Building Interactive Apps: A Guide to WebSocket Integration in Node.

Master WebSocket integration in Node.js for building interactive apps with our comprehensive guide. Elevate your development skills today.

Himanshu Pant

Published: October 24, 2023

Key takeaways

Real-Time Communication: WebSockets support long-during two-way communication between the client and the server; it supports real-time data transfer unlike the conventional use of HTTP.
Versatile Uses: WebSockets are the most effective in the contexts of using real-time data, for instance, stream data, games, collaborating platforms, and financial services since they use minimal resources and the time latency is minimal.
Implementation Steps: WebSockets uses a few layers which are created with the help of a server in Node. for example, js, installation of requirements, setting up of the WebSocket server and enabling real time communication, as well as creating a basic HTML page for use in communicating with the WebSocket to send and receive messages.

Overview of WebSockets

WebSockets offer a persistent connection between client and server that enables real-time communication. They provide a standardized way of sending data from the server to the client and vice versa. Unlike HTTP , they do not require the client to repeatedly request data from the server.

What are WebSockets?

It is a communication protocol with full-duplex communication channels on a single TCP connection between a server and a client. This protocol utilizes a ‘handshake process’ to establish a client-server connection wherein both parties can communicate and receive data. The protocol is implemented as a JavaScript API in web browsers. It can be used with server-side programming languages like Node.js.

It allows real-time, two-way communication between a web browser and a server, enabling the server to send data to the browser without requesting it explicitly.

What are the uses?

WebSockets are a communication protocol that provides full-duplex, bidirectional communication channels over a single, long-lived connection between a client (usually a web browser) and a server. Unlike traditional HTTP requests that are request-response based and stateless, Web Sockets allow ongoing, real-time communication between the client and server. Here are some common use cases for Web Sockets:

Real-Time Web Applications
Gaming
Live Data Streaming
Collaborative Applications
IoT (Internet of Things)
Online Auctions and Bidding
Customer Support and Help Desks
Live Dashboards and Monitoring
Financial Applications
Voice and Video Calls:

How do they work?

In a nutshell, working with WebSockets involves three main steps:

Opening a WebSocket connection. The process of establishing a WebSocket connection is known as the opening handshake, and consists of an HTTP request/response exchange between the client and the server.
Data transmission over WebSockets. After a successful WebSocket handshake, the client and server can exchange messages (frames) over a persistent WebSocket connection. WebSocket messages may contain string (plain text) or binary data.

Closing a Web Socket connection. Once the persistent WebSocket connection has served its purpose, it can be terminated; both the client and the server can initiate the closing handshake by sending a close message.

Advantages of WebSockets

Bi-directional communication
Real-time data transfer
Low latency
Scalability
Efficient use of resources

Set up your project environment

Setup the project

Create a new directory for your project and navigate to it:

mkdir websocket-project

cd websocket-project

mkdir websocket-project

cd websocket-project

Initialize the Node.js Project

Initialize a package.json file for your project:

npm init -y

1	npm init -y

Install Dependencies

Install the required dependencies for the server using:

npm install express ws

1	npm install express ws

Create Server Code

Create a server.js file and open it in your preferred text editor:

touch server.js

Add the following code to set up an Express server and WebSocket integration:

const express = require('express');
const http = require('http');
const WebSocket = require('ws');

const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });

wss.on('connection', (ws) => {
  console.log('Client connected');

  ws.on('message', (message) => {
    console.log(`Received: ${message}`);
    ws.send(`Server received: ${message}`);
  });
});

app.get('/', (req, res) => {
  res.sendFile(__dirname + '/index.html');
});

server.listen(3000, () => {
  console.log('Server is listening on port 3000');
});

				
					
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						const express = require('express');
const http = require('http');
const WebSocket = require('ws');
 
const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });
 
wss.on('connection', (ws) => {
  console.log('Client connected');
 
  ws.on('message', (message) => {
    console.log(`Received: ${message}`);
    ws.send(`Server received: ${message}`);
  });
});
 
app.get('/', (req, res) => {
  res.sendFile(__dirname + '/index.html');
});
 
server.listen(3000, () => {
  console.log('Server is listening on port 3000');
});

					

			

5. Create HTML User Interface:

Create an index.html file and open it in your preferred text editor:

touch index.html

Add the following HTML code:

<!DOCTYPE html>

<html lang="en">

<head>

  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>WebSocket Test</title>

</head>

<body>

  <input type="text" id="messageInput" placeholder="Type a message">

  <button id="sendButton">Send</button>

  <div id="output"></div>
  <script>
    const socket = new WebSocket('ws://localhost:3000');

    socket.onopen = (event) => {
      console.log('WebSocket connection opened');
    };

    socket.onmessage = (event) => {
      const output = document.getElementById('output');
      output.innerHTML = `Received: ${event.data}`;
    };
    socket.onclose = (event) => {
      console.log('WebSocket connection closed');
    };

    const sendButton = document.getElementById('sendButton');
    sendButton.addEventListener('click', () => {
      const messageInput = document.getElementById('messageInput');
      const message = messageInput.value;
      socket.send(message);
    });

  </script>
</body>
</html>

				
					
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						<!DOCTYPE html>
 
<html lang="en">
 
<head>
 
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>WebSocket Test</title>
 
</head>
 
<body>
 
  <input type="text" id="messageInput" placeholder="Type a message">
 
  <button id="sendButton">Send</button>
 
  <div id="output"></div>
  <script>
    const socket = new WebSocket('ws://localhost:3000');
 
    socket.onopen = (event) => {
      console.log('WebSocket connection opened');
    };
 
    socket.onmessage = (event) => {
      const output = document.getElementById('output');
      output.innerHTML = `Received: ${event.data}`;
    };
    socket.onclose = (event) => {
      console.log('WebSocket connection closed');
    };
 
    const sendButton = document.getElementById('sendButton');
    sendButton.addEventListener('click', () => {
      const messageInput = document.getElementById('messageInput');
      const message = messageInput.value;
      socket.send(message);
    });
 
  </script>
</body>
</html>

					

			

Here is the file structure for the app

websocket-project/

├─node_modules/

├─ server.js

├─ index.html

└── package.json

6. Run the Server

Start the server by running

node server.js

7. Access the User InterfaceOpen a web browser and navigate to http://localhost:3000. You should see the simple UI with an input box and a “Send” button. Messages sent from the UI will be echoed back by the server and displayed on the page.