如何呈现实现接口的组件？

Question

假设我有一个接口(或实际组件)ListItemRenderer和一个MyRendererComponent实现该接口的组件(或扩展基本组件)

@Component({
    selector: 'my-renderer',
    template: '<div>My renderer</div>'
})
export class MyRendererComponent implements ListItemRenderer {
    ...
}

我想将这个具体的实现传递给另一个组件,例如

@Component({
    selector: 'my-list',
    template: `
        <ul [renderer]="renderer" [items]="items">
            <li *ngFor="let item of items">
                <!-- what goes here? -->
            </li>
        </ul>
    `
})
export class MyList {
    @Input() renderer: ListItemRenderer;
    @Input() items: any[];
    ...
}

显然,父组件将具有renderer类型的公共属性ListItemRenderer.问题是,我如何在我的网站中使用该组件<li>(参见上文中的" 内容？ ")？

Answer 1

要使用*ngFor你动态添加组件,需要像/sf/answers/2542782791/中所dcl-wrapper解释的那样(不赞成使用,但我没有尝试为包装器组件引入另一个名称.)DynamicComponentLoaderViewContainerRef.createComponent()

@Component({
  selector: '[dcl-wrapper]', // changed selector in order to be used with `<li>`
  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)
    });
  }

  ngOnChanges() {
    this.updateComponent();
  }

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

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

并使用它

@Component({
    selector: 'my-list',
    template: `
        <ul  [items]="items">
            <li *ngFor="let item of items" dcl-wrapper [type]="renderer" ></li>
        </ul>
    `
})
export class MyList {
    @Input() renderer: ListItemRenderer;
    @Input() items: any[];
    ...
}