Blog: Events in Angular2 (https://thingsofgeek.com/2016/07/03/events-in-angular2.html)

broadcaster.ts

import {Subject} from 'rxjs/Subject';
import {Observable} from 'rxjs/Observable';
import 'rxjs/add/operator/filter';
import 'rxjs/add/operator/map';

interface BroadcastEvent {
  key: any;
  data?: any;
}

export class Broadcaster {
  private _eventBus: Subject<BroadcastEvent>;

  constructor() {
    this._eventBus = new Subject<BroadcastEvent>();
  }

  broadcast(key: any, data?: any) {
    this._eventBus.next({key, data});
  }

  on<T>(key: any): Observable<T> {
    return this._eventBus.asObservable()
      .filter(event => event.key === key)
      .map(event => <T>event.data);
  }
}

example.component.ts

// child.ts
@Component({
    selector: 'child'
})
export class ChildComponent {
  constructor(private broadcaster: Broadcaster) {
  }
  
  registerStringBroadcast() {
    this.broadcaster.on<string>('MyEvent')
      .subscribe(message => {
        ...
      });
  }

  emitStringBroadcast() {
    this.broadcaster.broadcast('MyEvent', 'some message');
  }
}

jh-feed.directive.js

if (!feed.isLocalScreen) {
  // Until this timeout is reached, the "you are muted" notification
  // will not be displayed again
  var mutedWarningTimeout = now();
  scope.$on('muted.byRequest', function() {
    mutedWarningTimeout = secondsFromNow(3);
    MuteNotifier.muted();
  });
  scope.$on('muted.byUser', function() {
    // Reset the warning timeout
    mutedWarningTimeout = now();
  });
  scope.$on('muted.Join', function() {
    mutedWarningTimeout = now();
    MuteNotifier.joinedMuted();
  });
  scope.$watch('vm.feed.isVoiceDetected()', function(newVal) {
    // Display warning only if muted (check for false, undefined means
    // still connecting) and the timeout has been reached
    if (newVal && feed.getAudioEnabled() === false && now() > mutedWarningTimeout) {
      MuteNotifier.speaking();
      mutedWarningTimeout = secondsFromNow(60);
    }
  });
}