angular emit output

1  @Output() open: EventEmitter<any> = new EventEmitter();
2
3
4  toggel() {
5  	this.open.emit(null);
6  }	

1      
2        content_copy
3      
4      @Component({
5  selector: 'zippy',
6  template: `
7  <div class="zippy">
8    <div (click)="toggle()">Toggle</div>
9    <div [hidden]="!visible">
10      <ng-content></ng-content>
11    </div>
12 </div>`})
13export class Zippy {
14  visible: boolean = true;
15  @Output() open: EventEmitter<any> = new EventEmitter();
16  @Output() close: EventEmitter<any> = new EventEmitter();
17
18  toggle() {
19    this.visible = !this.visible;
20    if (this.visible) {
21      this.open.emit(null);
22    } else {
23      this.close.emit(null);
24    }
25  }
26}
27