app.py

import gradio as gr

def show_exam_html():
    with open("exam.html", "r") as file:
        return file.read()

def show_index_html():
    with open("index.html", "r") as file:
        return file.read()

def main():
    with gr.Blocks() as demo:
        gr.HTML(show_index_html())

        # A hidden HTML component to store and display exam.html content
        exam_html = gr.HTML(show_exam_html(), visible=False)
        
        def start_exam():
            return gr.update(visible=True), gr.update(visible=False)
        
        # Simulate the navigation event
        gr.Button("Start Exam").click(start_exam, inputs=[], outputs=[exam_html, gr.HTML(show_index_html())])

    demo.launch()

if __name__ == "__main__":
    main()