vue动态路由（后端传值）

思路：
总的来说就是从后端拿到路由数据，动态添加到路由表中。
问题：
如果有登录得先配置静态路由
细节：

 1. 在路由中配置静态路由：
//定义静态路由
const staticRoutes = [
  {
    path: '/login',
    name: 'Login',
    component: () => import(/* webpackChunkName: "Login" */ '../views/Login'),
  },
];
 2. 在路由中设置路由守卫
//定义全局守卫
router.beforeEach(async (to, from, next) => {
  //获取登录状态
  const token = localStorage.getItem('token');
  if (!token && to.name !== 'Login') {
    return next('/login');
  } else if (!token && to.name === 'Login') {
    if (!token) next();
  } else {
    if (!store.state.hasGetRoute) {
      // 如果没有获取路由信息，先从vuex获取路由信息而后跳转
      store.dispatch('getRouteList').then(() => {
        router.addRoutes(store.state.routeList);
        // 如果直接使用 next() 刷新后会一直白屏
        next({ ...to, replace: true });
      });
    } else {
      // 如果已经获取路由信息，直接跳转
      next();
    }
  }
});
3.vuex的中一些配置
const store = new Vuex.Store({
  state: {
    routeList: [],
    hasGetRoute: false,
  },
  mutations: {
    setRouteList(state, data) {
      // 用路由解析函数解析 List 为真正的路由列表
      state.routeList = filterAsyncRouter(data);
      // 修改路由获取状态
      state.hasGetRoute = true;
    },
  },
  actions: {
    getRouteList({ commit }) {
      return new Promise(resolve => {
      //axios获取路由结构
        MetroApi({
          url: '/user/get-user',
        }).then(res1 => {
          MetroApi({
            url: '/role/menu-list',
            params: {
              roleId: res1.data.roleId,
            },
          }).then(res => {
            let data = res.data;
            //循环遍历出route结构，并添加动态路由
            let navList = data.map(item => {
              return {
                name: item.menuName,
                path: item.frontPath,
              };
            });
            localStorage.setItem('navList', JSON.stringify(navList));
            let routes = [
              {
                path: '/',
                name: 'Index',
                component: () => import('@/components/Layout'),
                redirect: 'Workbench',
                children: [...data],
              },
            ];
            // 注意这里取出的是 JSON 格式的路由列表
            commit('setRouteList', routes);
            resolve();
          });
        });
      });
    },
  },
});
4.vuex中一些额外的方法
const loadView = viewPath => {
  // 用字符串模板实现动态 import 从而实现路由懒加载
  return () => import(`@/views${viewPath}`);
};

const filterAsyncRouter = routeList => {
  return routeList.filter(route => {
    if (route.frontPathComponent) {
      // 利用懒加载函数将实际页面赋值给它
      route.component = loadView(route.frontPathComponent);
      route.name = route.menuName;
      route.path = route.frontPathComponent || '/';
      if (route.menuType === 'M' && route.children.length > 0) {
        route.redirect = route.children[0].frontPathComponent;
      }
    }
    // 判断是否存在子路由，并递归调用自己,如果不是路由就去掉(C、M这个是后台传来的层级)
    if (route.menuType === 'C') {
      route.children = [];
    }
    if (route.children && route.children.length) {
      route.children = filterAsyncRouter(route.children);
    }
    return true;
  });
};