Angular2 Broadcaster

<!DOCTYPE html>
<html>

  <head>
    <title>angular2 playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://code.angularjs.org/2.0.0-beta.15/angular2-polyfills.js"></script>
    <script src="https://code.angularjs.org/tools/system.js"></script>
    <script src="https://code.angularjs.org/tools/typescript.js"></script>
    <script src="config.js"></script>
    <script src="https://code.angularjs.org/2.0.0-beta.15/Rx.js"></script>
    <script src="https://code.angularjs.org/2.0.0-beta.15/angular2.dev.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
  </body>

</html>

/* Styles go here */

### Angular2 Starter Plunker - Typescript - Beta 0

A simple plunker demonstrating Angular2 usage:
- Uses SystemJS + TypeScript to compile on the fly
- Includes binding, directives, http, pipes, and DI usage.

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  //map tells the System loader where to look for things
  map: {
    app: "./src"
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    }
  }
});

//main entry point
import {bootstrap} from 'angular2/platform/browser';
import {App} from './app';

bootstrap(App, [])
  .catch(err => console.error(err));

//our root app component
import {Component} from 'angular2/core';
import {Child} from './child';
import {Broadcaster} from './broadcaster';

@Component({
  selector: 'my-app',
  providers: [Broadcaster],
  template: `
<h3>
  Angular 2 Broadcast Example
</h3>

<main>
	<child [childID]="1">
	  <child [childID]="2"></child>
	  <child [childID]="3"></child>
  </child>
  <child [childID]="4">
	  <child [childID]="5"></child>
	  <child [childID]="6"></child>
  </child>
</main>
  `,
  directives: [Child]
})
export class App {
}

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);
  }
}

import {Injectable} from 'angular2/core';
import {Observable} from 'rxjs/Observable';
import {Broadcaster} from './broadcaster';

@Injectable()
export class MessageEvent {
  constructor(private broadcaster: Broadcaster) {}

  fire(data: string): void {
    this.broadcaster.broadcast(MessageEvent, data);
  }

  on(): Observable<string> {
    return this.broadcaster.on<string>(MessageEvent);
  }
}

import {Component, Input} from 'angular2/core';
import {Broadcaster} from './broadcaster';
import {MessageEvent} from './message_event';

@Component({
  selector: 'child',
  template: `
  <div class="container">
    <b>Child#{{childID}}</b>
    <button (click)="emit()">Emit</button>
    <span>{{message}}</span>
    <ng-content></ng-content>
  </div>
`,
  styles: [`
.container {
  border: solid 1px black;
  padding: 5px;
  margin: 5px;
}
`],
  providers: [
    MessageEvent
  ],
})
export class Child {
  @Input() childID: string;
  message: string;
  _timer: any;

  constructor(
    private broadcaster: Broadcaster,
    private messageEvent: MessageEvent
  ) {}

  ngOnInit() {
    // this.registerStringBroadcast();
    this.registerTypeBroadcast();
  }

  registerStringBroadcast() {
    this.broadcaster.on<string>('message')
      .subscribe(message => {
        this.message = message;
        if (this._timer) {
          clearTimeout(this._timer);
        }
        this._timer = setTimeout(() => {
          this.message = '';
          this._timer = null;
        }, 3000);
      });
  }

  registerTypeBroadcast() {
    this.messageEvent.on()
      .subscribe(message => {
        this.message = message;
        if (this._timer) {
          clearTimeout(this._timer);
        }
        this._timer = setTimeout(() => {
          this.message = '';
          this._timer = null;
        }, 3000);
      });
  }

  emit() {
    // this.emitStringBroadcast();
    this.emitTypeBroadcast();
  }

  emitStringBroadcast() {
    this.broadcaster.broadcast('message', `Message from ${this.childID}`);
  }

  emitTypeBroadcast() {
    this.messageEvent.fire(`Message from ${this.childID}`);
  }
}