ❌**
Hier wird der Wert der globalen Variablen `counter` verändert, was die Funktion nicht rein macht, da der Zustand außerhalb der Funktion beeinflusst wird und das Ergebnis sich bei gleichen Aufrufen unterscheidet.
```js
let counter = 0;
function incrementCounter() {
// Diese Funktion erhöht den Wert von counter und gibt den neuen Wert zurück
counter++;
return counter;
}
// Testen der Funktion mit Seiteneffekt
console.log(incrementCounter()); // Ausgabe: 1
console.log(incrementCounter()); // Ausgabe: 2 (nicht das gleiche Ergebnis bei gleichen Aufrufen)
```
**Positives Beispiel ✅**
```js
function add(a, b) {
// Diese Funktion gibt die Summe von a und b zurück
return a + b;
}
// Testen der reinen Funktion
console.log(add(2, 3)); // Ausgabe: 5
console.log(add(2, 3)); // Ausgabe: 5 (immer das gleiche Ergebnis)
```
### Höhere Ordnung
Funktionen höherer Ordnung sind Funktionen, die andere Funktionen als Argumente nehmen oder Funktionen zurückgeben. Dies ermöglicht flexible und wiederverwendbare Codebausteine.
```js
const add = (a) => (b) => a + b;
const add5 = add(5);
console.log(add5(10)); // 15
```
## Soft Skills für Entwickler 🤝
### Kommunikation
Gute Kommunikation ist unerlässlich. Du musst in der Lage sein, Deine Ideen und Lösungen klar und präzise zu vermitteln. Dies gilt sowohl für die Zusammenarbeit mit anderen Entwicklern als auch für die Kommunikation mit Nicht-Technikern.
### Teamarbeit
Die Fähigkeit, effektiv im Team zu arbeiten, ist entscheidend. Dies umfasst das Teilen von Wissen, das Unterstützen von Kollegen und das gemeinsame Lösen von Problemen. Teamarbeit fördert auch die Weiterentwicklung und das Lernen innerhalb des Teams.
### Problemlösung
Problemlösungsfähigkeiten sind zentral für die Arbeit eines Entwicklers. Du musst in der Lage sein, komplexe Probleme zu analysieren, zu zerlegen und effektive Lösungen zu finden. Eine strukturierte Herangehensweise an Problemlösungen hilft dabei, effizienter zu arbeiten.
### Anpassungsfähigkeit
Die Technologie entwickelt sich ständig weiter. Als Entwickler musst Du bereit sein, neue Technologien und Methoden zu lernen und Dich an Veränderungen anzupassen. Anpassungsfähigkeit ermöglicht es Dir, auf neue Herausforderungen flexibel zu reagieren.
## Code-Reviews und Pair-Programming 🧑🤝🧑
### Code-Reviews
Code-Reviews sind ein wichtiger Bestandteil der Softwareentwicklung. Sie ermöglichen es, Fehler frühzeitig zu erkennen und den Code zu verbessern. Durch regelmäßige Code-Reviews wird die Codequalität erhöht und das Wissen im Team geteilt.
### Pair-Programming
Pair-Programming ist eine Technik, bei der zwei Entwickler gemeinsam an einem Computer arbeiten. Einer schreibt den Code, während der andere ihn überprüft. Diese Methode fördert den Wissensaustausch und die Zusammenarbeit im Team.
## Test-Driven Development (TDD) 🧪
### Vorteile von TDD
Test-Driven Development (TDD) ist eine Methode, bei der Tests geschrieben werden, bevor der eigentliche Code entwickelt wird. Dies hilft, klare Anforderungen zu definieren und sicherzustellen, dass der Code die erwarteten Ergebnisse liefert.
### Beispiel für TDD in JavaScript
```js
// Test schreiben
const assert = require('assert');
function add(a, b) {
return a + b;
}
assert.strictEqual(add(1, 2), 3);
assert.strictEqual(add(-1, 1), 0);
// Code implementieren
function add(a, b) {
return a + b;
}
```
TDD führt zu einem robusteren und weniger fehleranfälligen Code, da jede Funktionalität durch Tests abgedeckt ist.
## Weitere hilfreiche Prinzipien und Techniken
### Modularität
Modularität bedeutet, den Code in kleine, unabhängige Module aufzuteilen. Jedes Modul sollte eine klar definierte Aufgabe haben. Dies erleichtert das Testen, Warten und Wiederverwenden von Code.
```js
// Unmodularer Code
function processData(data) {
// Datenvalidierung
if (!Array.isArray(data)) {
throw new Error('Invalid data');
}
// Datenverarbeitung
const processed = data.map(item => item * 2);
// Datenausgabe
console.log(processed);
return processed;
}
// Modularer Code
function validateData(data) {
if (!Array.isArray(data)) {
throw new Error('Invalid data');
}
}
function processData(data) {
return data.map(item => item * 2);
}
function logData(data) {
console.log(data);
}
const inputData = [1, 2, 3, 4, 5];
validateData(inputData);
const processedData = processData(inputData);
logData(processedData);
```
### Automatisiertes Testen
Automatisiertes Testen ist unerlässlich, um sicherzustellen, dass der Code korrekt funktioniert und dass neue Änderungen keine bestehenden Funktionalitäten brechen. Unit-Tests, Integrationstests und End-to-End-Tests sind gängige Testarten.
```js
const { expect } = require('chai');
// Funktion zum Testen
function add(a, b) {
return a + b;
}
// Unit-Test
describe('add', () => {
it('should return the sum of two numbers', () => {
expect(add(1, 2)).to.equal(3);
expect(add(-1, 1)).to.equal(0);
});
});
```
### Dokumentation
Gute Dokumentation ist entscheidend, um anderen Entwicklern (und Deinem zukünftigen Ich) zu helfen, den Code zu verstehen. Dies umfasst sowohl Kommentare im Code (z.B. bei JavaScript JSDoc) als auch externe Dokumentation wie README-Dateien.
```js
/**
* Addiert zwei Zahlen.
*
* @param {number} a - Die erste Zahl.
* @param {number} b - Die zweite Zahl.
* @return {number} Die Summe der beiden Zahlen.
*/
function add(a, b) {
return a + b;
}
```
[Documentation - JSDoc ReferenceWhat JSDoc does TypeScript-powered JavaScript support?](https://www.typescriptlang.org/docs/handbook/jsdoc-supported-types.html)
## Fazit 🎉
Guter Code ist klar, lesbar und wartbar. Er ermöglicht effiziente Zusammenarbeit und erleichtert die Wartung und Weiterentwicklung von Projekten.
Durch die Anwendung von Best Practices und Prinzipien wie Klarheit vor Cleverness, Konsistenz und DRY kannst Du die Qualität Deines Codes erheblich verbessern. Funktionale Programmierung und die Entwicklung wichtiger Soft Skills tragen ebenfalls dazu bei, ein erfolgreicher Entwickler zu werden.
Denke daran, dass Du Code nicht nur für Dich selbst schreibst, sondern auch für andere Entwickler und für Dein zukünftiges Ich.
---
If you like my posts, it would be nice if you follow my [Blog](https://blog.disane.dev) for more tech stuff. | disane |
1,911,754 | My next.js Experience | Learning next.js this year was like a big bowl of vinegar mixed with some bad mixture, but after... | 0 | 2024-07-04T15:44:13 | https://dev.to/sunday_david_efa6b513398f/my-nextjs-experience-2koe | nextjs, react, vite, prisma | Learning next.js this year was like a big bowl of vinegar mixed with some bad mixture, but after drinking it, I receive strength and become heal. Thanks to the next community for their good work. I expect vue.js to be like that. | sunday_david_efa6b513398f |
1,911,446 | Kubernetes CRD: the versioning joy | (The tribulations of a Kubernetes operator developer) I am a developer of the Network Observability... | 0 | 2024-07-04T15:44:09 | https://dev.to/jotak/kubernetes-crd-the-versioning-joy-6g0 | kubernetes, devops, softwareengineering, theycoded | _(The tribulations of a Kubernetes operator developer)_
I am a developer of the [Network Observability operator](https://operatorhub.io/operator/netobserv-operator), for Kubernetes / OpenShift.
A few days ago, we released our 1.6 version -- which I hope you will try and appreciate, but this isn't the point here. I want to talk about an issue that was reported to us soon after the release.
> _The error says: risk of data loss updating "flowcollectors.flows.netobserv.io": new CRD removes version v1alpha1 that is listed as a stored version on the existing CRD_
What's that? It was a first for the team. This is an error reported by [OLM](https://olm.operatorframework.io/).
## Investigating
Indeed, we used to serve a `v1alpha1` version of our CRD. And indeed, we are now removing it. But we didn't do it abruptly. We thought we followed all the guidelines of an API versioning lifecycle. I think we did, except for one detail.
Let's rewind and recap the timeline:
- `v1alpha1` was the first version, introduced in our operator 1.0
- in 1.2, we introduced a new `v1beta1`. It was the new preferred version, but the storage version was still `v1alpha1`. Both versions were still served, and a conversion webhook allowed to convert from one to another.
- in 1.3, `v1beta1` became the stored version. At this point, after an upgrade, every instance of our resource in _etcd_ are in version `v1beta1`, right? (spoiler: it's more complicated).
- in 1.5 we introduced a `v1beta2`, and we flagged `v1alpha1` as deprecated.
- in 1.6, we make `v1beta2` the storage version, and removed `v1alpha1`.
And **BOOM**!
A few users complained about the error message mentioned above:
> _risk of data loss updating "flowcollectors.flows.netobserv.io": new CRD removes version v1alpha1 that is listed as a stored version on the existing CRD_
And they are stuck: OLM won't allow them to proceed further. Or they can entirely remove the operator and the CRD, and reinstall.
In fact, this is only some early adopters of NetObserv who have been seeing this. And we didn't see it when testing the upgrade prior to releasing. So what happened? I spent the last couple of days trying to clear out the fog.
When users installed an old version <= 1.2, the CRD keeps track of the storage version in its status:
```bash
kubectl get crd flowcollectors.flows.netobserv.io -ojsonpath='{.status.storedVersions}'
["v1alpha1"]
```
Later on, when users upgrade to 1.3, the new storage version becomes `v1beta1`. So, this is certainly what now appears in the CRD status. This is certainly what now appears in the CRD status? (Padme style)
```bash
kubectl get crd flowcollectors.flows.netobserv.io -ojsonpath='{.status.storedVersions}'
["v1alpha1","v1beta1"]
```
Why is it keeping `v1alpha1`? Oh, I know! Upgrading the operator did not necessarily _change_ anything in the custom resources. Only resources that have been changed post-install would have make the _apiserver_ write them to _etcd_ in the new storage version; but different versions may coexist in _etcd_, hence the `status.storedVersions` field being an array and not a single string. That makes sense.
Certainly, I can do some dummy edition of my custom resources to make sure they are in the new storage version. The _apiserver_ will replace the old one with a new one, so it will use the updated storage version. Let's do this. Then check again:
```bash
kubectl get crd flowcollectors.flows.netobserv.io -ojsonpath='{.status.storedVersions}'
["v1alpha1","v1beta1"]
```
Hmm...
So, I am now _almost_ sure I don't have any `v1alpha1` remaining in my cluster, but the CRD doesn't tell me that. What I learned is that the CRD status **is not a source of truth** for what's in _etcd_.
Here's what the doc says:
> `storedVersions` lists all versions of CustomResources that were ever persisted. Tracking these versions allows a migration path for stored versions in _etcd_. The field is mutable so a migration controller can finish a migration to another version (ensuring no old objects are left in storage), and then remove the rest of the versions from this list. Versions may not be removed from `spec.versions` while they exist in this list.
But how to ensure no old objects are left in storage? While poking around, I haven't found any simple way to inspect what custom resources are in _etcd_, and in which version. It seems like no one wants to be responsible for that, in the core kube ecosystem. It is like a black box.
- _Apiserver_? it deals with incoming requests but it doesn't actively keep track / stats of what's in _etcd_.
There is actually a metric (gauge) showing which objects the _apiserver_ stored. It is called `apiserver_storage_objects`:
But it tells nothing about the version -- and even if it did, it would probably not be reliable, as it's generated from the _requests_ that the _apiserver_ deals with, it is not keeping an active state of what's in _etcd_, as far as I understand.
- _etcd_ itself? It is a binary store, it knows nothing about the business meaning of what comes in and out.
- And not talking about _OLM_, which is probably even further from knowing that.
If you, reader, can shed some light on how you would do that, ie. how you would ensure that no deprecated version of a custom resource is still lying around somewhere in a cluster, I would love to hear from you, don't hesitate to let me know!
There's the [etcdctl](https://github.com/etcd-io/etcd/blob/main/etcdctl/README.md) tool that allows to interact with _etcd_, if you know exactly what you're looking for, and how this is stored in _etcd_, etc. But expecting our users to do this for upgrading? Meh...
## Kube Storage Version Migrator
Actually, it turns out the kube community has a go-to option for the whole issue. It's called the [Kube Storage Version Migrator](https://kubernetes.io/docs/tasks/manage-kubernetes-objects/storage-version-migration/) (SVM). I guess in some flavours of Kubernetes, it might be enabled by default and triggers for any custom resource. In OpenShift, [the trigger for automatic migration is not enabled](https://github.com/openshift/cluster-kube-storage-version-migrator-operator?tab=readme-ov-file#kube-storage-version-migrator-operator), so it is up to the operator developers (or the users) to generate the migration requests.
In our case, this is how the migration request looks like:
```yaml
apiVersion: migration.k8s.io/v1alpha1
kind: StorageVersionMigration
metadata:
name: migrate-flowcollector-v1alpha1
spec:
resource:
group: flows.netobserv.io
resource: flowcollectors
version: v1alpha1
```
Under the hood, the SVM just rewrites the custom resources without any modification, to make the _apiserver_ trigger a conversion (possibly via your webhooks, if you have some) and make them stored in the new storage version.
To make sure the resources have really been modified, we can check their `resourceVersion` before and after applying the `StorageVersionMigration`:
```bash
# Before
$ kubectl get flowcollector cluster -ojsonpath='{.metadata.resourceVersion}'
53114
# Apply
$ kubectl apply -f ./migrate-flowcollector-v1alpha1.yaml
# After
$ kubectl get flowcollector cluster -ojsonpath='{.metadata.resourceVersion}'
55111
# Did it succeed?
$ kubectl get storageversionmigration.migration.k8s.io/migrate-flowcollector-v1alpha1 -o yaml
# [...]
conditions:
- lastUpdateTime: "2024-07-04T07:53:12Z"
status: "True"
type: Succeeded
```
Then, all you have to do is trust SVM and _apiserver_ to have effectively rewritten all the deprecated versions in their new version.
Unfortunately, we're not entirely done yet.
```bash
kubectl get crd flowcollectors.flows.netobserv.io -ojsonpath='{.status.storedVersions}'
["v1alpha1","v1beta1"]
```
Yes, the CRD status isn't updated. It seems like it's not something SVM would do for us. So OLM will still block the upgrade. We need to manually edit the CRD status, and remove the deprecated version -- now that we're 99.9% sure it's not there (I don't like the other 0.1% much).
## Revisited lifecycle
To repeat the versioning timeline, here is what it seems we should have done:
- `v1alpha1` was the first version, introduced in our operator 1.0
- in 1.2, we introduced a new `v1beta1`. Storage version is still `v1alpha1`
- in 1.3, `v1beta1` becomes the stored version.
- ⚠️ **The operator should check the CRD status and, if needed, create a `StorageVersionMigration`, and then update the CRD status to remove the old storage version** ⚠️
- in 1.5 `v1beta2` is introduced, and we flag `v1alpha1` as deprecated
- in 1.6, `v1beta2` is the new storage version, **we run again through the `StorageVersionMigration` steps** (so we're safe when `v1beta1` will be removed later). We remove `v1alpha1`
- Everything works like a charm, hopefully.
For the anecdote, in our case with NetObserv, all this convoluted scenario is probably just resulting from a false-alarm, the initial OLM error being a false positive: our FlowCollector resource manages workload installation, and have a status that reports the deployments readiness. On upgrade, new images are used, pods are redeployed, so the FlowCollector status changes. So, it had to be rewritten in the new storage version, `v1beta1`, prior to the removal of the deprecated version. The users who have seen this issue could simply have manually removed the `v1alpha1` from the CRD status, and that's it.
While one could argue that OLM is too conservative here, blocking an upgrade that should pass because all the resources in storage must be fine, in its defense, it probably has no simple way to know that. And messing up with resources made inaccessible in _etcd_ is certainly a scenario we really don't want to run into. This is something that operator developers have to deal with.
I hope this article will help prevent future mistakes for others. This error is quite tricky to spot, as it can reveal itself long after the fact. | jotak |
1,909,079 | My journey into Mobile Development. | Starting mobile development seems too surreal because I’ve always admired learning how to create... | 0 | 2024-07-04T15:43:44 | https://dev.to/yeeshadev/my-journey-into-mobile-development-3f1d | mobile, hng, reactnative | Starting mobile development seems too surreal because I’ve always admired learning how to create amazing applications that can be downloaded into our phones, but on the other hand, it seemed quite difficult in some corner of my mind and I couldn’t do it at all. Joining tech itself was surreal as ever since I was curious; that’s why I started learning web development anyway. The first app I ever built was a calculator. I remember saying “wow! this works…see? Just click it and you will get the result.” So happy and showing my siblings and friends. As my career moved forward in web development, I felt like starting something new so why not? Mobile Development since I already had some you experience using React.js.
With that, began my journey in React Native and no regrets about it yet. In anticipation of this thrilling trip through HNG Internship for me shall come one day; let me give some insights about commonly used terms in the industry interchangeably applied though. Before that, let me introduce to you why I decided to start HNG in the first place.
**Why HNG Internship**
Being an aspiring mobile passionate developer, I am excited to be a part of the HNG Internship. The reason this particular program appeals to me is because of its comprehensive curriculum and hands-on approaches to learning, which would help lay a solid base in mobile development. The HNG Internship makes available the perfect platform that is needed in gaining practical experience and networking with peers in the industry. You can learn more details about this wonderful program from their official website and explore opportunities for hiring some talented developers.
**Comparing Mobile Development Platforms**
**1.Native Development
iOS (Swift/Objective-C):**
Pros:
- Performance: Native apps are written in a platform-specific language and hence are optimized a lot to provide a smoother user experience.
- Access to Device Features: Access to all the features of iOS devices.
- Consistent UI: Uses Apple's Human Interface Guidelines for a consistent and intuitive user interface.
Cons:
- Cost and Time: Separate development for iOS and Android.
- Learning Curve: Swift and Objective-C have a steeper learning curve when compared to some other languages.
**2. Android (Java/Kotlin):**
Pros:
- Flexibility: It has an extended number of options concerning customization and system integration.
- Large Community: Many developers are working over it with loads of resources and libraries.
- High Performance: Very high performance since it allows native compilation.
Cons:
- Fragmentation: Development is tough due to many different types of devices and versions of OSes.
- It requires development and testing time, with large resources.
**3. React Native (Cross-Platform Development):**
Pros:
- Code Reusability: This means the same code works for both iOS and Android.
Large Community: The Community is large, and there are a lot of plugins and Libraries at disposal.
- Live Reloading: It allows the developer to instantly view the change.
Cons:
- Performance: It's not as fast as native applications particularly where heavy tasks are concerned.
- Native Modules: It requires sometimes to write custom Native modules.
**4. Flutter:**
Pros:
- Single Codebase: A single codebase for iOS and Android.
- Performance: It provides near-native performance because Dart compiles endenga.
- Rich UI: It has an exhaustive set of widgets with a rich set of pre-designed UI components.
Cons:
- Large Size: App size may be larger compared to native apps.
- Learning Curve: Since many developers are not much familiar with Dart, it is a bit difficult to learn.
**Conclusion**
A good development platform and architectural pattern are important for the success of any mobile application. Since each of them has strengths and trade-offs, the choice would be majorly based on the needs of a project. I look forward with this journey at HNG Internship to immersively go through these technologies, make good mentorship, and contribute to some really innovative projects.
If you are interested in joining or discussing the HNG Internship should check out their [official website] (https://hng.tech/internship). They also have an option for premium where you get exclusive informations about the program, job opportunities, CV Reviews, Certificate after the internship and many more.To get the full details check [here](https://hng.tech/premium)
Thanks for joining me on this little walkthrough, and I look forward to sharing other insights and experiences while learning the ropes in this exciting field. | yeeshadev |
1,911,753 | Exploring Frontend Technologies: Svelte vs. Alpine.js | Introduction Frontend development has seen a massive evolution over the years, introducing a... | 0 | 2024-07-04T15:43:27 | https://dev.to/sherif_san/exploring-frontend-technologies-svelte-vs-alpinejs-4il6 |
Introduction
Frontend development has seen a massive evolution over the years, introducing a plethora of frameworks and libraries to enhance user experiences. While giants like ReactJS, Angular, and Vue.js often dominate the conversation, there are some niche players that offer unique advantages. In this article, we'll dive into two such technologies: Svelte and Alpine.js. We'll explore their core principles, use cases, and why they might be better suited for certain projects. Additionally, I'll share my thoughts on using ReactJS during the HNG internship and how I feel about this journey.
Svelte: The Compiler Approach
What is Svelte?
Svelte is a relatively new frontend framework created by Rich Harris. Unlike traditional frameworks that do much of their work in the browser, Svelte shifts that work to compile time. This means that instead of shipping a framework to the client, Svelte applications compile down to highly optimized vanilla JavaScript at build time.
Key Features of Svelte
- **No Virtual DOM**: Svelte eliminates the need for a virtual DOM, which can lead to faster and more efficient updates.
- **Truly Reactive**: With Svelte, reactivity is built into the language itself. You simply declare your state and bindings, and Svelte handles the rest.
- **Minimal Bundle Size**: Since Svelte compiles components down to minimal JavaScript, the bundle sizes are often significantly smaller compared to other frameworks.
Use Cases for Svelte
Svelte is ideal for projects where performance is critical, and bundle size needs to be minimized. It's also great for developers who prefer a more straightforward, less boilerplate-heavy development experience.
Alpine.js: The Lightweight Contender
What is Alpine.js?
Alpine.js is a minimalistic framework designed for adding interactivity to your HTML. It draws inspiration from frameworks like Vue.js but aims to be lightweight and easy to integrate into existing projects without a build step.
Key Features of Alpine.js
- **Tiny Footprint**: With a very small file size, Alpine.js can be included in any project with minimal impact on load times.
- **Declarative Syntax**: Similar to Vue and Angular, Alpine uses a declarative syntax that makes it easy to understand and write.
- **No Build Process**: Alpine.js doesn't require a build step, making it perfect for adding interactivity to static sites or enhancing server-rendered pages.
Use Cases for Alpine.js
Alpine.js shines in scenarios where you need to add a sprinkle of JavaScript interactivity without the overhead of a full-fledged framework. It's perfect for static sites, server-rendered pages, or any project where simplicity and speed are priorities.
Comparing Svelte and Alpine.js
Learning Curve
- **Svelte**: Has a moderate learning curve. If you're familiar with modern JavaScript and frameworks, you'll find Svelte's syntax and reactivity straightforward to grasp.
- **Alpine.js**: Very low learning curve. If you know basic HTML, CSS, and JavaScript, you can start using Alpine.js almost immediately.
Performance
- **Svelte**: Offers superior performance due to its compilation approach, making it ideal for high-performance applications.
- **Alpine.js**: While not as performant as Svelte, Alpine's small size and direct DOM manipulation make it quite efficient for its use cases.
Ecosystem and Community
- **Svelte**: Has a growing ecosystem with tools like SvelteKit, and a vibrant, supportive community.
- **Alpine.js**: Smaller ecosystem but rapidly growing. Its simplicity means you can often use it alongside other tools without conflict.
My Journey with ReactJS in the HNG Internship
During the HNG internship, ReactJS is the primary framework we'll be using. React is a powerful, component-based library that allows developers to build dynamic user interfaces with ease. I'm excited to delve deeper into React, leveraging its rich ecosystem, and state management tools like Redux or Context API.
React's virtual DOM, component-based architecture, and vast community support make it a versatile tool for building scalable applications. I anticipate working on real-world projects, collaborating with other interns, and honing my skills to become proficient in React development.
Conclusion
Both Svelte and Alpine.js offer unique advantages depending on the project's requirements. Svelte is perfect for high-performance applications with its compile-time optimization, while Alpine.js excels in simplicity and ease of integration for lightweight interactive components.
As I embark on my journey with the HNG internship, I'm eager to expand my knowledge and skills in frontend development, particularly with ReactJS. The hands-on experience and mentorship opportunities will undoubtedly be invaluable.
If you're interested in learning more about the HNG Internship program, check out these links:
- [HNG Internship](https://hng.tech/internship)
- [HNG Premium](https://hng.tech/premium) | sherif_san |
|
1,910,379 | 40 Days Of Kubernetes (10/40) | Day 10/40 Kubernetes Namespace Explained Video Link @piyushsachdeva Git... | 0 | 2024-07-04T15:42:17 | https://dev.to/sina14/40-days-of-kubernetes-1040-e1e | kubernetes, 40daysofkubernetes | ## Day 10/40
# Kubernetes Namespace Explained
[Video Link](https://www.youtube.com/watch?v=yVLXIydlU_0)
@piyushsachdeva
[Git Repository](https://github.com/piyushsachdeva/CKA-2024/)
[My Git Repo](https://github.com/sina14/40daysofkubernetes)
In this section, we're going to explain `namespace` in `kubernetes`.
It's a method by which single `cluster` used by and organization can be divided and categorized into multiple sub-clusters and managed individually. Different projects run simultaneously with different teams and departments work in parallel. [source](https://www.armosec.io/glossary/kubernetes-namespace/)
When we create a workload like `pod`, `deployment`, `service` and so on without mentioning a `namespace`, it's actually created in `default` `namespace`.
By provisioning a `kubernetes` cluster, it creates own `namespace` named `kube-system` and all of its components will be in the `kube-system` namespace.
Each workload for example `pod` in a `namespace` can easily interact with each other with the `hostname` of their `pod`. But for interact to other `namespace` `pod`, they have to use `FQDN`.
(Photo from the video)
- Get all `namespace`s:
```cosnole
root@localhost:~# kubectl get namespaces
NAME STATUS AGE
default Active 2d
kube-node-lease Active 2d
kube-public Active 2d
kube-system Active 2d
local-path-storage Active 2d
```
- Get all in `kube-system` namespace:
```console
root@localhost:~# kubectl get all --namespace=kube-system
NAME READY STATUS RESTARTS AGE
pod/coredns-7db6d8ff4d-bftnd 1/1 Running 1 (33h ago) 2d
pod/coredns-7db6d8ff4d-zs54d 1/1 Running 1 (33h ago) 2d
pod/etcd-lucky-luke-control-plane 1/1 Running 1 (33h ago) 2d
pod/kindnet-fbwgj 1/1 Running 1 (33h ago) 2d
pod/kindnet-hxb7v 1/1 Running 1 (33h ago) 2d
pod/kindnet-kh5s6 1/1 Running 1 (33h ago) 2d
pod/kube-apiserver-lucky-luke-control-plane 1/1 Running 1 (33h ago) 2d
pod/kube-controller-manager-lucky-luke-control-plane 1/1 Running 1 (33h ago) 2d
pod/kube-proxy-42h2f 1/1 Running 1 (33h ago) 2d
pod/kube-proxy-dhzrs 1/1 Running 1 (33h ago) 2d
pod/kube-proxy-rlzwk 1/1 Running 1 (33h ago) 2d
pod/kube-scheduler-lucky-luke-control-plane 1/1 Running 1 (33h ago) 2d
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 2d
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/kindnet 3 3 3 3 3 kubernetes.io/os=linux 2d
daemonset.apps/kube-proxy 3 3 3 3 3 kubernetes.io/os=linux 2d
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/coredns 2/2 2 2 2d
NAME DESIRED CURRENT READY AGE
replicaset.apps/coredns-7db6d8ff4d 2 2 2 2d
```
**Note** we're using `kind`!
```console
root@localhost:~# kubectl get all
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d
root@localhost:~# kubectl get all -n=default
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d
root@localhost:~# kubectl get all --namespace=default
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d
```
---
#### 1. Create/Delete `namespace`
in declarative way:
```yaml
---
apiVersion: v1
kind: Namespace
metadata:
name: demo
```
```console
root@localhost:~# vim namespace.yaml
root@localhost:~# kubectl create -f namespace.yaml
namespace/demo created
root@localhost:~# kubectl get namespaces
NAME STATUS AGE
default Active 2d
demo Active 9s
kube-node-lease Active 2d
kube-public Active 2d
kube-system Active 2d
local-path-storage Active 2d
```
- Delete `namespace`
```console
root@localhost:~# kubectl delete ns/demo
namespace "demo" deleted
```
in imperative way:
```console
root@localhost:~# kubectl create ns demo
namespace/demo created
root@localhost:~# kubectl get ns
NAME STATUS AGE
default Active 2d
demo Active 8s
kube-node-lease Active 2d
kube-public Active 2d
kube-system Active 2d
local-path-storage Active 2d
```
#### 2. Create/Delete `deployment` in a `namespace`
```console
root@localhost:~# kubectl create deploy nginx-demo --image=nginx -n demo
deployment.apps/nginx-demo created
root@localhost:~# kubectl get deploy
No resources found in default namespace.
root@localhost:~# kubectl get deploy -n demo
NAME READY UP-TO-DATE AVAILABLE AGE
nginx-demo 1/1 1 1 18s
```
#### 3. Communicate between 2 namespaces:
```console
root@localhost:~# kubectl get all -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod/nginx-test-574bc578fc-cj5fb 1/1 Running 0 5m16s 10.244.2.2 lucky-luke-worker2 <none> <none>
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d <none>
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
deployment.apps/nginx-test 1/1 1 1 5m16s nginx nginx app=nginx-test
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
replicaset.apps/nginx-test-574bc578fc 1 1 1 5m16s nginx nginx app=nginx-test,pod-template-hash=574bc578fc
root@localhost:~# kubectl get all -n demo -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod/nginx-demo-745b695d7d-hh28q 1/1 Running 0 7m48s 10.244.1.2 lucky-luke-worker <none> <none>
NAME READY UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR
deployment.apps/nginx-demo 1/1 1 1 7m48s nginx nginx app=nginx-demo
NAME DESIRED CURRENT READY AGE CONTAINERS IMAGES SELECTOR
replicaset.apps/nginx-demo-745b695d7d 1 1 1 7m48s nginx nginx app=nginx-demo,pod-template-hash=745b695d7d
```
- Both can have communication and we test it by `curl` with `ip`
```console
# curl 10.244.2.2
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
# curl 10.244.1.2
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
```
- Scaling both `deployment`
```console
root@localhost:~# kubectl scale --replicas=3 deploy nginx-test
deployment.apps/nginx-test scaled
root@localhost:~# kubectl scale --replicas=3 deploy nginx-demo -n demo
deployment.apps/nginx-demo scaled
root@localhost:~# kubectl get pod,deploy
NAME READY STATUS RESTARTS AGE
pod/nginx-test-574bc578fc-cj5fb 1/1 Running 0 14m
pod/nginx-test-574bc578fc-cqj5r 1/1 Running 0 10s
pod/nginx-test-574bc578fc-nxt4j 1/1 Running 0 10s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-test 3/3 3 3 14m
root@localhost:~# kubectl get pod,deploy -n demo
NAME READY STATUS RESTARTS AGE
pod/nginx-demo-745b695d7d-hh28q 1/1 Running 0 16m
pod/nginx-demo-745b695d7d-rp88f 1/1 Running 0 19s
pod/nginx-demo-745b695d7d-sc8rg 1/1 Running 0 19s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/nginx-demo 3/3 3 3 16m
```
- Creating `service` for both `deployment`
(Photo from the video)
Test in `default` namespace:
```console
root@localhost:~# kubectl expose --name svc-test deploy/nginx-test --port 80
service/svc-test exposed
root@localhost:~# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx-test-574bc578fc-cj5fb 1/1 Running 0 29m
nginx-test-574bc578fc-cqj5r 1/1 Running 0 15m
nginx-test-574bc578fc-nxt4j 1/1 Running 0 15m
root@localhost:~# kubectl exec -it nginx-test-574bc578fc-cj5fb -- sh
# cat /etc/resolv.conf
search default.svc.cluster.local svc.cluster.local cluster.local
nameserver 10.96.0.10
options ndots:5
# curl svc-demo.demo.svc.cluster.local
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
```
Test in `demo` namespace:
```console
root@localhost:~# kubectl expose --name svc-demo deploy/nginx-demo --port 80 -n demo
service/svc-demo exposed
root@localhost:~# kubectl get pod -n demo
NAME READY STATUS RESTARTS AGE
nginx-demo-745b695d7d-hh28q 1/1 Running 0 35m
nginx-demo-745b695d7d-rp88f 1/1 Running 0 19m
nginx-demo-745b695d7d-sc8rg 1/1 Running 0 19m
root@localhost:~# kubectl exec -it nginx-demo-745b695d7d-hh28q -n demo -- sh
# cat /etc/resolv.conf
search demo.svc.cluster.local svc.cluster.local cluster.local
nameserver 10.96.0.10
options ndots:5
# curl svc-test.default.svc.cluster.local
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
```
| sina14 |
1,911,752 | Amazon Bedrock – Consistent Anthropic FM pricing across regions | AWS typically offers varying prices for each service across its global regions. However, if we look... | 0 | 2024-07-04T15:40:32 | https://roadtoaws.com/2024/06/22/amazon-bedrock-consistent-anthropic-fm-pricing-across-regions/ | aws, cloud, llm, ai | AWS typically offers varying prices for each service across its global regions. However, if we look at Amazon Bedrock Anthropic On-Demand and Batch prices we see a different pattern. They are consistent across regions. The primary variation lies in the model versions available in each region. As new regions are continuously added to Amazon Bedrock, it’s a good idea to look at what each region offers.
Amazon Bedrock is available in 13 AWS regions:
- US East (N. Virginia)
- US West (Oregon)
- Asia Pacific (Tokyo)
- Asia Pacific (Singapore – limited access)
- Asia Pacific (Sydney)
- Asia Pacific (Mumbai)
- Canada (Central)
- Europe (London)
- Europe (Frankfurt)
- Europe (Paris)
- Europe (Ireland – limited access)
- South America (São Paulo)
- AWS GovCloud (US-West)
💡 Note: Due to limited access in Ireland, Singapore and GovCloud, these regions are excluded from my analysis, leaving us with 10 regions for comparison.
`Anthropic uses "Haiku" for its smallest model, "Sonnet" for the mid-range option, and "Opus" for its top-tier model.`
On June 21, 2024, Anthropic introduced Claude 3.5 Sonnet, claiming it can match or exceed OpenAI's GPT-4o or Google's Gemini across numerous tasks. This new model is exclusively available through the Anthropic API, Amazon Bedrock, and Google Cloud's Vertex AI. Since this is a new model, it is currently only available from us-east-1 at the time of this blog post.
When it comes to Amazon Bedrock, the rule of thumb you've come to know about AWS pricing and service availability no longer applies. If you are based in Europe, you have learned that the region with the most services is Ireland (eu-west-1) and that the cheapest option is usually Stockholm (eu-north-1).
With Bedrock, this all changes; the region that offer the most Anthropic FM's for Europe is Frankfurt (eu-central-1). If you're developing with Generative AI in Europe, Frankfurt is now your best choice.
In the US, your rule of thumb remains the same, with us-east-1 being the region that provides the most functionality, but there is a catch: the highest-end model, Claude 3 Opus is only available in Oregon.
Amazon Bedrock's on-demand and batch pricing is consistent across regions (e.g., you pay the same for Claude 3 Haiku in Oregon and Canada). In fact, Claude Sonnet 3 and 3.5 cost the same. This uniform pricing strategy underscores AWS's commitment to making advanced Generative AI models accessible and affordable for developers.
## Provisioned Throughput pricing
When we look at the provisioned throughput pricing, we see fewer choices. We are limited to Claude Instant and Claude 2.0/2.1 models and with only 4 regions. Frankfurt is right behind the top US regions in terms of prices, with Tokyo being the most expensive.
## Summary
AWS demonstrates its strong commitment to Generative AI through multiple actions. It offers competitive pricing for Anthropic's foundation models, continually expands Bedrock's availability to new regions, and promptly makes the latest foundation models accessible to its users.
These efforts highlight AWS's dedication to advancing and supporting Generative AI, providing developers with the latest tools at affordable prices. | mishi |
1,909,377 | ReactJs vs VueJs: A Comparison Between Frontend Technologies. | When starting a new project, one of the difficult questions frontend developers ask is “What... | 0 | 2024-07-04T15:38:24 | https://dev.to/yeeshadev/reactjs-vs-vuejs-a-comparison-between-frontend-technologies-34pi | webdev, react, frontend | When starting a new project, one of the difficult questions frontend developers ask is “What framework should I use for this project”?
When deciding which JavaScript framework to choose for an existing project, it usually refers to Angular vs. React vs. Vue. For this blog, we are going to focus on Vue and React and make a comparison between them.
## What is ReactJS?
React is a free and open-source front-end JavaScript library for building component based user interfaces. It is maintained by Meta (formerly Facebook) and a community of individual developers. It can be used to develop single-page mobile applications or sever rendered application using NextJS(A React Framework).
## Features of ReactJS
1. **Virtual DOM:** It uses a 'Virtual DOM' to optimize rendering. A lightweight in-memory copy of the real 'DOM' has to be maintained while updates are being made.
2. **Component-Based Architecture:** React enforces the development of reusable, modular components on which the apps are based to drive modularity and reusability of code.
3. **JSX:** React introduces JSX, a syntax extension allowing one to directly write in a fusion of HTML and JavaScript, enhancing the developer experience.
4. **Unidirectional Data Flow:** React enforces a one-way data binding pattern supporting the integrity of data and also eases debugging.
## Pros of ReactJS
Performance is maximized by the Virtual DOM, especially in dynamic apps.
- **Community and Ecosystem:** With a large community and great ecosystem, one will rarely be left with libraries, tools, or support.
- **Flexibility:** Any library or framework will go along with React; hence it enables the developer to structure their applications the way they want to.
## Cons of ReactJS
- **Learning Curve:** JSX and unidirectional data flow can sometimes be a problem for freshers.
- **Boilerplate Code:** React sometimes demands more boilerplate code than other frameworks.
## Vue.js: The Progressive JavaScript Framework
Vue.js is an advanced Javascript framework to build user interfaces developed by Evan You. It has been designed to be progressively adoptable, directly implying that you could use as much or little of Vue as you need.
## Key Features of Vue.js
1. **Reactive Data Binding:** The Reactivity system of Vue automatically tracks all your dependencies and, in case of any change in data, it triggers DOM updates.
2. **Component-Based Architecture:** Vue, much like React, follows the approach that enables building powerful applications using serviceable, reusable components.
3. **Single-File Components:** Vue allows its component to be written in a single file wherein HTML, CSS, and JavaScript are combined, thereby making development easier and more straightforward.
4. **Directives:** Vue has picked a few of the commonly used ones out of the box. Vance already comes with a number of prebuilt directives such as `v-bind`, `v-model`, etc. These give very useful, effective ways to interact with the DOM.
5.**API Styles:** Vue components can be written in two different API styles; Options API and Composition API. To learn more, visit [official documentation](https://vuejs.org/guide/introduction.html).
Other advantages are;
• Easy to learn: This particular framework has rather simple and intuitive syntax. It is most favorable for beginners.
• Flexibility: Vue can be used both for small and big projects and in applications ranging from small to large, with ease of learning.
• Well-documented: On this front, the [official documentation](https://vuejs.org/guide/introduction.html) in this regard seems to be faultless. It is clearly structured and full of material that developers might refer to in the course of building with it.
## Cons of Vue.js
- **Smaller Community:** Vue is diminished when contrasted with the network of people behind React, which can constrain the quantity of third-party libraries and different advancement assets accessible.
- **Difficulties with mobile support:** Older versions of iOS and Safari browsers can cause certain problems with Vue.js applications.
## Comparing ReactJS vs. Vue.js
| Feature | ReactJS | Vue.js |
|----------------------------|-------------------------------------------------|-------------------------------------------------|
| **Learning Curve** | More difficult because of JSX and one-way data flow | Easier with a more intuitive syntax |
| **Performance** | High, thanks to the virtual DOM | High, with efficient reactivity system |
| **Community and Ecosystem**| Large and matured | Growing but smaller than React's |
| **Flexibility** | Very flexible, can use with other libraries | Flexible, suitable for different scales of projects |
| **Component Architecture** | Strongly focuses on reusable components | Focuses on single-file components |
## Looking Ahead with HNG Internship
HNG Internship mainly deals with ReactJS. This comes with an opportunity to master one of the powerful frontend libraries. I look forward with excitement to learning how to hone my skill in ReactJS by using its component-based architecture for building dynamic and efficient web applications. The practical experience and contributions to collaborative projects will help build my understanding and proficiency in ReactJS.
This is the link to their
[official website](https://hng.tech/internship), for anyone who wants a detailed information on the HNG Internship. A number of opportunities are also available on their [premium services](https://hng.tech/premium).
Learning ReactJS as part of the internship will be impactful in honing my technical skills; besides, it will also provide strong backing for subsequent projects. I'm so excited to start this learning journey, which is full of potential for making a difference with web applications using ReactJS. | yeeshadev |
1,911,751 | Supercharge Your Website Relaunch: The Power of Performance Optimization | Are you planning a website relaunch? 👀 Don't overlook the game-changing impact of performance... | 0 | 2024-07-04T15:37:48 | https://dev.to/platformsh/supercharge-your-website-relaunch-the-power-of-performance-optimization-h74 | devops, productivity, frontend, testing | **Are you planning a website relaunch? 👀**
Don't overlook the game-changing **impact of performance optimization**. Let's dive into why speed matters and how you can **make your site lightning-fast**.
**Why Performance Optimization is Crucial 🔑**
1. Enhanced User Experience: Fast sites = happy users
2. Improved Search Engine Visibility: Speed is a ranking factor
3. Increased Conversion Rates: Faster sites convert better
4. Reduced Operational Costs: Efficient sites are cheaper to run
5. Competitive Advantage: Outpace your rivals with a speedy site
**Key Areas to Focus On 🎯**
1️⃣ Frontend Performance
Optimize for:
- Largest Contentful Paint (LCP)
- Cumulative Layout Shift (CLS)
- First Contentful Paint (FCP)
- Interaction to Next Paint (INP)
2️⃣ Server-Side Responsiveness
Reduce:
- Time to First Byte (TTFB)
- Total Blocking Time (TBT)
3️⃣ Caching
Implement:
- Browser caching
- Server-side caching
4️⃣ Asset Optimization
- Minimize and compress CSS and JavaScript
- Implement asset bundling
- Reduce HTTP requests
5️⃣ Image Optimization
- Compress images
- Implement lazy loading
- Use modern image formats
6️⃣ Monitoring
Establish comprehensive systems to track performance metrics
Taking Action 💪
- Set clear performance targets
- Prioritize performance in design and development
- Optimize content for speed
- Implement efficient hosting and infrastructure
- Adopt lightweight frameworks
- Conduct thorough testing
- Implement continuous monitoring and optimization
**Overcoming Roadblocks 🚧**
Be aware of common challenges:
- Industry norms
- Lack of awareness or expertise
- Misaligned priorities
- Budget and time constraints
- Limited accountability
**✨ Pro tip: Explicitly request performance optimization to keep it a priority throughout development. ✨**
**The Bottom Line 📊**
Performance optimization isn't just a nice-to-have – it's a must-have for successful website relaunches. By focusing on speed and efficiency, you'll create a better user experience, improve your search rankings, and gain a competitive edge in your industry.
Ready to dive deeper into performance optimization for your website relaunch? 🤔 Check out the **[full blog post](https://platform.sh/blog/website-relaunch-performance/?utm_source=devto&utm_medium=organic_social&utm_campaign=blog-post)** on the for more insights and strategies. | celestevanderwatt |
1,911,750 | Unleashing the Power of Lucide: The Ultimate Icon Library for Modern Web Development | Icons are crucial for improving the user experience of your modern web application. Icons, which not... | 0 | 2024-07-04T15:37:42 | https://dev.to/sheraz4194/unleashing-the-power-of-lucide-the-ultimate-icon-library-for-modern-web-development-2kmi | lucide, icons, webdev, nextjs | > Icons are crucial for improving the user experience of your modern web application. Icons, which not only make the interface more intuitive but also add to its visual appeal that can uplift the entire design. Lucide icon library has been the talk of town in web development community, and we will dissect every part of it today on this blog post. A deep dive on what it provides, some benefits and how you can take advantage of this platform. When done, I hope to have convinced you of the simple fact that Lucide is THE icon set for modern web development
## What the heck is Lucide?
Lucide stands out as a modern web element, icon-based UI component library crafted for the contemporary needs of web developers. Well, this one offers a plethora of good-looking and widely configurable collection of icons that makes it an amazing choice in top projects. In the end, Lucide is a fork of Feather Icons that carries over simplicity and elegance from its predecessor while expanding with new capabilities focused on catering to modern requirements for developers.
## Why Use it?
1. **Comprehensive Icon Set:** The complete icon set of Lucide can be found here Regardless, Lucide provides you with icons for the navigation(with different sizes), social media(platforms logos) and file types etc as well. We add new icons weekly, while our library keeps growing to meet UX & UI trends.
2. **Highly customizable:** One of the standout features of Lucide is its high level of customizability. You can easily change the size, stroke width, color, and other attributes of the icons to match your design needs. This feature of lucide allows you to create a cohesive and consistent look across your entire application.
3. **Lightweight and Fast:** Lucide is really lightweight and fast. The icons of lucide are built using SVG, which makes sure that they load quickly and look crisp on all screen sizes and resolutions. This performance optimization is very important for maintaining a smooth user experience and Search Engine Optimization(SEO), especially in applications with heavy icon usage.
4. **Easy Integration:** Integrating Lucide into your project is a breeze. Whether you’re using React, Vue, Angular, or plain HTML/CSS, Lucide provides simple integration options. The library is well-documented, making it trouble-free to get started and find the icons of your need.
5. **Open Source and Actively Maintained:** Lucide is an open-source project, which means it benefits from the contributions and feedback of a vibrant developer community. The library is actively maintained. It ensures that it stays up-to-date with the latest web development standards, practices and new design trends.
## Getting Started with Lucide
Let’s learn the steps to get started with Lucide in a React or Next project.
### Installation:
You can install Lucide using npm or yarn. Run the following command in your working project directory:
```npm install lucide-react```
or
```yarn add lucide-react```
### Usage
After Installing , you can start using Lucide icons in your React components. Here’s a simple example:
```
import React from 'react';
import { Home, Settings } from 'lucide-react';
export default function LucideDemo () {
return (
<div>
<Home size={48} color="#000" />
<Settings size={48} color="#000" />
</div>
);
};
```
In the example above, we’re importing the LucideHome and LucideSettings icons from lucide-react and using them in a simple react component. The size and color props allow us to customize the visual appearance of the icons
### How to customize Lucide Icons?
Lucide icons are highly customizable. The examples below explains how you can modify the stroke width and color.
```
<Settings size={48} color="teal" strokeWidth={2} />
```
You can also style with Tailwind CSS or custom CSS
```
<Home className="w-12 h-12 text-teal-900 stroke-2" />
```
## Advanced Usage:
### Using with Other Frameworks:
If you’re using a different framework, Lucide has you covered. The library provides bindings for Vue, Angular, Solid, Svelte, Prereact and other popular frameworks as well. Check the [Official Documentation](https://lucide.dev/) for detailed instructions on how you can integrate Lucide with your preferred framework.
Icon Packs:
Lucide also supports icon packs, which allows you to extend the library with additional icons. This feature is particularly useful if you have custom icons like font-awesome, that you want to use alongside the standard Lucide icons.
### Accessibility:
Ensuring that your application is accessible to all users is crucial. You can accessibility to your icons in lucide. You can add aria-label attributes like other html tags to your icons to provide descriptive labels for screen readers:
```
<Home aria-label="Home" />
```
## Conclusion
Lucide is a powerful and flexible icon library that can enhance the visual appeal and usability of your web applications made with any framework. With its comprehensive icon set, high customizability, lightweight design, and ease of integration, Lucide stands out as a top choice for modern web development. No matter if you’re crafting a small personal project or a large enterprise application, Lucide provides the tools you need to create beautiful and user-friendly interfaces.
Give Lucide a try in your next project, and experience the benefits of a well-crafted comprehensive icon library. Your users will appreciate the polished look and feel of your web application, and you’ll enjoy its simplicity and efficiency
| sheraz4194 |
1,911,749 | Scenestamps: Movie Scenes and Quotes Database | Scenestamps is a innovative website that allows users to easily share and discover specific scenes... | 0 | 2024-07-04T15:32:45 | https://dev.to/johnpinto/scenestamps-movie-scenes-and-quotes-database-76n | webdev, database, flask, sqlite |
Scenestamps is a innovative website that allows users to easily share and discover specific scenes from movies, TV shows, and other video content. Unlike traditional video platforms, Scenestamps is designed specifically for cataloging and sharing individual moments, complete with detailed timestamps and descriptions.
Link : https://scenestamps.com
---
**Tech Stack** :
- Flask
- Sqlite
- HTML
- CSS
- JS
- NGINX
---
The key features of Scenestamps include:
**Search and Discovery**
Users can search for scenes by keyword, show/movie title, or even specific actors. The platform makes it easy to find and browse through a wide range of memorable moments from various media.
**Timestamp Sharing**
When creating a new scene post, users can input precise timestamps to indicate the start and end times of the clip they want to share. This allows viewers to quickly jump to the exact moment being referenced.
**Tagging and Organization**
Scenes can be tagged with relevant keywords, making it simple to group and find related content. Users can also browse all scenes associated with a particular tag.
**Social Sharing**
Scenestamps provides built-in social sharing options, allowing users to easily spread their favorite scenes across platforms like Twitter, Facebook, and more.
For those looking to create a centralized hub for cataloging and discussing memorable moments from films, TV shows, and other video content, Scenestamps provides a solid foundation and set of features to build upon. With continued refinement and promotion, this niche platform could find an engaged audience of movie and TV enthusiasts. | johnpinto |
1,911,747 | Come correggere l'errore "Currently using Missing or invalid module" | Durante lo sviluppo di un sito drupal, può capitare di installare un modulo e poi cancellare i file... | 0 | 2024-07-04T15:32:11 | https://dev.to/mcale/come-correggere-lerrore-currently-using-missing-or-invalid-module-2pma | drupal, fix, italian | Durante lo sviluppo di un sito drupal, può capitare di installare un modulo e poi cancellare i file senza disabilitarlo, oppure durante la disintallazione qualcosa non va a buon fine e il DB rimane sporco.
In questi casi può comparire l'errore:
```bash
[error] Currently using Missing or invalid module.
The following module is marked as installed in
the core.extension configuration,
but it is missing:
* phpass
```
L'errore normalmente compare se si prova a effettuare `drush updatedb`, in questo caso non è bloccante ma è solo noioso vederlo.
L'errore diventa bloccante quando si prova a installare o disinstallare un modulo, in quel momento si viene bloccati.
Nell'esempio che ho riportato stavo effettuando test di aggiornamento di un sito da Drupal 9 a 10, ma dopo l'aggiornamento (avvenuto con successo), sono dovuto tornare alla versione 9.
Cambiando versione, senza procedure di rollback guidate che eseguivano le operazioni necessarie, ho causato la problematica; il modulo `phpass` introdotto in Drupal 10 non era più presente su sito.
### Come risolvere l'errore
La risoluzione è molto semplice, basta rimuovere dalla configurazione `core.extension` il riferimento al modulo, così il sito non vede più il modulo attivo e non lo cerca più.
Il comando da eseguire è questo:
```bash
drush config:delete core.extension module.phpass
```
Dopo averlo eseguito sarete liberi di installare ogni modulo che desiderate! | mcale |
1,911,748 | [catchy title here] | I have been working on creating and writing my own python game so far I have import... | 0 | 2024-07-04T15:32:01 | https://dev.to/myrojyn/catchy-title-here-3mbl | python, beginners, journeybeforedestination | I have been working on creating and writing my own python game so far I have
`import random`
and
print(''' ascii art ''')
which ya isn't really anything but it's a fun isn't really anything. | myrojyn |
1,911,746 | User account creation using BASH | Introduction In today's fast-paced development environments, automation is key to managing system... | 0 | 2024-07-04T15:26:47 | https://dev.to/gbenga_okunniyi/user-account-creation-using-bash-39p3 | Introduction
In today's fast-paced development environments, automation is key to managing system operations efficiently. As a SysOps engineer, automating the process of creating user accounts, setting up their groups, and managing passwords can save a significant amount of time and reduce errors. This guide walks you through a Bash script designed to automate these tasks, providing detailed explanations for each step.
The Script
The script, create_users.sh, performs the following tasks:
Reads a text file containing usernames and group names.
Creates users and assigns them to specified groups.
Sets up home directories with appropriate permissions.
Generates random passwords for the users.
Logs all actions to /var/log/user_management.log.
Stores generated passwords securely in /var/secure/user_passwords.csv.
```
#!/bin/bash
# Log file
LOG_FILE="/var/log/user_management.log"
PASSWORD_FILE="/var/secure/user_passwords.csv"
# Check if the text file is provided
if [ -z "$1" ]; then
echo "Usage: $0 <name-of-text-file>"
exit 1
fi
# Check if the file exists
if [ ! -f "$1" ]; then
echo "File $1 does not exist."
exit 1
fi
# Create necessary directories and files
mkdir -p /var/secure
touch $LOG_FILE
touch $PASSWORD_FILE
# Set permissions for the password file
chmod 600 $PASSWORD_FILE
# Function to generate random passwords
generate_password() {
tr -dc A-Za-z0-9 </dev/urandom | head -c 12
}
# Read the file line by line
while IFS=';' read -r user groups; do
# Remove whitespace
user=$(echo "$user" | xargs)
groups=$(echo "$groups" | xargs)
# Check if the user already exists
if id "$user" &>/dev/null; then
echo "User $user already exists. Skipping password setting." | tee -a $LOG_FILE
continue
fi
# Create the user's personal group if it doesn't exist
if ! getent group "$user" >/dev/null; then
groupadd "$user"
echo "Group $user created." | tee -a $LOG_FILE
fi
# Create the user and assign the personal group as their primary group
useradd -m -g "$user" "$user"
if [ $? -eq 0 ]; then
echo "User $user created successfully." | tee -a $LOG_FILE
else
echo "Failed to create user $user." | tee -a $LOG_FILE
continue
fi
# Add the user to additional groups
if [ -n "$groups" ]; then
IFS=',' read -ra group_array <<< "$groups"
for group in "${group_array[@]}"; do
group=$(echo "$group" | xargs)
if ! getent group "$group" >/dev/null; then
groupadd "$group"
echo "Group $group created." | tee -a $LOG_FILE
fi
usermod -aG "$group" "$user"
echo "User $user added to group $group." | tee -a $LOG_FILE
done
fi
# Generate a random password
password=$(generate_password)
echo "$user:$password" | chpasswd
# Store the password securely
echo "$user,$password" >> $PASSWORD_FILE
echo "Password for user $user set and stored securely." | tee -a $LOG_FILE
done < "$1"
echo "User creation process completed. Check $LOG_FILE for details."
```
Explanation
Log and Password Files
The script maintains a log file to record all actions and a password file to store generated passwords securely.
```
LOG_FILE="/var/log/user_management.log"
PASSWORD_FILE="/var/secure/user_passwords.csv"
```
Input Validation
Ensuring the script is provided with the correct input is crucial for its operation.
```
if [ -z "$1" ]; then
echo "Usage: $0 <name-of-text-file>"
exit 1
fi
if [ ! -f "$1" ]; then
echo "File $1 does not exist."
exit 1
fi
```
Directory and File Creation
Creating necessary directories and setting permissions for secure operations.
```
mkdir -p /var/secure
touch $LOG_FILE
touch $PASSWORD_FILE
chmod 600 $PASSWORD_FILE
```
Generate Password Function
A simple function to generate random passwords.
`generate_password() {
tr -dc A-Za-z0-9 </dev/urandom | head -c 12
}
`
User and Group Management
The core logic to create users, assign groups, and handle existing users gracefully.
```
while IFS=';' read -r user groups; do
user=$(echo "$user" | xargs)
groups=$(echo "$groups" | xargs)
if id "$user" &>/dev/null; then
echo "User $user already exists. Skipping password setting." | tee -a $LOG_FILE
continue
fi
if ! getent group "$user" >/dev/null; then
groupadd "$user"
echo "Group $user created." | tee -a $LOG_FILE
fi
useradd -m -g "$user" "$user"
if [ $? -eq 0 ]; then
echo "User $user created successfully." | tee -a $LOG_FILE
else
echo "Failed to create user $user." | tee -a $LOG_FILE
continue
fi
if [ -n "$groups" ]; then
IFS=',' read -ra group_array <<< "$groups"
for group in "${group_array[@]}"; do
group=$(echo "$group" | xargs)
if ! getent group "$group" >/dev/null; then
groupadd "$group"
echo "Group $group created." | tee -a $LOG_FILE
fi
usermod -aG "$group" "$user"
echo "User $user added to group $group." | tee -a $LOG_FILE
done
fi
password=$(generate_password)
echo "$user:$password" | chpasswd
echo "$user,$password" >> $PASSWORD_FILE
echo "Password for user $user set and stored securely." | tee -a $LOG_FILE
done < "$1"
```
Conclusion
Automating user management tasks using Bash scripts can significantly improve efficiency and accuracy in system operations. This guide and the accompanying script provide a robust solution for user creation, group assignment, and secure password management.
For more information on DevOps and automation, check out these resources:
[HNG Internship](https://hng.tech/internship)
[HNG Hire](https://hng.tech/)
By following these steps, you can ensure a streamlined process for managing users in your development environment.
link to my github: https://github.com/Gbenga001/user_account_automation_with_bash
| gbenga_okunniyi |
|
1,911,742 | The Ultimate Guide to JavaScript Strings: From Basics to Advanced Techniques | JavaScript strings are fundamental to web development, allowing us to manipulate and work with text... | 0 | 2024-07-04T15:25:19 | https://dev.to/pr4san/the-ultimate-guide-to-javascript-strings-from-basics-to-advanced-techniques-36cd | webdev, javascript, beginners, programming | JavaScript strings are fundamental to web development, allowing us to manipulate and work with text in our applications. In this comprehensive guide, we'll explore everything you need to know about JavaScript strings, from the basics to advanced techniques. We'll cover creation, manipulation, and best practices, all accompanied by original examples to illustrate each concept.
## Table of Contents
1. [Introduction to Strings](#introduction-to-strings)
2. [Creating Strings](#creating-strings)
3. [String Properties](#string-properties)
4. [String Methods](#string-methods)
5. [String Templates](#string-templates)
6. [String Comparison](#string-comparison)
7. [Unicode and Internationalization](#unicode-and-internationalization)
8. [Regular Expressions with Strings](#regular-expressions-with-strings)
9. [Performance Considerations](#performance-considerations)
10. [Common Pitfalls and Best Practices](#common-pitfalls-and-best-practices)
## Introduction to Strings
In JavaScript, a string is a sequence of characters used to represent text. Strings are immutable, meaning once created, their contents cannot be changed. However, we can perform various operations on strings to create new strings based on the original.
## Creating Strings
There are several ways to create strings in JavaScript:
1. Using single quotes:
```javascript
let singleQuoted = 'Hello, World!';
```
2. Using double quotes:
```javascript
let doubleQuoted = "Hello, World!";
```
3. Using backticks (template literals):
```javascript
let backticks = `Hello, World!`;
```
4. Using the String constructor:
```javascript
let constructedString = new String("Hello, World!");
```
Note that using the `String` constructor creates a String object, which is different from a primitive string. It's generally recommended to use literal notation (single or double quotes) for better performance and simplicity.
Example: Creating a string library name generator
```javascript
function generateLibraryName() {
const adjectives = ['Rapid', 'Dynamic', 'Quantum', 'Cyber', 'Neuro'];
const nouns = ['Script', 'Code', 'Logic', 'Syntax', 'Function'];
const randomAdjective = adjectives[Math.floor(Math.random() * adjectives.length)];
const randomNoun = nouns[Math.floor(Math.random() * nouns.length)];
return `${randomAdjective}${randomNoun}.js`;
}
console.log(generateLibraryName()); // Outputs something like "QuantumSyntax.js"
```
## String Properties
The most commonly used property of a string is `length`, which returns the number of characters in the string.
Example: Checking if a password meets a minimum length requirement
```javascript
function isPasswordLongEnough(password, minLength = 8) {
return password.length >= minLength;
}
console.log(isPasswordLongEnough("short")); // false
console.log(isPasswordLongEnough("longenoughpassword")); // true
```
## String Methods
JavaScript provides a rich set of methods to manipulate strings. Here are some of the most commonly used ones:
### 1. Accessing Characters
- `charAt(index)`: Returns the character at the specified index.
- `charCodeAt(index)`: Returns the Unicode value of the character at the specified index.
Example: Creating a simple Caesar cipher
```javascript
function caesarCipher(str, shift) {
return str.split('').map(char => {
if (char.match(/[a-z]/i)) {
const code = char.charCodeAt(0);
const offset = char.toLowerCase() === char ? 97 : 65;
return String.fromCharCode((code - offset + shift) % 26 + offset);
}
return char;
}).join('');
}
console.log(caesarCipher("Hello, World!", 3)); // Outputs: "Khoor, Zruog!"
```
### 2. Searching and Extracting
- `indexOf(substring)`: Returns the index of the first occurrence of a substring.
- `lastIndexOf(substring)`: Returns the index of the last occurrence of a substring.
- `slice(startIndex, endIndex)`: Extracts a portion of the string.
- `substring(startIndex, endIndex)`: Similar to slice, but doesn't support negative indexes.
- `substr(startIndex, length)`: Extracts a specified number of characters.
Example: Extracting a domain name from an email address
```javascript
function getDomainFromEmail(email) {
const atIndex = email.indexOf('@');
if (atIndex === -1) return null;
return email.slice(atIndex + 1);
}
console.log(getDomainFromEmail("[email protected]")); // Outputs: "example.com"
```
### 3. Modifying
- `toLowerCase()`: Converts the string to lowercase.
- `toUpperCase()`: Converts the string to uppercase.
- `trim()`: Removes whitespace from both ends of the string.
- `replace(searchValue, replaceValue)`: Replaces occurrences of a substring.
Example: Creating a title case function
```javascript
function toTitleCase(str) {
return str.toLowerCase().split(' ').map(word => {
return word.charAt(0).toUpperCase() + word.slice(1);
}).join(' ');
}
console.log(toTitleCase("the quick brown fox")); // Outputs: "The Quick Brown Fox"
```
### 4. Splitting and Joining
- `split(separator)`: Splits the string into an array of substrings.
- `join(separator)`: Joins array elements into a string.
Example: Reversing words in a sentence
```javascript
function reverseWords(sentence) {
return sentence.split(' ').reverse().join(' ');
}
console.log(reverseWords("Hello World! How are you?")); // Outputs: "you? are How World! Hello"
```
## String Templates
Introduced in ES6, template literals provide an easy way to create multi-line strings and embed expressions.
Example: Creating a simple HTML template
```javascript
function createUserCard(user) {
return `
<div class="user-card">
<h2>${user.name}</h2>
<p>Age: ${user.age}</p>
<p>Email: ${user.email}</p>
</div>
`;
}
const user = { name: "John Doe", age: 30, email: "[email protected]" };
console.log(createUserCard(user));
```
## String Comparison
Comparing strings in JavaScript can be done using comparison operators (`<`, `>`, `<=`, `>=`) or the `localeCompare()` method for more precise comparisons.
Example: Implementing a basic spell checker
```javascript
function spellCheck(word, dictionary) {
if (dictionary.includes(word)) return true;
return dictionary.find(dictWord => {
if (Math.abs(dictWord.length - word.length) > 1) return false;
let differences = 0;
for (let i = 0; i < Math.max(word.length, dictWord.length); i++) {
if (word[i] !== dictWord[i]) differences++;
if (differences > 1) return false;
}
return true;
});
}
const dictionary = ["apple", "banana", "cherry", "date"];
console.log(spellCheck("aple", dictionary)); // Outputs: "apple"
console.log(spellCheck("grape", dictionary)); // Outputs: undefined
```
## Unicode and Internationalization
JavaScript strings are Unicode-based, which means they can represent a wide range of characters from different languages and symbol sets.
Example: Counting emoji in a string
```javascript
function countEmoji(str) {
const emojiRegex = /\p{Emoji}/gu;
return (str.match(emojiRegex) || []).length;
}
console.log(countEmoji("Hello! 👋 How are you? 😊")); // Outputs: 2
```
## Regular Expressions with Strings
Regular expressions are powerful tools for pattern matching and manipulation of strings.
Example: Validating a complex password
```javascript
function isPasswordComplex(password) {
const minLength = 8;
const hasUpperCase = /[A-Z]/;
const hasLowerCase = /[a-z]/;
const hasNumbers = /\d/;
const hasNonAlphas = /\W/;
return password.length >= minLength
&& hasUpperCase.test(password)
&& hasLowerCase.test(password)
&& hasNumbers.test(password)
&& hasNonAlphas.test(password);
}
console.log(isPasswordComplex("Abc123!@#")); // true
console.log(isPasswordComplex("Simplepass")); // false
```
## Performance Considerations
When working with strings, especially in performance-critical applications, consider the following:
1. Use string concatenation (`+=`) sparingly in loops. Instead, use array joining or template literals.
2. When possible, use string methods like `startsWith()` or `endsWith()` instead of regular expressions for simple checks.
3. For large-scale string manipulations, consider using specialized libraries or Web Workers.
Example: Optimized string building
```javascript
function buildLargeString(n) {
const parts = [];
for (let i = 0; i < n; i++) {
parts.push(`Part ${i + 1}`);
}
return parts.join(' - ');
}
console.log(buildLargeString(1000).length); // More efficient than repeated concatenation
```
## Common Pitfalls and Best Practices
1. Remember that strings are immutable. Operations like `replace()` return new strings.
2. Be cautious with `==` for string comparison, as it may lead to unexpected type coercion. Use `===` instead.
3. When working with user input, always sanitize and validate strings to prevent security vulnerabilities.
4. Use template literals for multi-line strings and string interpolation for better readability.
Example: Sanitizing user input
```javascript
function sanitizeInput(input) {
const map = {
'&': '&',
'<': '<',
'>': '>',
'"': '"',
"'": ''',
"/": '/',
};
const reg = /[&<>"'/]/ig;
return input.replace(reg, (match)=>(map[match]));
}
console.log(sanitizeInput("<script>alert('XSS')</script>"));
// Outputs: "<script>alert('XSS')</script>"
```
In conclusion, JavaScript strings are versatile and powerful. From basic operations to complex manipulations, understanding strings is crucial for effective JavaScript programming. By mastering these concepts and techniques, you'll be well-equipped to handle text processing in your web applications efficiently and securely. | pr4san |
1,911,745 | Buy verified cash app account | https://dmhelpshop.com/product/buy-verified-cash-app-account/ Buy verified cash app account Cash app... | 0 | 2024-07-04T15:24:58 | https://dev.to/mocap21972/buy-verified-cash-app-account-2mam | webdev, javascript, beginners, programming | https://dmhelpshop.com/product/buy-verified-cash-app-account/
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Email:[email protected] | mocap21972 |
1,911,167 | Decorator Function inside Factory Function | INTRO 🔔 Recently I had to create a function with multiple methods🤔. So I created a Factory... | 25,283 | 2024-07-04T15:24:52 | https://dev.to/sundarbadagala081/decorator-function-inside-factory-function-5ae8 | javascript, webdev, programming, development | ## INTRO 🔔
Recently I had to create a function with multiple methods🤔. So I created a `Factory Function`😎. If you don't know what a factory function is then don't worry😉, I will tell you in simple words that `The function always returns an object called a factory function`. For more information visit this 👉🏻 [factory factions🔗](https://www.linkedin.com/pulse/factory-functions-javascript-nikhil-nishad/) 👈🏻. Then after I realised that all the methods have the same validation check🔬. So I decided to create a decorator function to check the validation of all the methods😵💫. So I started researching different blogs on how to achieve that but I didn't find any perfect solution, Even though I found, those are very complicated to understand and don't have an organised code format😒.
Today we will discuss how to implement the decorator function inside the factory function.📝
## FACTORY FUNCTION 🔔
As mentioned earlier, a factory function is simply a function that returns an object without using the keyword new so the end result of the function is the return of an object. 🚀
👉🏻 **ADVANTAGES**
- 📌 First, it's a simple it's just a function it's there's no setup there's no fuss it's just a function and it's really easy to read
- 📌 No duplicate code and our logic is isolated in one place
- 📌 Have data privacy
👉🏻 **EXAMPLE**
```js
//-----------------FACTORY FUNCTION----------------------
const factoryFn = (...args) => {
const sum = () => {
return args.reduce((curr, acc) => curr + acc, 0);
};
const multiple = () => {
return args.reduce((curr, acc) => curr * acc, 1);
};
const max=()=>{
return Math.max(...args)
}
return {
sum,
multiple,
max
};
};
const fn1 = factoryFn(1, 2, 3, 4);
console.log(fn1.sum());
console.log(fn1.multiple());
console.log(fn1.max());
```
```js
//-------------------FACTORY FUNCTION WITH IIFE-----------------
const factoryFn = (() => {
const sum = (...args) => {
return args.reduce((curr, acc) => curr + acc, 0);
};
const multiple = (...args) => {
return args.reduce((curr, acc) => curr * acc, 1);
};
const max = (...args) => {
return Math.max(...args);
};
return {
sum,
multiple,
max,
};
})();
console.log(factoryFn.sum(1, 2, 3, 4));
console.log(factoryFn.multiple(1, 2, 3, 4));
console.log(factoryFn.max(1, 2, 3, 4));
```
## DECORATOR FUNCTION 🔔
A decorator function💥 is simply a function💥 that receives another function💥 as a parameter and then returns a new function💥 with extended behaviour. So you can pass a function💥 into a decorator function💥 and you'll get a new function💥 back that does more than the function💥 you passed in.
We already created one post for the 👉🏻[decorator function](https://dev.to/sundarbadagala081/javascript-decorator-functions-19l1)👈🏻. Please visit that post for more information. 👍🏻
## DECORATOR WITH FACTORY FUNCTION 🔔🔔🔔
After a long discussion, finally, we came to the main topic 😛.
Here the code to implement decorator function inside the factory function 👇🏻👇🏻👇🏻
```js
const factoryFn = (() => {
const sum = (args) => {
return args.reduce((curr, acc) => curr + acc, 0);
};
const multiple = (args) => {
return args.reduce((curr, acc) => curr * acc, 1);
};
const max = (args) => {
return Math.max(...args);
};
const decorator = (callback) => {
return (args) => {
const isValidate = args.some((item) => Number.isInteger(item));
if (!isValidate) {
throw new TypeError("arguments cannot be non-integer");
}
return callback(args);
};
};
const passingFn = (fn, params) => {
const newFn = decorator(fn);
return newFn(params);
};
return {
sum(...params) {
return passingFn(sum, params);
},
multiple(...params) {
return passingFn(multiple, params);
},
max(...params) {
return passingFn(max, params);
},
};
})();
console.log(factoryFn.sum(1, 2, 3, 4));
console.log(factoryFn.multiple(1, 2, 3, 4));
console.log(factoryFn.max(1, 2, 3, 4));
```
- 📌Created one method named `passingFn` to avoid code duplication. That function helps to declare a new function by decorating existed function and returns that declared a function with enhanced feature (nothing but validation check)
- 📌`decorator` method, we already discussed that. That returns the function that we passed as a callback with a validation check.
- 📌The remaining methods are already existing ones
## CONCLUSION 🔔
I hope you guys understand how to implement decorator function inside the factory function.
We will meet in next with another concept
Peace 🙂
| sundarbadagala081 |
1,911,732 | Factory Design Pattern | O padrão de design Factory é amplamente utilizado na programação orientada a objetos. Ele oferece uma... | 0 | 2024-07-04T15:23:44 | https://dev.to/rflpazini/factory-design-pattern-4e9n | go, designpatterns, coding, softwaredevelopment | O padrão de design Factory é amplamente utilizado na programação orientada a objetos. Ele oferece uma interface para criar objetos, mas permite que as subclasses decidam quais classes instanciar. Neste artigo, vamos explorar como implementar o padrão Factory em Golang, entender seus benefícios e analisar um exemplo prático de uso inspirado em situações do dia-a-dia.
## O que é o Factory?
O Factory define uma interface para criar objetos, mas delega a responsabilidade de instanciar a classe concreta às subclasses. Isso promove a criação de objetos de maneira desacoplada e flexível, permitindo que o código seja mais modular e fácil de manter.
## Benefícios
* Desacoplamento: Separa a criação de objetos da sua implementação, promovendo um código mais limpo e modular.
* Flexibilidade: Facilita a introdução de novas classes sem modificar o código existente.
* Manutenção: Torna o código mais fácil de manter e evoluir, pois a lógica de criação está centralizada em um único lugar.
## Implementando uma Factory
Vamos utilizar um exemplo do dia-a-dia para ilustrar o padrão Factory: um sistema para pedidos de comida, onde alguns diferentes tipos de refeições (Pizza e Salada) podem ser criados.
### 1 - Criando a interface
Primeiro, precisamos definir uma interface que será implementada por todas as "classes concretas" de refeições.
```go
package main
type Food interface {
Prepare()
}
```
### 2 - Criando um ENUM e implementando a interface
Para facilitar a nossa vida durante o desenvolvimento e evitar de digitar algo errado durante a validação, uma boa prática é criar um ENUM para ter uma consistência e também facilitar caso queiramos adicionar novas comidas no futuro
```go
package main
type FoodType int
const (
PizzaType FoodType = iota
SaladType
)
type Food interface {
Prepare()
}
```
E agora vamos implementar a interface `Food`. No exemplo vamos apenas exibir uma mensagem, na vida real aqui é onde seria criado o objeto que estamos trabalhando
```go
package main
type FoodType int
const (
PizzaType FoodType = iota
SaladType
)
type Food interface {
Prepare()
}
type Pizza struct{}
func (p Pizza) Prepare() {
fmt.Println("Preparing a Pizza...")
}
type Salad struct{}
func (s Salad) Prepare() {
fmt.Println("Preparing a Salad...")
}
```
### 3 - Criando a Factory
Agora, vamos criar a factory que decidirá qual classe concreta instanciar com base no enum que recebeu como parâmetro.
```go
package main
type FoodFactory struct{}
func (f FoodFactory) CreateFood(ft FoodType) Food {
switch ft {
case PizzaType:
return &Pizza{}
case SaladType:
return &Salad{}
default:
return nil
}
}
```
### 4 - Utilizando a Factory
Finalmente, vamos utilizar a fábrica para criar nossas comidas.
```go
package main
func main() {
kitchen := FoodFactory{}
pizza := kitchen.CreateFood(PizzaType)
if pizza != nil {
pizza.Prepare()
}
salad := kitchen.CreateFood(SaladType)
if salad != nil {
salad.Prepare()
}
}
```
Esse será o resultado após rodarmos nossa aplicação:
```shell
Preparing a Pizza...
Preparing a Salad...
```
### Resumo do que fizemos
1. Interface `Food`: Define o contrato que todas as refeições concretas devem seguir, garantindo que todas implementem o método Prepare.
2. Enum `FoodType`: Utiliza constantes tipadas para representar os diferentes tipos de comida, aumentando a legibilidade e a segurança do código.
3. Classes concretas (`Pizza` e `Salad`): Implementam a interface Food e fornecem suas próprias implementações do método Prepare.
4. `FoodFactory`: Contém a lógica de criação de objetos. O método CreateFood decide qual classe concreta instanciar com base no enum FoodType.
5. Método `main`: Demonstra o uso da fábrica para criar diferentes objetos e chamar seus métodos, ilustrando a flexibilidade e o desacoplamento proporcionados pelo padrão Factory.
## Conclusão
O padrão de design Factory é uma poderosa ferramenta para promover o desacoplamento e a flexibilidade na criação de objetos. Em Golang, a implementação deste padrão é direta e eficaz, permitindo a criação de sistemas modulares e fáceis de manter. Com o uso de interfaces e fábricas, podemos centralizar a lógica de criação e simplificar a evolução do código à medida que novos requisitos surgem. | rflpazini |
1,907,100 | Elixir Agent - A simple way to sharing data between processes without implement process or GenServer | Intro For newbies, it's hard for fully understanding Elixir process (also GenServer). For... | 0 | 2024-07-04T15:22:40 | https://dev.to/manhvanvu/elixir-agent-module-a-simple-way-to-sharing-data-between-processes-without-implement-our-process-or-genserver-5b5k | elixir, agent | ## Intro
For newbies, it's hard for fully understanding Elixir process (also `GenServer`). For easy to work with process, Elixir provides `Agent` module to support sharing data (state) between two or more processes.
## Explain
In Elixir, every single line of code is run in a process and because Elixir is functional programming then we don't have global variable (of course, we have a big benefit for this that is much more less side effect - From avoided using global variable).
To share data between functions we use process dictionary or pass variable as param.
But for between different processes we need more effort to share data (if not used Ets table & `:persistent_term` - a limited way). We need add code to send & receive a message, also we need to handle state to store global variable (can use process dictionary).
For much more convenient to sharing data between process we can use `Agent` for holding global data (state) to share between processes or simple between functions in different point of times in a process.
## Implement a Agent
We can implement a module using `Agent` or directly (less convenient).
```Elixir
defmodule AutoId do
use Agent
def start_link(initial_id) do
Agent.start_link(fn -> initial_value end, name: __MODULE__)
end
def last_id do
Agent.get(__MODULE__, & &1)
end
def set_id(new_id) do
Agent.update(__MODULE__, &(&1 + new_id))
end
def new_id do
Agent.get_and_update(__MODULE__, fn id -> {id, id + 1} end)
end
end
```
In this example, we make a module to sharing a way to get unique id for all processes in system by call `AudoId.new_id()`.
We can add to a application supervisor or manual start by call `AutoId.start_link(0)` before using (remember Agent process will crash if our process is crashed).
To add to a application supervisor (or our supervisor) we add code like:
```Elixir
children = [
{AutoId, 0}
]
Supervisor.start_link(children, strategy: :one_for_one)
```
For start manual `AutoId` process just add code like:
```Elixir
AutoId.start_link(1_000)
```
And in somewhere in source code we can use by call `AutoId` functions like:
```Elixir
my_id = AutoId.new_id()
#...
# reset id
AutoId.set_id(1_000_000)
other_id = AutoId.new_id()
```
`Agent` is simple enough for using and we don't need implement `GenServer` or write new process for sharing data.
`Agent` is process then it can be handover or overload, for in case we need get/set data (state) in limited time we can use `timeout` param (default is 5_000 ms).
`Agent` also provides config for `child_spec` for supervisor like `GenServer` & support distributed, hot code swapping for more use cases.
| manhvanvu |
1,911,741 | Event-Driven Architecture: reconcile Notification and Event-Carried State Transfer patterns | Event-driven architectures have tremendous benefits: decoupling application components brings... | 0 | 2024-07-04T15:14:54 | https://dev.to/aws-builders/event-driven-architecture-reconcile-notification-and-event-carried-state-transfer-patterns-5697 | eventdriven, eventbridge, event, serverless | Event-driven architectures have tremendous benefits: decoupling application components brings improved resilience, the ability to isolate non-scalable workloads from unpredictable user traffic and better user experience (returning a response before we do the complexe processing).
However, their design is not easy and can lead to numerous debates among developers and architects: should we have very minimalistic events, requiring consumers to fetch additional information? do we need fully-qualified events? ..
In this post, I explain the different types of events and propose a way to simply reconcile the different approaches by relying on AWS EventBridge. A Github repo with fully functional examples awaits you at the end of the article!
## Different approaches to event design
A common pattern is the "Notification" event, one that just contains an identifier. Here is an example for an OrderCreated event:
```
{ "orderId": "1234567" }
```
This minimal event has the advantage of not requiring any knowledge of the business domain model: there is little risk of violating the interface contract when modifying the producer app. If a consumer wants to know more, they can fetch data with the communicated identifier (and if the source system has a GraphQL API, they can fetch only whatever data is necessary for them).
Another approach is the "Event-carried State Transfer" events (named after the famous "REpresentational State Transfer", aka REST APIs). The event has all the domain data related to the event. Here is an example for the same OrderCreated event:
```
{
"id": "1234567",
"status": "PAYMENT_ACCEPTED",
"customer": "Bob",
"content": [ ... ]
}
```
The benefit associated to this approach is that the event can be consumed without any additional information. It also enhances filtering options that the Event Bus will provide: we can for example choose to only consume events representing an order that has the `PAYMENT_ACCEPTED` status (for example to send an order confirmation email).
A third way consists of publishing a "Delta", i.e. also transmitting the previous state in addition to the current state.
Here is a summary of the advantages and limitations of each approach:
## Reconciling the Notification approach and the Event-carried State Transfer approach
We may want to take advantage of the benefits of each approach
* without unnecessarily complicating the architecture of the producer or consumer applications
* without sometimes having control over the applications source code.
This is where a serverless approach mixing EventBridge event bus and Lambda makes sense. In this approach, we will set up
* EventBus rules matching "_Notification_" type events
* and enrichment micro-services which will retrieve data from the corresponding business domain and republish the enriched event.
I will start with a simple example, before showing how we can extend this pattern. At the bottom of this article you will find a link to a repository that implements both examples.
### The simple version: single enrichment
In this example, a payment management application publishes a `PAYMENT` type event bearing only the event id (a notification event).
On the EventBridge side, a rule will explicitly match these events by checking that no additional data is provided
```
{
"detail-type": ["PAYMENT"],
"detail.payment_data.id": [{ "exists": false }]
}
```
If this rule matches an event, it will invoke a Lambda which will publish the same event, but enriched with domain data.
We will therefore see two events successively in the event bus (with the same business id):
* the notification event
```
{
"version": "0",
"id": "a23a7513-b67a-d455-f90c-1f9ddbd14820",
"detail-type": "PAYMENT",
"source": "PaymentSystem",
"account": "112233445566",
"time": "2024-07-04T09:06:47Z",
"region": "eu-west-1",
"resources": [],
"detail": {
"id": "2237082"
}
}
```
* and the fully-qualified (ECST) one:
```
{
"version": "0",
"id": "51bbf35e-97d8-8f80-1cc2-debac66460e6",
"detail-type": "PAYMENT",
"source": "PaymentSystem",
"account": "112233445566",
"time": "2024-07-04T09:06:49Z",
"region": "eu-west-1",
"resources": [],
"detail": {
"id": "2237082",
"payment_data": {
"id": "2237082",
"type": "Credit",
"description": "Credit Card - HSBC",
"status": "Confirmed",
"state": "Paid",
"value": 1700,
"currency": "EUR",
"date": "2018-12-15"
}
}
}
```
(here, the event structure is a little more complex than in the theoretical part, as I display the typical structure of an EventBridge event, which encapsulates the business content with some metadata.)
The EventBridge event bus provides:
* Decoupling between Producers and Consumers with scalable and highly available middleware
* Advanced event matching capabilities
* events logging, archiving and replaying
* Retry management for synchronous invocations made by the event bus in case of error.
* Input Transform to format the event as expected by the consumer, without having to deploy this transformation as a Lambda function.
All of these features are demonstrated in the code available at the end of the article.
### A more complex enrichment
Let's imagine a more complex case: the payment system publishes a payment event. But this payment is linked to an order, which has its own life cycle, managed in several other applications. And this order is linked to a customer, which also has its own life cycle, managed in a CRM app.
Here we will implement more complex pattern matching logic, but the code of the enrichment functions does not change!
## Deploy these examples
In this blog post, I demonstrated how to reconcile the two main event management models, using AWS EventBridge and AWS Lambda
You will find in [this Github repo](https://github.com/psantus/event-driven-notification-vs-ecst) two CloudFormation templates to deploy these fully functional examples.
---
Do you want to get started with event-driven architecture and need support? TerraCloud is here to help you! [Contact me!](https://www.terracloud.fr/en/a-propos/qui-suis-je/)
[](https://www.terracloud.fr)
| psantus |
1,911,739 | 10 Cool CodePen Demos (June 2024) | A collection of 10 cool demos shared on CodePen during June 2024 | 0 | 2024-07-04T15:14:22 | https://alvaromontoro.medium.com/10-cool-codepen-demos-june-2024-228a94f56e04 | css, webdev, showdev, html | ---
title: 10 Cool CodePen Demos (June 2024)
published: true
description: A collection of 10 cool demos shared on CodePen during June 2024
tags: CSS,webdev,showdev,html
cover_image: https://dev-to-uploads.s3.amazonaws.com/uploads/articles/tfw3mg1mfnyng0ca29pp.png
canonical_url: https://alvaromontoro.medium.com/10-cool-codepen-demos-june-2024-228a94f56e04
---
## from beneath
[Sophia Wood (a.k.a. Fractal Kitty)](https://codepen.io/fractalkitty) mixes poetry and code in her pieces. Don’t just run the p5.js demo! Review the code, explore the comments, and interpret JavaScript differently!
{% codepen https://codepen.io/fractalkitty/pen/KKLjGxj %}
---
## Diorama — Milk
I like the dioramas that [Ricardo Oliva Alonso](https://codepen.io/ricardoolivaalonso) creates in ThreeJS. This time, it is a cozy coffee shop in a milk carton with whimsical vibes from Ghibli movies. The shadows and lines make this demo amazing.
{% codepen https://codepen.io/ricardoolivaalonso/pen/ExzJzZZ %}
---
## Step Indicator
[Jon Kantner](https://codepen.io/jkantner) always builds beautifully crafted components that are full of small details and micro-interactions. This step indicator exemplifies how having a clean design and soft animations can go a long way.
{% codepen https://codepen.io/jkantner/pen/KKLXjbK %}
---
## Parallax background
This is a simple idea that [misala](https://codepen.io/p0waqqatsi) smoothly implemented. Scroll up and down to see the background levels move at different speeds, creating a depth effect that helps transition into the content. It uses some vanilla JS; it would be interesting to see if it’s possible with scroll-driven animations.
{% codepen https://codepen.io/p0waqqatsi/pen/vYwqQxV %}
---
## CSS-Only Custom Range Slider
[Temani Afif](https://codepen.io/t_afif) combines modern CSS features like scroll-driven animations, anchor positioning, and the at-property rule (sorry, not all of them will be available in all browsers at the moment) to create this cool slider with three HTML tags and no JavaScript.
{% codepen https://codepen.io/t_afif/pen/JjqNEbZ %}
---
## No JS char by char on scroll reveal effects
Give [Ana Tudor](https://codepen.io/thebabydino) an SVG filter and a scroll-driven animation, and she will perform CSS magic. Do you want an example? Check this text reveal that would have been unthinkable not long ago without breaking all words (and letters) into spans. CSS Magic, I tell you.
{% codepen https://codepen.io/thebabydino/pen/KKLWBJZ %}
---
## 3D truchet
Lose yourself in this infinite labyrinth of traces and intersections. Pull the mouse around, pinch in and out to move forward and backward, and interact with it. Try as you may, you won’t escape this self-generating maze created by [Liam Egan](https://codepen.io/shubniggurath/).
{% codepen https://codepen.io/shubniggurath/pen/xxNLPxg %}
---
## Scroll Blurred Words
The idea behind this demo is similar to what Ana Tudor did with CSS above. However, [Jhey Tompkins](https://codepen.io/jh3y/) used JavaScript and the splitting technique to provide more options and smoother transitions. And the result is simply beautiful.
{% codepen https://codepen.io/jh3y/pen/eYaGzqv %}
---
## Sudoku with CSS Grid and :has experiment
The sudoku board coded by [Myriam](https://codepen.io/mynimi) is not playable (yet), but it showcases the power of CSS selectors in a fun way. When you select a cell, all the other cells that could impact its value will be highlighted to facilitate the number selection.
{% codepen https://codepen.io/mynimi/pen/rNgErxj %}
---
## Spray Paint Trail
Imagine that your mouse leaves a spray paint trail as you move it around the screen. Now, stop imagining it and try this demo by [Ethan](https://codepen.io/pleasedonotdisturb/). It may not be too practical, but it is really fun for a while. Then, it becomes a bit annoying but still fun.
{% codepen https://codepen.io/pleasedonotdisturb/pen/NWVZMya %}
---
If you like these demos, check the article with 10 Cool CodePen demos from May 2024: https://dev.to/alvaromontoro/10-cool-codepen-demos-may-2024-1cpb | alvaromontoro |
1,911,740 | Dive into the Fascinating World of Blockchain with Berkeley DeCal Course! 🚀 | Explore the fundamental concepts of blockchain technology, including decentralization, cryptography, and real-world applications in finance, supply chain, and healthcare. | 27,844 | 2024-07-04T15:14:14 | https://getvm.io/tutorials/blockchain-fundamentals-decal-2018-berkeley-decal | getvm, programming, freetutorial, universitycourses |
As someone who is deeply fascinated by the rapid advancements in technology, I'm excited to share with you an incredible learning opportunity - the Blockchain Fundamentals Decal course offered by the renowned University of California, Berkeley.
## Explore the Foundations of Blockchain
This course provides a comprehensive introduction to the fundamental concepts of blockchain technology, delving into its history, key components, and the myriad of real-world applications in industries like finance, supply chain, and healthcare. 🌐
## Highlights of the Course
- Gain a solid understanding of the core principles of blockchain, such as decentralization, cryptography, and consensus mechanisms. 🔒
- Explore popular blockchain platforms like Bitcoin and Ethereum, and discover their unique features and capabilities. 💰
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- Engage in hands-on projects and exercises to reinforce your understanding of blockchain concepts. 🛠️
## Recommended for All Learners
Whether you're a student, an entrepreneur, or a professional in the tech industry, this course is an excellent starting point to dive into the fascinating world of blockchain. It provides a solid foundation for further exploration and potential involvement in the rapidly evolving blockchain ecosystem. 🌱
So, what are you waiting for? Embark on this exciting journey and unlock the secrets of blockchain technology by enrolling in the Blockchain Fundamentals Decal course today! 🎉
Check out the course playlist on YouTube: [https://www.youtube.com/playlist?list=PLSONl1AVlZNU0QTGpbgEQXKHcmgYz-ddT](https://www.youtube.com/playlist?list=PLSONl1AVlZNU0QTGpbgEQXKHcmgYz-ddT)
## Enhance Your Learning Experience with GetVM Playground
To truly immerse yourself in the fascinating world of blockchain technology, I highly recommend utilizing the GetVM Playground. This powerful online coding environment seamlessly integrates with the Blockchain Fundamentals Decal course, allowing you to put the concepts you've learned into practice. 🌟
With GetVM's Playground, you can easily access and experiment with the course materials, diving deeper into the technical aspects of blockchain. The intuitive interface and real-time feedback make it the perfect companion for your learning journey. 💻
By combining the comprehensive course content with the hands-on Playground experience, you'll be able to solidify your understanding and gain practical skills that can be applied in the real world. Unlock the full potential of the Blockchain Fundamentals Decal course by exploring the GetVM Playground today! 🔍
Access the Playground here: [https://getvm.io/tutorials/blockchain-fundamentals-decal-2018-berkeley-decal](https://getvm.io/tutorials/blockchain-fundamentals-decal-2018-berkeley-decal)
---
## Practice Now!
- 🔗 Visit [Blockchain Fundamentals Decal | Berkeley DeCal Course](https://www.youtube.com/playlist?list=PLSONl1AVlZNU0QTGpbgEQXKHcmgYz-ddT) original website
- 🚀 Practice [Blockchain Fundamentals Decal | Berkeley DeCal Course](https://getvm.io/tutorials/blockchain-fundamentals-decal-2018-berkeley-decal) on GetVM
- 📖 Explore More [Free Resources on GetVM](https://getvm.io/explore)
Join our [Discord](https://discord.gg/XxKAAFWVNu) or tweet us [@GetVM](https://x.com/getvmio) ! 😄 | getvm |
1,911,738 | Read Committed transaction isolation in PostgreSQL | Recently I was reading “Designing Data-Intensive Applications” book. It covers lots of topics related... | 0 | 2024-07-04T15:13:47 | https://dev.to/olegelantsev/read-committed-transaction-isolation-in-postgresql-3c4d | postgres, database | Recently I was reading “Designing Data-Intensive Applications” book. It covers lots of topics related to creation of reliable, scalable and maintainable data systems and one of the chapter covers a concept of transactions - its meaning, use cases, levels of isolation and reasons why application developers should choose the right one. While many books and articles cover transaction isolation level with pure SQL examples for database users, I decided to go a bit deeper and check how a theory gets connected with actual implementation. As a software engineer with C++ background, it's interesting to check out the source code of one of the widely used open source databases - PostgreSQL. According to Statista it takes 4th place in most popular databases 2023. Typically first go Microsoft SQL, MySQL, Oracle and PostgreSQL.
To make the study interesting and constructive and limit the study scope, I will try to answer a question - how does transaction isolation work in general, and how database maintains READ COMMITTED isolation level in particular?
There are 4 transaction isolation levels in PostgreSQL:
* DIRTY READ
* READ COMMITTED
* REPEATABLE READ
* SERIALIZABLE
Read committed level guarantees that:
* transaction will see only committed results (no dirty reads). Transaction won’t see uncommitted changes of other concurrently running transactions
* writing to the database will overwrite only committed data (no dirty writes)
Let's start with some SQL code and illustrations, and then explore the source code. First create a simple table:
```
CREATE TABLE public.employees (
id SERIAL PRIMARY KEY,
name VARCHAR NOT NULL,
surname VARCHAR NOT NULL,
);
```
One row is sufficient for our case:
```
INSERT INTO accounts ("name", "surname") VALUES ("Phil", "Smith")
```
Lets run the following magic query
```
# SELECT xmin, xmax, ctid, * FROM employees;
xmin | xmax | ctid | id | name | surname
--------+------+-------+----+------+---------
218648 | 0 | (0,1) | 1 | Phil | Smith
(1 row)
```
Interesting numbers are in the response. Those are initial tuple attribute values for the inserted record of the first employee, but lets run two other transactions A and B concurrently (or sequentially for simplicity):
```
-- transaction A
BEGIN;
UPDATE employees SET name = "Bob" WHERE id = 1;
COMMIT;
-- transaction B
BEGIN;
SELECT name FROM employees WHERE id = 1;
SELECT name FROM employees WHERE id = 1;
COMMIT;
```
and run the magic query again
```
# SELECT xmin, xmax, ctid, * FROM employees;
xmin | xmax | ctid | id | name | surname
--------+------+-------+----+------+---------
218651 | 0 | (0,2) | 1 | Bob | Smith
```
`xmin` has slightly increased, and ctid has changed as well. Those are quite a clue for understanding how MVCC works. But let's take a step back and try to see what happens when those transactions run concurrently, i.e. what names become visible to transaction B.
The diagram above illustrates non-repeatable read problem with read-committed guarantee. Transaction B accesses the seemingly same row twice. First time SELECT reads the value after the transaction A executed an update on that row, but before that change was committed. READ COMMITTED isolation level prevents dirty (uncommitted) reads. Next in a timeline, transaction A commits the changes and transaction B accesses that row again. This time it will read an updated row, or actually a new tuple. By the way this may be dangerous in certain contexts, e.g. financial domain when performing the changes in account’s balance, thus for those tasks a stronger isolation might be needed.
## So how does transaction isolation work in PostgreSQL?
Without concurrency control, client may see inconsistent half-written data. The way to guarantee consistent view is by introducing isolation for the requests, and the basic approach is through adding table level read-write locks, but such locks create a high level of contention between read and update transactions, resulting in very slow access. Here comes MVCC that allows concurrent read and write operations without locking the entire table. It may implement multiple levels of isolation, and Read Committed is a default one in PostgreSQL. What a particular transaction sees depends on its isolation level. With read committed level transactions see a snapshot of the database at the start of each transaction, i.e. see point-in-time consistent views. This isolation is achieved through data versioning - due to concurrent transactions there might be multiple versions of rows at a time visible to different transactions. Each row modification is associated with transaction, that either created, modified or deleted row. Each row also contains a visibility marker, indicating when row is visible and when it becomes invisible (after deletion or update). Isolation provides guarantees for concurrent data access.
## How exactly does MVCC track versions?
Remember that magic query we ran and the produced results? Let's try to understand what those mean and have a look at tuple declaration in http_details.h. HeapTupleFields catches my attention because it contains t_xmin, t_xmax and t_infomask from HeapTupleHeaderData also seems an important attribute - they seem to provide tuples with the necessary versioning, visibility levels required for transaction isolation. There are more attributes of course, but these must be describing the basic cases.
```
typedef struct HeapTupleFields
{
TransactionId t_xmin; /* inserting xact ID */
TransactionId t_xmax; /* deleting or locking xact ID */
union
{
CommandId t_cid; /* inserting or deleting command ID, or both */
TransactionId t_xvac; /* old-style VACUUM FULL xact ID */
} t_field3;
} HeapTupleFields;
```
From the same header I read that
* `t_infomask` is uint16 attribute and among other things it has bits enriching the `xmin` and `xmax` values, describing whether those are COMMITTED, INVALID or FROZEN.
* `xmin` - is used to store transaction XID, assigned at INSERT and UPDATE commands
* `xmax` - kinda invalidating or expiring a tuple, set by UPDATE or DELETE. It might be also used for row locks
## What happens when row gets updated while being repeatably read by another transaction?
### Create new tuple
When a transaction updates a tuple, it actually creates a new version of it (AKA copy-on-write approach) with its own XID and New tuple's header has XMin value equal to transaction XID - 218648.
### Mark old tuple for deletion
The old tuple's Xmax (Transaction ID of the last transaction to modify the tuple) is set to the XID of the updating transaction. Future transactions should not be able to see it (at least after commit). When tuple has non-zero xmax may actually have a few interpretations depending on the other flags set in tuple header (e.g. xmax is also assigned when tuple is locked for update), but for simplicity I will omit those details.
### Vacuum old tuple
The Xmin and Xmax values are also used during the garbage collection process to determine which tuples are no longer visible to any active transaction. Tuples with an Xmax that is less than the current transaction's XID and when no other current transactions access the old tuple (e.g. deleted or replaced) - they can be safely removed during vacuuming.
There are more interesting things happen to the states of tuples, transactions and snapshots. For example, tuple state and its visibility is well described in [heapam_visibility.c](https://github.com/postgres/postgres/blob/master/src/backend/access/heap/heapam_visibility.c)
## Why don't concurrent transactions see new tuple until XID 218649 is committed?
At a start up of each transaction, one requests a snapshot object, containing information about all running transactions. Let's have a look at procarray.c file and very descriptive comment of GetSnapshotData function:
Having a snapshot object describing currently running transactions and XIDs "boundaries" is quite helpful for complying with READ COMMITTED isolation level. From the example above, no other transaction of such isolation level will see "name = Bob" until transaction 3 is successfully committed.
[heapam_visibility.c](https://github.com/postgres/postgres/blob/master/src/backend/access/heap/heapam_visibility.c) seems to be the right place to look for understanding how a snapshot type impacts the tuple visibility for transaction.
Those functions rely on tuple header fields (Xmin, Xmax and a few flag values), snapshot object to determine the visibility of the tuple to other transactions.
## The end
It was surprisingly fun to read PostgreSQL source code. Git blame reported that some lines were more than 20 years old. Methods frequently are well documented with comments and not only describe what a particular function does, but also conditions under which this function must be invoked, what kind of locks it uses, what optimisations were tried before, etc. For those who wants to dig deeper and explore the tuple states I recommend to start with [htup_details.h](https://github.com/postgres/postgres/blob/cca97ce6a6653df7f4ec71ecd54944cc9a6c4c16/src/include/access/htup_details.h).
| olegelantsev |
1,911,736 | What is the most widely used website that utilizes Node.js in production? | Node.js has become a popular choice for building scalable and high-performance web applications. Many... | 0 | 2024-07-04T15:10:47 | https://dev.to/ndiaga/what-is-the-most-widely-used-website-that-utilizes-nodejs-in-production-56k3 | Node.js has become a popular choice for building scalable and high-performance web applications. Many high-profile websites and companies use Node.js in their production environments. Here are some of the most widely used websites that utilize Node.js, along with a look at their use cases and how they benefit from Node.js:
1. Netflix
Website: Netflix
Use Case: Netflix, a leading streaming service, uses Node.js for its user interface and server-side applications.
Why Node.js?
Performance: Node.js’s non-blocking I/O operations and event-driven architecture allow Netflix to handle high levels of concurrent connections and deliver content efficiently.
Scalability: Node.js helps Netflix manage and scale its vast user base and data requirements.
Technologies: Netflix uses Node.js for its front-end application, while other technologies like Java and Python are used for different aspects of its backend infrastructure.
2. LinkedIn
Website: LinkedIn
Use Case: LinkedIn uses Node.js for its mobile server-side services.
Why Node.js?
Efficiency: Node.js allowed LinkedIn to handle a high number of concurrent connections and manage real-time interactions.
Speed: The lightweight nature of Node.js helps LinkedIn maintain fast and responsive services for its global user base.
Technologies: LinkedIn’s mobile server uses Node.js, while its core application relies on other technologies like Java for server-side operations.
3. Walmart
Website: Walmart
Use Case: Walmart uses Node.js for its online shopping platform and to improve the performance of its e-commerce site.
Why Node.js?
Scalability: Node.js’s asynchronous processing capabilities help Walmart handle large volumes of traffic, especially during peak shopping seasons like Black Friday.
Performance: Walmart improved the performance of their site’s checkout process and reduced page load times with Node.js.
Technologies: Walmart employs a combination of technologies including Node.js for the front-end and various other technologies for back-end services.
4. eBay
Website: eBay
Use Case: eBay uses Node.js for its real-time applications, such as chat and notifications.
Why Node.js?
Real-Time Processing: Node.js’s event-driven model supports eBay’s real-time features like live chat and notifications.
Performance: Node.js helps eBay manage a large number of concurrent connections efficiently.
Technologies: eBay’s tech stack includes Node.js for real-time interactions, along with other technologies like Java for different backend processes.
5. Trello
Website: Trello
Use Case: Trello, a popular project management tool, uses Node.js for both its server-side and real-time features.
Why Node.js?
Real-Time Collaboration: Node.js’s WebSocket capabilities enable real-time updates and collaboration on Trello boards.
Scalability: Node.js helps Trello manage large numbers of simultaneous users and interactions.
Technologies: Trello uses Node.js for real-time features and other technologies for various aspects of its infrastructure.
6. Reddit
Website: Reddit
Use Case: Reddit uses Node.js for parts of its web infrastructure, particularly for certain API endpoints and microservices.
Why Node.js?
Efficiency: Node.js handles many API requests and microservices efficiently.
Scalability: Node.js helps Reddit manage high traffic volumes and support a large user community.
Technologies: Reddit’s infrastructure includes Node.js for certain services, along with other technologies like Python for different backend components.
7. PayPal
Website: PayPal
Use Case: PayPal uses Node.js for some of its backend services and APIs.
Why Node.js?
Performance: Node.js provides fast performance for processing a high volume of transactions.
Developer Productivity: Node.js's unified JavaScript environment simplifies development for PayPal’s teams.
Technologies: PayPal integrates Node.js into their tech stack alongside other languages and technologies for different functionalities.
8. NASA’s Jet Propulsion Laboratory (JPL)
Website: NASA JPL
Use Case: NASA’s JPL uses Node.js for web applications and mission-critical systems.
Why Node.js?
Reliability: Node.js supports mission-critical applications that require high reliability and real-time capabilities.
Scalability: Node.js helps JPL manage complex systems and data flows for space missions.
Technologies: Node.js is used alongside other technologies for various space exploration projects and applications.
How Node.js Benefits These Websites
1. High Performance:
Node.js’s event-driven, non-blocking I/O model allows these websites to handle high traffic volumes and deliver fast, real-time interactions.
2. Scalability:
Node.js’s architecture supports the scaling of applications to handle increased user loads and complex data processing tasks.
3. Real-Time Capabilities:
Features like WebSockets and asynchronous processing enable real-time updates and interactions, crucial for applications like messaging and notifications.
4. Developer Efficiency:
Node.js uses JavaScript on both the front-end and back-end, simplifying the development process and improving productivity.
Tools and Resources for Node.js Integration
If you’re considering using Node.js for your projects, here are some tools and resources that might be helpful:
Node.js Official Site: Download Node.js, access documentation, and explore resources.
Express.js: A popular Node.js framework for building web applications.
Socket.io: A library for real-time web applications using WebSockets.
Mongoose: An ODM library for MongoDB and Node.js.
Summary
Node.js is a versatile and powerful platform used by many high-profile websites for various purposes, including performance optimization, scalability, real-time features, and developer efficiency. Websites like Netflix, LinkedIn, Walmart, eBay, Trello, Reddit, PayPal, and NASA’s JPL leverage Node.js for its unique advantages in handling complex, high-traffic applications.
For more information on using Node.js and finding tools for your own projects, you can visit PrestaTuts.com for a range of resources and modules.
If you have more questions or need specific advice, feel free to ask! | ndiaga |
|
1,911,734 | Functional Interface in Java | Functional Interface in Java A functional interface in Java is an interface that contains... | 0 | 2024-07-04T15:09:00 | https://dev.to/codegreen/functional-interface-in-java-4ma5 | java8, java, functional, interview | ### Functional Interface in Java
A functional interface in Java is an interface that contains exactly one abstract method. It can have any number of default methods or static methods.
* **Syntax:** Declared using the `@FunctionalInterface` annotation.
* **Example:**
```java
@FunctionalInterface
public interface MyFunctionalInterface {
void abstractMethod();
default void defaultMethod() {
System.out.println("Default method implementation");
}
static void staticMethod() {
System.out.println("Static method implementation");
}
}
```
**Conclusion:** Functional interfaces are the foundation of functional programming in Java, facilitating the use of lambda expressions and method references. They promote concise and readable code by allowing methods to be treated as first-class citizens. | manishthakurani |
1,909,013 | What is Digital Marketing ? | Digital marketing is a form of marketing that leverages the internet and digital technologies, such... | 0 | 2024-07-02T13:50:42 | https://dev.to/arjunk_53/what-is-digital-marketing--3m4j | [Digital marketing](https://arjunkokkadan.in/) is a form of marketing that leverages the internet and digital technologies, such as computers and mobile devices, to connect with customers. Unlike traditional media (such as print, radio, or television), digital marketing uses various digital channels to reach consumers wherever they spend the most time.
Scope of digital marketing
Digital marketing is witnessing rapid growth due to increased internet penetration, smartphone usage, and online activities. Businesses are allocating larger portions of their budgets to digital marketing efforts. Compared to traditional marketing, digital marketing is more cost-effective. Small businesses can compete with larger ones by leveraging digital channels without hefty budgets. Digital marketing allows businesses to transcend geographical boundaries. Companies can target audiences worldwide, expanding their reach beyond local markets.
Techniques of digital marketing
Digital marketing techniques encompass a wide range of strategies and practices aimed at promoting products or services through various digital channels. Here are some of the most effective and commonly used digital marketing techniques:
1. Search Engine Optimization (SEO)
Definition: The process of improving the visibility of a website or a web page in search engines through organic (non-paid) search results.
Keyword Research: Identifying and targeting the right keywords that potential customers use to search for products or services.
2. Content Marketing
Definition: Creating and distributing valuable, relevant, and consistent content to attract and engage a clearly defined audience.
Blogging: Writing informative and engaging blog posts.
Video Content: Producing videos for platforms like YouTube and social media.
Infographics: Creating visual representations of information or data.
E-books and Whitepapers: Offering in-depth information to capture leads and establish authority.
3. Social Media Marketing
Definition: Using social media platforms to promote products or services and engage with the audience.
Organic Social Media: Posting regular updates, engaging with followers, and building a community.
Paid Social Media: Running ad campaigns to reach a broader or more targeted audience.
Social Media Management: Using tools to manage and schedule posts, track performance, and engage with followers.
4. Email Marketing
Definition: Sending targeted email campaigns to nurture leads, promote products, and maintain customer relationships.
Newsletters: Regularly sending updates and curated content to subscribers.
Automated Campaigns: Sending emails triggered by specific actions or dates.
Personalization: Tailoring email content to different segments of the audience.
5. Pay-Per-Click (PPC) Advertising
Definition: Paying for ads that appear on search engines and other platforms, where advertisers pay a fee each time their ad is clicked.
Search Ads: Ads displayed on search engine results pages.
Display Ads: Banner ads shown on websites within ad networks.
Remarketing: Targeting users who have previously visited your site.
for more visit my website [best digital marketing strategist in Kannur ](https://arjunkokkadan.in/) | arjunk_53 |
|
1,911,733 | Github Readme Profile update with new social media cards stats | A post by Kenan Bharatbhai Gain | 0 | 2024-07-04T15:04:37 | https://dev.to/kenangain/github-readme-profile-update-with-new-social-media-cards-stats-50m4 | git, github, developer, ai |
| kenangain |
1,900,179 | Setting up a helm OCI registry with ArgoCD hosted on Azure | With an increasing number of helm charts, some configuration blocks are bound to get duplicated. This... | 0 | 2024-07-04T14:58:53 | https://dev.to/nastaliss/setting-up-a-helm-oci-registry-with-argocd-hosted-on-azure-4idd | kubernetes, helm, azure, devops | With an increasing number of helm charts, some configuration blocks are bound to get duplicated. This is not usually a big problem when writing Kubernetes configuration as readability and simplicity of the configuration is most of the time more valued than factorization.
However, keeping 10+ helm charts consistent often means a lot of copy pasting back and forth to keep the same naming convention, labels and logic up to date. This is why I wanted a way to use a _helpers.tpl file shared between multiple charts.
There are a few ways to achieve that :
- Creating a _helpers.tpl file at the root of the helm chart repository and creating symlinks in every chart directory. This can only work if all of your charts are in the same repository. However some of my charts were stored alongside the code to make deployment easier. So this solution could not work for me.
- Creating a _helpers.tpl file in a discrete repository, then using this repository as a sub-module in every chart repository. This can (and has) worked for me in the past. However working with sub-modules can be a pain to integrate in CI, and in ArgoCD.
- Using the new OCI registry support in helm. This is used actively by bitnami in their common chart. Since helm 3.8.0 this feature is supported by default.
## Hosting and logging into an OCI registry on azure
OCI images are supported by default by Azure Container Registries (ACR).
Here is the minimal Terraform configuration to create an ACR, a service principal and export its username / password to be able to login from the CI to push the OCI images and pull them from ArgoCD.
```hcl
# oci-registry.tf
data "azuread_client_config" "current" {}
# Deploy the ACR
resource "azurerm_container_registry" "registry" {
name = "<acr-name>"
resource_group_name = "<resource-group-name>"
location = "<my-location>"
admin_enabled = false
sku = "Basic"
public_network_access_enabled = true
zone_redundancy_enabled = false
}
# Deploy an application to contribute to the ACR
resource "azuread_application" "oci_contributor" {
display_name = "OCI contributor"
owners = [data.azuread_client_config.current.object_id]
prevent_duplicate_names = true
device_only_auth_enabled = true
}
# Associate an azure service principal (SP) to generate credentials
resource "azuread_service_principal" "oci_contributor" {
application_id = azuread_application.oci_contributor.application_id
description = "OCI contributor"
owners = [data.azuread_client_config.current.object_id]
}
# Create a password for the SP
resource "azuread_service_principal_password" "oci_contributor" {
service_principal_id = azuread_service_principal.oci_contributor.object_id
}
# Gives the SP the right to contribute to the ACR
resource "azurerm_role_assignment" "oci_contributor" {
scope = azurerm_container_registry.acr.id
role_definition_name = "AcrPush"
principal_id = azuread_service_principal.oci_contributor.object_id
description = "Give OCI Contributor rights to contribute to container registry"
}
# Output the SP client_id to reference it in the CI
output "oci_contributor_service_principal_client_id" {
value = azuread_service_principal.oci_contributor.application_id
}
# Output the SP password to reference it in the CI
output "oci_contributor_service_principal_password" {
value = azuread_service_principal_password.oci_contributor.value
sensitive = true
}
```
Once this is deployed, we can create a new repository that will contain our chart(s) we want to share.
## Creating the helpers repository chart
Create a repository and populate it as follows :
```
.
├── .github/
│ └── workflows/
│ ├── deploy-test.yaml
│ └── release.yaml
├── common/
│ ├── templates/
│ │ └── security.yaml
│ └── Chart.yaml
├── .gitignore
└── README.md
```
The Chart.yaml will contain the following:
```yaml
# Chart.yaml
apiVersion: v2
name: common
description: Shared helper function across different helm charts
type: application
appVersion: "1.16.0"
version: 0.1.0
```
Make sure to ignore tgz files when testing
```gitignore
# .gitignore
*.tgz
```
## Writing a simple helper function
Here we will write two simple helper function to populate the [SecurityContext](https://kubernetes.io/docs/tasks/configure-pod-container/security-context/) for a pod and a container.
```yaml
# security.yaml
{{/*
# DESCRIPTION
# Generate The pod's securityContext and to comply with namespaces with the annotation pod-security.kubernetes.io/enforce set to restricted
# PARAMETERS
- user (optional): The user to run the container as. Defaults to 10000
# USAGE
# {{ include "common.security.podSecurityContext.restricted" dict | indent 4 }}
*/}}
{{- define "common.security.podSecurityContext.restricted" -}}
{{- $user := .user | default 10000 -}}
runAsNonRoot: true
runAsUser: {{ $user }}
runAsGroup: {{ $user }}
fsGroup: {{ $user }}
seccompProfile:
type: RuntimeDefault
{{- end -}}
{{/*
# DESCRIPTION
# Generate The container's SecurityContext and to comply with namespaces with the annotation pod-security.kubernetes.io/enforce set to restricted
# PARAMETERS
No parameters, just include the snippet and give it an empty dict
# USAGE
# {{ include "common.security.containerSecurityContext.restricted" dict | indent 4 }}
*/}}
{{- define "common.security.containerSecurityContext.restricted" -}}
allowPrivilegeEscalation: false
capabilities:
drop: ["ALL"]
{{- end -}}
```
I won't go into details for this file as this is standard helm template. This is just an example.
## Building the OCI image manually
First let's check we are able to build the OCI image and push it to the registry.
Get your login / password from the two outputs in the terraform module.
Run
```bash
cd common
helm registry login <acr-name>.azurecr.io --username <acr-username> --password <acr-password>
helm package .
helm push *.tgz "oci://<acr-name>.azurecr.io/helm"
```
This will build your helm package and push it to the acr in the helm/common path (as the chart is named `common`) and under the 0.1.0 tag, defined in `Chart.yaml`.
## Using the common chart as a dependency
In another helm chart, you can use the common helm chart as a dependency by adding these lines in the Chart.yaml
```yaml
# other-chart/Chart.yaml
[...]
dependencies:
- name: common
repository: oci://<acr-name>.azurecr.io/helm
version: 0.1.0
```
You will then need to run `helm dependency update` or `helm dep up` if you hate typing.
This will create (or update) the Chart.lock, which is required for deploying the chart.
Then calling the function will look something like this:
```yaml
# other-chart/templates/deployment.yaml
[...]
spec:
securityContext:
{{- include "common.security.podSecurityContext.restricted" (dict "user" 101) | nindent 8 }}
containers:
[...]
```
## Passing credentials to ArgoCD
In your ArgoCD helm chart, you will need to add the following config in the valueFile.
```yaml
argo-cd:
configs:
repositories:
helm-oci:
username: <acr-username>
password: <acr-password>
url: <acr-name>.azurecr.io/helm
type: helm
enableOCI: "true"
name: helm-oci
```
When you have update argocd with this config, you should see the following in the settings:
## Automatizing the helm chart release
To prevent making a billion release tags while testing, I setup an alpha and beta mechanism on the helm chart's release system:
- When working on a branch, you immediately bump the version in the Chart.yaml and begin working.
- On every commit, create a tag `<helm chart version>-alpha` that you can use to test on your chart that uses the common dependency
- When you have tested everything, merge to main
- On every commit to main, create a tag `<helm chart version>-beta`
- To do a proper release, tag the commit you want to release with `v<helm chart version>`, this will create the tag `<helm chart version>`
We will write two github action files :
```yaml
## deploy-test.yaml
name: Build image and push to registry
on:
push:
branches:
- '**'
concurrency:
group: ${{ github.ref }}
cancel-in-progress: true
jobs:
package-and-push-common-main:
runs-on: helm-helpers-release-runner
defaults:
run:
working-directory: ./common
steps:
- uses: actions/checkout@v3
- name: Set up Helm
uses: azure/setup-helm@v3
- name: Login to Azure Container Registry
run: |
helm registry login ${{ vars.DOCKER_PROD_REGISTRY }} \
--username ${{ secrets.DOCKER_PROD_USERNAME }} \
--password ${{ secrets.DOCKER_PROD_PASSWORD }}
- name: Get chart version
id: get_chart_version
uses: mikefarah/[email protected]
with:
cmd: yq e '.version' ./common/Chart.yaml
- name: Set calculated chart version
if: ${{ github.ref != 'refs/heads/main' }}
run: |
echo "CURRENT_VERSION=${{ steps.get_chart_version.outputs.result }}-alpha" >> $GITHUB_ENV
- name: Set calculated chart version
if: ${{ github.ref == 'refs/heads/main' }}
run: |
echo "CURRENT_VERSION=${{ steps.get_chart_version.outputs.result }}-beta" >> $GITHUB_ENV
- name: Build and push chart
run: |
helm package . --version "$CURRENT_VERSION"
helm push "common-${CURRENT_VERSION}.tgz" "oci://${{ vars.DOCKER_PROD_REGISTRY }}/helm"
```
and
```yaml
# release.yaml
name: Deploy
on:
push:
tags:
- v*.*.*
concurrency:
group: ${{ github.ref }}
cancel-in-progress: true
jobs:
release:
runs-on: helm-helpers-release-runner
defaults:
run:
working-directory: ./common
steps:
- uses: actions/checkout@v3
- name: Set up Helm
uses: azure/setup-helm@v3
- name: Login to Azure Container Registry
run: |
helm registry login ${{ vars.OCI_REGISTRY_URL }} \
--username ${{ secrets.OCI_REGISTRY_USERNAME }} \
--password ${{ secrets.OCI_REGISTRY_PASSWORD }}
- name: Get chart version
id: get_chart_version
uses: mikefarah/[email protected]
with:
cmd: yq e '.version' ./common/Chart.yaml
- name: Ensure tag matches chart version
run: |
current_version=${{ steps.get_chart_version.outputs.result }}
if [[ "${{ github.ref }}" != "refs/tags/v$current_version" ]]; then
echo "Tag does not match chart version"
exit 1
fi
- name: Build and push chart
run: |
helm package .
helm push *.tgz "oci://${{ vars.OCI_REGISTRY_URL }}/helm"
```
In the latter, I added a check to make sure the tag is matching the actual Chart version (this happened a lot when working with it :)).
---
This article was written in collaboration with the Learning Planet Institute, check them out on [twitter](https://twitter.com/lpiparis_) | nastaliss |
1,911,731 | Writing Virtual Machine Scale Set | INTRODUCTION **VMSS (VIRTUAL MACHINE SCALE SET) **It is a feature in Azure that allows... | 0 | 2024-07-04T14:56:53 | https://dev.to/agana_adebayoo_876a06/writing-virtual-machine-scale-set-c6p | hagital, vmss, cloud, azure | ---
## **INTRODUCTION**
**VMSS (VIRTUAL MACHINE SCALE SET) **It is a feature in Azure that allows you to deploy and manage a group of identical virtual machines (VMs) as a single entity. VMSS is designed for high availability and scalability, making it ideal for applications that require automatic scaling based on demand.
Virtual Machine Scale Sets (VMSS) in Azure provide a service-level agreement (SLA) of up to 99.99 percent for your virtual machines (VMs). This SLA ensures that your VMs deployed within a VMSS will have a high level of availability and reliability.
The SLA guarantees that Microsoft Azure will deliver the specified level of uptime for your VM instances in a VMSS configuration. If Azure fails to meet the SLA, you may be eligible for service credits.
TABLE OF CONTENT
1. INTRODUCTION.
2. CREATING YOUR VMSS VIA AZURE PORTAL.
3. AUTO SCALING CONFIGURATION.
4. NETWORK SETTING.
**CREATING YOUR VMSS VIA AZURE PORTAL**
YOUR SUBSCRIPTION, RESOURCE GROUP AND NAME ARE START U ESSENTIALS IN CREATING YOUR VMs AND VMSS, SUBSCRIPTION NAMES MOST OMES AS DEFAULT WHILE OTHERS CAN BE NAMED ACCORDING TO THE NEED OR ADMINISTRATORS OR AS JOB DEMANDS.
AUTO SCALING MUST BE CONFIGURED AND ADDING SCALING CONDITIONS BASED ON CPU METRIX,
THE FINAL SET UP ON YOUR BASIC PAGE IS TO SELECT YOUR SSH PUBLIC KEY AND AND CREATING YOUR KEY PAIR NAME, SETTINGS ON THE SPOT PAGE.
.
**<u>NETWORK SETTING</u>**
A NETWORK INTERFACE ALLOWS AZURE VIRTUAL MACHINE TO COMMUNICATE WITH THE INTERNET AND CO-PREMISES RESOURCES, A VM CAN HAVE ONE OR MORE RESOURCES.
CLICK ON THE NETWORK NAME AND SELECT LOAD BALANCER.
**CLICK ON CREATE AND REVIEW** TO DEPLOY CREATED RESOURCES AND AFTER FULLY DEPLOYING , GENERATE YOUR NEW PAIR KEY BY DOWNLOADING PRIVATE KEY AND CREATE RESOURCE.
**<u>N.B</u>**
AVAILABILITY IN ZONES CAN AFFECT RATES AND SPECIFICATION SELECTION, WHEN THERE IS A CHALLENGE IN DEPLOYING SUCH RESOURCES IT IS ADVISABLE TO CHANGE OR OPT FOR AN ALTERNATIVE ZONE, THOUGH HIGHER RATES MAY APPLY.
DEPLOYED RESOURCES CAN BE CHECKED ON LINUX FOR STRESS CHECK AND FURTHER DEPLOYMENT.
THE FOLLOWING STEPS WILL TAKE YOU THROUGH WINDOWS **RESIZING OF DEPLOYED RESOURCES**, FOR IMMEDIATE ACTION FOR THE PURPOSE OF LEARNING.
**SUMMARY**
VMSS (Virtual Machine Scale Sets) in Azure is a powerful feature that allows for automatic scaling of virtual machine instances based on demand. By leveraging VMSS, you can ensure that your applications have a reliable and highly available infrastructure to meet your business needs. It provides resiliency against hardware failures and planned maintenance events, distributing VM instances across fault domains and update domains, VMSS is a valuable tool for achieving scalability and reliability in Azure.
| agana_adebayoo_876a06 |
1,911,730 | Leveraging Software Testing As A Service For Enhanced Quality Assurance | Software Testing As A Service: An Overview Software Testing as a Service (STaaS) is an increasingly... | 0 | 2024-07-04T14:54:22 | https://dev.to/saumya27/leveraging-software-testing-as-a-service-for-enhanced-quality-assurance-hf1 | testing, qa |
**Software Testing As A Service: An Overview**
Software Testing as a Service (STaaS) is an increasingly popular model that allows organizations to outsource their software testing needs to third-party providers. This approach offers numerous benefits, including cost savings, access to specialized expertise, and the ability to scale testing efforts as needed. In this article, we will explore the key components and advantages of STaaS, and how it can contribute to the success of your software development projects.
**What is Software Testing as a Service?**
Software Testing as a Service (STaaS) is a cloud-based delivery model where testing activities are performed by an external service provider. These providers offer a range of testing services, including functional testing, performance testing, security testing, and more. STaaS enables organizations to leverage the expertise of professional testers and advanced testing tools without the need for significant in-house resources.
**Key Components of STaaS**
Functional Testing: Ensures that the software functions as expected and meets the specified requirements. This includes testing individual features, user interfaces, and overall system behavior.
**Performance Testing:** Evaluates the software’s performance under various conditions, such as load, stress, and scalability. This helps identify bottlenecks and ensure the application can handle expected user traffic.
**Security Testing:** Assesses the software for vulnerabilities and security flaws that could be exploited by malicious actors. This includes penetration testing, vulnerability scanning, and code reviews.
**Automation Testing:** Utilizes automated testing tools to execute repetitive test cases, improving efficiency and accuracy. Automation testing is particularly useful for regression testing and continuous integration/continuous deployment (CI/CD) pipelines.
**Usability Testing:** Focuses on the user experience, ensuring that the software is intuitive and easy to use. This involves testing the user interface design, navigation, and overall user satisfaction.
Advantages of STaaS
**Cost Savings:** Outsourcing testing to a STaaS provider can reduce the costs associated with hiring and training in-house testers, as well as purchasing and maintaining testing tools and infrastructure.
**Access to Expertise:** STaaS providers employ skilled testers with extensive experience in various testing methodologies and tools. This expertise can enhance the quality and reliability of your software.
**Scalability:** STaaS allows organizations to scale their testing efforts up or down based on project needs. This flexibility ensures that testing resources are available when required, without the need for long-term commitments.
**Faster Time-to-Market:** By leveraging the efficiency of professional testing services, organizations can identify and address defects more quickly, leading to faster release cycles and improved time-to-market.
**Focus on Core Competencies:** Outsourcing testing allows development teams to focus on core activities, such as feature development and innovation, while leaving the testing to experts.
**Conclusion**
Software Testing as a Service (STaaS) offers a compelling solution for organizations looking to enhance their software quality while reducing costs and leveraging specialized expertise. By outsourcing testing activities to professional providers, businesses can benefit from improved efficiency, scalability, and faster time-to-market. As software development continues to evolve, STaaS is likely to play an increasingly important role in ensuring the success of software projects. | saumya27 |
1,911,718 | What is Try-With-Resources, in Java? #InterviewQuestion | What is Try-With-Resources? Try-with-resources in Java is a feature introduced in Java 7... | 0 | 2024-07-04T14:30:37 | https://dev.to/codegreen/what-is-try-with-resources-in-java-1knl | java, errors, interview | ##What is Try-With-Resources?
Try-with-resources in Java is a feature introduced in Java 7 to automatically manage resources that implement `AutoCloseable` or `Closeable` interfaces. It ensures these resources are closed properly after they are no longer needed, even if an exception occurs.
###Example
```java
public class TryWithResourcesExample {
public static void main(String[] args) {
String fileName = "example.txt";
try (FileReader fileReader = new FileReader(fileName);
BufferedReader bufferedReader = new BufferedReader(fileReader)) {
String line;
while ((line = bufferedReader.readLine()) != null) {
System.out.println(line);
}
} catch (IOException e) {
System.err.println("Error reading file: " + e.getMessage());
}
}
}
```
###Explanation
- **Syntax:** Resources are declared within the parentheses of the try statement.
- **Automatic Closing:** After the try block finishes execution, or if an exception occurs, the resources are automatically closed in the reverse order of their creation.
- **Exception Handling:** Any exceptions that occur within the try block can be caught and handled in the catch block as usual.
###Conclusion
Try-with-resources simplifies resource management in Java programs by ensuring that resources are closed properly without needing explicit `finally ` blocks. It improves code readability and reduces the likelihood of resource leaks.
| manishthakurani |
1,910,590 | How to Fetch Data from an API using the Fetch API in JavaScript | Fetching data from an API (Application Programming Interface) is a common task in web development. It... | 0 | 2024-07-04T14:47:20 | https://dev.to/oluwadamisisamuel1/how-to-fetch-data-from-an-api-using-the-fetch-api-in-javascript-21m9 | javascript, programming, beginners, webdev | Fetching data from an API (Application Programming Interface) is a common task in web development. It allows you to get data from a server and use it in your web application.
The `Fetch API` provides a simple and modern way to make HTTP requests in JavaScript. This article will guide you through the basics of using the Fetch API to retrieve data.
## Introduction to the Fetch API
The Fetch API is built into modern browsers and provides a way to make network requests similar to `XMLHttpRequest (XHR)`. However, it is more powerful and flexible. It uses `Promises`, which makes it easier to handle asynchronous operations and avoid `callback hell`.
## Basic Usage
To fetch data from an API, you need to follow these steps:
- Make a request using the fetch function.
- Process the response.
- Handle any errors.
## Making a Request
The fetch function takes a URL as an argument and returns a Promise. Here’s a basic example:
```
fetch('https://api.example.com/data')
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
In this example:
- `fetch('https://api.example.com/data')` initiates a `GET request` to the specified URL.
- `.then(response => response.json())` processes the response and converts it to JSON format.
- `.then(data => console.log(data))` logs the data to the console.
- `.catch(error => console.error('Error:', error))` handles any errors that occur during the fetch operation.
## Handling Different Response Types
The Fetch API allows you to handle various response types, including `JSON`, `text`, and `Blob`. Here’s how to handle the different types:
#### JSON
Most APIs return data in JSON format. You can use the `json()` method to parse the response:
```
fetch('https://api.example.com/data')
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
#### Text
If the API returns plain text, use the text() method:
```
fetch('https://api.example.com/text')
.then(response => response.text())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
#### Blob
For binary data, such as images or files, use the blob() method:
```
fetch('https://api.example.com/image')
.then(response => response.blob())
.then(imageBlob => {
const imageUrl = URL.createObjectURL(imageBlob);
const img = document.createElement('img');
img.src = imageUrl;
document.body.appendChild(img);
})
.catch(error => console.error('Error:', error));
```
## Handling HTTP Methods
The Fetch API supports various HTTP methods, including `GET`, `POST`, `PUT`, and `DELETE`. You can specify the method and other options using an options object.
#### GET Request
A GET request is the default method. Here's how to make a GET request:
```
fetch('https://api.example.com/data')
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
#### POST Request
To send data to the server, use a POST request. Include the method, headers, and body in the options object:
```
fetch('https://api.example.com/data', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({ key: 'value' })
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
#### PUT Request
A PUT request updates existing data on the server. It’s similar to a POST request:
```
fetch('https://api.example.com/data/1', {
method: 'PUT',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({ key: 'updatedValue' })
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
#### DELETE Request
To delete data from the server, use a DELETE request:
```
fetch('https://api.example.com/data/1', {
method: 'DELETE'
})
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
## Handling Errors
Errors can occur during a fetch operation due to network issues, server errors, or invalid responses. You can handle these errors using the `.catch()` method:
```
fetch('https://api.example.com/data')
.then(response => {
if (!response.ok) {
throw new Error('Network response was not ok ' + response.statusText);
}
return response.json();
})
.then(data => console.log(data))
.catch(error => console.error('There has been a problem with your fetch operation:', error));
```
In this example, we check if the response is not ok (status code outside the range 200-299) and throw an error if it’s not.
## Conclusion
The Fetch API is a powerful and flexible tool for making HTTP requests in JavaScript. It simplifies the process of fetching data from an API and handling different response types. By understanding how to use the Fetch API, you can build more dynamic and responsive web applications. Remember to always handle errors gracefully to ensure a smooth user experience. | oluwadamisisamuel1 |
1,911,729 | What are new features of Java 8 #interviewQuestion | New Features in Java 8 Java 8 introduced several significant features: Lambda... | 0 | 2024-07-04T14:46:55 | https://dev.to/codegreen/what-are-new-features-of-java-8-interviewquestion-kmf | java8 | ### New Features in Java 8
Java 8 introduced several significant features:
1. **Lambda Expressions**
* **Syntax:** Lambda expressions enable functional programming.
* **Example:**
```java
List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
names.forEach(name -> System.out.println(name));
```
2. **Stream API**
* **Functional Operations:** Stream API facilitates processing collections with functional-style operations.
* **Example:**
```java
List<String> names = Arrays.asList("Alice", "Bob", "Charlie");
long count = names.stream().filter(name -> name.startsWith("A")).count();
```
3. **Date and Time API**
* **Improved API:** Provides a comprehensive set of classes for date and time manipulation.
* **Example:**
```java
LocalDate today = LocalDate.now();
LocalDateTime dateTime = LocalDateTime.of(today, LocalTime.of(14, 30));
```
4. **Default Methods in Interfaces**
* **Interface Evolution:** Allows adding methods to interfaces without breaking existing implementations.
* **Example:**
```java
public interface MyInterface {
default void defaultMethod() {
System.out.println("Default method implementation");
}
}
```
5. **Optional Class**
* **Null Handling:** Encourages explicit handling of nullable values to avoid \`NullPointerException\`.
* **Example:**
```java
Optional<String> optionalName = Optional.ofNullable(name);
optionalName.ifPresent(System.out::println);
```
Java 8's features promote cleaner code, improved performance, and better support for modern programming paradigms. | manishthakurani |
1,911,728 | VIDEO | How to implement Image Similarity Search with Python | What is Image Similarity Search API? Image Similarity Search API is a powerful tool that... | 0 | 2024-07-04T14:46:27 | https://www.edenai.co/post/how-to-implement-image-similarity-search-with-python | ai, api, python | ## What is [Image Similarity Search API](https://www.edenai.co/feature/similarity-search-apis?referral=how-to-implement-image-similarity-search-with-python)?
[Image Similarity Search API](https://www.edenai.co/feature/similarity-search-apis?referral=how-to-implement-image-similarity-search-with-python) is a powerful tool that allows developers to compare images based on their visual content and retrieve similar images from a database or the web. This technology leverages advanced algorithms to analyze the visual features of images, such as colors, textures, and shapes, and identify similarities between them.
## Image Similarity SearchHow Does it Work?
The Image Similarity Search API works by extracting key features from an input image and comparing them with features from other images in a dataset. It employs techniques like deep learning and computer vision to understand the content of images and measure their similarity.
When a query image is provided to the API, it processes the image and generates a feature vector representing its visual characteristics. Then, it searches through a collection of images to find those with similar feature vectors. The similarity between images is typically measured using distance metrics like Euclidean distance or cosine similarity.
For an in-depth comparison of the top APIs for enhancing visual content analysis, delve into our article "[Best Image Similarity Search Solutions of 2024](https://www.edenai.co/post/best-image-similarity-search-apis?referral=how-to-implement-image-similarity-search-with-python)".
## Diverse Applications of Image Similarity Search
**- E-commerce Optimization:** Online retailers utilize image similarity search to offer personalized product recommendations based on visual similarities, enhancing user experience and driving sales.
**- Efficient Content Management:** Media companies and digital asset platforms employ image similarity search to organize and retrieve images efficiently, streamlining workflow and content categorization processes.
**- Creative Inspiration in Art and Design:** Artists and designers leverage image similarity search to discover visually similar images, artwork, or designs for inspiration, facilitating creative ideation and exploration.
**- Security and Surveillance:** Security agencies utilize image similarity search for suspect identification, object tracking, and pattern analysis across surveillance footage, enhancing crime prevention and investigation capabilities.
## How to use Image Similarity Search on Eden AI
### Step 1: Create an Account on Eden AI
To get started with the Eden AI API, you need to sign up for an account on the Eden AI platform. Once registered, you will get an API key that grants you access to the diverse set of image Similarity providers available on the platform.
_**[Get your API Key for FREE](https://app.edenai.run/user/register?referral=how-to-implement-image-similarity-search-with-python)**_
### Step 2: Choose Your Image Source
Before diving into the code, decide where your query image is located:
**- File URL:** If your image is hosted online, you'll use its URL.
**- Local File:** If your image is stored locally on your machine, you'll provide its file path.
### Step 3: Get the Python Code Snippet
Now, let's get to the code. Depending on your image source choice, you'll use different code snippets.
**Using File URL**
If you're using a file hosted online, here's the Python code snippet:
```
import json
import requests
headers = {"Authorization": "Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoiOWRmYTBmMDEtOTZlNS00ZWVjLTlhMTEtODM4M2Y2YjM0ZTY2IiwidHlwZSI6ImFwaV90b2tlbiJ9.vxdZl0DF2xO9xOnpBwNNXv8XA3D5fOxTX-JEBNlNkqk"}
url = "https://api.edenai.run/v2/image/search/launch_similarity"
json_payload = {
"providers": "sentisight",
"file_url": "🔗 URL of your image"
}
response = requests.post(url, json=json_payload, headers=headers)
result = json.loads(response.text)
print(result["sentisight"])
```
Ensure to replace "🔗 URL of your image" with the actual URL of your image. The image you specify here will be used as the query for the similarity search.
**Using Local File**
If your image is stored locally, use the following code snippet:
```
import json
import requests
headers = {"Authorization": "Bearer your_bearer_token_here"}
url = "https://api.edenai.run/v2/image/search/launch_similarity"
data = {"providers": "sentisight"}
files = {'file': open("🖼️ path/to/your/image.png", 'rb')}
response = requests.post(url, data=data, files=files, headers=headers)
result = json.loads(response.text)
print(result['sentisight'])
```
Replace "🖼️ path/to/your/image.png" with the actual path to your image file. This image will serve as the query for the similarity search.
Additionally, you can change the value of "providers" in both codes to any supported provider on Eden AI you want to use for the image similarity search.
By following these steps, you can harness the power of Eden AI's Image Similarity Search API to find visually similar images with ease. Whether you are working with images hosted online or stored locally, Eden AI provides a seamless and efficient way to integrate image similarity search into your projects. Experiment with different providers and customize the search to suit your specific needs, making the most out of this powerful tool.
## Adding New Images to Your Dataset for Image Similarity Search
In the previous tutorial, we learned how to use the Eden AI Image Similarity Search API to find similar images using a URL or local file. Now, by learning how to add new images to your dataset, you can continually update and refine your image library, making your similarity searches even more effective. Whether you are adding images from an online source or uploading them directly from your device, these steps will help you manage your dataset with ease.
### Step-by-Step Guide
Original Code from Eden AI Documentation
Before we dive into the specific cases, here is the original code from [Eden AI documentation](https://docs.edenai.co/reference/image_search_upload_image_create?referral=how-to-implement-image-similarity-search-with-python):
```
import requests
url = "https://api.edenai.run/v2/image/search/upload_image"
payload = {
"response_as_dict": True,
"attributes_as_list": False,
"show_original_response": False
}
headers = {
"accept": "application/json",
"content-type": "application/json",
"authorization": "Bearer your_bearer_token_here"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)
```
#### Adding Images via URL
When adding images via URL, you send the image URL to the API endpoint, which then processes and adds the image to your dataset.
```
import requests
url = "https://api.edenai.run/v2/image/search/upload_image"
payload = {
"response_as_dict": True,
"attributes_as_list": False,
"show_original_response": False,
"providers": "sentisight,nyckel",
"image_name": "test.jpg",
"file_url": "http://edenai-resource-example.jpg"
}
headers = {
"accept": "application/json",
"content-type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)
```
**Modified Code Example**
Here is how you can modify the code to add an image via URL:
**1. Payload Modifications:** Add "providers", "image_name", and "file_url" to the payload.
- Specify the providers you want to use.
- Provide the name of the image (optional).
- Specify the URL of the image you want to add to your dataset.
**2. Header Modifications:** Remove the "authorization" header since it's not required for URL uploads.
**3. Request Modifications:** Use the "requests.post" method with payload and headers to send the request to the API endpoint.
#### Adding Images via Local File
When adding images from a local file, you need to send the file data directly to the API.
```
import requests
url = "https://api.edenai.run/v2/image/search/upload_image"
payload = {
"response_as_dict": True,
"attributes_as_list": False,
"show_original_response": False,
"providers": "sentisight",
"image_name": "car5.jpeg"
}
headers = {
"authorization": "Bearer dummy_token_for_demo_purposes"
}
files = {'file': open("./Assets/car3.jpeg", "rb")}
response = requests.post(url, data=payload, files=files, headers=headers)
print(response.text)
```
**Modified Code Example**
Here is how you can modify the code to add an image via local file:
**1. Payload Modifications:** Add "providers" and "image_name" to the payload.
- Specify the providers you want to use.
- Provide the name of the image.
2. Header Modifications:
- Ensure that the "authorization" header remains unchanged as it's still required for file uploads.
- Remove "accept" and "content-type" since it is not required for local file uploads.
3. Specify the path to the local file you want to upload.
**4. Request Modifications:** Use the "requests.post" method with both payload, files, and headers to send the request to the API endpoint.
By following these steps, you can easily add new images to your dataset for image similarity search with Eden AI. Keeping your image library updated will enhance the accuracy and relevance of your searches, providing better results over time. Whether you're adding images via URL or local file, Eden AI's API simplifies the process, allowing you to focus on building and refining your application.
## Video Tutorial
To help you visualize these steps, we have prepared a video tutorial demonstrating both how to run an image similarity search and how to add images to your dataset. Watch the video below to follow along and see the process in action:
**_[Watch the video HERE](https://youtu.be/98LowXIr6I4)_**
## Benefits of using Eden AI's unique API
Using Eden AI API is quick and easy.
### Save time and cost
We offer a unified API for all providers: simple and standard to use, with a quick switch that allows you to have access to all the specific features very easily (diarization, timestamps, noise filter, etc.).
### Easy to integrate
The JSON output format is the same for all suppliers thanks to Eden AI's standardization work. The response elements are also standardized thanks to Eden AI's powerful matching algorithms.
### Customization
With Eden AI you can integrate a third-party platform: we can quickly develop connectors. To go further and customize your API request with specific parameters, check out our documentation.
You can see Eden AI documentation [here](https://docs.edenai.co/docs/image-analysis?referral=how-to-implement-image-similarity-search-with-python).
## Next step in your project
The Eden AI team can help you with your Image Similarity Search integration project. This can be done by :
- Organizing a product demo and a discussion to understand your needs better. You can book a time slot on this link: [Contact](https://www.edenai.co/contact?referral=how-to-implement-image-similarity-search-with-python)
- By testing the public version of Eden AI for free: however, not all providers are available on this version. Some are only available on the Enterprise version.
- By benefiting from the support and advice of a team of experts to find the optimal combination of providers according to the specifics of your needs
- Having the possibility to integrate on a third-party platform: we can quickly develop connectors.
_**[Create your Account on Eden AI](https://app.edenai.run/user/register?referral=how-to-implement-image-similarity-search-with-python)**_ | edenai |
1,911,727 | Beginner's Guide to NLP and NLTK 🐍📑 | Natural Language Processing (NLP) is a field of artificial intelligence that focuses on the... | 0 | 2024-07-04T14:45:35 | https://dev.to/kammarianand/beginners-guide-to-nlp-and-nltk-433 | python, nlp, datascience, ai | Natural Language Processing (NLP) is a field of artificial intelligence that focuses on the interaction between computers and humans through natural language. It involves processing and analyzing large amounts of natural language data. One of the popular libraries for NLP in Python is the Natural Language Toolkit (NLTK). This article provides a beginner's guide to NLP and NLTK, along with examples in Python code.
#### What is NLTK?
The Natural Language Toolkit (NLTK) is a powerful Python library used for working with human language data (text). It provides easy-to-use interfaces to over 50 corpora and lexical resources, along with a suite of text processing libraries for classification, tokenization, stemming, tagging, parsing, and more.
#### Installation
First, let's install NLTK. You can do this using pip:
```bash
pip install nltk
```
After installing, you'll need to download the necessary NLTK data. This can be done within a Python script or an interactive shell:
```python
import nltk
nltk.download('all')
```
### Basic NLP Tasks with NLTK
#### 1. Tokenization
Tokenization is the process of breaking text into individual words or sentences.
```python
import nltk
from nltk.tokenize import word_tokenize, sent_tokenize
text = "NLTK is a leading platform for building Python programs to work with human language data."
# Sentence Tokenization
sentences = sent_tokenize(text)
print("Sentences:", sentences)
# Word Tokenization
words = word_tokenize(text)
print("Words:", words)
```
**Output:**
```
Sentences: ['NLTK is a leading platform for building Python programs to work with human language data.']
Words: ['NLTK', 'is', 'a', 'leading', 'platform', 'for', 'building', 'Python', 'programs', 'to', 'work', 'with', 'human', 'language', 'data', '.']
```
#### 2. Stopwords Removal
Stopwords are common words that typically do not carry much meaning and are often removed from text during preprocessing.
```python
from nltk.corpus import stopwords
# Define stop words
stop_words = set(stopwords.words('english'))
# Filter out stop words
filtered_words = [word for word in words if word.lower() not in stop_words]
print("Filtered Words:", filtered_words)
```
**Output:**
```
Filtered Words: ['NLTK', 'leading', 'platform', 'building', 'Python', 'programs', 'work', 'human', 'language', 'data', '.']
```
#### 3. Stemming
Stemming reduces words to their root form.
```python
from nltk.stem import PorterStemmer
ps = PorterStemmer()
stemmed_words = [ps.stem(word) for word in filtered_words]
print("Stemmed Words:", stemmed_words)
```
**Output:**
```
Stemmed Words: ['nltk', 'lead', 'platform', 'build', 'python', 'program', 'work', 'human', 'languag', 'data', '.']
```
#### 4. POS Tagging
Part-of-Speech (POS) tagging involves labeling each word in a sentence with its corresponding part of speech, such as noun, verb, adjective, etc.
```python
from nltk import pos_tag
# POS Tagging
pos_tags = pos_tag(words)
print("POS Tags:", pos_tags)
```
**Output:**
```
POS Tags: [('NLTK', 'NNP'), ('is', 'VBZ'), ('a', 'DT'), ('leading', 'VBG'), ('platform', 'NN'), ('for', 'IN'), ('building', 'VBG'), ('Python', 'NNP'), ('programs', 'NNS'), ('to', 'TO'), ('work', 'VB'), ('with', 'IN'), ('human', 'JJ'), ('language', 'NN'), ('data', 'NNS'), ('.', '.')]
```
#### 5. Named Entity Recognition (NER)
Named Entity Recognition identifies and classifies named entities in text into predefined categories such as person names, organizations, locations, dates, etc.
```python
from nltk.chunk import ne_chunk
# Named Entity Recognition
entities = ne_chunk(pos_tags)
print("Named Entities:", entities)
```
**Output:**
```
Named Entities: (S
(GPE NLTK/NNP)
is/VBZ
a/DT
leading/VBG
platform/NN
for/IN
building/VBG
(GPE Python/NNP)
programs/NNS
to/TO
work/VB
with/IN
human/JJ
language/NN
data/NNS
./.)
```
####6. One-Hot Encoding
Encoding words is a fundamental task in Natural Language Processing (NLP), especially when preparing text data for machine learning models. One common technique for encoding words is through one-hot encoding or using word embeddings like Word2Vec or GloVe. Here's a simple example of how to encode words using one-hot encoding in Python:
Example: One-Hot Encoding
```python
# Example text
text = "This is a simple example of one-hot encoding."
# Split the text into words
words = text.split()
# Create a vocabulary of unique words
vocab = set(words)
# Initialize a dictionary to store one-hot encodings
one_hot_encoding = {}
# Assign a unique index to each word in the vocabulary
for i, word in enumerate(vocab):
one_hot_encoding[word] = [1 if i == j else 0 for j in range(len(vocab))]
# Print the one-hot encoding for each word
for word, encoding in one_hot_encoding.items():
print(f"{word}: {encoding}")
```
**Output:**
```
This: [1, 0, 0, 0, 0, 0, 0]
a: [0, 1, 0, 0, 0, 0, 0]
simple: [0, 0, 0, 1, 0, 0, 0]
example: [0, 0, 0, 0, 1, 0, 0]
is: [0, 0, 1, 0, 0, 0, 0]
of: [0, 0, 0, 0, 0, 1, 0]
encoding.: [0, 0, 0, 0, 0, 0, 1]
```
### Explanation:
1. **Splitting Text**: The example text is split into individual words.
2. **Vocabulary Creation**: Unique words (vocabulary) are identified from the text.
3. **One-Hot Encoding**: Each word in the vocabulary is assigned a unique one-hot encoding vector. The vector has the same length as the vocabulary, with a `1` at the index corresponding to the word's position in the vocabulary and `0` elsewhere.
4. **Printing Results**: Each word along with its one-hot encoding vector is printed.
### Notes:
- **Limitations**: One-hot encoding creates sparse vectors and does not capture semantic relationships between words.
- **Alternative Methods**: Word embeddings like Word2Vec, GloVe, or using pre-trained models (like BERT) provide dense vector representations that encode semantic meaning and context of words.
This example demonstrates a basic approach to encoding words using one-hot encoding, which is useful for understanding the concept and implementing simple text encoding tasks in NLP.
---
#### Sentiment Analysis : using Transformers lib in python
Here's an example of performing sentiment analysis using the `pipeline` function from the `transformers` library by Hugging Face.
### Sentiment Analysis with Transformers
The `transformers` library by Hugging Face provides easy-to-use pre-trained models for various NLP tasks, including sentiment analysis. We'll use the `pipeline` function to perform sentiment analysis on some example text.
#### Installation
First, you need to install the `transformers` library:
```bash
pip install transformers
```
#### Sentiment Analysis Example
Here's how you can use the `pipeline` function for sentiment analysis:
```python
from transformers import pipeline
# Initialize the sentiment analysis pipeline
sentiment_pipeline = pipeline('sentiment-analysis')
# Example text
text = [
"I love using NLTK and transformers for NLP tasks!",
"This is a terrible mistake and I'm very disappointed.",
"The new update is amazing and I'm really excited about it!"
]
# Perform sentiment analysis
results = sentiment_pipeline(text)
# Print the results
for i, result in enumerate(results):
print(f"Text: {text[i]}")
print(f"Sentiment: {result['label']}, Confidence: {result['score']:.2f}")
print()
```
**Output:**
```
Text: I love using NLTK and transformers for NLP tasks!
Sentiment: POSITIVE, Confidence: 0.99
Text: This is a terrible mistake and I'm very disappointed.
Sentiment: NEGATIVE, Confidence: 0.99
Text: The new update is amazing and I'm really excited about it!
Sentiment: POSITIVE, Confidence: 0.99
```
### Explanation
- **Initialization**: We initialize the sentiment analysis pipeline using the `pipeline` function from the `transformers` library.
- **Example Text**: We provide a list of example sentences to analyze.
- **Perform Sentiment Analysis**: The `pipeline` function processes the text and returns the sentiment along with the confidence score.
- **Output**: The results are printed, showing the sentiment (positive or negative) and the confidence score for each sentence.
---
some real-world applications of NLP:
1. **Chatbots and Virtual Assistants**: Assistants like Siri, Alexa, and Google Assistant use NLP to understand and respond to user queries.
2. **Sentiment Analysis**: Used in social media monitoring to analyze public sentiment about products, services, or events.
3. **Machine Translation**: Services like Google Translate use NLP to translate text between languages.
4. **Spam Detection**: Email services use NLP to identify and filter out spam messages.
5. **Text Summarization**: Automatically summarizing long documents or articles.
6. **Speech Recognition**: Converting spoken language into text, used in voice-activated systems.
7. **Text Classification**: Categorizing documents into predefined categories, such as news articles or support tickets.
8. **Named Entity Recognition (NER)**: Identifying and classifying entities like names, dates, and locations in text.
9. **Information Retrieval**: Enhancing search engines to understand user queries better and retrieve relevant information.
10. **Optical Character Recognition (OCR)**: Converting printed text into digital text for processing.
11. **Question Answering**: Building systems that can answer questions posed in natural language, such as IBM's Watson.
12. **Content Recommendation**: Recommending articles, products, or services based on the content of previous interactions.
13. **Autocorrect and Predictive Text**: Enhancing typing experiences on smartphones and other devices.
14. **Customer Support Automation**: Automating responses to common customer inquiries using NLP.
15. **Market Intelligence**: Analyzing market trends and consumer opinions from various text sources like reviews and social media.
---
### Conclusion
This article briefly introduces Natural Language Processing (NLP) and the Natural Language Toolkit (NLTK) library in Python. We covered fundamental NLP tasks such as tokenization, stopwords removal, stemming, POS tagging, and named entity recognition with examples and outputs. NLTK is a versatile library with many more advanced features, and this guide should give you a good starting point for further exploration.
---
About Me:
🖇️<a href="https://www.linkedin.com/in/kammari-anand-504512230/">LinkedIn</a>
🧑💻<a href="https://www.github.com/kammarianand">GitHub</a> | kammarianand |
1,911,726 | What is Cryptojacking - A Beginner's Guide | Cryptojacking refers to the unauthorized use of someone else’s computer, smartphone, tablet, or... | 0 | 2024-07-04T14:41:57 | https://dev.to/bloxbytes/what-is-cryptojacking-a-beginners-guide-e55 | crypto, cryptojacking, blockchain | Cryptojacking refers to the unauthorized use of someone else’s computer, smartphone, tablet, or server to mine cryptocurrency. Hackers achieve this by either persuading the victim to click on a malicious link in an email that loads cryptomining code on the computer or by infecting a website or online ad with JavaScript code that auto-executes once loaded in the victim’s browser. This illicit activity can severely degrade the performance of the infected device and can cause significant financial damage to organizations due to increased electricity and hardware costs.
## Understanding Crypto Development
Crypto development encompasses the creation of new cryptocurrencies, the improvement of existing blockchain technologies, and the development of decentralized applications (DApps). Developers work on building secure and efficient blockchain protocols, enhancing transaction speeds, and improving the scalability of the blockchain networks. They also focus on creating robust wallets and exchange platforms, ensuring the security of transactions, and developing smart contracts that automate processes without intermediaries.
## Types of Cryptojacking Attacks
### Browser-based Cryptojacking
Browser-based cryptojacking, or drive-by cryptomining, occurs when a user visits a website infected with malicious JavaScript code. This code runs in the background, using the visitor’s CPU power to mine cryptocurrency. The victim may not realize their device is being used for mining, although they might notice a decrease in performance or increased fan noise. This attack can be particularly effective as it doesn’t require the user to download or install any software.
### File-based Cryptojacking
File-based cryptojacking involves infecting a user’s device with a malware program that runs in the background, mining cryptocurrency without the user’s knowledge. This malware is often delivered through phishing emails, malicious downloads, or software vulnerabilities. Once installed, the malware connects to a remote server and begins mining cryptocurrency, consuming significant amounts of CPU resources and electricity. This can lead to increased wear and tear on hardware, higher energy bills, and a slower system.
## Common Symptoms of Cryptojacking
### Performance Issues
One of the most noticeable symptoms of cryptojacking is a significant slowdown in device performance. Users may experience lagging applications, slower processing speeds, and overall reduced efficiency. This performance degradation occurs because the cryptomining process consumes a large amount of CPU power, leaving fewer resources available for other tasks.
### Overheating Devices
Cryptojacking causes devices to work harder than usual, leading to increased heat generation. This can result in overheating, which may cause the device’s fans to run continuously at high speed to cool the system down. Overheating can also lead to hardware damage and reduced lifespan of the device.
### Unusual Network Activity
An increase in network traffic can be another indicator of cryptojacking. This occurs because the mining process often involves downloading and uploading large amounts of data. Users may notice unusual spikes in network activity or increased data usage on their devices. Monitoring network traffic can help in identifying and mitigating cryptojacking attacks.
## How to Detect Cryptojacking
### Monitoring Tools
Using specialized monitoring tools can help detect cryptojacking activities. These tools can analyze CPU usage, track unusual network activity, and identify suspicious processes running on the device. By setting up alerts for abnormal behavior, users can quickly respond to potential cryptojacking attempts and mitigate the damage.
### Security Software
Comprehensive security software can provide an additional layer of protection against cryptojacking. Antivirus programs and anti-malware solutions can detect and block malicious scripts and programs designed for cryptojacking. Regularly updating security software ensures that the latest threats are recognized and mitigated promptly.
### Network Analysis
Conducting regular network analysis can help in identifying cryptojacking activities. By monitoring network traffic and analyzing data packets, security teams can spot unusual patterns indicative of cryptomining. Network analysis tools can also help in tracing the source of the attack and implementing measures to prevent future incidents.
## Preventive Measures
### Updating Software and Systems
Keeping software and systems up to date is one of the most effective ways to prevent cryptojacking. Software updates often include security patches that fix vulnerabilities exploited by cryptojacking malware. Regularly updating operating systems, browsers, and applications can significantly reduce the risk of infection.
### Browser Extensions and Ad Blockers
Installing browser extensions and ad blockers can help prevent browser-based cryptojacking. These tools can block malicious scripts and ads that contain cryptojacking code. Some extensions specifically target cryptojacking scripts, providing an additional layer of protection while browsing the web.
### Educating Users
Educating users about the risks and symptoms of cryptojacking is crucial for prevention. By raising awareness about phishing emails, suspicious downloads, and the importance of using strong security practices, organizations can reduce the likelihood of cryptojacking attacks. Regular training sessions and security updates can help keep users informed and vigilant.
## Response Strategies to Cryptojacking Incidents
### Immediate Actions to Take
When cryptojacking is detected, immediate action is required to minimize damage. Disconnect the affected device from the network to prevent further mining activity and data exfiltration. Run a full system scan using updated antivirus software to identify and remove the cryptojacking malware. It’s also essential to change passwords and enable two-factor authentication to secure accounts potentially compromised by the attack.
### Long-term Solutions and Best Practices
Implementing long-term solutions and best practices can help prevent future cryptojacking incidents. Regularly review and update security policies, ensuring they include measures to detect and prevent cryptojacking. Conduct regular security audits and vulnerability assessments to identify and mitigate potential weaknesses. Additionally, consider using endpoint detection and response (EDR) tools to monitor and respond to threats in real-time.
## The Role of Crypto Development in Combating Cryptojacking
### Enhancing Blockchain Security
Crypto development plays a crucial role in enhancing [blockchain security](https://bloxbytes.com/blockchain-security/) and combating cryptojacking. Developers work on creating more secure blockchain protocols that are resistant to attacks. They also develop tools and solutions that help detect and prevent cryptojacking activities. By continuously improving blockchain security, developers can reduce the risk of cryptojacking and protect the integrity of the network.
### Developing Robust Crypto Solutions
Developing robust crypto solutions is essential for preventing cryptojacking. This includes creating secure wallets, implementing strong encryption methods, and developing smart contracts that can detect and prevent unauthorized mining activities. By focusing on security during the development process, developers can create solutions that are less vulnerable to cryptojacking and other cyber threats.
## Future Trends in Cryptojacking and Blockchain Security
### Emerging Threats
As technology evolves, so do the methods used by cybercriminals. Emerging threats in cryptojacking include more sophisticated malware that can evade detection and target a wider range of devices. Hackers may also use artificial intelligence and machine learning to enhance their cryptojacking techniques, making it more challenging to detect and prevent attacks.
### Innovations in Blockchain Solutions
Innovations in [Managed blockchain solutions](https://bloxbytes.com/managed-blockchain-solutions/) will play a vital role in combating cryptojacking. Advances in blockchain technology, such as improved consensus algorithms and enhanced security features, can help prevent unauthorized mining activities. Additionally, new tools and solutions that leverage blockchain’s transparency and immutability can provide more effective ways to detect and respond to cryptojacking incidents.
## Conclusion
Cryptojacking poses a significant threat to both individual users and organizations. Understanding the various types of cryptojacking attacks, recognizing the symptoms, and implementing preventive measures can help mitigate the risk. By leveraging advancements in crypto development and blockchain solutions, the security of blockchain networks can be enhanced, providing a safer environment for all users. Staying informed about emerging threats and innovations in blockchain security will be crucial in the ongoing battle against cryptojacking.
| bloxbytes |
1,911,536 | Do you know Promises in JS ? (Basic) | Introduction Hey forks ! In this blog post, we are going to explore 10 tricky JavaScript... | 0 | 2024-07-04T14:40:32 | https://dev.to/margish288/do-you-know-promises-in-js-basic-1kk6 | javascript, webdev, programming, interview | ## Introduction
Hey forks !
In this blog post, we are going to explore 10 tricky JavaScript questions that test your understanding of Promises and asynchronous behaviour of Javascript.
### What are Promises and how to handle it in JS ?
- JavaScript Promises are a powerful tool for handling **asynchronous operations**.
- They represent a value that may be available now, in the future, or never.
- Promises simplify complex asynchronous code by providing a more readable and maintainable structure. With methods like .then(), .catch(), and .finally(), Promises allow you to chain operations and handle errors gracefully.
- Building on Promises, async and await are syntactic sugar that make asynchronous code look and behave more like synchronous code.
- The async keyword declares an asynchronous function, which returns **a Promise**, while the await keyword **pauses the execution** until the Promise is resolved.
- This modern approach simplifies **error handling** and reduces the need for complex Promise chains, making your code cleaner and more maintainable.
- Understanding Promises and async/await is essential for writing modern, efficient JavaScript code, especially when dealing with APIs, timers, or any asynchronous tasks.
Now let's start solving some basic promise related output based questions which might help you to crack the interviews.
### Example 1:
Code
```
let p = new Promise((resolve, reject) => {
resolve("Hello");
});
p.then(value => console.log(value));
console.log("World");
```
output ✅:
```
World
Hello
```
> Explanation 💡:
- The `console.log("World")` executes immediately.
- The Promise resolves and logs "Hello" after the synchronous code has finished executing.
---
### Example 2:
Code
```
let p = new Promise((resolve, reject) => {
reject("Error");
});
p.catch(error => console.log(error));
console.log("After promise");
```
output ✅:
```
After promise
Error
```
> Explanation 💡:
- The `console.log("After promise")` executes immediately.
- The Promise is rejected and logs "Error" after the synchronous code has finished executing.
---
### Example 3:
Code
```
let p = new Promise((resolve, reject) => {
resolve("First");
});
p.then(value => {
console.log(value);
return "Second";
}).then(value => console.log(value));
console.log("Third");
```
output ✅:
```
Third
First
Second
```
> Explanation 💡:
- The `console.log("Third")` executes immediately.
- The Promise resolves and logs "First", then the chained then logs "Second".
---
### Example 4:
Code
```
let p = Promise.resolve("Success");
p.then(value => {
console.log(value);
throw new Error("Fail");
}).catch(error => console.log(error.message));
console.log("Done");
```
output ✅:
```
Done
Success
Fail
```
> Explanation 💡:
- The `console.log("Done")` executes immediately.
- The Promise resolves and logs "Success", then the error is caught and "Fail" is logged.
---
### Example 5:
Code
```
let p = new Promise((resolve, reject) => {
setTimeout(() => resolve("Timeout"), 1000);
});
p.then(value => console.log(value));
console.log("Immediate");
```
output ✅:
```
Immediate
Timeout
```
> Explanation 💡:
- The `console.log("Immediate")` executes immediately.
- The Promise resolves after 1 second and logs "Timeout".
---
### Example 6:
Code
```
async function asyncFunc() {
return "Async";
}
asyncFunc().then(value => console.log(value));
console.log("Function");
```
output ✅:
```
Function
Async
```
> Explanation 💡:
- The `console.log("Function")` executes immediately.
- The `asyncFunc` resolves and logs "Async" after the synchronous code has finished executing.
---
### Example 7:
Code
```
let p = new Promise((resolve, reject) => {
resolve("Resolved");
});
p.finally(() => console.log("Finally"))
.then(value => console.log(value));
console.log("End");
```
output ✅:
```
End
Finally
Resolved
```
> Explanation 💡:
- The `console.log("End")` executes immediately.
- The Promise finally logs "Finally" and then logs "Resolved".
---
### Example 8:
Code
```
async function asyncFunc() {
return new Promise((resolve, reject) => {
setTimeout(() => resolve("Done"), 500);
});
}
asyncFunc().then(value => console.log(value));
console.log("Start");
```
output ✅:
```
Start
Done
```
> Explanation 💡:
The `console.log("Start")` executes immediately.
The asyncFunc resolves and logs "Done" after 500ms.
---
### Example 9:
Code
```
let p = Promise.resolve("First");
p.then(value => {
console.log(value);
return Promise.resolve("Second");
}).then(value => console.log(value));
console.log("Third");
```
output ✅:
```
Third
First
Second
```
> Explanation 💡:
- The `console.log("Third")` executes immediately.
- The Promise resolves and logs "First", then the chained then logs "Second".
---
### Example 10:
Code
```
async function asyncFunc() {
console.log("Inside function");
return "Async";
}
asyncFunc().then(value => console.log(value));
console.log("Outside function");
```
output ✅:
```
Inside function
Outside function
Async
```
> Explanation 💡:
- The asyncFunc logs "Inside function" immediately.
- The `console.log("Outside function")` executes immediately.
- The asyncFunc resolves and logs "Async" after the synchronous code has finished executing.
---
That’s all from my side, keep practising forks 🔥!!!
🫡See you in next blog.
Happy Coding 💻... | margish288 |
1,911,725 | The Ultimate Self-Updating Monorepo Starter Template! | Motivation: The Beginning of the Journey Every time I embarked on a new side project, I found myself... | 0 | 2024-07-04T14:39:29 | https://dev.to/parthikrb/the-ultimate-self-updating-monorepo-starter-template-83j | webdev, react, monorepo, biome | **Motivation: The Beginning of the Journey**
Every time I embarked on a new side project, I found myself entangled in the tedious process of setting up the basics. Configuring the component library, setting up linting rules, integrating a styling library like TailwindCSS, and establishing a unit testing setup—these tasks were repetitive and cumbersome. The challenge multiplied when building enterprise-level monorepo applications, where laying down a solid foundation consumed a significant chunk of time.
I knew there had to be a better way. This realization sparked my journey to create an open source React monorepo starter template that could automate much of the setup and ongoing maintenance, allowing me to focus on what truly mattered—building great features.
**The Idea Takes Shape**
The vision was clear: I needed a template that could keep itself updated with minimal intervention and leverage the best tools available in the React ecosystem. The goal was to make the initial setup as smooth as possible and ensure that maintenance would not become a burden.
**Choosing the Right Tools**
The first step was selecting the right tools. I wanted to incorporate modern, efficient, and well-supported tools that would streamline development and maintenance.
_Bun_ - Package Manager: I chose Bun for its speed and efficiency. As a package manager, it handles dependencies and scripts remarkably fast, which is crucial for a monorepo setup.
_Vite_ - Bundler: For bundling, Vite stood out due to its lightning-fast performance and instant feedback during development. It drastically reduced the time I spent waiting for builds, making the development process more enjoyable.
_Biome_ - Linter and Formatter: Ensuring code quality is non-negotiable. Biome integrates both linting and formatting, maintaining code consistency across the project with ease.
_Bun Workspace_ - Monorepo Management: Managing multiple packages within a single repository required a robust solution. Bun workspace provided an efficient and unified way to handle monorepo management.
_Renovate_ - Dependency Updater: One of my main goals was to reduce manual maintenance. Renovate automates dependency updates, ensuring my project remains current without constant manual intervention.
_Kodiakhq_ - PR Manager: To manage pull requests efficiently, Kodiakhq came into play. It streamlined the process of integrating changes and updates, further reducing the workload.
**Bringing It All Together**
With the tools selected, it was time to bring everything together into a cohesive template. The process involved a lot of trial and error, tweaking configurations, and ensuring compatibility between tools. The end result was a template that not only simplified the initial setup but also maintained itself over time.
**The Journey in Action**
Cloning the Repository: The first step was to clone the repository from GitHub. This template was now accessible to anyone looking to streamline their React monorepo projects.
```
git clone https://github.com/parthikrb/bun-monorepo-starter-template.git
```
Installing Dependencies: With Bun as the package manager, installing dependencies was swift and efficient.
```
cd bun-monorepo-starter-template
bun install
```
Running the Development Server: Using Vite, the development server was up and running in no time, providing instant feedback and a smooth development experience.
```
bun run dev
```
Exploring the Project Structure: The modular and scalable project structure made it easy to navigate and understand, setting the stage for efficient development.
**_The Road Ahead: Future Enhancements_**
While the template has come a long way, there's still more to do to make it even better. Here are some of the enhancements planned for the pipeline:
_Creating a Comprehensive README_: A well-documented README is essential for any open source project. The plan is to create a detailed README that guides users through the setup process, explains the project structure, and provides examples of how to use the template effectively.
_Leveraging Vitest Workspace for Unit Tests_: Testing is a critical part of any development process. Integrating Vitest, a fast and efficient test runner, into the workspace will provide robust unit testing capabilities, ensuring code reliability and quality.
_Creating Sample Best-in-Class CI Pipelines_: Continuous Integration (CI) pipelines are vital for maintaining code quality and facilitating smooth deployments. Developing sample CI pipelines using tools like GitHub Actions will showcase best practices and help users set up their own efficient CI/CD workflows.
**Reflecting on the Journey**
Creating this React monorepo starter template has been an incredibly rewarding experience. It not only simplified my development process but also had the potential to help other developers facing the same challenges. By automating repetitive tasks and leveraging modern tools, I was able to focus more on innovation and less on setup.
Thank you for following along on my journey. I hope this template helps you as much as it has helped me. Happy coding! | parthikrb |
1,911,724 | Seeking Arabic Open-Source MERN Stack Blog Projects | Hello Dev.to community! I’m currently working on a project to create a blog using the MERN (MongoDB,... | 0 | 2024-07-04T14:37:44 | https://dev.to/mrxmaidx/seeking-arabic-open-source-mern-stack-blog-projects-57ho | Hello Dev.to community!
I’m currently working on a project to create a blog using the MERN (MongoDB, Express.js, React, Node.js) stack and I’m specifically looking for open-source projects or resources available in Arabic. My goal is to build a blog that caters to Arabic-speaking users and developers.
What I'm Looking For:
Open-source MERN stack projects in Arabic.
Projects with documentation or interfaces translated into Arabic.
Any tutorials, guides, or resources focused on the MERN stack for Arabic developers.
How You Can Help:
Share any repositories or projects you know of that fit this description.
Point me to any communities or forums where I might find Arabic-speaking MERN developers.
If you have experience with translating projects or creating Arabic content, I’d love to hear your tips and advice.
Additionally, if there aren’t many resources available, I’m considering taking an existing open-source MERN blog project and translating it into Arabic. If you’re interested in collaborating on this, please let me know!
Thank you for your help!
Best,
[IlYas Maidi] | mrxmaidx |
|
1,911,722 | env0 Workflows: Simplifying Advanced IaC Setups and Managing Dependencies | As infrastructure scales, managing its increasing complexity and the dependencies between different... | 0 | 2024-07-04T14:35:24 | https://www.env0.com/blog/env0-workflows-simplifying-advanced-iac-setups-and-managing-dependencies | devops, infrastructureascode, tooling, cloud | As infrastructure scales, managing its increasing complexity and the dependencies between different components becomes more challenging. This is where the env0 Workflows feature becomes essential, offering a solution to address today's complexities in [Infrastructure as Code](https://www.env0.com/blog/infrastructure-as-code-101) (IaC) workloads.
In this write-up, we’ll discuss the capabilities, use cases, and features of Workflows in detail.
**What are env0 Workflows?**
============================
[env0](https://www.env0.com/) Workflows provide a structured approach to managing groups of related environments by defining their dependencies and orchestrating the entire process. This ensures that all dependencies are satisfied and the workflow runs smoothly from start to finish.
Workflows are particularly useful for managing systems divided into multiple sub-systems, allowing you to oversee the entire system as a cohesive unit while retaining control over individual stacks. They simplify the process of breaking down IaC stacks into smaller, more manageable parts.
With Workflows, you can describe complex deployment relationships and initiate partial or full runs to create and update sub-environments.
This ensures proper sequencing of resource deployment and allows changes to any sub-environment to auto-update dependent components.
Workflows also help manage environment variables and sensitive credentials across different stacks, ensuring consistency and security.
Whether your IaC is monolithic or split into microservice-based stacks, Workflows are a massive step forward in describing and managing complex deployments.
> **_Disclaimer_**
> Workflows is an Enterprise plan feature. Visit here to learn more about [env0 pricing and plans](https://www.env0.com/pricing).
**How Workflows Work**
======================
A workflow is based on a [workflow template](https://docs.env0.com/docs/create-a-new-workflow#creating-a-workflow-in-the-ui) along with the IaC stack templates that you intend to deploy in your workflow environment.
The Workflow YAML file, **env0.workflow.yml**, is used to define the hierarchy of the dependencies and configuration of IaC sub-environments within a workflow declaratively.
To better understand how Workflows work, let us take an example.
Below is the definition of the **env0.workflow.yml** consisting of two environments that deploy VPC, and an EC2 instance that depends on that VPC:
environments:
vpc:
name: 'Virtual Network'
templateName: 'VPC'
vm:
name: 'VM'
templateName: 'EC2'
needs:
- vpc
This method works when we have the respective IaC templates created in place for Virtual Network and VM stacks.
It is also important to note that each Workflow sub-environment can also reference the directories for individual IaC components, not only from different repositories but even from different VCS providers.
Let’s take the same example above to make it clearer.
Here we are referencing the VPC directory from our GitHub VCS repo and the EC2 directory from our Gitlab VCS repo to define our sub-environments in the Workflow YAML:
environments:
vpc:
name: 'Virtual Network'
vcs:
type: 'terraform'
terraformVersion: '1.5.7'
repository: 'https://github.com/adityamurali155/env0-workflow-example'
path: 'vpc'
vm:
name: 'VM'
vcs:
type: 'terraform'
terraformVersion: '1.5.7'
repository: 'https://gitlab.com/adityamurali155/env0-workflow-example'
path: 'ec2'
needs:
- vpc
Notice the **needs** block makes one environment dependent on another (EC2 depends on VPC, in this case). You can add more [parameters](https://docs.env0.com/docs/create-a-new-workflow) as you see fit to define your custom Workflow YAML file.
Following on the template creation approach, with our VPC and EC2 templates now in place, we are set to develop our workflow template, which references the **env0.workflow.yml** file located in the root directory of our repository.
The next step is to deploy a workflow environment using our workflow template. This workflow environment shows us a vivid dependency graph that illustrates the relationship between our Virtual Network and VM sub-environments.
In this example, no variables or information are shared between the sub-environments. This presents an opportunity to leverage the Workflows' core capability of [Environment Outputs](https://www.env0.com/blog/environment-output-variables-easy-and-secure-output-piping), which allows one IaC sub-environment's output to serve as another's input.
For instance, you can output the VPC subnet ID from the Virtual Network environment and use it as input for the VM environment, ensuring the EC2 instance is deployed into the correct VPC.
This method facilitates the secure transfer of sensitive credentials or data between sub-environments dynamically via the env0 platform abd eliminates the need for local storage of sensitive information or hard-coded variables in your IaC -enhancing the security of your sub-environments.
We’ll go into the detailed mechanics of Workflows with Environment Outputs in a moment.
**Advantages of env0 Workflows**
================================
The capabilities of Workflows prove to be invaluable, particularly in scenarios like those discussed below:
* **Dependency Management:** As emphasized earlier, Workflows excels at managing dependencies between different environments. The Workflow YAML file allows you to declaratively define all the IaC stacks you plan to deploy and specifies any dependencies between them. Additionally, Workflows visually represent these dependencies, making it easier to understand and manage complex infrastructure setups. This visual aid simplifies troubleshooting and planning, enhancing overall deployment efficiency.
* **Targeted Deploy/Destroy:** With env0 Workflows, you can deploy or destroy specific parts of your infrastructure without affecting the entire workflow. This partial or selective deployment feature is handy in scenarios where you might only need to update or roll back certain IaC components. You could also destroy a specific IaC environment without affecting others, reducing the risk of unintended changes to other parts of your infrastructure.
* **Multiple IaC Tools Support:** Workflows enable teams to use different IaC tools within the same workflow. For instance, one team can use Terraform to provision infrastructure, while another team uses CloudFormation. Both teams can still share environment variables or sensitive credentials through Environment Outputs for their infrastructure, ensuring seamless collaboration and integration.
* **Custom integration:** Workflows can seamlessly integrate with other env0 features, such as [custom flows](https://docs.env0.com/docs/custom-flows), [drift detection](https://docs.env0.com/docs/drift-detection), and [approval policies](https://docs.env0.com/docs/approval-policies). For example, you can configure custom flows to run hooks (like installing a web server) after deploying an EC2 IaC stack in a workflow.
You can also configure the workflow to run policies using an [OPA plugin](https://docs.env0.com/docs/opa-plugin) after every environment is deployed to ensure meeting security and compliance requirements.
**Practical Example**
=====================
Now, let us delve into a practical working example of how Workflows operate.
Here are three environments where we need to deploy a Virtual Network, an AKS cluster that depends on the virtual network, and a Helm chart that installs FluxCD, which depends on the AKS cluster.
The respective **env0.workflow.yml** looks like this:
environments:
vnet:
name: 'Virtual Network'
templateName: 'Virtual Network'
aks:
name: 'AKS Cluster'
templateName: 'AKS Cluster'
needs:
- vnet
flux:
name: 'Flux Installation'
templateName: 'FluxCD'
needs:
- aks
First, make sure that you have created your IaC stack templates:
Create your [workflow template](https://docs.env0.com/docs/create-a-new-workflow#creating-a-workflow-in-the-ui) and select **Run Now** to create a workflow environment.
Make sure that your environment name exactly matches that of the name defined in the Workflow YAML file.
We have defined the subnet ID as an output value to be used by the AKS cluster in the VNet config, and the subnet ID as an input value in the AKS config.
#vnet config
output “aks_subnet_id” {
value = azurerm_subnet.az-subnet.id
description = "Output the subnet ID to AKS cluster"
}
# aks config
variable "vnet_subnet_id" {
type = string
description = "Take the subnet ID as input."
}
Before deploying the VNet environment, we’ll switch to the AKS environment and set the input value for the AKS environment (**vnet\_subnet\_id**) as the environment output value of the VNet environment (**aks\_subnet\_id**):
Similarly, the Flux environment expects input values from the AKS environment, and the outputs are defined in the AKS config.
#aks config
output "host" {
value = module.cluster.cluster_fqdn
sensitive = true
}
output "client_certificate" {
value = module.cluster.client_certificate
sensitive = true
}
output "client_key" {
value = module.cluster.client_key
sensitive = true
}
output "cluster_ca_certificate" {
value = module.cluster.cluster_ca_certificate
sensitive = true
}
#flux config
variable "aks_cluster_fqdn" {
type = string
}
variable "aks_client_certificate" {
type = string
sensitive = true
}
variable "aks_client_key" {
type = string
sensitive = true
}
variable "aks_cluster_ca_certificate" {
type = string
sensitive = true
}
We’ll switch to the Flux environment and set our input variables.
Here, we are able to pass sensitive Kubernetes connection credentials as environment output to Helm for configuring and installing flux in our AKS cluster.
> Note: Environment Outputs cannot be marked as sensitive in UI on the fly. Therefore, it is necessary to make the sensitive variables marked as “sensitive=true” in your IaC config itself.
Lastly, after configuring all the values, we switch to the VNet environment (as it should deploy first) and run the workflow:
After a while, we can see our entire workflow functioning properly:
### **Less is More: Partial Workflow Deployment**
Often, we might forget to set up values correctly between different environments. Redeploying all environments to fix these issues is not ideal and can be time-consuming.
With [Partial Workflow Deployment](https://docs.env0.com/docs/workflow-partial-deployment), you can redeploy or destroy a single sub-environment without affecting others.
Let's consider the previous example and take a scenario where we forgot to configure the environment output for the AKS environment.
In this case, the workflow would fail, as it relies on these outputs to function correctly.
To solve this issue, navigate to the AKS environment, configure the environment output, then click on the three dots in the AKS cluster block and select the **Run from here** option.
We will select the AKS cluster and re-run the environment. After this, we can confirm that our workflow is operating correctly again.
**Additional Use Cases**
========================
There are more possibilities for utilizing Workflows than what we have explored so far. Here are key use cases to consider:
### **1\. Multi-tool Setup**
As infrastructure grows more complex with the business expansion, different teams may handle multiple environments.
For example, one team can manage the DB stack and its dependencies (Billing and Configuration Services), while another team handles the EKS stack and its dependencies (Configuration and Notification Services).
Over time, as organizations scale, IaC deployments can grow even more intricate than the example we saw above. However, by using Workflows to define your IaC resources in a declarative approach, you can efficiently manage and track your entire IaC stack. Due to a clear presentation of their IaC stack statuses, the teams can collaborate and ensure smoother operations.
### **2\. Bulk Operations**
Bulk operations refer to performing the same operation across multiple environments or resources simultaneously.
In this example, the EC2 and S3 environments depend on an IAM role, both configured with a **Deny** effect for any operation on SNS topics. Later, the team decides to change the IAM role policy to **Allow** operations on the SNS topics, enabling the necessary permissions for EC2 and S3 environments to interact with those topics.
Utilizing Workflows simplifies making changes to one environment, automatically applying them to all dependent environments.
This streamlines tasks such as updating software versions, applying security patches, and modifying configurations across multiple IaC environments, thereby reducing the time these tasks take.
**Wrap Up**
===========
In conclusion, env0 Workflows stand out as a powerful and efficient way to manage complex infrastructure setups and dependencies in an Infrastructure-as-Code (IaC) environment.
Interested to learn more? [Schedule a technical demo](https://www.env0.com/demo-request) to see env0 in action! | env0team |
1,911,720 | Abrazo virtual | Check out this Pen I made! | 0 | 2024-07-04T14:33:40 | https://dev.to/tarik_oxte_3859fa8e793ba1/abrazo-virtual-1e5o | codepen | Check out this Pen I made!
{% codepen https://codepen.io/TARIK-OXTE/pen/KKjPaBp %} | tarik_oxte_3859fa8e793ba1 |
1,911,716 | Exploring Innovations in Insect Protein Market Landscape | In recent years, the global food industry has witnessed a notable shift towards sustainable and... | 0 | 2024-07-04T14:27:53 | https://dev.to/ganesh_dukare_34ce028bb7b/exploring-innovations-in-insect-protein-market-landscape-2c90 | In recent years, the global food industry has witnessed a notable shift towards sustainable and alternative protein sources. Among these, insect protein has emerged as a promising contender, offering a range of benefits from environmental sustainability to nutritional richness.
This article explores the evolving landscape of the [insect protein market](https://www.persistencemarketresearch.com/market-research/insect-protein-market.asp), highlighting key innovations, market trends, and the potential impact on the future of food.
The Rise of Insect Protein
Historically, insects have been consumed in various cultures worldwide for their nutritional value. In Western markets, however, the idea of insects as a mainstream food source has only gained traction in recent decades, driven largely by environmental concerns and the search for sustainable protein alternatives.
Environmental Benefits
One of the primary drivers behind the growing interest in insect protein is its significantly lower environmental footprint compared to traditional livestock farming. Insects require minimal land, water, and feed to cultivate, making them a highly efficient protein source. For instance, crickets require six times less feed than cattle to produce the same amount of protein, and they emit fewer greenhouse gases.
Nutritional Profile
In addition to being environmentally friendly, insects are nutritionally dense. They are rich in protein, healthy fats, vitamins, and minerals, making them a valuable addition to diets worldwide. For example, mealworms are high in protein, containing all essential amino acids necessary for human health.
Innovations Driving Market Growth
Several innovations are shaping the rapid expansion of the insect protein market:
Product Diversification
Initially, insect protein was predominantly available in whole or powdered form. However, innovative companies have begun to incorporate insect protein into a wide range of food products, including energy bars, pasta, snacks, and even beverages. This diversification not only expands consumer accessibility but also helps normalize the concept of eating insects in Western markets.
Technology and Farming Methods
Advancements in farming techniques have also played a crucial role in scaling insect protein production. Controlled environment agriculture (CEA), vertical farming, and automated systems have optimized efficiency and reduced costs, making insect protein more economically viable for large-scale production.
Culinary Innovation
Chefs and food scientists are exploring creative ways to incorporate insect protein into gourmet dishes, appealing to consumers' taste preferences and culinary sensibilities. This approach helps overcome the psychological barrier associated with consuming insects and enhances acceptance in mainstream food culture.
Market Challenges and Opportunities
Despite its growth trajectory, the insect protein market faces several challenges:
Regulatory Hurdles
Navigating regulatory frameworks remains a significant challenge for insect protein companies, particularly in Western markets where food safety standards and consumer acceptance are stringent. Clear guidelines and regulatory support are crucial for industry growth.
Consumer Perception
Overcoming consumer skepticism and cultural aversions to eating insects represents another hurdle. Education campaigns highlighting the environmental and nutritional benefits, as well as tasteful product presentation, are essential to shifting consumer perceptions.
Future Outlook
Looking ahead, the future of the insect protein market appears promising. Continued research and development, coupled with increasing consumer awareness of sustainability issues, are expected to drive market expansion. Innovations in processing technologies, flavor masking, and product integration will likely further accelerate consumer adoption.
Conclusion
In summary, the insect protein market is at a pivotal stage of growth, driven by sustainability concerns, technological advancements, and evolving consumer preferences. While challenges persist, such as regulatory hurdles and consumer perception, ongoing innovation and market expansion efforts are positioning insect protein as a viable and sustainable protein source for the future. As awareness grows and acceptance increases, insect protein has the potential to play a significant role in addressing global food security challenges while promoting environmental stewardship. | ganesh_dukare_34ce028bb7b |
|
1,911,715 | Monad Transformer in Java for handling Asynchronous Operations and errors (Part 2) | Introduction In the previous part we explained what is a monad, a monad transformer and... | 0 | 2024-07-04T14:25:45 | https://dev.to/billsoumakis/monad-transformer-in-java-for-handling-asynchronous-operations-and-errors-part-2-1pfk | programming, learning, java | ## Introduction
In the previous [part](https://dev.to/billsoumakis/monad-transformer-in-java-for-handling-asynchronous-operations-and-errors-4hoj) we explained what is a monad, a monad transformer and demonstrated the importance of the `TryT` monad transformer.
In this part we are going to introduce another monad transformer called `EitherT`.
## What is EitherT
`EitherT` is a monad transformer that encapsulates an `Either` monad inside a `CompletableFuture`.
This combination allows for chaining and composing asynchronous computations that may fail, using functional programming principles. The Either monad represents a value of one of two possible types. Instances of `Either` are either an instance of Left or Right.
* Left is typically used to represent an error or failure.
* Right is used to represent a success or valid result.
By wrapping an `Either` in a `CompletableFuture`, `EitherT` enables the handling of asynchronous operations that can fail or succeed in a functional way.
## Problems solved by `EitherT`
* Error Propagation: Propagates errors through the computation chain without the need for weird error-checking code.
* Composability: Allows for the composition of multiple asynchronous operations, each of which may fail, in an easy to work manner.
* Simplified Error Recovery: Provides straightforward mechanisms to recover from errors.
## Implementation
{% embed https://gist.github.com/VassilisSoum/0ce2425ea35b6e36e26b01054913a894 %}
## Examples
1. Basic usage
```java
import io.vavr.control.Either;
public class EitherTExample {
public static void main(String[] args) {
EitherT<String, Integer> successfulComputation = EitherT.right(42);
EitherT<String, Integer> failedComputation = EitherT.left("Error occurred");
successfulComputation.getFuture().thenAccept(result ->
System.out.println("Success: " + result)
);
failedComputation.getFuture().thenAccept(result ->
System.out.println("Failure: " + result)
);
}
}
```
In this example, we create two `EitherT` instances: one representing a successful computation and the other a failure. We then use the getFuture() method to access the underlying `CompletableFuture` and handle the results accordingly.
2. Composing Asychronous computations
```java
import java.util.concurrent.CompletableFuture;
import java.util.function.Function;
public class EitherTComposition {
public static void main(String[] args) {
EitherT<String, Integer> computation1 = EitherT.right(10);
EitherT<String, Integer> computation2 = computation1.flatMap(value -> EitherT.right(value * 2));
EitherT<String, Integer> computation3 = computation2.flatMap(value -> EitherT.right(value + 5));
computation3.getFuture().thenAccept(result ->
result.fold(
error -> System.out.println("Error: " + error),
value -> System.out.println("Success: " + value)
)
);
}
}
```
3. Error recovery and handling
```java
import java.util.function.Function;
public class EitherTErrorRecovery {
public static void main(String[] args) {
EitherT<String, Integer> failedComputation = EitherT.left("Initial error");
Function<String, EitherT<String, Integer>> recoverFunction = error -> EitherT.right(100);
EitherT<String, Integer> recoveredComputation = failedComputation.recoverWith(recoverFunction);
recoveredComputation.getFuture().thenAccept(result ->
result.fold(
error -> System.out.println("Error: " + error),
value -> System.out.println("Recovered Success: " + value)
)
);
}
}
```
## Conclusion
The `EitherT` class is a powerful tool for managing asynchronous computations and error handling in Java and it shows us that it is not hard to embrace functional programming constructs and philosophy in Java. | billsoumakis |
1,911,644 | DIFFERENCE BETWEEN FUNCTIONAL AND NON-FUNCTIONAL TESTING | The functional and non-functional testing both are necessary and important categories of software... | 0 | 2024-07-04T14:20:13 | https://dev.to/syedalia21/difference-between-functional-and-non-functional-testing-4cn6 |
The functional and non-functional testing both are necessary and important categories of software testing that help ensure the quality and reliability of a software application
## Functional Testing:-
Functional testing focuses on verifying that the software functions correctly according to its specifications. The majority of this testing is done in a black box manner without touching the source code of the application.
**Unit Testing:** Testing individual components or functions in isolation.
**Integration Testing:** Verifying that different components/modules work together as expected.
**System Testing:** Testing the entire system to ensure it meets the specified requirements.
**User Acceptance Testing (UAT):** Checking if the software satisfies user requirements and expectations.
## Non-Functional Testing:-
Non-functional testing its focuses on characteristics like performance, usability, reliability, and scalability.
**Performance Testing:** Evaluating how well the software performs under various conditions (e.g., load testing, stress testing).
**Usability Testing:** Assessing the user-friendliness of the software and its user interface.
**Security Testing:** Identifying vulnerabilities and ensuring the software is secure.
**Reliability Testing:** Testing the software’s stability and its ability to recover from failures.
**Scalability Testing:** Measuring how the software handles increased load or data volume.
## Example of Functional and Non Functional Testing
## Functional Testing Example:
For example for "Amazon" is the checkout process. In functional testing, we focus on this process to ensure it works as expected.
## Test Scenarios:
1. Adding items to the cart: Users can select and add products to their shopping cart.
2. Applying discounts: The system correctly applies discount codes before finalizing the purchase.
3. Checkout process: The application successfully processes payment information and completes the order.
4. In each case, input specific data (e.g., product selection, discount code), and verify that the output matches expectations (e.g., cart total updates, discount applied, order confirmation received).
## Non-Functional Testing Example:
For example for A mobile banking application is preparing for a major update. The development team conducts non-functional testing to ensure the update meets high performance, security, and usability standards.
**Security Testing:** Tests are performed to identify and fix vulnerabilities, ensuring user data is protected against unauthorized access.
**Performance Testing:** The application is tested under peak load conditions to guarantee smooth transactions during high traffic periods, like holidays.
**Usability Testing:** Feedback from a diverse user group is collected to refine the app’s interface, making it intuitive and easy to navigate for all users.
This focused approach to non-functional testing ensures the banking app is secure, efficient, and user-friendly, maintaining user trust and satisfaction with every update. | syedalia21 |
|
1,911,642 | How Google Ads Help to Boost Physiotherapy Services | Marketing in the present day has gone beyond conventional techniques, to highly sophisticated... | 0 | 2024-07-04T14:16:56 | https://dev.to/davidsmith45/how-google-ads-help-to-boost-physiotherapy-services-2ge4 |
Marketing in the present day has gone beyond conventional techniques, to highly sophisticated techniques such as Google Ads. When it comes to physiotherapy clinics, there is lot one can actually gain from Google Ads in terms of visibility and bookings of clients in relation to the delivery of services. Here, the author explores directions for change through the utilisation of Google Ads for physiotherapy services and the ways to leverage its opportunities.
## 1 Introduction to Google Ads for Physiotherapy Services
Promoting physiotherapy services and reaching the target patients requires having an online platform where the information about the services is likely to be viewed frequently and accessed quickly. Marked as useful here is the platform that has gained popularity over the years, and it is known as Google Ads.
Google Ads formally Google AdWords is an online advertising program launched by Google company. It enables firms to place their advertisements on Google’s search engine and other affiliated Google sites. For physiotherapy clinics that have an online presence, this can imply that potential patients will be able to discover the services you offer when they search for the keywords. This lies in the keyword “physiotherapy ads”, which works to make sure that your clinic is returned in the right searches.
## 2. Increased Visibility and Reach
On the same note, a major plus of employing Google Ads for physiotherapy services is the issue of visibility. When people look for phrases such as ‘physiotherapy available nearby’ or ‘the best physiotherapy services’ your ad will be shown to the target audience at the top of the page, before the actual search results. This prime positioning means that your clinic is among the first options that users are likely to interact with, thereby enhancing your chances of procuring new clients.
## 3. Targeted Advertising
Connections available at Google Ads are detailed so that [physiotherapy](https://www.physiomarketinggroup.com/services/ppc-ads/) clinics can target the appropriate audience successfully. In its current state, it’s possible to advertise depending on the following: location, age, gender, interests, and device type. For instance, if you are a physiotherapy clinic and you mainly deal with sport-related injuries then you can market your clinic to those who are into sports activities within your region. This specific niche makes certain the people who are most probably going to require your products see your advertisements.
## 4. Cost-Effective Marketing
Thus, Google Ads is not like many traditional forms of advertising that ad people would normally associate with as it runs on a pay-per-click basis. This is because the only time one has to make a payment is when the specific link is clicked, which makes it relatively cheap for everyone. It means that you can choose a variant according to your financial possibilities, and Google Ads has instruments that allow orienting on using of money. This flexibility ensures that any amount that you spend on advertising is well utilized to its maximum potential.
## 5. Keyword Optimization
Keywords, as you might guess, represent a critical factor that significantly influences the performance of your physiotherapy ads. It is pertinent to incorporate common search phrases used by people whenever they search for physiotherapy and physical therapy services, for instance, using popular search terms such as “Physiotherapy clinic,” “Back pain treatment” or “Sports injury therapy” in your ads and any other pages that the client might land on. There are places such as Google Keyword Planner that can assist in identifying other successful keywords assigned to the services offered. Through keywording your ads appropriately, then the ad you placed will be more relevant to the subject matter and hence it will feature more often on the clients’ screen.
## 6. Ad Extensions
Google Ads allows many ad extensions that may help increase the effectiveness of physiotherapy ads. Features like the call buttons, location information, and other site links can contribute to increasing the amount of information and attraction in your ad. For instance, call extension enable potential patients to call the clinic directly from the ad without many difficulties. In the same way, a location extension may assist users in locating your clinic’s address or even get timely directions hence making it easier for potential patients/visitor to visit.
## 7. Landing Page Optimization
The landing page is a single page which is viewed after a visitor has clicked a link on a social media platform, blog post or ad; this page is thus very important in converting clicks to appointments. If physiotherapy indicates the service you offer, when people click on your ads, they should be led to a page where you give brief and concise information. Make sure that your landing page contain nuts and bolts data about the condition, a convincing patient survey on the advantages of additional patient Listerine usage together with a clear CTA as “Book an Appointment Now”.
## 8. Measuring and Analyzing Performance
As for Google Ads, it offers enough service for the evaluation of ad campaigns’ effectiveness and this information can be refreshed in real-time. Others are click-through rate (CTR), conversion rate as well as cost per click (CPC) give an insight to the effectiveness of the ads. Such evaluative data can help define what types of promotion strategies have been successful and in what areas adjustments are needed. It also lets you enhance the efficiency of your campaigns incrementally, which is always helpful for the data scientist or the business owner.
Google AdWords provides a constantly evolving method that any physiotherapy clinic can use in order to increase its visibility on the Internet, attract new customers, and expand its circle of customers. Thus, to provide effective physiotherapy ads that deliver real results, there is a need to incorporate targeted advertising, the right keywords, and performance evaluation. Google Ads, in a competitive environment, makes all the difference that your clinic requires to succeed.
Implementing these strategies in your marketing approach helps in achieving the desired visibility of the clinic while at the same time enhancing the clinic’s Online branding thus enabling patients to easily locate and opt for its services. Target your physiotherapy practice with Google Ads now, and see the difference in your business.
| davidsmith45 |
|
1,911,641 | In-depth Analysis of Chrome's Core | 1. Introduction The Chrome core, also known as the Blink engine, is a rendering engine... | 0 | 2024-07-04T14:16:36 | https://dev.to/happyer/in-depth-analysis-of-chromes-core-1a8i | webdev, web, website, development | ## 1. Introduction
The Chrome core, also known as the Blink engine, is a rendering engine developed by Google for the Chrome browser. It is responsible for parsing HTML, CSS, and JavaScript code and converting it into visual web content. Blink is based on the WebKit project and has undergone extensive optimization and improvements to provide higher performance and richer features. This article will delve into the technical architecture of the Chrome core, detailed technical analysis, performance optimization of the V8 JavaScript engine, and developer tools and debugging features. Additionally, it will introduce the AI large model Gemini Nano built into Chrome version 127 and its application scenarios, showcasing the latest advancements in the intelligent capabilities of the Chrome browser.
## 2. Overview of Chrome Core
The Chrome core, also known as the Blink engine, is a rendering engine developed by Google for the Chrome browser. It is responsible for parsing HTML, CSS, and JavaScript code and converting it into visual web content. Blink is based on the WebKit project and has undergone extensive optimization and improvements to provide higher performance and richer features.
## 3. Technical Architecture Overview
The technical architecture of the Chrome core can be roughly divided into the following layers:
1. **Low-level Rendering Engine**: Responsible for handling basic web standards such as HTML and CSS, including tasks like layout, style computation, and rendering.
2. **JavaScript Engine**: The V8 JavaScript engine is one of the core components of the Chrome core. It is responsible for parsing and executing JavaScript code, providing an efficient runtime environment.
3. **Web API Layer**: Provides a series of APIs for interacting with the browser, allowing developers to control the browser's behavior using JavaScript, such as manipulating the DOM and managing network requests.
4. **Rendering Layer**: Converts the computed layout information into actual pixels displayed on the screen.
## 4. Detailed Technical Analysis
### 4.1. Layout and Style Computation
During the layout phase, the Chrome core calculates the position and size of each DOM element on the page. This process involves complex algorithms that need to consider various factors such as the box model, floating elements, and positioned elements. Style computation occurs after the layout phase, determining the visual style of each element, such as color, font, and border.
#### 4.1.1. Layout
The goal of the layout phase is to calculate the precise position and size of each DOM element on the page. The Chrome core uses algorithms based on the Flexbox and Grid layout models to handle complex layout requirements. The main steps of the layout process are as follows:
1. **Constructing the DOM Tree**: The browser first parses the HTML document and constructs the DOM tree structure.
2. **Style Parsing and Computation**: The browser then parses the CSS styles and applies them to the DOM elements. This process involves extensive calculations, such as computing the final styles and box model calculations.
3. **Layout Recursion**: Starting from the root node, the browser recursively traverses the DOM tree, calculating the layout information for each element, including position, size, and float status.
4. **Generating Layout Results**: Finally, the browser generates an object tree containing the layout information for all elements, known as the render tree.
#### 4.1.2. Style Computation
The style computation phase involves applying CSS styles to DOM elements. This process includes the following key steps:
1. **Reading CSS Styles**: The browser reads CSS style rules from external resources (such as CSS files and `<style>` tags).
2. **Constructing the CSSOM Tree**: The browser parses the CSS style rules into a CSS Object Model (CSSOM) tree structure, similar to the DOM tree but representing CSS rules instead of DOM elements.
3. **Computing Styles**: The browser traverses the DOM tree, applying the styles of parent and ancestor elements to the current element. This process involves rules such as inheritance and cascading.
4. **Generating Computed Styles**: Finally, the browser generates an object containing all effective styles for each DOM element, known as the computed style.
### 4.2. Rendering Process
#### 4.2.1. Key Rendering Process
When a user requests a webpage, the rendering process of the Chrome core is roughly as follows:
1. **Loading the Webpage**: After receiving the HTTP response, the browser starts parsing the HTML document.
2. **Constructing the DOM Tree**: The HTML parser converts tags into DOM nodes and constructs the DOM tree.
3. **CSS Parsing and Style Computation**: The CSS parser parses the CSS, generates the CSSOM tree, and combines it with the DOM tree to compute the final styles for each DOM node.
4. **Layout**: Based on the computed styles, the position and size of each element are determined.
5. **Painting**: The DOM tree is converted into a render tree, and painting is performed according to the render tree's instructions.
6. **Compositing and Displaying**: The painted layers are composited and finally displayed on the screen.
#### 4.2.2. Performance Optimization
To improve rendering performance, the Chrome core employs various optimization strategies:
- **Layer Compositing**: Promoting frequently repainted elements to independent layers to reduce unnecessary repaints.
- **Hardware Acceleration**: Utilizing the GPU for rendering to increase painting speed.
- **Lazy Loading**: Delaying the loading of elements not in the viewport to reduce initial load time.
#### 4.2.3. Rendering Technical Details
- **Reflow and Repaint**: Reflow refers to layout changes that require recalculating the position and size of elements, while repaint refers to changes in the visual style of elements. Both can cause performance degradation and should be minimized.
- **Virtual Scrolling**: For long pages, only the content within the current viewport is rendered, with other parts dynamically loaded through scroll events.
- **Cross-Origin Isolation and CSP**: Implementing security policies to restrict interactions between different origins, protecting user data from malicious scripts.
### 4.3. V8 JavaScript Engine
V8 is the JavaScript engine of the Chrome core, employing a generational garbage collection algorithm and an optimized JIT compiler to efficiently execute JavaScript code in the browser. V8 also provides a rich set of APIs and tools for debugging and performance analysis.
#### 4.3.1. V8's Memory Model
V8 uses a generational garbage collection mechanism, dividing memory into young and old generations to improve garbage collection efficiency.
#### 4.3.2. V8's Performance Optimization
- **Hot Code Optimization**: Analyzing the execution frequency of code and optimizing hot code.
- **Inline Caching**: Caching the results of function calls to reduce the overhead of function calls.
- **Escape Analysis**: Analyzing the scope of objects to determine if they can be allocated on the stack, reducing the pressure on garbage collection.
## 5. Developer Tools and Debugging
The Chrome core provides powerful developer tools, including element inspection, network analysis, and performance analysis, helping developers better understand and optimize web pages.
### 5.1. Element Inspector
Allows developers to view and modify the DOM tree and CSSOM tree in real-time, along with their styles.
### 5.2. Network Analysis Tool
Records and analyzes all network requests during the webpage loading process, helping identify performance bottlenecks.
### 5.3. Performance Panel
Provides detailed performance analysis, including frame rate, layout, and painting, helping developers find the root cause of performance issues.
## 6. AI Large Model Built into Chrome 127
The Chrome 127 version indeed includes an AI large model called Gemini Nano, marking a new era of intelligence for the browser.
### 6.1. Introduction to the AI Large Model in Chrome 127
The AI large model built into Chrome 127 is named Gemini Nano, an advanced large language model that can run locally on most modern desktops and laptops equipped with Chrome. The introduction of Gemini Nano provides users with powerful on-device AI capabilities, such as image recognition and natural language processing, without the need to worry about deploying and managing the model.
- **Main Features**: Gemini Nano is a powerful language model with excellent text generation, understanding, and reasoning capabilities. It can quickly respond to user needs on the browser side, providing real-time intelligent interaction experiences.
- **Technical Advantages**: Leveraging advanced deep learning technology, Gemini Nano demonstrates efficient performance and accuracy in handling complex tasks. It also has cross-platform compatibility, running stably on different devices and operating systems.
### 6.2. How to Use the AI Large Model in Chrome 127
To use the Gemini Nano large model in Chrome 127, follow these steps:
1. **Download Chrome 127 dev version**: Ensure your Chrome version is at least 127.0.6512.
2. **Enable Device Model**: Open a new tab in Chrome dev, enter `chrome://flags/#optimization-guide-on-device-model`, and select the `Enabled BypassPerfRequirement` option.
3. **Enable Gemini Nano**: Open a new tab again, enter `chrome://flags/#prompt-api-for-gemini-nano`, and select the `Enabled` option.
4. **Check Model Download Status**: Enter `chrome://components/` in the address bar to check the model's download status. If the component is successfully downloaded, the status will change to "Up-to-date," and the corresponding version number will be displayed next to the component.
### 6.3. Other New Features in Chrome 127
In addition to the built-in AI large model, Chrome 127 introduces several new features, including CSS font size adjustment, multi-parameter alternative text in generated content, and view transitions support in iframes. These new features aim to enhance the browser's performance and user experience. Through these new features, Chrome 127 not only strengthens its capabilities as a web development tool but also provides users with a richer and more intelligent browsing experience.
### 6.4. Main Functions and Application Scenarios of the AI Large Model
The integration of artificial intelligence (AI) with the Chrome browser is becoming increasingly prominent, manifesting in various aspects from the browser's underlying architecture to intelligent user interface interactions. Here are some key areas where Chrome and AI intersect:
#### 6.4.1. Intelligent Indexing and Search
Chrome's search functionality integrates AI technology, optimizing the relevance and accuracy of search results through machine learning algorithms. As users continue to use the browser, Chrome learns their search habits, providing more personalized search suggestions.
#### 6.4.2. Voice Search and Assistant
Chrome supports voice search functionality, powered by natural language processing (NLP) technology. Users can interact with the browser via voice commands for searches or other operations. Additionally, integration with Google Assistant allows users to perform more complex tasks, such as setting reminders and sending messages.
#### 6.4.3. Intelligent Recommendation System
Chrome intelligently recommends content based on users' browsing history, location information, and other relevant data, whether it be news, videos, or other web pages. This personalized recommendation system leverages machine learning algorithms to improve the accuracy and user satisfaction of recommendations.
#### 6.4.4. Privacy Protection and Intelligent Tracking Prevention
Chrome incorporates AI technology in protecting user privacy. For example, it can automatically identify and block third-party trackers while allowing users to customize privacy settings. AI plays a role in real-time analysis and learning of user browsing behavior to optimize privacy protection measures.
#### 6.4.5. Intelligent Reading Assistance
Certain versions of Chrome offer intelligent reading assistance features, such as simplifying page content and highlighting key information to help users read more efficiently. This feature utilizes text processing and natural language understanding technologies.
#### 6.4.6. Automation and Extensions
Chrome supports various intelligent extensions that can automate common browser tasks using AI technology. For instance, some extensions can automatically adjust the font size of articles based on the user's reading speed or automatically translate web content.
#### 6.4.7. TensorFlow Lite Machine Learning Framework
Google's TensorFlow Lite is a lightweight machine learning framework that can run on mobile devices. Although not specifically designed for Chrome, developers can use TensorFlow Lite to create intelligent applications within the Chrome browser, such as image recognition and voice recognition.
#### 6.4.8. WebAssembly and AI
WebAssembly is a new code format that allows high-performance compiled code to run on the web. This means complex AI algorithms can run in the browser with near-native performance, providing Chrome users with a richer AI experience.
## 7. Conclusion
Through an in-depth analysis of the Chrome core, we have gained an understanding of its low-level rendering engine, JavaScript engine V8, Web API layer, and rendering layer's technical architecture and working principles. Detailed technical analysis has revealed the layout and style computation, rendering process, and performance optimization strategies. The memory model and performance optimization techniques of the V8 engine further enhance the execution efficiency of JavaScript code. Developer tools provide robust support for web development and debugging.
Notably, the AI large model Gemini Nano built into Chrome version 127 marks a new era of intelligence for the browser. Gemini Nano not only excels in text generation, understanding, and reasoning but also quickly responds to user needs on the device side, providing real-time intelligent interaction experiences. Through features such as intelligent indexing and search, voice search and assistant, and intelligent recommendation systems, the integration of Chrome and AI brings users a more personalized and efficient browsing experience. In the future, as AI technology continues to evolve, the Chrome browser will achieve even greater breakthroughs in performance and intelligence.
## 8. Codia AI's products
Codia AI has rich experience in multimodal, image processing, development, and AI.
1.[**Codia AI Figma to code:HTML, CSS, React, Vue, iOS, Android, Flutter, Tailwind, Web, Native,...**](https://codia.ai/s/YBF9)
2.[**Codia AI DesignGen: Prompt to UI for Website, Landing Page, Blog**](https://codia.ai/t/pNFx)
3.[**Codia AI Design: Screenshot to Editable Figma Design**](https://codia.ai/d/5ZFb)
4.[**Codia AI VectorMagic: Image to Full-Color Vector/PNG to SVG**](https://codia.ai/v/bqFJ)
| happyer |
1,907,136 | How to stream on your LAN using VLC? | What is VLC? VLC is an open-source video media player that has been around for quite a... | 0 | 2024-07-04T14:13:22 | https://dev.to/apalebluedev/how-to-stream-on-your-lan-using-vlc-1h0j | vlc, oldschool, stream, localserver | ## What is VLC?
**VLC** is an open-source video media player that has been around for quite a long time. Chances are, if you've ever downloaded a movie (via legal methods, of course), you have probably used it. But do you know why it's called VLC?
> That is because it has very loose controls such as increasing volume more than 100%. 😂
> *(Note: This is a joke and not true.)*
VLC stands for **VideoLAN Client**. Let's learn about the LAN in VLC.
## A Bit of VLC History
The VideoLAN software originated as a French academic project in 1996. VLC used to stand for "VideoLAN Client" when VLC was a client of the VideoLAN project. Since VLC is no longer merely a client, that initialism no longer applies.
It was intended to consist of a client and server to stream videos from satellite dishes across a campus network. 📡 Originally developed by students at the École Centrale Paris, it is now developed by contributors worldwide and is coordinated by VideoLAN, a non-profit organization. 🌍 Rewritten from scratch in 1998, it was released under the GNU General Public License on February 1, 2001, with authorization from the headmaster of the École Centrale Paris. 🎓 The functionality of the server program, VideoLAN Server (VLS), has mostly been subsumed into VLC and has been deprecated. The project name has been changed to VLC media player because there is no longer a client/server infrastructure.
## Using VLC as Its Creators Intended
VLC was initially created to stream videos over a network, and while its usage has expanded greatly, it still retains this functionality. Here are some ways you can use VLC to take advantage of its network features:
### 1. Streaming Media Over a Network
VLC can stream media files over a local network, allowing you to share videos and music with other devices on the same network. 🎥🎶
**To stream a media file:**
1. Open VLC Media Player.
2. Click on `Media` in the menu bar.
3. Select `Stream...`.
4. Add the file you want to stream and click `Stream`.
5. Choose `Next` and select the output method as HTTP (by default the port is set to 8080).
6. Configure the stream settings to your preferences such as `active transcoding` and profile (optional).
### 2. Receiving a Stream
You can use VLC to receive a stream from another device on the network. 🌐
**To receive a stream:**
1. Open VLC Media Player.
2. Click on `Media` in the menu bar.
3. Select `Open Network Stream`.
4. Enter the network URL provided by the streaming source (IP address of the device where you set up the stream).
- On Windows, use the `ipconfig /all` command to get your local IPv4 address.
- On Linux, use `ifconfig` for the same.
- Example of IP: `192.168.56.19:8080`.
5. Click `Play`.
### 3. Using VLC as a Server
While the original VideoLAN Server (VLS) functionality has been integrated into VLC, you can still use VLC to set up a media server. 💻
**To set up VLC as a server:**
1. Open VLC Media Player.
2. Click on `Media` in the menu bar.
3. Select `Stream...`.
4. Add the file you want to serve and click `Stream`.
5. Choose `Next` and select the output method (e.g., HTTP, RTP).
6. Configure the stream settings and start the server.
### 4. Using VLC for Remote Playback
VLC has remote playback capabilities, allowing you to control playback on another device from your current device. 🎮
**To use VLC for remote playback:**
1. Enable VLC’s web interface on the device you want to control:
- Go to `Tools` -> `Preferences`.
- Select `All` under `Show settings` in the bottom-left corner.
- Navigate to `Interface` -> `Main interfaces`.
- Check the `Web` checkbox.
2. Use a web browser on your controlling device to access the web interface:
- Enter the IP address of the VLC device followed by `:8080` (e.g., `http://192.168.1.2:8080`).
By using these features, you can leverage VLC's network capabilities as its creators intended. Whether for streaming media across devices or setting up a simple media server, VLC's versatility makes it a powerful tool for both local and network-based media playback. 🚀
Hope you enjoyed the article! 😊 | apalebluedev |
1,911,639 | Understanding Event Bubbling and Capturing in JavaScript | Imagine you're at a concert, and someone in the front row shouts a question. The message travels back... | 0 | 2024-07-04T14:11:45 | https://dev.to/mananpoojara/understanding-event-bubbling-and-capturing-in-javascript-4227 | javascript, beginners, programming, webdev | Imagine you're at a concert, and someone in the front row shouts a question. The message travels back through the crowd, row by row, until it reaches the back. This is similar to how event bubbling works in JavaScript. Conversely, if the question starts from the back and moves to the front, that's event capturing. Let's dive into these concepts!
**Event Bubbling**
Event bubbling is like the message moving from the child element up to its parents. When an event is triggered on an element, it first runs the handlers on it, then on its parent, then all the way up on other ancestors.
**Event Capturing**
Event capturing, on the other hand, is the reverse process. The event is first captured by the outermost element and propagated to the inner elements. Think of it as the message moving from the back of the concert hall to the front.
Here's a simple HTML example to illustrate these concepts:
```html
<!DOCTYPE html>
<html>
<body>
<div id="grandparent">Grandparent
<div id="parent">Parent
<div id="child">Child</div>
</div>
</div>
<script>
document.getElementById('grandparent').addEventListener('click', () => alert('Grandparent clicked!'), true); // Capturing
document.getElementById('parent').addEventListener('click', () => alert('Parent clicked!'));
document.getElementById('child').addEventListener('click', () => alert('Child clicked!'));
</script>
</body>
</html>
```
In this example, clicking on "Child" will first print "Grandparent clicked!" (due to capturing) and then "Child clicked!" and "Parent clicked!" (due to bubbling).
**Preventing Event Bubbling and Capturing**
> Stopping Event Bubbling
To stop an event from bubbling up the DOM tree, use event.stopPropagation():
```javascript
Copy code
document.getElementById('child').addEventListener('click', (event) => {
alert('Child clicked!');
event.stopPropagation(); // Stops the event from bubbling up
});
```
> Stopping Event Capturing
To stop an event from capturing, you can use event.stopPropagation() in the capturing phase as well:
```javascript
Copy code
document.getElementById('grandparent').addEventListener('click', (event) => {
alert('Grandparent clicked!');
event.stopPropagation(); // Stops the event from capturing down
}, true); // Capturing phase
```
**Use Cases**
> Form Validation
Prevent form submission when validation fails using event capturing.
> Event Delegation
Handle events on dynamically added elements more efficiently using event bubbling.
**Here are some common mistakes developers make when dealing with events:**
> Forgetting to Remove Event Listeners:Always clean up event listeners to avoid memory leaks.
> Incorrect Use of stopPropagation
Using event.stopPropagation() incorrectly can prevent other important event handlers from executing.
## Conclusion
Event bubbling and capturing are fundamental concepts for handling events in JavaScript. Experiment with these examples to better understand how they work!
Got questions or examples? Leave a comment below and let's discuss!
| mananpoojara |
1,911,638 | The Augmented Dickey—Fuller (ADF) Test for Stationarity | Stationarity is a fundamental concept in statistical analysis and machine learning, particularly when... | 0 | 2024-07-04T14:11:38 | https://victorleungtw.com/2024/07/04/adf | stationarity, timeseries, adftest, finance | Stationarity is a fundamental concept in statistical analysis and machine learning, particularly when dealing with time series data. In simple terms, a time series is stationary if its statistical properties, such as mean and variance, remain constant over time. This constancy is crucial because many statistical models assume that the underlying data generating process does not change over time, simplifying analysis and prediction.
In real-world applications, such as finance, time series data often exhibit trends and varying volatility, making them non-stationary. Detecting and transforming non-stationary data into stationary data is therefore a critical step in time series analysis. One powerful tool for this purpose is the Augmented Dickey—Fuller (ADF) test.
### What is the Augmented Dickey—Fuller (ADF) Test?
The ADF test is a statistical test used to determine whether a given time series is stationary or non-stationary. Specifically, it tests for the presence of a unit root in the data, which is indicative of non-stationarity. A unit root means that the time series has a stochastic trend, implying that its statistical properties change over time.
### Hypothesis Testing in the ADF Test
The ADF test uses hypothesis testing to make inferences about the stationarity of a time series. Here’s a breakdown of the hypotheses involved:
- **Null Hypothesis (H0)**: The time series has a unit root, meaning it is non-stationary.
- **Alternative Hypothesis (H1)**: The time series does not have a unit root, meaning it is stationary.
To reject the null hypothesis and conclude that the time series is stationary, the p-value obtained from the ADF test must be less than a chosen significance level (commonly 5%).
### Performing the ADF Test
Here’s how you can perform the ADF test in Python using the `statsmodels` library:
```python
import pandas as pd
from statsmodels.tsa.stattools import adfuller
# Example time series data
data = pd.Series([your_time_series_data])
# Perform the ADF test
result = adfuller(data)
# Extract and display the results
adf_statistic = result[0]
p_value = result[1]
used_lag = result[2]
n_obs = result[3]
critical_values = result[4]
print(f'ADF Statistic: {adf_statistic}')
print(f'p-value: {p_value}')
print(f'Used Lag: {used_lag}')
print(f'Number of Observations: {n_obs}')
print('Critical Values:')
for key, value in critical_values.items():
print(f' {key}: {value}')
```
### Interpreting the Results
- **ADF Statistic**: A negative value, where more negative values indicate stronger evidence against the null hypothesis.
- **p-value**: If the p-value is less than the significance level (e.g., 0.05), you reject the null hypothesis, indicating that the time series is stationary.
- **Critical Values**: These values help to determine the threshold at different confidence levels (1%, 5%, 10%) to compare against the ADF statistic.
### Example and Conclusion
Consider a financial time series data, such as daily stock prices. Applying the ADF test might reveal a p-value greater than 0.05, indicating non-stationarity. In such cases, data transformations like differencing or detrending might be necessary to achieve stationarity before applying further statistical models.
In summary, the ADF test is an essential tool for diagnosing the stationarity of a time series. By understanding and applying this test, analysts can better prepare their data for modeling, ensuring the validity and reliability of their results.
| victorleungtw |
1,911,481 | Architecture orientée événement : réconcilier Notifications et Evénements "Complets" | Les architectures orientées événement offrent de nombreux bénéfices : le découplage entre les... | 0 | 2024-07-04T14:11:07 | https://dev.to/aws-builders/architecture-orientee-evenement-reconcilier-notifications-et-evenements-complets-1718 | eventdriven, eventbridge, event, serverless | Les architectures orientées événement offrent de nombreux bénéfices : le découplage entre les composants applicatifs permet une meilleure résilience à la panne, un flux de traitement adapté aux ressources disponibles, un faible temps d'attente pour l'utilisateur (pourquoi traiter de façon synchrone ce qu'il peut l'être après lui avoir répondu ?).
Cependant, leur conception n'est pas aisée et peut entraîner de nombreux débats : faut-il des événements très légers, à charge pour le consommateur de demander un éventuel complément d'information ? faut-il des événements complets ? ..
Dans ce billet, j'expose les différents types d'événements et propose une manière de réconcilier simplement les différentes approches en s'appuyant sur AWS EventBridge (un repo Github avec un exemple pleinement fonctionnel vous attend en fin de billet !).
## Les différents types d'événements
Un premier pattern est d'utiliser l'événement "Notification", qui contient juste un identifiant. En voici un exemple :
```
{ "orderId": "1234567" }
```
Cet événement minimaliste a pour avantage de ne nécessiter aucune connaissance de la modélisation du domaine métier : il y a peu de risque de violer le contrat d'interface notamment en cas d'évolution. Si un consommateur veut en savoir plus, il peut aller chercher la donnée à partir de l'identifiant communiqué (et si le système source présente une API GraphQL, il pourra aller chercher uniquement la donnée qui est nécessaire pour lui).
Une seconde approche se nomme "Event-carried State Transfer" (par analogie avec le "REpresentational State Transfer" qui caractérise les API REST), c'est à dire que l'événement porte l'état courant. En voici un exemple :
```
{
"id": "1234567",
"status": "PAYMENT_ACCEPTED",
"customer": "Bob",
"content": [ ... ]
}
```
Ce type d'événement a l'avantage de porter toute l'information disponible et ainsi d'épargner une requête au consommateur, mais aussi d'améliorer les options de filtrage dont on disposera au niveau du bus d'événement : on pourra par exemple choisir de ne consommer que les événements représentant une commande au statut `PAYMENT_ACCEPTED` (par exemple pour envoyer un mail de confirmation de commande).
Une troisième voie consiste à faire un "Delta", i.e. transmettre également l'état précédent en complément de l'état courant.
Voici un résumé des avantages et limites de chaque approche :
## Réconcilier l'approche Notification et l'approche Event-carried State Transfer
Dès lors, on peut vouloir tirer parti des bénéfices de chaque approche
* sans pour autant complexifier inutilement l'architecture des applications qui publient les événements comme de celles qui les consomment.
* sans parfois avoir la main sur le code source des applications.
C'est là qu'une approche serverless mêlant bus d'événement EventBridge et Lambda a tout son sens. Dans cette approche, on va mettre en place
* sur le bus d'événement des règles qui capturent les événements de type "_Notification_"
* et des micro-services d'enrichissement qui vont récupérer la donnée du domaine métier correspondant et republier l'événement enrichi.
Je commencerai par un exemple simple, avant de montrer comment on peut étendre ce pattern. En bas de cet article, vous trouverez un lien vers les deux implémentations qui suivent.
### La version simple : un seul enrichissement
Dans cet exemple, une application de gestion de paiement publie un événement de type `PAYMENT` portant uniquement l'id de l'événement (un événement de notification, donc).
Côté EventBridge, une règle va explicitement viser ces événements en vérifiant qu'aucune donnée supplémentaire n'est associée
```
{
"detail-type": ["PAYMENT"],
"detail.payment_data.id": [{ "exists": false }]
}
```
Si cette règle capture un événement, elle va l'envoyer vers une Lambda qui va publier le même événement enrichi.
On va donc trouver successivement dans le bus d'événement deux événements (ayant le même id métier) :
* la notification
```
{
"version": "0",
"id": "a23a7513-b67a-d455-f90c-1f9ddbd14820",
"detail-type": "PAYMENT",
"source": "PaymentSystem",
"account": "112233445566",
"time": "2024-07-04T09:06:47Z",
"region": "eu-west-1",
"resources": [],
"detail": {
"id": "2237082"
}
}
```
* et l'événement complet (ECST):
```
{
"version": "0",
"id": "51bbf35e-97d8-8f80-1cc2-debac66460e6",
"detail-type": "PAYMENT",
"source": "PaymentSystem",
"account": "112233445566",
"time": "2024-07-04T09:06:49Z",
"region": "eu-west-1",
"resources": [],
"detail": {
"id": "2237082",
"payment_data": {
"id": "2237082",
"type": "Credit",
"description": "Credit Card - HSBC",
"status": "Confirmed",
"state": "Paid",
"value": 1700,
"currency": "EUR",
"date": "2018-12-15"
}
}
}
```
(la structure d'événement est un peu plus complexe que dans la partie théorique : on retrouve ici la structure typique d'un événement EventBridge qui encapsule le contenu métier.)
Cet événement "pleinement qualifié" est ensuite envoyé
Le bus d'événement EventBridge fournit notamment :
* Le découplage entre Producteurs et Consommateurs avec un middleware scalable et hautement disponible
* Une logique avancée de filtrage/capture d'événements
* La possibilité de logger les événements et de les archiver pour re-jeu
* La gestion du retry pour les invocations synchrones faites par le bus d'événement.
* La transformation de l'événement pour l'adapter au format attendu par le consommateur, sans avoir à déployer cette transformation dans une fonction Lambda.
L'ensemble de ces fonctionnalités sont démontrées dans le code disponible en fin d'article.
### Un enrichissement plus complexe
Imaginons un cas plus complexe : le système de paiement publie un événement de paiement. Mais ce paiement est lié à une commande, qui a son propre cycle de vie, géré dans une plusieurs autres applications. Et cette commande est liée à un client, qui a également un cycle de vie propre, géré dans un CRM.
Ici on va mettre en place une logique de filtrage / capture plus complexe, mais le code des fonctions d'enrichissement ne change pas !
## Démo / mise en oeuvre concrète !
Nous avons démontré dans ce blog post comment réconcilier les deux principaux modèles de gestion d'événements, grâce à AWS EventBridge et AWS Lambda
Vous trouverez dans [ce repo Github](https://github.com/psantus/event-driven-notification-vs-ecst) deux modèles CloudFormation permettant de déployer ces exemples pleinement fonctionnels.
---
Vous souhaitez démarrer dans l'architecture orientée événements et vous avez besoin d'appui ? TerraCloud est là pour vous aider ! [Contactez-moi !](https://www.terracloud.fr/a-propos/qui-suis-je/)
[](https://www.terracloud.fr)
| psantus |
1,911,637 | Automotive Parts Aftermarket: Top Key Players and Their Competitive Strategies | In 2022, the automotive parts aftermarket generated revenues of US$ 548 billion, with projections... | 0 | 2024-07-04T14:10:15 | https://dev.to/swara_353df25d291824ff9ee/automotive-parts-aftermarket-top-key-players-and-their-competitive-strategies-2emn |
In 2022, the [automotive parts aftermarket](https://www.persistencemarketresearch.com/market-research/automotive-parts-aftermarket.asp) generated revenues of US$ 548 billion, with projections indicating growth to US$ 984 billion by 2033, driven by a compound annual growth rate (CAGR) of 5.5% from 2023 onwards. The market is bolstered by heightened consumer awareness of vehicle maintenance and repair, essential for sustaining vehicle efficacy and performance. Increasing sales of crossover and long-distance vehicles further spur demand, necessitating frequent servicing and part replacements. Enhanced vehicle design and production flexibility enable stronger customer customization, fostering market expansion. Moreover, advancements in vehicle materials and innovations have significantly extended the lifespan and quality of automobiles over the past decade. As vehicles age, there is a rising need for part replacements, repairs, and maintenance, underscoring the robust growth of the automotive parts aftermarket.
**Key Players:**
The global automotive parts aftermarket is fiercely competitive, characterized by a diverse array of key players leveraging innovative strategies to maintain market leadership and drive growth. Understanding the strategies adopted by these industry giants provides valuable insights into the evolving landscape of aftermarket automotive parts.
**Leading Key Players**
Robert Bosch GmbH: Renowned for its extensive portfolio of automotive aftermarket products, Bosch emphasizes innovation and quality. The company invests heavily in R&D to introduce advanced technologies such as IoT-enabled diagnostics tools and electric vehicle charging solutions.
Continental AG: A global leader in automotive technology, Continental AG focuses on enhancing product reliability and performance. The company's aftermarket strategy emphasizes partnerships with OEMs for supply chain efficiency and offers a comprehensive range of OE-quality replacement parts.
Denso Corporation: Known for its expertise in automotive electronics and components, Denso Corporation prioritizes sustainability and innovation. The company integrates eco-friendly materials in its aftermarket products and invests in AI-driven diagnostic solutions for enhanced vehicle maintenance.
ZF Friedrichshafen AG: ZF Friedrichshafen AG specializes in driveline and chassis technology, offering advanced aftermarket solutions tailored to meet evolving vehicle performance demands. The company's strategy includes expanding its global distribution network and integrating smart technologies for predictive maintenance.
Valeo SA: Valeo SA focuses on developing intuitive aftermarket solutions that enhance vehicle safety and comfort. The company's competitive strategy emphasizes agility and responsiveness to market trends, with a strong emphasis on customer-centric product development.
**Competitive Strategies**
Innovation and R&D: Key players in the automotive parts aftermarket prioritize continuous innovation to stay ahead of market trends. Investments in R&D enable the development of next-generation technologies, including electric vehicle components, autonomous driving systems, and connected car solutions.
Strategic Partnerships: Collaborations with OEMs, distributors, and e-commerce platforms enhance supply chain efficiency and market reach. Strategic alliances enable key players to offer a broader range of products and services while ensuring timely delivery and customer satisfaction.
Digital Transformation: Embracing digitalization is pivotal for competitive advantage in the aftermarket sector. Leading players invest in digital platforms for e-commerce, data analytics for predictive maintenance, and customer relationship management systems to enhance operational efficiency and customer experience.
Focus on Sustainability: Increasing consumer awareness and regulatory pressures drive the adoption of sustainable practices in aftermarket operations. Key players integrate eco-friendly materials, support recycling initiatives, and promote remanufacturing processes to minimize environmental impact.
Customer-Centric Approach: Enhancing customer engagement through personalized services, technical support, and warranty programs is essential for building brand loyalty. Key players prioritize customer feedback and insights to tailor aftermarket solutions that meet diverse consumer needs and preferences.
**Future Outlook**
The future of the automotive parts aftermarket presents a landscape ripe with opportunities and challenges, shaped by evolving consumer behaviors, technological advancements, and global market dynamics. As we look ahead, several key trends and developments are poised to define the trajectory of this dynamic sector.
Continued Growth Trajectory
The automotive parts aftermarket is on a robust growth path, with projections indicating a steady compound annual growth rate (CAGR) of 5.5% from 2023 to 2033. By 2033, the market is expected to surpass US$ 984 billion, driven by increasing vehicle ownership, technological innovations, and rising consumer demand for reliable aftermarket solutions.
Shift Towards Electric and Hybrid Vehicles
The rapid adoption of electric and hybrid vehicles represents a transformative shift in the automotive industry. As governments worldwide implement stricter emissions regulations and consumers embrace sustainable mobility solutions, there is a growing demand for aftermarket components tailored to electric propulsion systems. This includes batteries, charging infrastructure, and specialized maintenance services, presenting new avenues for growth and innovation.
Technological Advancements
Advancements in vehicle technology, including artificial intelligence (AI), connected systems, and autonomous driving capabilities, are reshaping the aftermarket landscape. These technologies not only enhance vehicle performance and safety but also necessitate sophisticated aftermarket solutions. Manufacturers and service providers are increasingly focusing on developing smart components, predictive maintenance tools, and digital platforms to cater to the evolving needs of modern vehicles and consumers.
Emphasis on Sustainability and Circular Economy
Environmental sustainability is becoming a driving force in the automotive industry, influencing consumer choices and regulatory frameworks. The aftermarket sector is responding by promoting eco-friendly practices such as remanufacturing, recycling of automotive parts, and reducing carbon footprints throughout the product lifecycle. Sustainable initiatives not only enhance brand reputation but also align with global efforts towards achieving carbon neutrality and reducing resource consumption.
Regional Market Dynamics
Regional variations in consumer preferences, economic conditions, and regulatory environments continue to shape the automotive parts aftermarket. Mature markets like North America and Europe emphasize quality, reliability, and technological innovation. In contrast, emerging markets in Asia-Pacific and Latin America offer substantial growth opportunities driven by increasing vehicle penetration rates, urbanization, and rising middle-class incomes.
Digital Transformation and Customer Experience
Digitalization is revolutionizing the aftermarket customer experience, enabling seamless online transactions, personalized service recommendations, and real-time vehicle diagnostics. Digital platforms and e-commerce channels empower consumers to research, purchase, and schedule services with ease, driving efficiency and enhancing customer satisfaction. This digital transformation also fosters greater transparency, collaboration, and operational efficiency across the aftermarket supply chain.
| swara_353df25d291824ff9ee |
|
1,911,547 | Optimizing Fuzzy Search Across Multiple Tables: pg_trgm, GIN, and Triggers | PostgreSQL offers significant improvements beyond single-column indexing, which YugabyteDB also... | 0 | 2024-07-04T14:03:26 | https://dev.to/yugabyte/optimizing-fuzzy-search-across-multiple-tables-pgtrgm-gin-and-triggers-4d1p | yugabytedb, postgres, sql, database | PostgreSQL offers significant improvements beyond single-column indexing, which YugabyteDB also leverages. For searches where the full value is not known, the pg_trgm extension can generate multiple trigrams, and GIN indexes these multiple values per row. Additionally, bitmap scans can combine indexes on different columns within a table. However, challenges arise when predicates span across different tables in a join. Here, triggers come into play, allowing the creation of custom indexing by maintaining user-defined columns dedicated to fuzzy searches.
Here is an example using a table of Cities and Countries which I build from [gvenzl/sample-data](https://github.com/gvenzl/sample-data):
```sql
\! curl -s https://raw.githubusercontent.com/gvenzl/sample-data/main/countries-cities-currencies/uninstall.sql > countries.sql
\! curl -s https://raw.githubusercontent.com/gvenzl/sample-data/main/countries-cities-currencies/install.sql | awk '/D a t a l o a d/{print "do $$ begin"}/ COMMIT /{print "end; $$ ;"}{print}' >> countries.sql
\i countries.sql
```
I want to list the cities that have 'port' in their city name or country name:
```sql
yugabyte=# select city.name, country.name
from cities city
join countries country using(country_id)
where city.name ilike '%port%' or country.name ilike '%port%';
name | name
----------------+---------------------
Port Moresby | Papua New Guinea
Port of Spain | Trinidad and Tobago
Port au Prince | Haiti
Porto Novo | Benin
Port Vila | Vanuatu
Port Louis | Mauritius
Lisbon | Portugal
(7 rows)
```
Which index to create to accelerate this search?
## Trigrams and GIN index on both tables
Because I do a fuzzy search, I can create the `pg_trgm` extension and a GIN index on both columns:
```sql
create extension if not exists pg_trgm;
create index on cities using gin (name gin_trgm_ops);
create index on countries using gin (name gin_trgm_ops);
```
Unfortunately, it cannot be used with my query because the two columns are on two tables and bitmap scan can only combine bitmaps for one table:
```sql
yugabyte=# explain (costs off)
select city.name, country.name
from cities city
join countries country using(country_id)
where city.name ilike '%port%' or country.name ilike '%port%';
QUERY PLAN
-----------------------------------------------------------------------------------------------
Nested Loop
-> Seq Scan on cities city
-> Index Scan using countries_pk on countries country
Index Cond: ((country_id)::text = (city.country_id)::text)
Filter: (((city.name)::text ~~* '%port%'::text) OR ((name)::text ~~* '%port%'::text))
(5 rows)
```
I can re-write the query with a UNION:
```sql
yugabyte=# explain (costs off)
select city.name, country.name
from cities city
join countries country using(country_id)
where city.name ilike '%port%'
union
select city.name, country.name
from cities city
join countries country using(country_id)
where country.name ilike '%port%';
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------------------------------
HashAggregate
Group Key: city.name, country.name
-> Append
-> YB Batched Nested Loop Join
Join Filter: ((city.country_id)::text = (country.country_id)::text)
-> Index Scan using cities_name_idx1 on cities city
Index Cond: ((name)::text ~~* '%port%'::text)
-> Index Scan using countries_pk on countries country
Index Cond: ((country_id)::text = ANY (ARRAY[(city.country_id)::text, ($1)::text, ($2)::text, ..., ($1023)::text]))
-> YB Batched Nested Loop Join
Join Filter: ((city_1.country_id)::text = (country_1.country_id)::text)
-> Index Scan using countries_name_idx1 on countries country_1
Index Cond: ((name)::text ~~* '%port%'::text)
-> Index Scan using cities_countries_fk001 on cities city_1
Index Cond: ((country_id)::text = ANY (ARRAY[(country_1.country_id)::text, ($1025)::text, ($1026)::text, ..., ($2047)::text]))
(15 rows)
```
This works, but the user may have some constraints with the ORM that cannot generate such a query.
## Maintain an additional column for searching
I create an additional column in "cities" that will concatenate the name of the city and the name of the country, with a GIN index on trigrams:
```sql
alter table cities add fuzzy_search text;
create index on cities using gin (fuzzy_search gin_trgm_ops);
update cities
set fuzzy_search = format('%s %s',cities.name, countries.name)
from countries where countries.country_id = cities.country_id
;
```
I can now query on this "fuzzy_search" column:
```sql
yugabyte=# explain (costs off)
select city.name, country.name
from cities city
join countries country using(country_id)
where fuzzy_search ilike '%port%';
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------
YB Batched Nested Loop Join
Join Filter: ((city.country_id)::text = (country.country_id)::text)
-> Index Scan using cities_fuzzy_search_idx on cities city
Index Cond: (fuzzy_search ~~* '%port%'::text)
-> Index Scan using countries_pk on countries country
Index Cond: ((country_id)::text = ANY (ARRAY[(city.country_id)::text, ($1)::text, ($2)::text, ..., ($1023)::text]))
(6 rows)
```
This is why SQL databases have triggers: to add some data logic transparent to the application.
The code for triggers depends on your application and access patterns to reduce the overhead. The cases I will cover are:
- inserting a new city that references a country must add the country name to the search column
- updating a city must update it in the search column
- inserting, updating, or deleting a country must update the search column on all cities referencing it.
If you have foreign key with cascade constraint, you may not need all those cases.
Here are my triggers:
```sql
-- Trigger for insert, update, and delete on cities
create or replace function trg_cities_fuzzy_search() returns trigger as $$
begin
if tg_op = 'INSERT' or tg_op = 'UPDATE' then
new.fuzzy_search := format('%s %s', new.name, (select name from countries where country_id = new.country_id));
return new;
end if;
end;
$$ language plpgsql;
create trigger trg_cities_fuzzy_search
before insert or update or delete on cities
for each row execute function trg_cities_fuzzy_search();
-- Trigger for update and delete on countries
create or replace function trg_countries_fuzzy_search() returns trigger as $$
begin
if tg_op in ( 'UPDATE' , 'INSERT' ) then
update cities
set fuzzy_search = format('%s %s', cities.name, new.name)
where country_id = new.country_id;
return new;
elsif tg_op = 'DELETE' then
update cities
set fuzzy_search = format('%s', name)
where country_id = old.country_id;
return old;
end if;
end;
$$ language plpgsql;
create trigger trg_countries_fuzzy_search
after update or delete on countries
for each row
execute function trg_countries_fuzzy_search();
```
The most important is to add tests to cover all DML that can happen on those tables and verify that the "fuzzy_search column" is always correct. In other words, no rows returned by:
```sql
select format('%s %s',city.name, country.name) , fuzzy_search as names
from cities city
join countries country using(country_id)
where format('%s %s',city.name, country.name) != fuzzy_search
;
```
If you have stress tests for critical use cases that modify those tables, you should also verify that the overhead is acceptable.
By implementing this solution, the changes needed in the application are minimal: simply build the criteria based on the column specifically designated for fuzzy search. This approach offers the benefits of denormalization (filtering before joining) without the drawbacks (such as having to add data logic in the application code and tests to maintain consistency).
This example is compatible with PostgreSQL, YugabyteDB, and any PostgreSQL-compatible databases, implying support for GIN indexes and triggers of course. | franckpachot |
1,911,635 | Need to have VSCode settings for a Next.js project | Do you find it difficult to navigate your NextJS project or do you get lost when you are editing... | 0 | 2024-07-04T14:03:22 | https://dev.to/maxwiggedal/vscode-settings-for-nextjs-project-7ld | nextjs, webdev, vscode, beginners | Do you find it difficult to navigate your NextJS project or do you get lost when you are editing multiple pages/routes/layouts/components at once? Look no further!
## Custom Labels
VSCode supports custom labels for the files that are currently being displayed. I have put together some labels that work amazingly with a typical NextJS project setup.
```json
"workbench.editor.customLabels.patterns": {
"**/app/**/layout.tsx": "${dirname(1)}/${dirname} - Layout",
"**/app/**/page.tsx": "${dirname(1)}/${dirname} - Page",
"**/app/**/route.ts": "${dirname(1)}/${dirname} - Route",
"**/app/**/_components/**/*.tsx": "${filename} - ${dirname(2)}/${dirname(1)} - Component",
"**/components/**/*.tsx": "${filename} - Component",
"**/data-layer/**/*.ts": "${filename} - Data Layer",
"**/entities/**/*.ts": "${filename} - Entity",
"**/hooks/**/*.ts": "${filename} - Hook",
"**/lib/**/*.ts": "${filename} - Library",
"**/utils/**/*.ts": "${filename} - Utility",
"**/env/**/*.ts": "${filename} - Environment"
}
```
You can always modify it to match your project needs!
To correctly setup the settings for your project create a directory called `.vscode` with a `settings.json` file inside of it. Then simply add your settings in there and it will apply for everyone in the project that uses VSCode.
## NextJS TypeScript Version
Do not forget to set your TypeScript version to the one provided by NextJS. You can do so by opening the command palette in VSCode by pressing `CTRL + SHIFT + P` or `F1` and then entering `>TypeScript: Select TypeScript Version...` after you have done so you want to select `Use Workspace Version`.
This will also add:
```json
"typescript.tsdk": "node_modules\\typescript\\lib"
```
to `settings.json` in the `.vscode` directory of your project.
## Result
You can easily identify what file belongs to what directory and therefore you for example do not have multiple "page.tsx" that you have to guess which one is correct. | maxwiggedal |
1,911,634 | A Q&A Review of Coding Ninjas Full Stack Development Job Bootcamp | 1. What inspired you to join this bootcamp, and what were your goals when you first signed up? The... | 0 | 2024-07-04T14:01:11 | https://dev.to/mira_mathur/a-qa-review-of-coding-ninjas-full-stack-development-job-bootcamp-f0f | **1. What inspired you to join this bootcamp, and what were your goals when you first signed up?**
The structured content and roadmap of the curriculum inspired me to choose this program. I was looking forward to becoming a full stack developer, and this bootcamp promised to provide a comprehensive path towards that goal.
**2. How did the bootcamp meet your expectations, and what were the most valuable aspects of the program for you?**
I landed multiple offers during and after the program. The most valuable aspects were the scheduled tests and curated questions, which provided ample practice opportunities.
**3. In what ways did the program help you improve your skills and knowledge as a full stack developer?**
The program covered a comprehensive set of topics, including front-end and back-end development, databases, server architecture, and deployment strategies. The hands-on experience was particularly beneficial in solidifying my understanding of these areas.
**4. How did the job assistance component of the program help you in your job search, and what kind of support did you receive?**
The placement cell reached out to me regularly, even after completing the program, for potential job openings. Their support was exceptional, and they did a fabulous job in assisting with my job search.
**5. Can you describe any particularly memorable or impactful moments during your time in the bootcamp?**
One memorable moment was being in the top 3 star performers of the week during the backend courses. Seeing my name up there was a great feeling and a testament to the hard work and dedication I put into the program.
**6. How would you describe the instructors and mentors in the program, and how did they contribute to your learning experience?**
The mentors had vast experience and knowledge in their domain areas. They made difficult problems and algorithms easier to understand by first explaining concepts using pen and paper before moving to hands-on exercises. Their teaching approach greatly enhanced my learning experience.
**7. Did you feel like the program was well-organized and efficient in terms of its structure and curriculum?**
Yes. Each component was thoughtfully arranged to build upon the previous one, allowing for a seamless learning experience that was logical and coherent.
**8. What advice would you give to someone who is considering joining this bootcamp?**
I would advise anyone, from freshers looking to land a good job at the start of their career to professionals seeking a thorough understanding of web development, to give this course a try. The comprehensive curriculum and support system make it an excellent choice for anyone serious about becoming a full stack developer.
**9. Lastly, would you recommend this bootcamp to others who are interested in becoming full stack developers? If so, why?**
Yes, I would definitely recommend this bootcamp for full stack development. It offers 24x7 doubt-solving support, highly skilled teaching assistants, certificates upon course completion with a minimum grade of 60%, regular tests and assignments, and a well-designed course structure that helps individuals become proficient in web development.
**9. What advice do you have for aspiring learners?**
Focus on what you can do, instead of blaming your circumstances. The world is full of opportunities for those who take action on their dreams.
_As responded by Supratik De, Senior Software Engineer @ UKG._ | mira_mathur |
|
1,836,383 | Protecting Sensitive Data using Ansible Vault | Introduction: In this tutorial we will explore Ansible Vault which is a feature of ansible... | 0 | 2024-07-04T13:58:07 | https://dev.to/ideategudy/protecting-sensitive-data-using-ansible-vault-5h7k | ansible, devops, cloudcomputing, security | ## Introduction:
In this tutorial we will explore Ansible Vault which is a feature of ansible that comes pre-installed. We will discuss what Ansible Vault is, and how it can be used for effective management of information such as passwords, API keys, files and other sensitive data.
## Prerequisites:
You need to have Ansible installed to be able to follow along with this tutorial. If you don’t have Ansible installed yet follow this tutorial on how to [install Ansible on Ubuntu 20.04](https://www.cherryservers.com/blog/how-to-install-and-configure-ansible-on-ubuntu-20-04).
Proceed with this guide once your server has been configured with the above requirements.
### Table of Contents
- What is Ansible
- What is Ansible Vault
- How to use Ansible Vault
- Best Practices for Using Ansible Vault
- Conclusion
### What is Ansible
Ansible is an open-source automation tool that simplifies IT tasks such as configuration management, application deployment, and orchestration by allowing users to automate repetitive tasks using simple, declarative YAML-based scripts called playbooks.
### What is Ansible Vault
Ansible Vault is a feature of ansible which provides a secure way for managing sensitive information such as API keys, password or even private data within your playbook or file. Ansible Vault uses the AES256 algorithm which is a symmetric form of encryption that uses a single key (or password ) for encrypting and decrypting data unlike the asymmetric that uses a private and public key pair.
Ansible Vault has several arguments used to manipulate files such as `create, edit, view, encrypt, decrypt, rekey, encrypt_string, decrypt_string`
### How to use Ansible Vault
The `ansible-vault` command acts as the primary interface for managing encrypted content within Ansible. It facilitates the encryption of files initially and subsequently enables operations such as viewing, editing or decrypting the encrypted data.
#### How to create a new encrypted file
Use the `ansible-vault create` command, followed by the name of the file to create a new encrypted file. This command will prompt you to enter and confirm the password for the newly created file.
```
ansible-vault create secret.yml
```
Your new file will open in your default text editor where you can type your secret texts and save.
Note: You can access your decrypted texts by providing the password or pass key you provided during encryption process.
#### How to encrypt an existing file
Use the `ansible-vault encrypt` command, followed by the name of the file, to encrypt an already existing file
```
ansible-vault encrypt file.txt
```
#### How to view an encrypted file
Use the `ansible-vault view`command, followed by the name of the file
```
ansible-vault view secret.yml
```
#### How to edit an encrypted file
Use the `ansible-vault edit` command, followed by the name of the file
```
ansible-vault edit secret.yml
```
#### How to decrypt an encrypted file
Use the `ansible-vault decrypt` command, followed by the name of the file
```
ansible-vault decrypt file.txt
```
#### How to change the password of an encrypted file
Use the `ansible-vault rekey` command, followed by the name of the file
```
ansible-vault rekey secret.yml
```
You will be prompted to enter the current password of the file and afterwards you can enter and confirm the new password
#### Saving your password to a file
Saving your password to a file (make sure the file is not tracking by version control) and specifying the path to the file is also another way of performing different operations without typing the password always on the terminal prompt.
This password should be auto generated by a password generator software and not hard coded to increase security.
#### Random Password Generator
This key should be kept private and should not be committed to version control
#### How to decrypt an encrypted file during playbook run-time
Let’s say for instance you encrypt your inventory/hosts file that has the IP address of your slave servers, you can run your playbook without decrypting first. Just specify the path to your password file in your command or input the password before playbook runs
`— — ask-vault-pass:` This will prompt you to input your password
ansible-playbook -i ../hosts main.yml --key-file ~/.ssh/ansible --ask-vault-pass
`- - vault-password-file:` This will use the password file directly without asking for password
```
ansible-playbook -i ../hosts main.yml --key-file ~/.ssh/ansible --vault-password-file ~/ansible_vault/vault_pass.txt
```
#### Using encrypted variables in playbook
You can access an encrypted variable file using the normal method by including your variable file in your playbook
```
---
- name: Configure Servers (Ubuntu and CentOS)
hosts: all
vars_files:
- secret_vars.yml
become: true
tasks:
- name: Update Repository Index (Ubuntu and CentOS)
package:
update_cache: yes
changed_when: false
- name: Clone github repo
git:
repo: "{{ github_repo }}"
dest: "/home/vagrant/test"
force: yes
```
### Best Practices for Using Ansible Vault
- Use Strong Passwords: Ensure passwords are complex and secure.
- Version Control: Track encrypted files in version control but never push your password file to it
- Backup Encrypted Files: Prevent data loss with regular backups.
- Password Access: Regularly audit who has access to view your password file.. you can use the chmod to set permissions
### Conclusion
Ansible Vault is a useful tool for managing secret information stored in files by encryption and decryption. To learn more about ansible vault visit the official ansible-vault documentation page. | ideategudy |
1,911,360 | Memoization in Javascript Explained | Code optimization is a critical aspect of web development and JavaScript offers various techniques to... | 0 | 2024-07-04T13:54:50 | https://dev.to/joanayebola/memoization-in-javascript-explained-3922 | beginners, tutorial, javascript | Code optimization is a critical aspect of web development and JavaScript offers various techniques to achieve this goal. One such powerful technique is **memoization.**
This article discusses the concept of memorization in JavaScript. We'll explore its benefits, understand when it's most effective, and equip you with various techniques to implement it in your code.
We'll also provide practical examples to illustrate how memorization can boost the performance of your applications. Finally, we'll discuss some considerations and best practices for using memorization effectively in your JavaScript projects.
### Table of Contents
1. [What is Memoization](#what-is-memoization)
2. [Benefits of Memoization](#benefits-of-memoization)
3. [When to Use Memoization](#when-to-use-memoization)
4. [Techniques for Memoization in JavaScript](#techniques-for-memoization)
5. [Practical Examples of Memoization](#practical-examples-of-memoization)
6. [Considerations and Best Practices for Memoization](#considerations-and-best-practices-for-memoization)
7. [Conclusion](#conclusion)
## What is Memoization?
Memoization, in the context of programming, is an optimization strategy that enhances a function's performance. It works by storing the results of previous function calls based on their inputs. When the function encounters the same inputs again, it retrieves the pre-computed result from this cache instead of re-executing the entire computation. This approach can significantly improve the speed of your JavaScript code, especially for functions that involve complex calculations or repetitive tasks.
## Benefits of Memoization
Memoization in JavaScript offers several benefits, primarily focused on improving performance by caching expensive function results. Here are the key advantages:
#### Performance Optimization:
Memoization helps speed up function execution by storing the results of expensive function calls and returning the cached result when the same inputs occur again. This avoids redundant computations.
```javascript
function fibonacci(n) {
if (n <= 1) return n;
// Memoization logic
if (!fibonacci.cache) {
fibonacci.cache = {};
}
if (fibonacci.cache[n]) {
return fibonacci.cache[n];
}
fibonacci.cache[n] = fibonacci(n - 1) + fibonacci(n - 2);
return fibonacci.cache[n];
}
```
#### Reduction in Recalculation
Especially useful for recursive algorithms like factorial or Fibonacci sequence calculations, memoization ensures that previously computed results are reused, reducing unnecessary recalculations.
```javascript
function factorial(n) {
if (n === 0 || n === 1) return 1;
if (!factorial.cache) {
factorial.cache = {};
}
if (factorial.cache[n]) {
return factorial.cache[n];
}
factorial.cache[n] = n * factorial(n - 1);
return factorial.cache[n];
}
```
#### Simplicity and Readability
Once implemented, memoization can simplify code by separating the caching logic from the main function logic, making the function easier to understand and maintain.
```javascript
const memoizedAdd = (function() {
const cache = {};
return function(x, y) {
const key = ${x},${y};
if (cache[key]) {
return cache[key];
}
const result = x + y;
cache[key] = result;
return result;
};
})();
```
#### Space-Time Tradeoff
While memoization saves computation time, it trades off with increased space complexity due to storing cached results. However, this tradeoff is often worthwhile for significant performance gains.
## When to Use Memoization
Memoization in JavaScript is particularly beneficial in scenarios where function calls are computationally expensive and frequently repeated with the same inputs. Here are specific situations where you should consider using memoization:
#### Recursive Functions
When implementing recursive algorithms such as calculating Fibonacci numbers, factorial, or traversing trees, memoization can drastically reduce the number of redundant function calls by caching previously computed results.
```javascript
function fibonacci(n, memo = {}) {
if (n in memo) return memo[n];
if (n <= 1) return n;
memo[n] = fibonacci(n - 1, memo) + fibonacci(n - 2, memo);
return memo[n];
}
```
#### Functions with Expensive Computations
If your function involves heavy computations or database queries that result in the same output for identical inputs across multiple calls, memoization can save processing time by storing results in memory.
```javascript
function fetchDataFromAPI(userId, cache = {}) {
if (userId in cache) {
return cache[userId];
}
const data = fetchDataFromExternalAPI(userId); // Expensive operation
cache[userId] = data;
return data;
}
```
#### Pure Functions
Memoization works best with pure functions, which always return the same output for the same inputs and have no side effects. This ensures the cached results remain consistent and predictable.
```javascript
function pureFunction(x, y, cache = {}) {
const key = ${x},${y};
if (key in cache) {
return cache[key];
}
const result = / Some computation /;
cache[key] = result;
return result;
}
```
#### Dynamic Programming
When implementing dynamic programming algorithms where solutions to subproblems are reused multiple times, memoization helps in storing these subproblem solutions efficiently.
```javascript
const memo = {};
function knapsack(capacity, weights, values, n) {
if (n === 0 || capacity === 0) return 0;
const key = ${n}-${capacity};
if (memo[key]) return memo[key];
if (weights[n-1] > capacity) {
return memo[key] = knapsack(capacity, weights, values, n-1);
} else {
return memo[key] = Math.max(values[n-1] + knapsack(capacity - weights[n-1], weights, values, n-1),
knapsack(capacity, weights, values, n-1));
}
}
```
#### Iterative Algorithms with Repeated Computations
Even in non-recursive scenarios, memoization can be applied to iterative algorithms where certain computations are repeated for the same inputs.
```javascript
function iterativeAlgorithm(inputs, cache = {}) {
if (inputs in cache) {
return cache[inputs];
}
let result = / Some iterative computation /;
cache[inputs] = result;
return result;
}
```
## Techniques for Memoization in JavaScript
Now that we understand what Memoization entails, here are some techniques for memoization in JavaScript:
### Caching Functions
This technique is particularly useful for optimizing applications that involve repetitive computations or resource-intensive operations.
####Simple Caching with Closures:
One of the straightforward ways to implement memoization is by using closures to maintain a cache within the function scope. Here’s how you can achieve it:
```javascript
function memoizedFunction() {
const cache = {}; // Cache object to store results
return function(input) {
if (input in cache) {
return cache[input]; // Return cached result if available
}
// Compute result for new input
const result = / Some expensive computation /;
// Store result in cache
cache[input] = result;
return result;
};
}
const memoized = memoizedFunction();
// Usage
console.log(memoized(5)); // Computes and caches result for input 5
console.log(memoized(5)); // Returns cached result for input 5
```
#### Using the cache Object:
Another approach is to directly attach a cache object to the function itself, especially useful when you want to keep the cache separate from other variables:
```javascript
function fibonacci(n) {
if (fibonacci.cache === undefined) {
fibonacci.cache = {};
}
if (n in fibonacci.cache) {
return fibonacci.cache[n];
}
if (n <= 1) {
return n;
}
fibonacci.cache[n] = fibonacci(n - 1) + fibonacci(n - 2);
return fibonacci.cache[n];
}
// Usage
console.log(fibonacci(6)); // Computes and caches results for fibonacci sequence up to 6
console.log(fibonacci(6)); // Returns cached result for fibonacci sequence up to 6
```
### Using a Map Object
Using a Map object in JavaScript is a modern and efficient way to implement memoization, as Map allows any type of keys, including objects.
```javascript
function memoizedFunction() {
const cache = new Map(); // Map object to store results
return function(input) {
if (cache.has(input)) {
return cache.get(input); // Return cached result if available
}
// Compute result for new input
const result = / Some expensive computation /;
// Store result in cache
cache.set(input, result);
return result;
};
}
const memoized = memoizedFunction();
// Usage
console.log(memoized(5)); // Computes and caches result for input 5
console.log(memoized(5)); // Returns cached result for input 5
```
### Memoization with Decorators (Optional: Advanced)
Memoization can also be applied using decorators in JavaScript, which is an advanced technique typically used in functional programming or with libraries like lodash.
```javascript
function memoize(fn) {
const cache = new Map();
return function(...args) {
const key = JSON.stringify(args);
if (cache.has(key)) {
return cache.get(key);
}
const result = fn.apply(this, args);
cache.set(key, result);
return result;
};
}
// Usage
const fibonacci = memoize(function(n) {
if (n <= 1) return n;
return fibonacci(n - 1) + fibonacci(n - 2);
});
console.log(fibonacci(6)); // Computes and caches results for fibonacci sequence up to 6
console.log(fibonacci(6)); // Returns cached result for fibonacci sequence up to 6
```
In this example, the memoize function wraps any function with memoization capability by storing results in a Map based on the function arguments (args). This technique is particularly powerful when you need to memoize any function dynamically.
## Practical Examples of Memoization
Let's discuss practical examples of memoization in JavaScript for both Fibonacci sequence calculation and expensive function calls like API requests:
### Fibonacci Sequence Calculation
The Fibonacci sequence is a classic example where memoization can significantly improve performance, especially for larger numbers.
```javascript
// Memoization function using closure
function fibonacci() {
const cache = {}; // Cache object to store computed results
return function(n) {
if (n in cache) {
return cache[n]; // Return cached result if available
}
if (n <= 1) {
return n;
}
// Compute result for new input
const result = fibonacci(n - 1) + fibonacci(n - 2);
// Store result in cache
cache[n] = result;
return result;
};
}
const memoizedFibonacci = fibonacci();
// Usage
console.log(memoizedFibonacci(6)); // Computes and caches results for fibonacci sequence up to 6
console.log(memoizedFibonacci(6)); // Returns cached result for fibonacci sequence up to 6
```
In this example, the fibonacci function uses memoization via closure to store previously computed Fibonacci numbers in the cache object. Subsequent calls to memoizedFibonacci with the same input retrieve the result from the cache, avoiding redundant calculations.
### Expensive Function Calls (e.g., API Calls)
Memoization is also valuable for optimizing functions that make expensive API calls, ensuring that repeated calls with the same parameters retrieve data from cache rather than re-executing the API request.
```javascript
// Example of an API fetching function with memoization
function fetchDataFromAPI(endpoint) {
const cache = {}; // Cache object to store fetched data
return async function() {
if (cache[endpoint]) {
return cache[endpoint]; // Return cached result if available
}
// Simulate API call
const response = await fetch(endpoint);
const data = await response.json();
// Store data in cache
cache[endpoint] = data;
return data;
};
}
const memoizedFetchData = fetchDataFromAPI('https://api.example.com/data');
// Usage
memoizedFetchData().then(data => {
console.log(data); // Fetches data from API and caches it
return memoizedFetchData(); // Returns cached data from previous fetch
}).then(data => {
console.log(data); // Returns cached data again without fetching from API
});
```
In this example, fetchDataFromAPI memoizes the results of API requests using a closure and an object cache. Each unique endpoint parameter ensures that API responses are cached and reused, minimizing network requests and improving application performance.
## Considerations and Best Practices for Memoization
Memoization in JavaScript can significantly improve performance, but there are important considerations and best practices to keep in mind to use it effectively:
### When to Avoid Memoization
1. Non-Pure Functions: Memoization works best with pure functions, which always return the same output for the same inputs and have no side effects. If your function modifies external state or relies on global variables that can change, memoization may produce incorrect results.
2. High Memory Usage: Memoization involves storing results in memory, which can lead to increased memory usage for applications with large inputs or when caching many results. Be mindful of memory constraints and consider trade-offs between performance gains and memory consumption.
3. Dynamic Inputs: Functions with dynamic or constantly changing inputs might not benefit from memoization. If the inputs change frequently and unpredictably, caching results might become ineffective or lead to stale data.
#### Handling Changing Inputs and Invalidation
1. Immutable Inputs: Ensure that function inputs are immutable or do not change during the function execution. This ensures that the cached results remain valid for the given inputs.
2. Cache Invalidation: Implement mechanisms to invalidate or clear the memoization cache when necessary, especially if the underlying data or conditions change. This can be achieved by resetting or updating the cache based on certain triggers or events.
```javascript
function clearCache() {
memoizedFunction.cache = {};
}
```
3. Time-based Expiration: For scenarios where data validity is time-sensitive (e.g., data fetched from an API that updates periodically), consider implementing expiration mechanisms to automatically clear cached results after a certain period.
### Clearing the Memoization Cache
Sometimes, you may need to clear the memoization cache explicitly, especially in applications where inputs or conditions change over time. Here’s a simple example of how you can clear the cache:
```javascript
function memoizedFunction(input) {
if (!memoizedFunction.cache) {
memoizedFunction.cache = {};
}
if (input in memoizedFunction.cache) {
return memoizedFunction.cache[input];
}
const result = / Some computation based on input /;
memoizedFunction.cache[input] = result;
return result;
}
// Example of clearing the cache
function clearCache() {
memoizedFunction.cache = {};
}
```
#### Conclusion
In Conclusion, memoization in JavaScript stands out as a powerful strategy for enhancing performance in computationally intensive applications. By caching the results of function calls based on their inputs, memoization avoids unnecessary recalculations.
That's all for this article! If you'd like to continue the conversation or have questions, suggestions, or feedback, feel free to reach out to connect with me on [LinkedIn](https://ng.linkedin.com/in/joan-ayebola). And if you enjoyed this content, consider [buying me a coffee](https://buymeacoffee.com/joanayebola) to support the creation of more developer-friendly contents. | joanayebola |
1,911,625 | Pub/Sub pattern vs Observer Pattern: what's the difference? | Over the past few weeks, I've been delving into the trending design patterns in frontend development.... | 27,620 | 2024-07-04T13:53:12 | https://dev.to/superviz/pubsub-pattern-vs-observer-pattern-whats-the-difference-10mb | javascript, learning, webdev, coding | Over the past few weeks, I've been delving into the trending design patterns in frontend development. I've covered the [Singleton](https://dev.to/superviz/design-pattern-1-singleton-for-frontend-developers-14p9), the [Facade](https://dev.to/superviz/design-pattern-2-facade-pattern-1dhl), the [Observer](https://dev.to/superviz/design-pattern-3-observer-pattern-36eo), and most recently, the [Pub Sub Pattern Design](https://dev.to/superviz/design-pattern-4-publishersubscriber-pattern-4jg9).
The last two articles focused on the Pub/Sub and Observer patterns. While these two patterns share some conceptual similarities, I thought it would be interesting to explore their differences. Hence, this post.
## Main difference
Both of these patterns have a concept of publishing something and subscribing to an observer, right? So what’s the difference?
The Observer pattern solves this by allowing the Client to attach itself as an Observer to the Store. When the iPhone arrives, the store notifies all attached Observers. While in the PubSub application, it publishes an event/data to an event broker, and then the subscribers listen for it. The publisher is unaware of its observers.
In our Client-Store scenario, the event broker of the PubSub application could be like a marketplace. It would need to keep track of product availability in the store. When a new iPhone arrives, the marketplace system would register this event and notify all subscribers (customers who expressed interest in the iPhone) by sending them an email or a push notification.
Observer patterns are mostly used when you want different parts of a single application to share data with each other, usually in real-time. In this case, the entity providing the data is aware of who is receiving it.
On the other hand, the Pub-Sub pattern allows data to be shared across multiple applications. This usually happens asynchronously but can be made synchronous using specific SDKs, like the SuperViz Real-time Data Engine. In this pattern, the one sharing the data doesn't know who's receiving it - they just put it out there for anyone interested.
The main difference is that the Pub-Sub pattern supports a more decoupled architecture, where the data sharers and receivers can work independently from each other. This is not the case in the Observer pattern.
### Use Cases for Observer Patterns
Observer Patterns are often used in GUI development, where one part of the application (the button) needs to notify another part of the application (the click event handler) when a certain event (the button being clicked) occurs.
### Use Cases for Publisher Subscriber Pattern
In the context of frontend development, Publisher Subscriber Patterns can be instrumental. For instance, in a complex web application, different components may need to exchange data in real-time, like in a chat application, tracking the GPS of a taxi, or even real-time stock market data updates. These are situations where different components need to stay updated without having a direct relationship with each other.
Let me know in the comments area if you have other scenarios where the Observer or the PubSub is helpful.
## Real-time Data Engine
If you're building a web application that requires real-time data sharing and communication, [SuperViz](http://superviz.com/) is an SDK tool worth considering. It offers a [real-time collaboration and communication SDK and API](https://docs.superviz.com/react-sdk/presence/real-time-data-engine), designed for developers building real-time web applications.
Using SuperViz, you can create a room with several participants. When publishing an event, it will be broadcasted to all the participants in the room who are accessing it through different devices and networks. This means that any updates made by one participant will be reflected in real time across all devices, providing a seamless and collaborative experience.
SuperViz provides the infrastructure necessary to build real-time, collaborative applications. This includes the ability to catch these events on your backend using webhooks, as well as to publish an event with a simple HTTP Request, to name a few features.
You can easily test it with our [open-source sample codes](https://github.com/SuperViz/samples) that run with a glance. | vtnorton |
1,911,624 | Pessoas desenvolvedoras precisam estudar todos os dias | A tecnologia está tão presente em nossas vidas que passamos a considerá-la como um item essencial.... | 0 | 2024-07-04T13:51:06 | https://dev.to/kecbm/pessoas-desenvolvedoras-precisam-estudar-todos-os-dias-5dea | braziliandevs, beginners, tutorial, productivity | 
**A tecnologia está tão presente em nossas vidas que passamos a considerá-la como um item essencial**. Podemos resolver todas as obrigações diárias por intermédio de um dispositivo que possua acesso à internet. Essa realidade só é possível porque as pessoas que trabalham nos bastidores das aplicações entregam seu melhor diariamente.
## O Mundo em Constante Evolução
A tecnologia muda constantemente. No tempo de nossos avós era bastante comum as pessoas se comunicarem por cartas. Demorava meses para receber notícias de um amigo ou parente na época, e muito provavelmente não era uma forma barata e acessível para entrar em contato com alguém, dado os custos com transporte. **Hoje podemos nos comunicar com qualquer pessoa no mundo, com poucos cliques**.
## A Importância de se Manter Atualizado
A tecnologia também se reinventa com o passar dos anos, para que seja possível desenvolver novos produtos e continuar impactando a vida das pessoas. Assim, **estudar todos os dias é uma característica básica de uma pessoa desenvolvedora**. Com a aprendizagem contínua ela irá evoluir seu conhecimento técnico e comportamental, o que irá impulsionar sua carreira.
## Benefícios da Aprendizagem Diária
Quando estudamos todos os dias vamos nos deparar com novos assuntos e novas situações, para adquirir conhecimento e praticar a habilidade de resolução de problemas. **Codificar todos os dias é afiar constantemente o machado para entregar cada vez mais valor através do seu trabalho**, seja ele para um empregador ou na sua própria empresa. É prazeroso solucionar um problema que você já estudou antes.
## Recursos para Estudo
Como pessoa desenvolvedora temos acesso a diversas fontes de conhecimento. Podemos aprender com livros, cursos on-line, eventos, comunidades de tecnologia e principalmente, codificando publicamente, o build in public. **Colocar a mão na massa é a melhor forma de aprender**. Em tecnologia isso significa desenvolver um projeto e disponibilizá-lo para as pessoas, subir para produção. Chamamos de produção o ambiente final da aplicação, todos os sites que você visita é a produção daquele sistema.
## Estratégias para uma Rotina de Estudo Eficiente
Para estudar todos os dias é crucial definir seu horário de estudo, determinando por quanto tempo você vai estudar e os temas nos quais você quer se aprofundar. Eu estudo 3 horas por dia, contemplando leitura, inglês e criação ou manutenção side project. Com o tempo e assuntos escolhidos, basta manter a disciplina e estudar todos os dias. **O que vai fazer você avançar é a disciplina e a persistência**.
O que faz de uma pessoa desenvolvedora especialista em sua função é o conhecimento acumulado ao longo do tempo de atuação e estudos. Na tecnologia vamos aprender muito na nossa rotina de trabalho, o que nos dará experiência de mercado. Mas o diferencial é nos mantermos sempre com o espírito de eternos aprendizes, para desbravarmos as novas opções que vão surgindo no mundo. **Mantenha seu compromisso com os estudos sempre em dia, porque o tempo não pára e nem espera por ninguém**.
> Imagens geradas pelo **DALL·E 3** | kecbm |
1,911,623 | 10 Terminal Tricks to Boost Your Productivity | In the rapidly evolving world of technology, efficiency is paramount. Despite being more... | 0 | 2024-07-04T13:50:58 | https://www.nilebits.com/blog/2024/07/10-terminal-tricks-boost-productivity/ | bash, linux, terminal, shell | In the rapidly evolving world of technology, efficiency is paramount. Despite being more user-friendly, many developers and IT professionals discover that utilizing graphical user interfaces (GUIs) is often slower and less efficient than using terminals. You will produce much more if you get proficient with terminal commands and strategies. This article will go over ten essential terminal techniques that can [boost](https://www.nilebits.com/blog/2024/03/software-engineers-tools-that-supercharge-productivity/) your everyday job output and efficacy.
1. Mastering Basic Navigation
One of the first steps to becoming proficient with the terminal is mastering basic navigation. Understanding how to quickly and efficiently move around the file system is crucial. Here are some fundamental commands:
pwd (Print Working Directory): This command displays the current directory you are in. It's useful for knowing your exact location in the file system.
```
$ pwd
/home/user/projects
```
cd (Change Directory): This command changes your current directory. For example, to navigate to the /home/user/projects directory:
```
$ cd /home/user/projects
```
ls (List): This command lists the contents of a directory. You can use various flags to modify its behavior, such as -l for a detailed list and -a to show hidden files.
```
$ ls -la
total 32
drwxr-xr-x 2 user user 4096 Jul 4 12:34 .
drwxr-xr-x 3 user user 4096 Jul 4 12:34 ..
-rw-r--r-- 1 user user 220 Jul 4 12:34 .bash_logout
-rw-r--r-- 1 user user 3771 Jul 4 12:34 .bashrc
-rw-r--r-- 1 user user 675 Jul 4 12:34 .profile
```
Understanding these basic commands is the foundation for efficient terminal usage.
2. Utilizing Aliases for Common Commands
Creating aliases for frequently used commands can save a lot of time. Aliases are shortcuts for longer commands. You can set them in your shell configuration file (e.g., .bashrc or .zshrc).
For example, if you often list files with ls -la, you can create an alias for it:
```
alias ll='ls -la'
```
Add this line to your .bashrc or .zshrc file and then source the file:
```
$ source ~/.bashrc
```
Now, you can simply type ll to execute ls -la.
3. Command History and Reuse
The terminal keeps a history of the commands you’ve executed, allowing you to reuse them without retyping. Use the history command to view your command history:
```
$ history
1 cd /home/user/projects
2 ls -la
3 pwd
...
```
You can quickly execute a previous command by using ! followed by the command number. For example, to run the first command again:
```
$ !1
```
Additionally, you can use the Ctrl + r shortcut to search through your command history. Start typing a command, and the terminal will search backward through the history for matches.
4. Tab Completion
Tab completion is a powerful feature that saves time and reduces errors. It automatically completes commands, file names, and directory names. For example, if you want to change to the /home/user/projects directory, you can type part of the path and press Tab:
```
$ cd /ho[TAB]/us[TAB]/pr[TAB]
```
The terminal will automatically complete the path if it's unambiguous. If there are multiple matches, pressing Tab twice will list the possible completions.
5. Using Pipes and Redirection
Pipes and redirection are fundamental concepts that allow you to connect commands and manipulate output efficiently.
Pipes (|): Use pipes to pass the output of one command as input to another. For example, to list files and search for a specific pattern:
```
$ ls -la | grep ".txt"
```
Redirection (> and >>): Use redirection to send command output to a file. The > operator overwrites the file, while >> appends to it. For example, to save the output of ls -la to a file:
```
$ ls -la > file_list.txt
```
To append the output:
```
$ ls -la >> file_list.txt
```
Understanding and utilizing these concepts can significantly streamline your workflow.
6. Advanced Search with grep and find
Efficient searching is essential for productivity. The grep and find commands are powerful tools for searching within files and directories.
grep: Use grep to search for patterns within files. For example, to search for the word "error" in a log file:
```
$ grep "error" /var/log/syslog
```
You can also use various options like -r for recursive search, -i for case-insensitive search, and -n to show line numbers.
find: Use find to search for files and directories. For example, to find all .txt files in the /home/user/projects directory:
```
$ find /home/user/projects -name "*.txt"
```
Combine find with exec to execute commands on the found items. For example, to delete all .tmp files:
```
$ find /home/user/projects -name "*.tmp" -exec rm {} \;
```
Mastering these search tools can save a significant amount of time when working with large codebases or datasets.
7. Customizing Your Shell Prompt
Customizing your shell prompt can improve your workflow by providing useful information at a glance. You can customize the prompt by modifying the PS1 variable in your shell configuration file.
For example, to display the username, hostname, and current directory:
```
PS1='\u@\h:\w\$ '
```
This results in a prompt like this:
```
user@hostname:/home/user/projects$
```
You can further customize the prompt with colors and additional information. For example, to add colors:
```
PS1='\[\e[1;32m\]\u@\h:\[\e[0m\]\[\e[1;34m\]\w\[\e[0m\]\$ '
```
This results in a colored prompt, making it easier to distinguish different parts of the prompt and improve readability.
8. Automating Tasks with Scripts
Automating repetitive tasks with scripts can drastically boost your productivity. [Shell scripts](https://www.linkedin.com/pulse/devops-automation-shell-scripts-amr-saafan-sfg0f/) allow you to combine multiple commands and logic into a single executable file.
For example, here’s a simple script to back up a directory:
```
#!/bin/bash
SOURCE_DIR="/home/user/projects"
BACKUP_DIR="/home/user/projects_backup"
mkdir -p $BACKUP_DIR
cp -r $SOURCE_DIR/* $BACKUP_DIR/
```
echo "Backup completed successfully."
Save this script as backup.sh, make it executable, and run it:
```
$ chmod +x backup.sh
$ ./backup.sh
```
This script creates a backup of the specified directory. By scripting repetitive tasks, you can save time and reduce the risk of errors.
9. Using tmux for Session Management
tmux is a terminal multiplexer that allows you to manage multiple terminal sessions within a single window. It enables you to detach and reattach sessions, making it ideal for long-running processes or remote work.
Starting tmux: Simply run tmux to start a new session:
```
$ tmux
```
Detaching and Reattaching: Detach from the session with Ctrl + b, followed by d. Reattach to the session with:
```
$ tmux attach
```
Splitting Panes: Split the terminal into multiple panes for multitasking. Split horizontally with Ctrl + b, followed by %. Split vertically with Ctrl + b, followed by ".
```
$ tmux split-window -h
$ tmux split-window -v
```
By mastering tmux, you can manage complex workflows and keep your terminal organized.
10. Using ssh for Remote Access
Secure Shell (ssh) is essential for accessing remote servers. Understanding ssh and its capabilities can greatly enhance your productivity when working with remote systems.
Connecting to a Remote Server: Use ssh to connect to a remote server:
```
$ ssh user@remote-server
```
Copying Files with scp: Use scp (Secure Copy) to transfer files between local and remote systems. For example, to copy a file from the local system to the remote server:
```
$ scp localfile.txt user@remote-server:/path/to/destination
```
Using ssh Keys: Enhance security and convenience by using ssh keys instead of passwords. Generate a key pair with:
```
$ ssh-keygen
```
Copy the public key to the remote server:
```
$ ssh-copy-id user@remote-server
```
By leveraging ssh and its related tools, you can efficiently manage and interact with remote systems.
Conclusion
Mastering the terminal can significantly boost your productivity by streamlining your workflow and reducing the time spent on repetitive tasks. The tricks and commands covered in this article are just the beginning. Continually exploring and learning new terminal techniques will further enhance your efficiency and effectiveness in your daily work.
Remember, the terminal is a powerful tool, and the more proficient you become, the more you can accomplish with less effort. Keep practicing these tricks, and soon you'll notice a substantial improvement in your productivity. | amr-saafan |
1,911,622 | Interactive and Hands-On Learning in Kindergarten Workbooks | The academic skill practice workbooks available for use in kindergarten education have changed from... | 0 | 2024-07-04T13:50:57 | https://dev.to/davidsmith45/interactive-and-hands-on-learning-in-kindergarten-workbooks-4a4l | The academic skill practice workbooks available for use in kindergarten education have changed from the more conventional printed handwriting assignments to those works that are more complex and contain both paper and pencil activities as well as manipulative and creative involvement of the young learners. The focus of this article is on elements of interactivity present in Tasks for Five-Year-Olds, the opportunities they open for a child, and ideas of fresh approaches to the practical activities for the development of Head Start [kindergarten workbooks](https://www.popularbook.ca/products/ebooks-for-kids).
## The Importance of Interactive Learning
Interactive learning therefore is a concept that enforces students' active participation in the learning process. For kindergarteners, this translated into something that cannot be just reading or listening. Interactive workbooks often include:
Games and Puzzles: These aspects can help a child learn problem-solving skills and make learning concepts in school effective through play.
Coloring and Drawing: Now, a number of art activities contribute to the development of fine motor skills and enable a child to be creative apart from learning.
Stickers and Manipulatives: All these objects may be helpful for matching, counting or telling sessions and make the concrete, what is abstract at first sight.
Digital Components: Most present-day exercise books are usually associated with applications or Websites so workbooks come with options such as sound, animation, and feedback.
## Hands-On Learning Benefits
As the name suggests, hands-on learning is a kind of learning where the students are taught in a practical manner. It enables fundamentals to be practically applied so that children can use all their senses effectively. This method is particularly beneficial for young children because: This method is particularly beneficial for young children because:
Kinesthetic Learning: The major learning area for young children focuses on the aspects of movement space and touch. More structured tasks as constructing with blocks, sorting shapes, or using letter tiles for touching and handling in addition to seeing, assist with consolidate knowledge through kinesthetic learning.
Real-World Connections: Practical lessons, for example, pretty much depict real life, this makes kids appreciate the usefulness of what they are learning. For example, a counting activity might be the use of money for purchases of items during the counting activity helping students associate math with reality.
Enhanced Engagement: Here, one is able to infer that children who are active engage themselves more and hence can retain information being taught. Practical assignments imply that knowledge is acquired with fun rather than forcing Kids to go through lots of exercises.
## Setting up the Great Interactive and Hands-On Workbooks
Designing workbooks that allow for an integration of the aspects of interactivity and manipulatives entails considerable effort. Here are some key considerations: Here are some key considerations:
Developmental Appropriateness: These activities ought to be appropriate for the ages of the children as well as the developmental level. This makes the tasks to be well within reach but a bit demanding to make the Lazarus work not to get frustrated emphasizing on the accomplishment of tasks.
Clear Instructions: It is quite important to notice that every activity should help students develop independent learning skills, but at the same time, all instructions on different tasks should be clear and easy to understand. This facilitates in conveying what is expected, and how it should be done, to the children.
Diverse Activities: They have a number of activities to ensure that all a child’s areas of learning ability are fed and that general boredom is discouraged. It is easy to make sessions varied since one can combine games, arts and crafts, storytelling, and physical activities.
Integration of Core Skills: Literacy, numeracy, and social skills highlighted should be an integral component of any workbook’s activities. For instance, there may be counting along with reading instructions as well as working in groups as one of the performed activities.
Integration of Core Skills: They see that there should be an enhanced integration of literacy, numeracy, as well as social skills into workbook activities. For instance, counting may require the realization that the numbers being counted are present on a chart, reading numbers in instructions may be necessary for an activity, and peer cooperation is required to accomplish an activity.
## Examples of Interactive and Hands-On Workbook activities
Interactive Storytelling: A type of using a workbook might be a story where the child creates pictures, stickers, etc., based on a story provided might even have a corresponding application for reading the story for the child.
Math Manipulatives: imaginable that counting exercises could include physically moveable items like beads or blocks in which children identically manipulate items, even counting and performing primitive arithmetic.
Science Explorations: Some of them can be as follows: The inclusion of simple experiments/nature scavenger hunts can be included in the form of suggestions for the children as they are also advised to observe, predict, and record their findings in the workbook.
Physical Activities: When tasks are performed physically; like when telling a story and having the kids act it out or using a book page where kids search for certain items around the class, it forms part of motor activity.
Conclusion
Bearing this in mind, it is highly important that specific subject activities in the context of the present study, namely, kindergarten KB workbooks included both interactive and hands-on learning designs. Due to the incorporation of fun in the learning process, these workbooks prepare the foundation for better education in the future. Of particular significance to early childhood education and the young learners and their parents, who are struggling to choose the best tools for learning, the development and design of such learning resources will remain highly relevant as an essential and defining component of young students’ education.
| davidsmith45 |
|
1,911,621 | Petite historique du langage Java | EN 1991, des ingénieurs de Sun Microsystems, regroupés en une équipe appelée équipe verte composée... | 0 | 2024-07-04T13:50:49 | https://dev.to/laroseikitama/petite-historique-du-langage-java-3l9a | webdev, java, beginners, programming | EN 1991, des ingénieurs de `Sun Microsystems`, regroupés en une équipe appelée `équipe verte` composée de:
- James Gosling
- Mike Sheridan
- Patrick Naughton
décident de créer Java mais, sous forme d'un projet nommé "Oak" mais celui-ci fut un échec.
Par la suite Bill Joy ( cofondateur de la firme `Sun Microsystems`) propose une nouvelle version appelée `Java`
1. Pourquoi?:
Les ingénieurs cherchaient a concevoir un langage applicable à des petits appareils électriques ( on parle là de `code embarqué`).
2. Procédé:
Ils se sont basés sur une syntaxe proche du langage C++, en reprenant le concept de la machine virtuelle déjà exploité auparavant par le Pascal UCSD.
3. Idée:
L'idée consistait d'abord à traduire un programme source, non pas directement en langage machine mais, dans un pseudo langage universel disposant des fonctionnalités communes à toutes les machines ( notion de `portabilité`).
Ce code intermédiaire, appelé `bytecode`, se trouve ainsi compact et portable sur n'importe quelle machine, à condition que celle-ci dispose d'un programme approprié (machine virtuelle) permettant de l'interpréter dans un langage compréhensible par la machine concernée.
## Définitions de mots clés:
1. **Sun Microsystems**:
Était un constructeur d'ordinateurs et éditeur de logiciels américain, racheté par Oracle Corporation le `20 Avril 2009` pour 7,4 milliards de dollars.
2. **Notion de portabilité**:
La portabilité d'un langage de programmation signifie que le code écrit dans ce langage peut être exécuté sur différentes plateformes et architectures sans nécessiter de modifications majeures.
C'est un aspect essentiel des langages de haut niveau comme le C, Java ou Python qui permettent aux développeurs de créer des applications multiplateformes plus facilement.
3. **Bytecode**:
Le bytecode est une représentation intermédiaire d'un programme source, souvent générée par des langages de programmation comme Java ou Python.
Contrairement au code source écrit par le développeur, le bytecode n'est pas directement exécutable par le processeur de l'ordinateur.
Il est plutôt destiné à être exécuté par une **machine virtuelle** (VM), telle que la Java Virtual Machine (JVM) pour Java ou la Python Virtual Machine (PVM) pour Python.
## Quelques points supplémentaires pour l'exactitude historique et la clarté :
- Java a été officiellement lancé par Sun Microsystems en 1995.
- Oak a été renommé Java en raison d'un conflit de nom avec une autre technologie existante.
- Java a été conçu avec la philosophie "**_write once, run anywhere_**" (écrire une fois, exécuter partout).
| laroseikitama |
1,911,620 | Unable to get the emails from outlook using this method (using graph api) | /// <summary> /// Initializes a new instance of <see... | 0 | 2024-07-04T13:44:15 | https://dev.to/gokulsusan_8de3e434b605e3/unable-to-get-the-emails-from-outlook-using-this-method-using-graph-api-3pd0 | /// <summary>
/// Initializes a new instance of <see cref="Office365MailServiceClient"/>.
/// </summary>
/// <param name="connectionParams">Connection string as a key value pair.</param>
public Office365MailServiceClient(Dictionary<string, string> connectionParams)
{
this.graphAuthenticatorV1 = new MSGraphAuthenticator(connectionParams, MSGraphAuthenticator.GraphAPIVersion.v1);
this.graphClientV1 = this.graphAuthenticatorV1.GetAuthenticatedClient();
}
private GraphServiceClient graphClientV1;
/// <summary>
/// Gets the mail folder name by id.
/// </summary>
/// <param name="parentFolderId">Parent Folder Id.</param>
/// <returns></returns>
public string GetMailFolderNameById(string parentFolderId)
=> graphClientV1.Me.MailFolders[parentFolderId].Request().GetAsync().Result?.DisplayName ?? string.Empty;
public List<Message> GetAllMails()
{
List<Message> mails = new List<Message>();
//var result = graphClientV1.Me.Messages.Request().GetAsync();
//IUserMessagesCollectionPage currentPage = result.Result;
IUserMessagesCollectionPage currentPage = graphClientV1.Me.Messages.Request().GetAsync().Result;
while (currentPage != null)
{
foreach (var mail in currentPage)
{
try
{
mails.Add(mail);
}
catch (Exception) { }
}
currentPage = (currentPage.NextPageRequest != null) ? currentPage.NextPageRequest.GetAsync().Result : null;
}
return mails;
}
getting this error:
at System.Threading.Tasks.Task.ThrowIfExceptional(Boolean includeTaskCanceledExceptions)
can anyone help me to get resolve this method?
-Thanks in advance. | gokulsusan_8de3e434b605e3 |
|
1,911,619 | A quick guide on Migrations in Ruby on Rails for beginners | Ruby on Rails (RoR), often simply referred to as Rails, is a popular web application framework... | 25,342 | 2024-07-04T13:43:43 | https://dev.to/dumebii/quick-guide-to-migrations-in-ruby-on-rails-for-beginners-4gmb | rails, ruby, codenewbie, beginners | Ruby on Rails (RoR), often simply referred to as Rails, is a popular web application framework written in Ruby. It is known for its simplicity, convention over configuration, and rapid development capabilities. One of the key features that make Rails a powerful tool for web developers is its handling of database migrations.
## Table of Contents
1. [What Are Migrations in Ruby on Rails?](#what-are-migrations-in-ruby-on-rails)
2. [How does Rails keep track of migrations?](#how-does-rails-keep-track-of-migrations)
3. [What is difference between model and migration in Rails?](#what-is-difference-between-model-and-migration-in-rails)
4. [How to create a Migration in Ruby on Rails](#how-to-create-a-migration-in-ruby-on-rails)
5. [How to define a migration in Ruby on Rails](#how-to-define-a-migration-in-ruby-on-rails)
6. [Running Migrations in Ruby on Rails](#running-migrations-in-ruby-on-rails)
7. [Rolling Back Migrations in Ruby on Rails](#rolling-back-migrations-in-ruby-on-rails)
8. [Managing Schema Changes in Ruby on Rails](#managing-schema-changes-in-ruby-on-rails)
8. [Best Practices for Migrations](#best-practices-for-migrations)
8. [Conclusion](#conclusion)
9. [References](#references)
## What Are Migrations in Ruby on Rails?
Migrations in Ruby on Rails are a way to manage database schema changes over time. They allow developers to evolve the database schema as the application grows and requirements change. With migrations, you can add, remove, or modify tables and columns in a systematic and version-controlled manner. Migrations provide a structured way to track and apply these changes, ensuring consistency across different development environments.
##How does Rails keep track of migrations?
Migrations are stored as files in the db/migrate directory, one for each migration class. The name of the file is of the form `YYYYMMDDHHMMSS_create_products. rb`, that is to say a UTC timestamp identifying the migration followed by an underscore followed by the name of the migration.
##What is difference between model and migration in Rails?
Rails Model (Active Record) works with **SQL**, and Rails Migration works with **DDL**. Rails Model supports ways to interact with the database, while Rails Migration changes the database structure. A migration can change the name of a column in a `books` table. A migration can remove the table `book_covers`.
## How to create a Migration in Ruby on Rails
To create a new migration in a Rails application, you can use the Rails generator command. This command generates a new migration file with a timestamp in its filename to ensure uniqueness and chronological ordering. Here's how you can create a migration to add a new table:
```bash
rails generate migration CreateUsers
```
This command creates a migration file in the `db/migrate` directory with a name like `20230703094523_create_users.rb`. The generated file contains an empty `change` method where you define the changes to the database schema.
## How to define a migration in Ruby on Rails
Once you have created a migration, you must define the changes you want to make. Rails provides several methods to manipulate the database schema within the `change` method. For example, to create a `users` table with some basic columns, you would modify the migration file as follows:
```ruby
class CreateUsers < ActiveRecord::Migration[6.1]
def change
create_table :users do |t|
t.string :name
t.string :email
t.timestamps
end
end
end
```
In this example:
- The migration contains a class `CreateUsers` that inherits from `ActiveRecord::Migration[6.1]`. As I'm using Rails 6.1, the migration superclass has [6.1]. If I was using Rails 5.2, then the superclass would be `ActiveRecord::Migration[5.2]`.
- `create_table` creates a new table named `users`.
- `t.string :name` and `t.string :email` add `name` and `email` columns of type `string`.
- `t.timestamps` adds `created_at` and `updated_at` columns, which are automatically managed by Rails.
## Running Migrations in Ruby on Rails
After defining your migration, you need to run it to apply the changes to the database. You can do this using the following command:
```bash
rails db:migrate
```
This command runs all pending migrations in the `db/migrate` directory, applying the changes defined in each migration file to the database. Rails keeps track of which migrations have been applied using a special `schema_migrations` table, ensuring that each migration is only run once.
## Rolling Back Migrations in Ruby on Rails
Sometimes, you may need to undo a migration if you made a mistake or need to revert to a previous state. Rails allows you to roll back migrations using the following command:
```bash
rails db:rollback
```
This command rolls back the most recent migration. If you need to roll back multiple migrations, you can specify the number of steps:
```bash
rails db:rollback STEP=3
```
Rolling back a migration reverses the changes made in the `change` method. For more complex changes, such as renaming a column, you may need to define `up` and `down` methods instead of a single `change` method to specify how to apply and undo the migration.
## Managing Schema Changes in Ruby on Rails
As your application grows, you will likely need to make many changes to your database schema. Rails migrations provide a systematic way to manage these changes, ensuring that your development, testing, and production environments stay in sync. By keeping track of schema changes in version-controlled migration files, you can collaborate with other developers more effectively and deploy updates with confidence.
## Best Practices for Migrations
Here are some best practices to keep in mind when working with Rails migrations:
1. **Keep Migrations Simple**: Each migration should focus on a single change to the database schema. This makes it easier to understand and manage the changes.
2. **Test Migrations**: Always test your migrations in a development environment before applying them to production. This helps catch any errors or unintended side effects.
3. **Use Descriptive Names**: Use descriptive names for your migration files to make it clear what changes they contain. For example, `AddEmailToUsers` is more descriptive than `UpdateUsers`.
4. **Backup Your Database**: Before running migrations in a production environment, ensure you have a backup of your database. This provides a safety net in case something goes wrong.
5. **Version Control**: Keep your migration files under version control to track changes and collaborate with other developers.
## Conclusion
Migrations are a powerful feature of Ruby on Rails that allow you to manage database schema changes in a systematic and version-controlled manner. By understanding how to create, define, run, and rollback migrations, you can keep your database schema in sync with your application's evolving requirements. Following best practices for migrations will help you maintain a clean and manageable codebase, ensuring that your Rails application remains robust and scalable.
##References
[How do Rails keep track of migrations?](https://guides.rubyonrails.org/v3.2/migrations.html#:~:text=Migrations%20are%20stored%20as%20files,the%20name%20of%20the%20migration)
[Dissecting Rails Migrations](https://blog.appsignal.com/2020/04/14/dissecting-rails-migrationsl.html)
[What is difference between model and migration in Rails?](https://www.codementor.io/@duykhoa12t/rails-migration-overview-17ouwntenm#:~:text=Rails%20Model%20(Active%20Record)%20works,can%20remove%20the%20table%20book_covers%20)
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