socket.io

npm install express socket.io


const express = require('express');
const app = express();
const http = require('http').Server(app);
const io = require('socket.io')(http);

const port = 3000;

// Serve the client-side files
app.use(express.static('public'));

// Store connected clients
const clients = new Set();

// Broadcast messages to all connected clients
function broadcast(message) {
  io.emit('message', message);
}

// Handle new connections
io.on('connection', (socket) => {
  clients.add(socket);

  // Handle incoming messages from clients
  socket.on('message', (message) => {
    broadcast(message);
  });

  // Handle client disconnections
  socket.on('disconnect', () => {
    clients.delete(socket);
  });
});

// Start the server
http.listen(port, () => {
  console.log(`Server listening on http://localhost:${port}`);
});


<!DOCTYPE html>
<html>

<head>
  <title>Chat App</title>
</head>

<body>
  <h1>Chat App</h1>
  <div>
    <textarea id="chatLog" rows="10" cols="40" readonly></textarea>
  </div>
  <div>
    <input type="text" id="message" placeholder="Type your message here">
    <button onclick="sendMessage()">Send</button>
  </div>

  <script src="/socket.io/socket.io.js"></script>
  <script>
    const chatLog = document.getElementById('chatLog');
    const messageInput = document.getElementById('message');
    const socket = io();

    // Update the chat log when a new message is received
    socket.on('message', function (message) {
      chatLog.value += message + '\n';
    });

    // Send the message to the server
    function sendMessage() {
      const message = messageInput.value;
      if (message.trim() !== '') {
        socket.emit('message', message);
        messageInput.value = '';
      }
    }
  </script>
</body>

</html>