javascript – angular2 – 将值从父路由传递到子路由

我有一条名为home的路线,它有三条儿童路线,文件,邮件和垃圾.在归属路由组件中,它有一个名为“user”的变量.我知道有几种方法可以在突出显示here的父组件和子组件之间传递信息,但我想如何在父/子路由之间传递信息.

{ path: 'home',  component: HomeComponent, children: [
        { path: 'documents',  component: DocumentsComponent },
        { path: 'mail',  component: MailComponent },
        { path: 'trash',  component: TrashComponent },
    ]
},

服务

import { Injectable } from '@angular/core';
@Injectable()
export class HomeService {
  // Mock user, for testing  
  myUser = {name:"John", loggedIn:true};
  // Is Super Admin
  isLogged():boolean {
    if(this.myUser.role == true){
      return true ; 
    }
    return false ; 
  }
}

零件

  constructor(public router: Router, public http: Http, private homeService: HomeService) {

  }

  isLogged(){
    return this.homeService.isLogged(); 
  }

模板

<div class="side-nav fixed" >
    <li style="list-style: none">
        <img alt="avatar" class="circle valign profile-image" height="64" src=
        "../images/avatar.jpg" width="64">
        <div class="right profile-name">
            <!-- Value not changing even with service --> 
            {{myUser.role}} 
        </div>
    </li>

解决方法:

您可以使用公共服务传递数据,如Angular Documentation中所述

基本上,您可以创建一个具有用户对象的服务,一旦您的父路由被加载或在父组件上执行某些操作,就可以更新该用户对象.

UserService

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

   @Injectable()
   export class UserService {
     // Observable user 
     user = new Subject<string>();
   }

然后,当子路由组件被加载时,您可以从服务中检索值.

HomeComponent

 @Component({
   ... 
 })
 export class HomeComponent{
   ... 
   constructor(private userService:UserService ){}
   someMethod = () =>{
      this.userService.user.next(<pass user object>);
   }
 }

MailComponent

 @Component({
   ... 
 })
 export class HomeComponent{
   ... 
   constructor(private userService:UserService ){
     this.userService.user.subscribe(userChanged);  
   }

   userChanged = (user) => {
     // Do stuff with user
   }
 }

如果在父级中添加提供程序,则服务对象在子级中将是相同的实例.

希望这可以帮助！！

标签：javascript,angular,angularjs,components,ngroute
来源： https://codeday.me/bug/20191008/1870318.html