出于相同目的在两个地方的路由器指令 [英] Router directives in two places for same purpose

问题描述

我在理解这里的逻辑时遇到了一些麻烦

根组件

import { Component } from "angular2/core";import { TopNavigationComponent } from "./shared/navigation.component";import { ArcListComponent } from "./arc/arc-list.component";import { ArcNewItemComponent } from "./arc/arc-new-item.component";从angular2/router"导入{RouteConfig}；从 "angular2/router" 导入 { ROUTER_DIRECIVES };@成分({选择器:ng2-app"，模板:`<section class="jumbotron full-height"><top-navigation></top-navigation><div class="容器"><路由器插座></路由器插座>

</节>`，指令:[TopNavigationComponent、ArcListComponent、ROUTER_DIRECTICIVES]})@RouteConfig([{path: "/", name: "Root", component: ArcListComponent, useAsDefault: true},{path: "/new", name: "New-item", component: ArcNewItemComponent}])导出类 RootComponent {}

顶部导航组件

import { Component } from "angular2/core";从 "angular2/router" 导入 { ROUTER_DIRECIVES };@成分({选择器:顶部导航"，templateUrl: "dev/shared/navigation.template.html",指令:[ROUTER_DIRECIVES]})导出类 TopNavigationComponent {}

导航.模板

<div class="容器"><!-- 品牌和切换被分组以获得更好的移动显示--><div class="navbar-header"><button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false"><span class="sr-only">切换导航</span><span class="icon-bar"></span><span class="icon-bar"></span><span class="icon-bar"></span><a class="navbar-brand" [routerLink]="['Root']">Angular2Arc</a>

<!-- 收集导航链接、表单和其他用于切换的内容--><div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1"><ul class="nav navbar-nav navbar-right"><li><a [routerLink]="['Root']">首页</a></li><li><a [routerLink]="['New-item']">添加新资源</a></li><li><a href="#">Github</a></li></div><!--/.navbar-collapse --></div><!--/.container-fluid --></nav>

我的问题是，虽然这可行，您能解释一下为什么我需要将路由器指令放在两个地方吗，以及是否有更好的方法来做到这一点?

解决方案

正如@Bhavik 所说，每次使用 RouterLink 或 RouterOutlet 时都需要 ROUTER_DIRECTIVES>(您也可以指定其中的每一个).

检查路由器的源代码

export const ROUTER_DIRECTIVES: any[] = CONST_EXPR([RouterOutlet, RouterLink]);

显然，每次使用其中任何一个时都添加它很烦人，因此您可以使用 PLATFORM_DIRECTIVES.这样，您只需在应用程序中添加一次，即可在整个应用程序中使用它.

bootstrap(App, [提供(PLATFORM_DIRECTIVES，{useValue:[ROUTER_DIRECTIVES]，多:真})]);

请注意，有一个 issue 公开提议添加 ROUTER_DIRECTIVES 到 ROUTER_PROVIDERS，所以我们甚至可以跳过上面建议的解决方案.这将使设置路由器变得更加容易.

I am having a bit of trouble understanding the logic here

root-component

import { Component } from "angular2/core";
import { TopNavigationComponent } from "./shared/navigation.component";
import { ArcListComponent } from "./arc/arc-list.component";
import { ArcNewItemComponent } from "./arc/arc-new-item.component";
import { RouteConfig } from "angular2/router";
import { ROUTER_DIRECTIVES } from "angular2/router";
@Component({
  selector: "ng2-app",
  template: `
    <section class="jumbotron full-height">
      <top-navigation></top-navigation>
      <div class="container">
        <router-outlet></router-outlet>
      </div>
    </section>
  `,
  directives: [TopNavigationComponent, ArcListComponent,ROUTER_DIRECTIVES]
})

@RouteConfig([
  {path: "/", name: "Root", component: ArcListComponent, useAsDefault: true},
  {path: "/new", name: "New-item", component: ArcNewItemComponent}
])

export class RootComponent {

}

top-navigation component

import { Component } from "angular2/core";
import { ROUTER_DIRECTIVES } from "angular2/router";

@Component({
    selector: "top-navigation",
    templateUrl: "dev/shared/navigation.template.html",
    directives: [ROUTER_DIRECTIVES]
})

export class TopNavigationComponent {

}

navigation.template

<nav class="navbar navbar-default">
  <div class="container">
    <!-- Brand and toggle get grouped for better mobile display -->
    <div class="navbar-header">
      <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#bs-example-navbar-collapse-1" aria-expanded="false">
        <span class="sr-only">Toggle navigation</span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
        <span class="icon-bar"></span>
      </button>
      <a class="navbar-brand" [routerLink]="['Root']">Angular2Arc</a>
    </div>

    <!-- Collect the nav links, forms, and other content for toggling -->
    <div class="collapse navbar-collapse" id="bs-example-navbar-collapse-1">
      <ul class="nav navbar-nav navbar-right">
        <li><a [routerLink]="['Root']">Home</a></li>
        <li><a [routerLink]="['New-item']">Add New Resource</a></li>
        <li><a href="#">Github</a></li>
      </ul>
    </div><!-- /.navbar-collapse -->
  </div><!-- /.container-fluid -->
</nav>

my question is while this works, can you explain why i need to put Router directives in two places, and if there is a better way to do this?

解决方案

As @Bhavik said ROUTER_DIRECTIVES is required everytime you use RouterLink or RouterOutlet (you can specify each one of them as well).

Check the source code for Router

export const ROUTER_DIRECTIVES: any[] = CONST_EXPR([RouterOutlet, RouterLink]);

Obviously adding it everytime you're using either of one of them is annoying, so you can make it simpler by using PLATFORM_DIRECTIVES. This way you'll add it once in your application and it will be available across of it.

bootstrap(App, [
    provide(PLATFORM_DIRECTIVES, {useValue: [ROUTER_DIRECTIVES], multi: true})
]);

Note that there's an issue open proposing to add ROUTER_DIRECTIVES to ROUTER_PROVIDERS, so we can even skip the solution suggested above. That would make setting up Router much easier.

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