// router.js
router.beforeEach((to, from, next) => {
 if (!to.meta.user) {
 // todo 請求接口獲取數據
 loadUserData().then(user => {
 // 存放源信息
 to.meta.user = user
 // 存在 vuex 中
 store.state.user = user
 if(user){
 next()
 }else{
 next({
 path: '/'
 })
 }
 })
 } else {
 next()
 }
})

// api.js
import axios from 'axios'

// 封裝ajax 的 fetch
export let fetch = (method, url, data, forceLogin = true) => {
 return new Promise((resolve, reject) => {
 axios({
 ...data,
 method: method,
 url: url
 }).then(response => {
 resolve(response.data)
 }).catch(err => {
 reject(err)
 })
 })
}

// 獲取用戶信息
export let loadUserData = () => {
 return new Promise((resolve, reject) => {
 let user = null
 let cacheKey = 'authUserJsonStr'
 let authUserJsonStr = sessionStorage.getItem(cacheKey)
 if (authUserJsonStr) {
 user = JSON.parse(sessionStorage.getItem(cacheKey))
 resolve(user)
 } else {
 fetch('GET', '/api/auth_info/', {}, false).then((data) => {
 user = data
 sessionStorage.setItem(cacheKey, JSON.stringify(user))
 resolve(user)
 }).catch(() => {
 resolve(null)
 })
 }
 })
}