Angular 2 - 如何在没有模板的情况下收听事件？

Question

问题

通常,在Angular 2中,可以通过以下语法监听事件:

<my-elem (customEvent)="customEventProcessor"></my-elem>

但是当我使用路由器时,该主机 - <my-elem>在任何模板中都不存在.相反,有一个<router-outlet>,我的组件在导航时加载.因此,我的问题的关键是,如何在不依赖模板的情况下强制我的主机听我的自定义事件？

可选细节

假设我有一些元素list-view,它是我的根组件的子元素.list-view通过正常语法侦听自定义事件:

<list-view (customEvent)="customEventProcessor()"></list-view>

为了完整list-view起见,发出事件的组件也具有可预测的结构:

<button (click)="onDetailsClick(propertyOfInterest)">Click here</button>

该list-view发送通过观察事件到父.

class ListView {

    ...

        public onDetailsClick(property: string): void {

            this.customEvent.next({ value: property });

        }

}

并且该事件触发了该customEventProcessor()功能.到现在为止还挺好.但是,当我使用路由器来控制是否list-view存在时,我不能(据我所知)插入命令来监视某些事件.

我不确定处理这种情况的最佳方法是什么.

Answer 1

此问题尚未解决(请参阅此github问题).这是目前可能的解决方案之一(见本文):

@Component({
  selector: 'my-app',
  directives: [RouterOutlet, RouterLink],
  template: `
    <h1>{{ message }}</h1>
    <a [router-link]="['./MyElem1']">MyElem1</a>
    <a [router-link]="['./MyElem2']">MyElem2</a>
    <router-outlet></router-outlet>
  `
})
@RouteConfig([
  { path: '/', redirectTo: '/my-elem1' },
  { path: '/my-elem1', name: 'MyElem1', component: MyElem1 },
  { path: '/my-elem2', name: 'MyElem2', component: MyElem2 },
])
export class App {
  message: string = 'Click on the button';

  @ViewChild(MyElem1) myElem1: MyElem1;
  @ViewChild(MyElem2) myElem2: MyElem2;

  constructor(router: Router) {
    let subs = null;
    router.subscribe(() => {
      if (subs) { subs.unsubscribe(); subs = null; }

      if (this.myElem1) {
        subs = this.myElem1.customEvent1.subscribe(m=>this.processCustomEvent(m));
      }
      if (this.myElem2) {
        subs = this.myElem2.customEvent2.subscribe(m=>this.processCustomEvent(m));
      }
    });
  }

  processCustomEvent(message) { this.message = message }
}