一個包裝器元件，以宣告方式新增動態元件

一種自定義元件，它將元件的型別作為輸入，並在其自身內部建立該元件型別的例項。更新輸入後，將刪除先前新增的動態元件，然後新增新元件。

@Component({
  selector: 'dcl-wrapper',
  template: `<div #target></div>`
})
export class DclWrapper {
  @ViewChild('target', {
    read: ViewContainerRef
  }) target;
  @Input() type;
  cmpRef: ComponentRef;
  private isViewInitialized: boolean = false;

  constructor(private resolver: ComponentResolver) {}

  updateComponent() {
    if (!this.isViewInitialized) {
      return;
    }
    if (this.cmpRef) {
      this.cmpRef.destroy();
    }
    this.resolver.resolveComponent(this.type).then((factory: ComponentFactory < any > ) => {
      this.cmpRef = this.target.createComponent(factory)
        // to access the created instance use
        // this.cmpRef.instance.someProperty = 'someValue';
        // this.cmpRef.instance.someOutput.subscribe(val => doSomething());
    });
  }

  ngOnChanges() {
    this.updateComponent();
  }

  ngAfterViewInit() {
    this.isViewInitialized = true;
    this.updateComponent();
  }

  ngOnDestroy() {
    if (this.cmpRef) {
      this.cmpRef.destroy();
    }
  }
}

這允許你建立動態元件

<dcl-wrapper [type]="someComponentType"></dcl-wrapper>

Plunker 的例子