Creating a WebSocket Server using Node.js

Now that we have our environment set up, it is time to dive into how to create a WebSocket server using Node.js. In this chapter, we will create a basic WebSocket server and understand how to manage connections and messages.

Basic WebSocket Server Setup

In the server.js file we created earlier, we have the basic structure of a WebSocket server. Let's go over that code line by line to understand it thoroughly.

Importing the ws Library

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First, we import the ws library, which provides the necessary tools to work with WebSockets.

Creating an Instance of the WebSocket Server

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We create a new instance of WebSocket Server and configure the server to listen on port 8080.

Handling New Connections

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The on method allows us to set up an event handler for incoming connections. Each time a client connects, this block of code will be executed, where ws represents the connected client's WebSocket.

Listening and Sending Messages

Within the connection block, we set up two events:

1. Listening for Client Messages:

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   Here, we set up a message event on the client's WebSocket to listen to any message the client sends. Then, we simply log the message to the server console.

2. Sending Messages to the Client:

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   We use the send method to send a message back to the client when the connection is established.

Starting the Server

Finally, we start the WebSocket server with the command

bash

The server will start running and be ready to receive connections at ws://localhost:8080.

Image Placeholder: [Diagram illustrating the connection and communication flow between the client and WebSocket server.]

Testing the WebSocket Server

To test our WebSocket server, we can use a simple WebSocket client tool like wscat or a client implemented in JavaScript in the browser.

Using wscat

1. Install wscat: Run the following command to install wscat globally on your machine.

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2. Connecting to the WebSocket Server: Once installed, use the following command to connect to your WebSocket server at ws://localhost:8080.

   bash
   

   You should see the message 'Hello! Message From Server!!', indicating that you have successfully connected. You can send messages from wscat which will be logged in your server terminal.

Using a Browser

You can also use the following code to connect to your server from the browser:

html

Save this code as index.html and open it in your browser. You should see messages in the browser console and in the server terminal.

Image Placeholder: [Screenshot of the browser console showing messages sent and received from the WebSocket server.]

With this, we have created and tested our first WebSocket server using Node.js. In the upcoming chapters, we will explore how to handle events and messages in a more advanced manner. Let's keep moving forward! 🚀