In this tutorial, we will create a real-time chat application using Node.js and WebSockets. Real-time communication is a crucial aspect of modern web applications, allowing users to interact with each other instantaneously. By leveraging WebSockets, we can establish a persistent connection between the client and server, enabling seamless data exchange.
Introduction to WebSockets
WebSockets provide a full-duplex communication channel over a single TCP connection, allowing both the client and server to send messages at any time. Unlike HTTP, WebSockets maintain a persistent connection, making them ideal for applications requiring real-time updates, such as chat apps, online gaming, and live notifications.
Setting Up the Node.js Environment
Step 1: Install Node.js
If you haven’t already installed Node.js, you can download it from the official website. Node.js includes npm, the package manager we will use to install dependencies.
Step 2: Create a Project Directory
mkdir websocket_chat
cd websocket_chat
Step 3: Initialize a Node.js Project
npm init -y
Step 4: Install Required Packages
npm install express socket.io
Building the Chat Application
Step 1: Create the Server
Create a file named server.js in your project directory and add the following:
const express = require('express');
const http = require('http');
const socketIo = require('socket.io');
const app = express();
const server = http.createServer(app);
const io = socketIo(server);
app.use(express.static('public'));
io.on('connection', (socket) => {
console.log('A user connected');
socket.on('chatMessage', (msg) => {
io.emit('chatMessage', msg);
});
socket.on('disconnect', () => {
console.log('User disconnected');
});
});
const PORT = process.env.PORT || 3000;
server.listen(PORT, () => console.log(`Server running on port ${PORT}`));
Step 2: Create the Client
Create public/index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Real-Time Chat</title>
<link rel="stylesheet" href="styles.css">
</head>
<body>
<div class="chat-container">
<ul id="messages"></ul>
<form id="chat-form">
<input id="message" autocomplete="off" placeholder="Type a message" />
<button type="submit">Send</button>
</form>
</div>
<script src="/socket.io/socket.io.js"></script>
<script src="main.js"></script>
</body>
</html>
Create public/styles.css
body {
font-family: Arial, sans-serif;
background-color: #f4f4f9;
display: flex;
justify-content: center;
align-items: center;
height: 100vh;
margin: 0;
}
.chat-container {
background-color: white;
padding: 20px;
border-radius: 5px;
box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
width: 300px;
}
#messages {
list-style-type: none;
padding: 0;
max-height: 300px;
overflow-y: auto;
margin-bottom: 10px;
}
#messages li {
padding: 8px;
background-color: #f1f1f1;
border-radius: 3px;
margin-bottom: 5px;
}
#chat-form {
display: flex;
}
#message {
flex: 1;
padding: 8px;
border: 1px solid #ddd;
border-radius: 3px;
margin-right: 5px;
}
button {
background-color: #007bff;
color: white;
border: none;
border-radius: 3px;
padding: 8px 12px;
cursor: pointer;
}
button:hover {
background-color: #0056b3;
}
Create public/main.js
const socket = io();
const messageForm = document.getElementById('chat-form');
const messageInput = document.getElementById('message');
const messagesList = document.getElementById('messages');
messageForm.addEventListener('submit', (e) => {
e.preventDefault();
const message = messageInput.value;
socket.emit('chatMessage', message);
messageInput.value = '';
});
socket.on('chatMessage', (message) => {
const li = document.createElement('li');
li.textContent = message;
messagesList.appendChild(li);
});
Running the Application
- Start the Node.js server:
node server.js
- Open your browser and go to:
http://localhost:3000/
- Open multiple tabs or browsers to test real-time messaging.
Conclusion
In this tutorial, we built a real-time chat application using Node.js and WebSockets. We used Socket.io to establish a persistent connection between the client and server, allowing for real-time message exchange. This foundational knowledge can be extended to build more complex applications that require real-time communication, such as collaborative tools, online gaming, and live updates.