Vue.js 全局前置和后置-路由守卫

全局前置路由守卫视频
全局后置路由守卫视频

12.路由守卫

1. 作用：对路由进行权限控制

2. 分类：全局守卫、独享守卫、组件内守卫

3. 全局守卫:

   //全局前置守卫：初始化时执行、每次路由切换前执行
   router.beforeEach((to,from,next)=>{
   	console.log('beforeEach',to,from)
   	if(to.meta.isAuth){ //判断当前路由是否需要进行权限控制
   		if(localStorage.getItem('school') === 'atguigu'){ //权限控制的具体规则
   			next() //放行
   		}else{
   			alert('暂无权限查看')
   			// next({name:'guanyu'})
   		}
   	}else{
   		next() //放行
   	}
   })
   
   //全局后置守卫：初始化时执行、每次路由切换后执行
   router.afterEach((to,from)=>{
   	console.log('afterEach',to,from)
   	if(to.meta.title){ 
   		document.title = to.meta.title //修改网页的title
   	}else{
   		document.title = 'vue_test'
   	}
   })
   

index.js About.vue

修改网页标题

components

Banner.vue

<template>
	<div class="col-xs-offset-2 col-xs-8">
		<div class="page-header">
			<h2>Vue Router Demo</h2>
			<button @click="back">后退</button>
			<button @click="forward">前进</button>
			<button @click="test">测试一下go</button>
		</div>
	</div>
</template>

<script>
	export default {
		name:'Banner',
		methods: {
			back(){
				this.$router.back()
				// console.log(this.$router)
			},
			forward(){
				this.$router.forward()
			},
			test(){
				this.$router.go(3)
			}
		},
	}
</script>

pages

About.vue

<template>
	<h2>我是About的内容</h2>
</template>

<script>
	export default {
		name:'About',
		/* beforeDestroy() {
			console.log('About组件即将被销毁了')
		},*/
		/* mounted() {
			console.log('About组件挂载完毕了',this)
			window.aboutRoute = this.$route
			window.aboutRouter = this.$router
		},  */
		mounted() {
			console.log('%%%',this.$route)
		},
	}
</script>

Detail.vue

<template>
	<ul>
		<li>消息编号：{{id}}</li>
		<li>消息标题：{{title}}</li>
	</ul>
</template>

<script>
	export default {
		name:'Detail',
		props:['id','title'],
		computed: {
			// id(){
			// 	return this.$route.query.id
			// },
			// title(){
			// 	return this.$route.query.title
			// },
		},
		mounted() {
			// console.log(this.$route)
		},
	}
</script>

Home.vue

<template>
	<div>
		<h2>Home组件内容</h2>
		<div>
			<ul class="nav nav-tabs">
				<li>
					<router-link class="list-group-item" active-class="active" to="/home/news">News</router-link>
				</li>
				<li>
					<router-link class="list-group-item" active-class="active" to="/home/message">Message</router-link>
				</li>
			</ul>
			<keep-alive include="News">
				<router-view></router-view>
			</keep-alive>
		</div>
	</div>
</template>

<script>
	export default {
		name:'Home',
		/* beforeDestroy() {
			console.log('Home组件即将被销毁了')
		}, */
		/* mounted() {
			console.log('Home组件挂载完毕了',this)
			window.homeRoute = this.$route
			window.homeRouter = this.$router
		},  */
	}
</script>

Message.vue

<template>
	<div>
		<ul>
			<li v-for="m in messageList" :key="m.id">
				<!-- 跳转路由并携带params参数，to的字符串写法 -->
				<!-- <router-link :to="`/home/message/detail/${m.id}/${m.title}`">{{m.title}}</router-link>&nbsp;&nbsp; -->

				<!-- 跳转路由并携带params参数，to的对象写法 -->
				<router-link :to="{
					name:'xiangqing',
					query:{
						id:m.id,
						title:m.title
					}
				}">
					{{m.title}}
				</router-link>
				<button @click="pushShow(m)">push查看</button>
				<button @click="replaceShow(m)">replace查看</button>
			</li>
		</ul>
		<hr>
		<router-view></router-view>
	</div>
</template>

<script>
	export default {
		name:'Message',
		data() {
			return {
				messageList:[
					{id:'001',title:'消息001'},
					{id:'002',title:'消息002'},
					{id:'003',title:'消息003'}
				]
			}
		},
		methods: {
			pushShow(m){
				this.$router.push({
					name:'xiangqing',
					query:{
						id:m.id,
						title:m.title
					}
				})
			},
			replaceShow(m){
				this.$router.replace({
					name:'xiangqing',
					query:{
						id:m.id,
						title:m.title
					}
				})
			}
		},
		beforeDestroy() {
			// console.log('Message组件即将被销毁了')
		},
	}
</script>

News.vue

<template>
	<ul>
		<li :style="{opacity}">欢迎学习Vue</li>
		<li>news001 <input type="text"></li>
		<li>news002 <input type="text"></li>
		<li>news003 <input type="text"></li>
	</ul>
</template>

<script>
	export default {
		name:'News',
		data() {
			return {
				opacity:1
			}
		},
		/* beforeDestroy() {
			console.log('News组件即将被销毁了')
			clearInterval(this.timer)
		}, */
		/* mounted(){
			this.timer = setInterval(() => {
				console.log('@')
				this.opacity -= 0.01
				if(this.opacity <= 0) this.opacity = 1
			},16)
		}, */
		activated() {
			console.log('News组件被激活了')
			this.timer = setInterval(() => {
				console.log('@')
				this.opacity -= 0.01
				if(this.opacity <= 0) this.opacity = 1
			},16)
		},
		deactivated() {
			console.log('News组件失活了')
			clearInterval(this.timer)
		},
	}
</script>

router

index.js

// 该文件专门用于创建整个应用的路由器
import VueRouter from 'vue-router'
//引入组件
import About from '../pages/About'
import Home from '../pages/Home'
import News from '../pages/News'
import Message from '../pages/Message'
import Detail from '../pages/Detail'

//创建并暴露一个路由器
const router =  new VueRouter({
	routes:[
		{
			name:'guanyu',
			path:'/about',
			component:About,
			meta:{title:'关于'}
		},
		{
			name:'zhuye',
			path:'/home',
			component:Home,
			meta:{title:'主页'},
			children:[
				{
					name:'xinwen',
					path:'news',
					component:News,
					meta:{isAuth:true,title:'新闻'}
				},
				{
					name:'xiaoxi',
					path:'message',
					component:Message,
					meta:{isAuth:true,title:'消息'},
					children:[
						{
							name:'xiangqing',
							path:'detail',
							component:Detail,
							meta:{isAuth:true,title:'详情'},

							//props的第一种写法，值为对象，该对象中的所有key-value都会以props的形式传给Detail组件。
							// props:{a:1,b:'hello'}

							//props的第二种写法，值为布尔值，若布尔值为真，就会把该路由组件收到的所有params参数，以props的形式传给Detail组件。
							// props:true

							//props的第三种写法，值为函数
							props($route){
								return {
									id:$route.query.id,
									title:$route.query.title,
									a:1,
									b:'hello'
								}
							}

						}
					]
				}
			]
		}
	]
})

//全局前置路由守卫————初始化的时候被调用、每次路由切换之前被调用
router.beforeEach((to,from,next)=>{
	console.log('前置路由守卫',to,from)
	if(to.meta.isAuth){ //判断是否需要鉴权
		if(localStorage.getItem('school')==='atguigu'){
			next()
		}else{
			alert('学校名不对，无权限查看！')
		}
	}else{
		next()
	}
})

//全局后置路由守卫————初始化的时候被调用、每次路由切换之后被调用
router.afterEach((to,from)=>{
	console.log('后置路由守卫',to,from)
	document.title = to.meta.title || '硅谷系统'
})

export default router

App.vue

<template>
  <div>
    <div class="row">
      <Banner/>
    </div>
    <div class="row">
      <div class="col-xs-2 col-xs-offset-2">
        <div class="list-group">
					<!-- 原始html中我们使用a标签实现页面的跳转 -->
          <!-- <a class="list-group-item active" href="./about.html">About</a> -->
          <!-- <a class="list-group-item" href="./home.html">Home</a> -->

					<!-- Vue中借助router-link标签实现路由的切换 -->
					<router-link class="list-group-item" active-class="active" to="/about">About</router-link>
          <router-link class="list-group-item" active-class="active" to="/home">Home</router-link>
        </div>
      </div>
      <div class="col-xs-6">
        <div class="panel">
          <div class="panel-body">
						<!-- 指定组件的呈现位置 -->
            <router-view></router-view>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
	import Banner from './components/Banner'
	export default {
		name:'App',
		components:{Banner}
	}
</script>

main.js

//引入Vue
import Vue from 'vue'
//引入App
import App from './App.vue'
//引入VueRouter
import VueRouter from 'vue-router'
//引入路由器
import router from './router'

//关闭Vue的生产提示
Vue.config.productionTip = false
//应用插件
Vue.use(VueRouter)

//创建vm
new Vue({
	el:'#app',
	render: h => h(App),
	router:router
})