Social App Notification System

This project implements a real-time notification system for a social app using PHP, MySQL, jQuery, and WebSockets (via Ratchet). It also includes a long polling fallback for environments where WebSockets are not supported.

Prerequisites

• PHP 7.4 or higher
• MySQL 5.7 or higher
• Composer (for installing Ratchet)
• A web server (e.g., Apache or Nginx)
• Node.js (optional, for WebSocket testing)
• Port 8080 open for WebSocket server

Installation

1. Clone or Download the Project Download the project files or clone the repository to your local machine.

2. Install Dependencies Install Ratchet for WebSocket support using Composer:

   composer require cboden/ratchet

3. Set Up the Database

   • Create a MySQL database named social_app.
   • Execute the schema.sql file to create the notifications table:

     mysql -u your_username -p social_app < schema.sql

   • Update the database credentials (your_username, your_password, social_app) in notification_system.php and fetch_notifications.php.

4. Configure the Web Server

   • Place index.html and fetch_notifications.php in your web server's root directory (e.g., /var/www/html for Apache).
   • Ensure PHP is enabled on your web server.

5. Run the WebSocket Server Start the WebSocket server by running:

   php notification_system.php

   This will start the server on ws://localhost:8080. Ensure port 8080 is open. Bettwe use IP instead of localhost for testing in LAN.

Usage

1. Access the Application

   • Open index.html in a web browser (e.g., http://localhost/index.html).
   • Enter a User ID and Message in the input fields.
   • Click Send Notification to send a notification.

2. Real-Time Notifications

   • Notifications are sent via WebSocket and displayed in real-time to all connected clients.
   • If WebSocket fails, the system switches to long polling, fetching notifications from fetch_notifications.php every few seconds.

3. Database Storage

   • Notifications are stored in the notifications table in the MySQL database for persistence.

Files

• notification_system.php: WebSocket server using Ratchet to handle real-time notifications.
• index.html: Frontend interface using jQuery for sending and displaying notifications.
• fetch_notifications.php: Backend script for long polling fallback to fetch notifications.
• schema.sql: SQL script to create the notifications table.

Notes

• Replace your_username, your_password, and social_app in the PHP files with your actual MySQL credentials and database name.
• For production, secure the WebSocket connection with WSS (WebSocket Secure) and implement user authentication.
• If WebSockets are not feasible, you can rely solely on long polling by removing the WebSocket code and using only fetch_notifications.php.
• Ensure your web server and WebSocket server are running simultaneously.

Troubleshooting

• WebSocket Connection Fails: Check if port 8080 is open and the WebSocket server (notification_system.php) is running.
• Database Errors: Verify MySQL credentials and ensure the notifications table exists.
• Notifications Not Displaying: Ensure jQuery is loaded and check the browser console for errors.

License

This project is licensed under the MIT License.