import { Component, OnInit } from '@angular/core'; import { FeedService } from '../shared/feed.service'; import { ConnectionState } from '../shared/interfaces'; @Component({ selector: 'home', templateUrl: 'app/home/home.component.html' }) export class HomeComponent implements OnInit { error: any; constructor(private service: FeedService) { } ngOnInit() { this.service.connectionState .subscribe( connectionState => { if (connectionState == ConnectionState.Connected) { console.log('Connected!'); } else { console.log(connectionState.toString()); } }, error => { this.error = error; console.log(error); }); if (this.service.currentState === ConnectionState.Connected) { console.log(' connected....'); } else { console.log('not connected'); } } }