How to Use WebSockets With Angular Applications

WebSockets provide a powerful way to enable real-time communication between the client and server in web applications. When combined with Angular, WebSockets can enhance user experience by providing instant updates. This article discusses how to effectively use WebSockets with Angular applications.

What are WebSockets?

WebSockets are a protocol that allows for two-way communication between a client and server over a single, long-lived connection. Unlike traditional HTTP requests, where each request initiates a new connection, WebSockets maintain an open connection, allowing for the continuous exchange of data. This is particularly useful in applications requiring real-time updates, such as chat applications, live notifications, or gaming platforms.

Setting Up Angular Application

Before integrating WebSockets, ensure you have an Angular application ready. If you don’t have one, you can create a new Angular project using the Angular CLI:

ng new my-websocket-app

Navigate to the project directory:

cd my-websocket-app

Installing Required Packages

Angular doesn’t come with WebSocket support out of the box, but you can easily use the native WebSocket API. However, for better abstractions and enhanced functionality, you can use libraries like ngx-socket-io. To install ngx-socket-io, run the following command:

npm install ngx-socket-io --save

Configuring WebSocket Service

Next, create a new service that will handle WebSocket connections. Run the following command:

ng generate service websocket

Then, open the generated websocket.service.ts file and set up your WebSocket service:

import { Injectable } from '@angular/core';
import { Socket } from 'ngx-socket-io';
@Injectable({
  providedIn: 'root'
})
export class WebsocketService {
  constructor(private socket: Socket) {}
sendMessage(msg: string) {
    this.socket.emit('message', msg);
  }
getMessages() {
    return this.socket.fromEvent('message');
  }
}

This service establishes methods to emit messages to the server and to listen for incoming messages.

Configuring Socket.IO Module

To use the ngx-socket-io library, you need to configure the SocketIoModule in your Angular application. Open the app.module.ts file and import SocketIoModule:

import { SocketIoModule, SocketIoConfig } from 'ngx-socket-io';
const config: SocketIoConfig = { url: 'http://localhost:3000', options: {} };
@NgModule({
  declarations: [/* your components */],
  imports: [
    // Other imports
    SocketIoModule.forRoot(config)
  ],
  providers: [],
  bootstrap: [/* your main component */]
})
export class AppModule {}

Replace the URL in the config object with the address of your WebSocket server.

Using WebSocket in Components

Now that your service is ready, you can use it in your components. For instance, if you have a chat application, inject the WebsocketService into your component:

import { Component, OnInit } from '@angular/core';
import { WebsocketService } from './websocket.service';
@Component({
  selector: 'app-chat',
  templateUrl: './chat.component.html',
  styleUrls: ['./chat.component.css']
})
export class ChatComponent implements OnInit {
  messages: string[] = [];
  messageInput: string;
constructor(private websocketService: WebsocketService) {}
ngOnInit() {
    this.websocketService.getMessages().subscribe((message: string) => {
      this.messages.push(message);
    });
  }
sendMessage() {
    this.websocketService.sendMessage(this.messageInput);
    this.messageInput = '';
  }
}

In this ChatComponent, the incoming messages are listened to and added to an array, which can be displayed in your template.

Creating the HTML Template

Lastly, create a simple HTML template for your chat application to display messages and handle user input:

<div>
  <div *ngFor="let message of messages">{{ message }}</div>
  <input [(ngModel)]="messageInput" placeholder="Type a

How to Use WebSockets With Angular Applications