17-----vue前端权限管理

原理：

1.后台同学返回一个json格式的路由表，再这个实例中，我们使用的是文件动态路由的形式;

2.动态路由，每个路由根据自己的权限字段，设定好权限字段。

3.利用vue-router的beforeEach、addRoutes、localStorage来配合上边两步实现效果;

4.左侧菜单栏根据拿到转换好的路由列表进行展示;

大体步骤：拦截路由->后台取到路由->保存路由到localStorage(用户登录进来只会从后台取一次，其余都从本地取,所以用户，只有退出在登录路由才会更新)

1、首先定义我们的路由文件：

import Login from './views/Login.vue'
import NotFound from './views/404.vue'
import Home from './views/Home.vue'
import Main from './views/Main.vue'
import Table from './views/nav1/Table.vue'
import Form from './views/nav1/Form.vue'
import user from './views/nav1/user.vue'
import Page4 from './views/nav2/Page4.vue'
import Page5 from './views/nav2/Page5.vue'
import Page6 from './views/nav3/Page6.vue'
import echarts from './views/charts/echarts.vue'
import UserManager from './views/users/UserManager'
import Permission from './views/users/Permission'
import Role from './views/users/Role'

let routes = [
    {
        path: '/login',
        component: Login,
        name: '',
        hidden: true
    },
    {
        path: '/404',
        component: NotFound,
        name: '',
        hidden: true
    },
    //{ path: '/main', component: Main },
];
export default routes;

export const powerRouter = [
    {
        path: '/',
        component: Home,
        name: '系统管理',
        iconCls: 'fa el-icon-message',//图标样式class
        role:['role'],
        children: [
            { path: '/main', component: Main, name: '主页', hidden: true }, // 子菜单列表
            // { path: '/table', component: Table, name: 'Table' },
            //{ path: '/form', component: Form, name: 'Form' },
            // { path: '/permission', component: Permission, name: '权限管理' },
            { path: '/role', component: Role, name: '角色管理' },
            { path: '/user', component: UserManager, name: '用户管理' },
        ]
    },
    {
        path: '/',
        component: Home,
        name: '导航二',
        iconCls: 'fa fa-id-card-o',
        role:['role'],
        children: [
            { path: '/page4', component: Page4, name: '页面4' },
            { path: '/page5', component: Page5, name: '页面5' }
        ]
    },
    {
        path: '/',
        component: Home,
        name: '',
        iconCls: 'fa fa-address-card',
        leaf: true,//只有一个节点
        // role:['cmdb','role','user'],
        children: [
            { path: '/page6', component: Page6, name: '导航三' }
        ]
    },
    {
        path: '/',
        component: Home,
        name: 'Charts',
        iconCls: 'fa fa-bar-chart',
        // role:['cmdb','role','user'],
        children: [
            { path: '/echarts', component: echarts, name: 'echarts' }
        ]
    },
    {
        path: '*',
        hidden: true,
        // role:['role','user'],
        redirect: { path: '/404' }
    }
];

router.js

2、路由拦截： main.js

import routes from './routes'
import { powerRouter  } from './routes.js';


// 路由卫士，判断路由权限
router.beforeEach((to, from, next) => {
    if (store.state.user) { //判断role 是否存在
        // console.log('dddddddddd', store.state.user);
        if (store.state.newrouter.length !== 0) {
            next();
        } else {
            let newrouter = [];
            let _role = store.state.user.roles;    // ##从后端获取权限，默认权限是['admin','user']这种数组形式
            _role.forEach((i) => {
                console.log("_role:::::::::::::::::::",_role);
                console.log('i::::::', i);// ##遍历里面的权限
                powerRouter.forEach((k) => {
                    console.log("powerRouter::::::::::::",powerRouter);
                    console.log("k:::::::::::::::::",k)
                    // ##遍历定义的路由信息
                    if (k.role==null){
                       return true;
                    }
                    k.role.forEach((j) => {
                        console.log("k.role:::::::::::::::::",k.role);
                        console.log("j:::::::::::::::::",j)
                            if (j === i) {                         // ##相关参数做比对，符合权限的，添加到路由
                                newrouter.push(k);
                                console.log('kkkkkkk', k);
                                console.log('jjjjjjj', j);
                                console.log('iiiiii', i);
                            }
                        }
                    )
                });
            });
            //404的页面再最后加，不然总数访问到的都是404界面
            newrouter.push({
                path: '*',
                redirect: '/404'
            });
            console.log('11111111', _role)
            router.addRoutes(newrouter); //添加动态路由
            store.dispatch('NewRouter', newrouter).then(res => {
                next({...to})
            }).catch(() => {

            })
        }
    } else {
        if (['/login'].indexOf(to.path) !== -1) {
            next()
        } else {
            next('/login')
        }
    }
});

main.js

3、vuex路由管理。

import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex);
// 创建基本状态
const state = {
    user: JSON.parse(localStorage.getItem('user')) || '',
    newrouter: []
};
// 创建改变状态的方法
const mutations = {
    // 登录
    LOGIN(state) {
        state.user = JSON.parse(localStorage.getItem('user'))
        newrouter: []
    },
    // 登出
    LOGOUT(state) {
        state.user = ''
        localStorage.removeItem('token')
        localStorage.removeItem('user')
        newrouter:  []
    },
    NewRouter(state, newrouter) {
        state.newrouter = newrouter
    },
    CleanRouter(state) {
        state.newrouter = []
    }
}
// 创建驱动actions可以使得mutations得以启动
const actions = {
    // 这里先来一个驱动LOGIN的东西就叫login吧
    login({commit}) {
        commit('LOGIN')
    },
    // 同样来个logout
    logout({commit}) {
        commit('LOGOUT')
    },
    NewRouter({commit}, newrouter) {
        commit('NewRouter', newrouter)
    },
    CleanRouter({commit}) {   // 登陆之前清控路由表
        commit('CleanRouter')
    }
}

export default new Vuex.Store({
    state,
    mutations,
    actions
})

store.js

4、前端根据过滤出的路由生成侧边栏，替换到路由：

    computed: {
                  routes() {
                    return this.$store.state.newrouter            
                 }
             },

5、剩下的就是侧边栏路由遍历信息：

6、这样就形成了，不同的用户登录具有不同的展示和权限。