如何从Angular 2中的子组件事件触发父组件中的本地引用？

Question

I am trying to work out how to trigger a local reference in a parent component template ie #rightNav from a child component template click event (click)="rightNav.open()" using Material 2 sidenav . I think I need to use the @ViewChild annotation, but not sure how.

Child component template (app-conditions-list):

<div *ngFor="let condition of conditions" [class.selected]="condition === selectedCondition"
            (click)="rightNav.open()"></div>

Parent component template (condition component):

import { Component} from '@angular/core';
import { ConditionsListComponent } from './listComponent/conditions-list.component';


@Component({
    moduleId: module.id,
    selector: 'app-conditions',
    template: `
            <md-sidenav #rightNav align="end" mode="side">
            "Condition details will open here on click event"
            </md-sidenav>
            <app-conditions-list></app-conditions-list>`,
    styleUrls: ['./conditions.component.css'],
    directives: [
        ConditionsListComponent,
    ]
})

export class ConditionsComponent  {
    title = "Conditions Manager"
}

The child component is nested in the parent component template. Thanks!

Answer 1

You can add an output to the child component and listen to events from it

export class ConditionsListComponent {
  @Output() navOpen:EventEmitter = new EventEmitter();
}

You can use a template variable to refer to sibling elements like:

<div #rightNav align="end" mode="side" (close)="close($event)"</div>
<app-conditions-list (navOpen)="rightNav.open()"></app-conditions-list>`,

and event an event like

<div *ngFor="let condition of conditions" [class.selected]="condition === selectedCondition"
        (click)="navOpen.next(null)"></div>

Answer 2

You'd need to bubble your event up from your child to your parent :

The child :  

export class ConditionsListComponent  {
   @Output('myEvent') myEvent = new EventEmitter();

   private bubbleUp($event:Event){

     myEvent.emit($event)
  }
}

It's view :

  <div *ngFor="let condition of conditions" [class.selected]="condition === selectedCondition"
        (click)="bubbleUp($event)"></div>

And the parent :

     import { Component} from '@angular/core';

@Component({
moduleId: module.id,
selector: 'app-conditions',
template: `
        <div #rightNav align="end" mode="side" (close)="close($event)"</div>
        <app-conditions-list (myEvent)='gotTheEvent($event)' ></app-conditions-list>`,
styleUrls: ['./conditions.component.css'],
providers: [],
directives: [
    ConditionsListComponent,
]
})

export class ConditionsComponent  {
   title = "Conditions Manager";

   gotTheEvent($event){

     console.log('I got this event from my child',$event);

    //you can do whatever you want : 

     rightNav.open()
  }
}