How to use socket.io-client in angular 4

Question

Server side is php laravel echo websocket and I am trying to connect by Angular 4. I tried using ng2-socket-io - npm and also laravel-echo - npm but none of them were successfully. If anyone know any documentation or tutorial how I can use it, please help

Answer 1

Hi @giga Working example is given below.

SETUP

npm i socket.io-client --save
npm i @types/socket.io-client --save

Server-side (nodejs)

var express = require('express');
var path = require('path');
var app = express();
var server = require('http').Server(app);
var io = require('socket.io')(server);

var port = 8000;

app.use(express.static(path.join(__dirname, "public")));

io.on('connection', (socket) => {
console.log('new connection made');

socket.on('event1', (data) => {
  console.log(data.msg);
});

socket.emit('event2', {
  msg: 'Server to client, do you read me? Over.'
});

socket.on('event3', (data) => {
  console.log(data.msg);
  socket.emit('event4', {
    msg: 'Loud and clear :)'
  });
});
});

server.listen(port, () => {
  console.log("Listening on port " + port);
});

Client-side - Angular4 code

import { Component, OnInit } from '@angular/core';
import * as io from 'socket.io-client';

@Component({
    moduleId: module.id,
    selector: 'ch-home',
    styleUrls: ['home.styles.css'],
    templateUrl: 'home.template.html'
})

export class HomeComponent implements OnInit {
    messageText: string;
    messages: Array<any>;
    socket: SocketIOClient.Socket;

  constructor() {
   // this.socket = io.connect('http://localhost:8000');
   this.socket = io.connect();
  }

  ngOnInit() {
        this.messages = new Array();

        this.socket.on('message-received', (msg: any) => {
            this.messages.push(msg);
            console.log(msg);
            console.log(this.messages);
        });
      this.socket.emit('event1', {
          msg: 'Client to server, can you hear me server?'
      });
      this.socket.on('event2', (data: any) => {
        console.log(data.msg);
        this.socket.emit('event3', {
            msg: 'Yes, its working for me!!'
        });
      });
      this.socket.on('event4', (data: any) => {
          console.log(data.msg);
      });
   }

   sendMessage() {
    const message = {
      text: this.messageText
    };
    this.socket.emit('send-message', message);
    // console.log(message.text);
    this.messageText = '';
  }

}

Answer 2

Setup

npm install socket.io-client --save
npm install @types/socket.io-client --save-dev

As a service:

import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import * as io from 'socket.io-client';

@Injectable()
export class ChatService {
  private socket: SocketIOClient.Socket;

  constructor() {
    this.socket = io('http://localhost:3000');
  }

  // EMITTER
  sendMessage(msg: string) {
    this.socket.emit('sendMessage', { message: msg });
  }

  // HANDLER
  onNewMessage() {
    return Observable.create(observer => {
      this.socket.on('newMessage', msg => {
        observer.next(msg);
      });
    });
  }
}

In component:

import { Component, OnInit } from '@angular/core';
import { ChatService } from './chat-service';

@Component({
  // ...blabla...
})
export class ChatComponent implements OnInit {
  msgInput: string = 'lorem ipsum';

  constructor(
    private chatService: ChatService,
  ) { }

  ngOnInit() {
    this.chatService.onNewMessage().subscribe(msg => {
      console.log('got a msg: ' + msg);
    });
  }

  sendButtonClick() {
    this.chatService.sendMessage(this.msgInput);
  }
}

Answer 3

In addition the VithuBati's answer you need to install: npm i socket.io-client --save npm i @types/socket.io-client --save

Answer 4

Following the solution of @MA-Maddin, I did this implementation:

at Service:socket.service

import { Injectable } from '@angular/core';
import * as io from 'socket.io-client';
import {Observable} from 'rxjs';
@Injectable({
providedIn: 'root'
})
export class SocketService {
private socket:SocketIOClient.Socket;

constructor() { 
  this.socket=io('http://localhost:3300');
}
emit(event:string, data:any){
  this.socket.emit(event,data);
}
on(event:string){
  return Observable.create(observer=>{
   this.socket.on(event,data=>{
    observer.next(data);
   });
  })
 }
}

At Component

 import { Component, OnInit, Input, ViewChild, ViewEncapsulation} from 
'@angular/core';
import { AuthService } from 'src/app/auth/auth.service';
import Socket from '../../services/socket.service';

@Component({
  selector: 'app-lobby-chat',
  templateUrl: './lobby-chat.component.html',
  styleUrls: ['./lobby-chat.component.css'],
  encapsulation: ViewEncapsulation.None,
})
export class LobbyChatComponent implements OnInit {
  constructor(private socket:Socket) {
  this.socket.on('getMessage').subscribe(data=>{
  console.log(data);
  });
  }
  pushMessage(msg){
  this.socket.emit('sendMessage',msg);
  }
}

This will update your bindings correctly.