如何在Angular2的路由器插座中发出事件

Question

我有主 appComponent 和

<div class="appComponent">
<div class="row nav navbar">
    <div class="col-sm-8 text-left nav logo">Manacola</div>
    <button class="col-sm-1  col-sm-offset-1  btn btn-primary openGraph" (click)="openGraph()">Graph</button>
    <button class="col-sm-1   btn btn-primary openGraph" *ngIf="loggedIn" (click)="logout()">Logout</button>
</div>
<router-outlet ></router-outlet>

我想从另一个登录组件发出数据。 关键是当我按下loginComponent 中的“登录”按钮时，我希望*ngIf="loggedIn" 在appComponent 中设置为“true”。 有这样的工作会很好：

<router-outlet (isLogged) = 'loggedIn = $event' ></router-outlet>   

Answer 1

这是一个很棒的小实用服务，用于在 angular2 应用程序中代理事件。请注意，您实际上应该只使用这种类型的事件代理在解耦组件之间进行通信（例如在 router-outlet 的父级和子级之间）

示例：

....
import { EventBrokerService, IEventListener } "EventBrokerService";

@Component({
    selector: "my-listening-component",
    template: `
        <div *ngIf="indicator">I am On!</div>
        <div *ngIf="!indicator">I am Off!</div>
    `
})
@Injectable()
export class MyListeningComponent implements OnDestroy {
    public indicator: boolean = false;
    private _myEventListener: IEventListener;
    constructor(private _eventBroker: EventBrokerService) {
        this._myEventListener = _eventBroker.listen<boolean>("my-event",(value:boolean)=>{
             this.indicator = value;
        });
    }
    public ngOnDestroy() {
        this._myEventListener.ignore();
    }
}

@Component({
    selector: "my-sending-component",
    template: `
        <button (click)="canYouHearMe(true)>Turn me on</Button>
        <button (click)="canYouHearMe(false)>Turn me off</Button>
    `
})
@Injectable()
export class MySendingComponent {
    constructor(private _eventBroker: EventBrokerService) {
    }
    public canYouHearMe(value:boolean) {
        _eventBroker.emit<boolean>("my-event",value);
    }
}

EventBrokerService.ts 文件：

import { Injectable } from '@angular/core';
import { Subscription } from 'rxjs';
import { Subject }    from 'rxjs';

interface IEventListener {
    ignore() : void;
}
interface IBrokeredEventBase {
    name:string;
    emit( data: any ): void;
    listen( next: (data: any) => void ): IEventListener;
}
interface IBrokeredEvent<T> extends IBrokeredEventBase  {
    emit( data: any ): void;
    listen( next: (data: any) => void ): IEventListener;
}
class EventListener implements IEventListener {
    constructor( private _subscription: Subscription ) {
    }
    public ignore() : void {
        this._subscription.unsubscribe();
    }
}

class BrokeredEvent<T> implements IBrokeredEvent<T> {
    private _subject: Subject<T>;
    constructor( public name: string ) {
        this._subject = new Subject<T>();
    }
    public emit( data: T ): void {
        this._subject.next(data);
    }
    public listen(next: (value: T) => void): IEventListener {
        return new EventListener(this._subject.subscribe( next ));
    }
}
@Injectable()
export class EventBrokerService {
    private _events: { [name: string]: IBrokeredEventBase };
    constructor() {
        this._events = {};
    }
    public register<T>(eventName: string ) : BrokeredEvent<T> {
        var event = this._events[eventName];
        if ( typeof event === 'undefined' ) {
            event = this._events[eventName] = new BrokeredEvent<T>(eventName);
        }
        return event as BrokeredEvent<T>;
    }
    public listen<T>(eventName: string, next: (value: T) => void) : IEventListener {
        return this.register<T>(eventName).listen(next);
    }
    public emit<T>(eventName: string, data: T) : void {
        return this.register<T>(eventName).emit(data);
    }
}

不要忘记在 angular2 模块中将 EventBrokerService 注册为提供程序。

Answer 2

您可以在路由器出口处渲染的组件中定义@Output 事件发射器。 如下定义路由器出口。

*.html
<router-outlet (activate)="onActivate($event)"></router-outlet>

在您的组件中，您可以这样做。

onActivate(elementRef) {
    elementRef.<the @Output eventEmitter>.subscribe(event => {
        console.log(event);
    });
}

这样你可以将事件发送到渲染路由器出口的组件。这是因为@Output 事件发射器是事件流，您可以订阅这些事件。