Angular2 - Class - EventEmitter

EventEmitter 就是用于发出一个event，一般用于output

@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);
    }
  }
}

可以和Rxjs的 subscribe一起用，具体看 angular2 + redux 使用。里面会用 rxjs 和 immutable

传值方法主要是emit。
emit(value: T) { super.next(value); }

未来修改方向是Rxjs,来替代emit等方法

subscribe(generatorOrNext?: any, error?: any, complete?: any): any {
  let schedulerFn;
  let errorFn = (err: any) => null;
  let completeFn = () => null;

  if (generatorOrNext && typeof generatorOrNext === 'object') {
    schedulerFn = this._isAsync ? (value) => { setTimeout(() => generatorOrNext.next(value)); } :
                                  (value) => { generatorOrNext.next(value); };

    if (generatorOrNext.error) {
      errorFn = this._isAsync ? (err) => { setTimeout(() => generatorOrNext.error(err)); } :
                                (err) => { generatorOrNext.error(err); };
    }

    if (generatorOrNext.complete) {
      completeFn = this._isAsync ? () => { setTimeout(() => generatorOrNext.complete()); } :
                                   () => { generatorOrNext.complete(); };
    }
  } else {
    schedulerFn = this._isAsync ? (value) => { setTimeout(() => generatorOrNext(value)); } :
                                  (value) => { generatorOrNext(value); };

    if (error) {
      errorFn =
          this._isAsync ? (err) => { setTimeout(() => error(err)); } : (err) => { error(err); };
    }

    if (complete) {
      completeFn =
          this._isAsync ? () => { setTimeout(() => complete()); } : () => { complete(); };
    }
  }

  return super.subscribe(schedulerFn, errorFn, completeFn);
}