什么后台管理权限

    vue如何控制用户的权限
    我们是这样做的，用户登录后，后台会返回这个用户的权限，比如用字段auth表示，我们就根据这个auth字段
    从我们实现创建好的路由表中，找到符合其权限的路由表，然后利用this.$router.addRoutes将其
    对应的路由表动态添加，这样接可以得到不同用户权限的路由了
    权限的目得就是防止一些用户的违规操作，不同的用户就有不同的权限 注意addRoutes([]) 里边是参数是一个数组
    正常权限为三种： 接口权限 路由菜单权限 按钮权限

搭建后台服务器(这里我使用express)

 yarn init -y
 yarn add express
const express = require("express")

const app = new express();

const host = "3000";
app.get("/user",(req,res) => {
  let response = {
    code: 200,
    token: 'jdqd11 dqwdqwdeq  awdqawdqewq',
    auth: ["user"]
  }
  res.send(response)
})
app.listen(host,()=> {
  console.log("service启动" + " " + 'http://localhost:' + host);
})
启动是 node index.js
后端url地址： http://localhost：3000

搭建vue项目

 npx vue create permission
 yarn add axios 
 yarn add vuex 
 yarn add router

整个vue项目文件入下图所示：

image.png

在router文件下新建常规路由 index.js,在router.beforeEach前置守卫这里边进行路由拦截

• 引入

import Vue from 'vue'
import VueRouter from 'vue-router';
import Store from '../store';
Vue.use(VueRouter)
let whiteList = ["/"] ; // 登录页面
const routes = [
  {
    path:'/',
    name: 'login',
    component: () => import("../views/login.vue")
  },
]

const router = new VueRouter({
  routes
})
router.beforeEach(async (to,from,next) => {
  let token = localStorage.getItem("token");
  let auth = Store.state.permission.auth;
  if(token) {
    if(auth.length === 0) {
      let roles = await Store.dispatch("permission/actionAuth")
      if(roles.length) {
        let filterRoutes = await Store.dispatch("permission/createRoutes",roles)
        console.log("filterRoutes",filterRoutes);
        router.addRoutes(filterRoutes)
        next({...to,replace: true}) // 防止 addRoutes添加过慢，造成的页面白屏 //
      } else { // 如果后端真没有数据，直接返回登录也买你
        next(`/?url=${to.fullPath}`)
      }
    } else {
      next()
    }
  } else {
    if(whiteList.indexOf(to.path)!=-1) {
      next()
    } else {
      next(`/?url=${to.fullPath}`)
    }
  }
})
export default router

在router文件下新建动态路由 permission.js

// const Demo1 = () => import("../views/Demo1.vue")
const  Demo2 = () => import("../views/Demo2.vue")
const Demo3 = () => import("../views/Demo3.vue")
const Demo4 = () => import("../views/Demo4.vue")
const Demo5 = () => import("../views/Demo5.vue")
const Demo6 = () => import("../views/Demo6.vue")
import Demo1 from '../views/Demo1.vue'
// 每个都是携带这个user的和admin的，还有一种写法就是后端直接返回一个 ['administration'] 直接 把 const rotutes = asyncRoutes

// 其它的就是 根据 filter 加上 some 和 includes结合判断，动态添加在 this.$router.addRoutes(a)
export const asyncRoutes = [
  {
    path: '/demo1',
    name: 'Demo1',
    meta: {
      roles: ['admin','user']
    },
    component: Demo1,
    children: [
      {
        path: '/demo6',
        name: 'Demo6',
        meta: {
          roles: ['admin','user']
        },
        component: Demo6
      }
    ],

  },
  {
    path: '/demo2',
    name: 'Demo2',
    meta: {
      roles: ['admin']
    },
    component: Demo2
  },
  {
    path: '/demo3',
    name: 'Demo3',
    meta: {
      roles: ['admin','user']
    },
    component: Demo3
  },
  {
    path: '/demo4',
    name: 'Demo4',
    meta: {
      roles: ['admin','user']
    },
    component: Demo4
  },
  {
    path: '/demo5',
    name: 'Demo5',
    meta: {
      roles: ['admin']
    },
    component: Demo5
  },
  { // 404所有的人都可以访问
    path: '*',
    name: '404',
    meta: {
      roles: ['admin',"user"]
    },
    component: () => import("../views/404.vue")
  }
]

新建store文件夹，在store文件下新建modules文件夹和index.js，在modules文件下新建permission.js

• permissions.js

import axios from '../../../fetch/index';
import {asyncRoutes} from '../../router/permission';
export default {
  namespaced: true,
  state: {
    auth: [],
    token: "" || localStorage.getItem("token"),
    routes: []
  },
  getters: {

  },
  mutations: {
    setAuth(state,auth) {
      state.auth = auth;
    },
    setToken(state,token) {
      state.token = token;
      localStorage.setItem("token",token)
    },
    setRoutes(state,routes) {
      console.log("routes",routes);
      state.routes = routes;
    }
  },
  actions: {
    // 拿到后台管理权限的数据
    actionAuth({commit}) {
     return new Promise((resolve,reject) => {
       axios.get("user").then(res => {
        let { code, auth,token } = res.data;
        if(code === 200) {
          commit("setAuth",auth)
          commit("setToken",token)
          resolve(auth)
        }
      }).catch(err=> {
        reject(err)
      })
     })
    },
    // 过滤角色
    async createRoutes({commit},roles) {
      console.log("roles",roles);
      return new Promise((resolve,reject) => {
        if(roles.length) {
          let res = asyncRoutes.filter(item => {
            return item.meta.roles.some(role => {
              return roles.includes(role)
            })
          })
          commit("setRoutes",res)
          resolve(res)
        } else {
          reject("err")
        }
      })
    }
  }
}

• index.js

import Vue from 'vue'
import Vuex from 'vuex'
import permission from './modules/permission';
Vue.use(Vuex)

export default new Vuex.Store({
  modules: {
    permission
  }
})

新建fetch文件夹，在featch文件夹下新建index.js和api.js

• api.js

 
const api = {
  user: {
    name: '用户权限',
    url: '/user'
  }
}
export default api

• index.js

import axios from 'axios'
import api from '../fetch/api'
const newAxios  = axios.create({
  // 公共的请求url地址
  baseURL:process.env.VUE_APP_API,
  timeout: 60000
})

newAxios.interceptors.request.use(config => {
  console.log("config",config.url);
  config.url = api[config.url].url
  return config
},error=> {
  Promise.reject(error)
})

newAxios.interceptors.response.use(res => {
  // 在这里边一般处理响应的状态的结果，比如 200 403 404等等
  return res
},error=> {
  Promise.reject(error)
})
export default newAxios

新建vue.config.js 前端处理后端跨域问题

• vue.config.js

module.exports = {
  devServer: {
    proxy: {
      "/api": {
        target: 'http://localhost:3000/', // target代理的就是后端的接口地址
        changeOrigin: true, // 是否允许跨域，默认就为true
        // secure: false, // 如果是https接口，需要配置这个参数
        pathRewrite: {
          "^/api": ""
        }
      }
    }
  }
}

login.vue进行登录

 <template>
  <div class="login">
    <button @click="login">登录</button>
  </div>
</template>

<script>
import { mapActions } from 'vuex'
export default {
  data() {
    return {

    }
  },
  methods: {
    ...mapActions("permission",["actionAuth"]),
    login() {
      this.actionAuth().then(res => {
          let path = this.$route.query.url || '/demo1' // 默认demo1是登录后的首页
          console.log("path",path) 
          this.$router.push(path)
      })
    }
  },
  created() {}
}
</script>

<style>

</style>

附加：按钮权限实现

• 新建utils文件夹 新建directive.js

import Vue from 'vue';
import Store from '../store';
Vue.directive('Auth', {
  // 当被绑定的元素插入到 DOM 中时……
  inserted: (el, binding) => {
    const value = binding.value;
    const auths = Store.state.permission.auth;
    if(auths.length) {
      let flag = value.some((item => auths.includes(item)))
      console.log("flag",flag);
      if(!flag) {
        el.parentNode.removeChild(el); // 如果不存在就删除掉
      }
    }
  }
});

• main.js引入 directive.js

 import Vue from 'vue'
import App from './App.vue'
import store from './store';
import router from './router';
Vue.config.productionTip = false
import axios from '../fetch/index';
Vue.prototype.$axios = axios
import './util/directive.js';
new Vue({
  router,
  store,
  render: h => h(App),
}).$mount('#app')

在demo3.vue中

<template>
  <div>demo4
    <button  v-Auth="['admin']">admin按钮</button>
    <button v-Auth="['admin','user']">user按钮</button>
  </div>
</template>

<script>
export default {

}
</script>

<style>

</style>

假如后台返回的是 ["user"]数组 ，页面显示如下

image.png