Vue 中如何進行權限控制？

// 定义路由
const routes = [
  {
    path: '/home', // 路径
    name: 'home', // 路由名称
    component: Home, // 路由对应的组件
    meta: {
      requireAuth: true, // 需要用户权限
      roles: ['admin', 'guest'] // 受访问限制的角色
    }
  },
  {
    path: '/login', // 路径
    name: 'login', // 路由名称
    component: Login // 路由对应的组件
  }
];

// 创建路由实例
const router = new VueRouter({
  routes // （缩写）相当于 routes: routes
});

// 添加路由前置守卫
router.beforeEach((to, from, next) => {
  // 判断该路由是否需要登录权限
  if (to.meta.requireAuth) {
    // 如果需要，则校验用户是否已经登录
    if (Vue.auth.loggedIn()) {
      // 判断当前用户是否有访问该路由的权限
      if (to.meta.roles.indexOf(Vue.auth.getUserRole()) !== -1) {
        next() // 用户有访问权限，直接进入页面
      } else {
        next('/denied') // 跳转到其他页面
      }
    } else {
      // 如果用户未登录，则跳转到登录页面
      next('/login')
    }
  } else {
    next() // 如果不需要登录权限，直接进入页面
  }
});

const routes = [
  {
    path: "/home",
    name: "home",
    component: Home,
    meta: {
      requireAuth: true,
      roles: ["admin", "guest"]
    }
  },
  {
    path: "/login",
    name: "login",
    component: Login
  }
];

const router = new VueRouter({
  routes
});

router.beforeEach((to, from, next) => {
  if (to.meta.requireAuth) {
    if (Vue.auth.loggedIn()) {
      if (to.meta.roles.indexOf(Vue.auth.getUserRole()) !== -1) {
        next();
      } else {
        next("/denied");
      }
    } else {
      next("/login");
    }
  } else {
    next();
  }
});

Vue.use(VueAuth, {
  auth: {
    login(req) {
      const username = req.body.username;
      const password = req.body.password;
      return axios.post("/api/login", {username, password}).then(res => {
        const data = res.data;
        localStorage.setItem("user", JSON.stringify(data.user));
        this.user.authenticated = true;
        return true;
      });
    },
    logout() {
      localStorage.removeItem("user");
      this.user.authenticated = false;
      return Promise.resolve();
    }
  },
  http: axios,
  tokenType: "Bearer",
  tokenName: "Authorization",
  storageType: "localStorage",
  user: {
    roles: JSON.parse(localStorage.getItem("user")).roles
  }
});