配置vue-element-template实现动态路由

模板地址：vue-element-template
作者配套系列文章：手摸手，带你用vue撸后台 系列二(登录权限篇)

前言

模板已经实现通过路由表，通过对路由表进行递归，实现导航栏动态生成。模板作者也提供了根据权限动态生成可访问路由表的实现方案。本篇介绍在这个基础上实现路由表根据权限动态生成路由表。

作者本人也有系列文章，本篇是在原篇基础上增加一些细节。

先说一说我权限控制的主体思路，前端会有一份路由表，它表示了每一个路由可访问的权限。当用户登录之后，通过 token 获取用户的 role ，动态根据用户的 role 算出其对应有权限的路由，再通过router.addRoutes动态挂载路由。

关联文件

/src/store/modules/user.js
/src/store/modules/permission.js
/src/store/index.js
/src/store/getters.js
/src/router/index.js
/src/permission.js
/src/layout/components/Sidebar/index.js

具体实现

1.获取用户权限

登录成功后，获取用户信息是获取到用户所拥有的权限，/src/store/modules/user.js。

const getDefaultState = () => {
  return {
    ...
    ...
    roles: [] // ①
  }
}

const mutations = {
  ...
  ...
  SET_ROLES: (state, roles) => {
    state.roles = roles
  }  // ②
}

const actions = {
  

  // get user info
  getInfo({ commit, state }) {
    return new Promise((resolve, reject) => {
      getInfo(state.token).then(response => {
        const { data } = response
        if (!data) {
        ...
        ...
        commit('SET_ROLES', data.Roles) // ③
        resolve(data)
      }).catch(error => {
        reject(error)
      })
    })
  },

/src/store/getters.js

const getters = {
  ...
  ...
  roles: state => state.user.roles
}

2.路由表配置

/src/store/index.js中增加asyncRoutes常量并暴露出去，在这个常量中的路由将去和权限进行匹配。在meta中对roles赋值，为空即所有人都可访问，并且导航栏也会递归出来，不为空代表只有对应权限的才可以访问。
constantRoutes中的路由是所有人都可以访问的。两个常量拼凑起来才是一个完整的路由表。
如果启用动态路由，constantRoutes最下面的404得放到asyncRoutes的最下面。

404 page must be placed at the end !!!

...
...
export const asyncRoutes = [
  {
    path: '/permission',
    component: Layout,
    meta: {
      title: 'permission',
      icon: 'test' 
    },
    children: [
      {
        path: 'admin',
        component: () => import('@/views/permission/admin'),
        meta: { title: 'admin', roles: ['超级管理员'] }
      },
      {
        path: 'everyone',
        component: () => import('@/views/permission/everyone'),
        meta: { title: 'everyone' }
      }
    ]
  },
  { path: '*', redirect: '/404', hidden: true }
]
...
...

3.增加权限管理函数

在src/store/modules/下增加permission.js

import { asyncRoutes, constantRoutes } from '@/router/index'

/**
 * Use meta.role to determine if the current user has permission
 * @param roles
 * @param route
 */
function hasPermission(roles, route) {
  if (route.meta && route.meta.roles) {
    return roles.some(role => route.meta.roles.includes(role))
  } else {
    return true
  }
}

/**
 * Filter asynchronous routing tables by recursion
 * @param routes asyncRoutes
 * @param roles
 */
export function filterAsyncRoutes(routes, roles) {
  const res = []

  routes.forEach(route => {
    const tmp = { ...route }
    if (hasPermission(roles, tmp)) {
      if (tmp.children) {
        tmp.children = filterAsyncRoutes(tmp.children, roles)
      }
      res.push(tmp)
    }
  })

  return res
}

const state = {
  routes: [],
  addRoutes: []
}

const mutations = {
  SET_ROUTES: (state, routes) => {
    state.addRoutes = routes
    state.routes = constantRoutes.concat(routes)
  }
}

const actions = {
  // 通过 角色 和 所有路由 匹配出对应角色拥有的路由权限
  generateRoutes({ commit }, roles) {
    return new Promise(resolve => {
      let accessedRoutes
      if (roles.includes('超级管理员')) {
        accessedRoutes = asyncRoutes || []
      } else {
        accessedRoutes = filterAsyncRoutes(asyncRoutes, roles)
      }
      commit('SET_ROUTES', accessedRoutes)
      resolve(accessedRoutes)
    })
  }
}

export default {
  namespaced: true,
  state,
  mutations,
  actions
}

/src/store/index.js

const store = new Vuex.Store({
  modules: {
    app,
    settings,
    user,
    permission //增加
  },
  getters
})

/src/permission.js

import router from './router'
import store from './store'
import { Message } from 'element-ui'
import NProgress from 'nprogress' // progress bar
import 'nprogress/nprogress.css' // progress bar style
import { getToken } from '@/utils/auth' // get token from cookie
import getPageTitle from '@/utils/get-page-title'

NProgress.configure({ showSpinner: false }) // NProgress Configuration

const whiteList = ['/login'] // no redirect whitelist

router.beforeEach(async(to, from, next) => {
  // start progress bar
  NProgress.start()

  // set page title
  document.title = getPageTitle(to.meta.title)

  // determine whether the user has logged in
  const hasToken = getToken()

  if (hasToken) {
    if (to.path === '/login') {
      // if is logged in, redirect to the home page
      next({ path: '/' })
      NProgress.done()
    } else {
      const hasGetUserInfo = store.getters.name
      if (hasGetUserInfo) {
        next()
      } else {
        try {
          // ****************************************
          // get user info
          const { Roles } = await store.dispatch('user/getInfo')
          const accessRoutes = await store.dispatch('permission/generateRoutes', Roles)
          router.addRoutes(accessRoutes)
          next({ ...to, replace: true })
          // *****************************************
        } catch (error) {
          // remove token and go to login page to re-login
          await store.dispatch('user/resetToken')
          Message.error(error || 'Has Error')
          next(`/login?redirect=${to.path}`)
          NProgress.done()
        }
      }
    }
  } else {
    /* has no token*/

    if (whiteList.indexOf(to.path) !== -1) {
      // in the free login whitelist, go directly
      next()
    } else {
      // other pages that do not have permission to access are redirected to the login page.
      next(`/login?redirect=${to.path}`)
      NProgress.done()
    }
  }
})

router.afterEach(() => {
  // finish progress bar
  NProgress.done()
})

4.store的路由表接管导航栏路由表由

这边是巨坑，对不了解vue的我简直致命
/src/store/getters.js

const getters = {
  ...
  roles: state => state.user.roles,
  addRouters: state => state.user.addRouters,
  permission_routes: state => state.permission.routes
}

/src/layout/components/Sidebar/index.js，修改sidebar-item组件，由store接管。

computed: {
    ...mapGetters([
      'permission_routes',
      'sidebar'
    ]),
    // routes() {
    //   return this.$router.options.routes
    // },

结语