Use in directives and components to emit custom events synchronously or asynchronously, and register handlers for those events by subscribing to an instance.

class EventEmitter<T> extends Subject {
  constructor(isAsync: boolean = false)
  __isAsync: boolean
  emit(value?: T)
  subscribe(generatorOrNext?: any, error?: any, complete?: any): Subscription
}

Constructor

Properties

Methods

Usage notes

In the following example, a component defines two output properties that create event emitters. When the title is clicked, the emitter emits an open or close event to toggle the current visibility state.

@Component({
  selector: 'zippy',
  template: `
  <div class="zippy">
    <div (click)="toggle()">Toggle</div>
    <div [hidden]="!visible">
      <ng-content></ng-content>
    </div>
 </div>`})
export class Zippy {
  visible: boolean = true;
  @Output() open: EventEmitter<any> = new EventEmitter();
  @Output() close: EventEmitter<any> = new EventEmitter();

  toggle() {
    this.visible = !this.visible;
    if (this.visible) {
      this.open.emit(null);
    } else {
      this.close.emit(null);
    }
  }
}

Access the event object with the $event argument passed to the output event handler:

<zippy (open)="onOpen($event)" (close)="onClose($event)"></zippy>

Notes

Uses Rx.Observable but provides an adapter to make it work as specified here: https://github.com/jhusain/observable-spec

Once a reference implementation of the spec is available, switch to it.