我试图在Angular中实现类似委托模式的东西.当用户点击a时nav-item,我想调用一个函数然后发出一个事件,而该事件又由一些其他组件监听事件来处理.
这是场景:我有一个Navigation组件:
import {Component, Output, EventEmitter} from 'angular2/core';
@Component({
// other properties left out for brevity
events : ['navchange'],
template:`
<div class="nav-item" (click)="selectedNavItem(1)"></div>
`
})
export class Navigation {
@Output() navchange: EventEmitter<number> = new EventEmitter();
selectedNavItem(item: number) {
console.log('selected nav item ' + item);
this.navchange.emit(item)
}
}
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这是观察组件:
export class ObservingComponent {
// How do I observe the event ?
// <----------Observe/Register Event ?-------->
public selectedNavItem(item: number) {
console.log('item index changed!');
}
}
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关键问题是,如何让观察组件观察相关事件?
event-delegation observable observer-pattern eventemitter angular
我需要澄清服务和组件属性之间的绑定以及angular2中的数据绑定
假设我有一个服务(单身)和一个组件
export class Service {
name = "Luke";
object = {id:1};
getName(){return this.name};
getObject(){return this.object};
}
export class Component implements OnInit{
name:string;
object:any;
constructor(private _service:Service){}
ngOnInit():any{
//Is this 2 way binding?
this.name = this._service.name;
this.object = this._service.object;
//Is this copying?
this.name = this._service.getName();
this.object = this._service.getObject();
}
}
Run Code Online (Sandbox Code Playgroud) 所以我知道你可以让两个不相关的组件通过服务相互通信,让一个组件在服务中发出一个事件,另一个组件在服务中订阅它.
我的问题:
服务可以直接调用组件中的函数吗?