更强大的vue ssr实现预取数据的方式

yarn add vue-ssr-prefetcher

npm install vue-ssr-prefetcher --save

import Vue from 'vue'
import createApp from './createApp'
// 1. 引入 serverPlugin
import { serverPlugin } from 'vue-ssr-prefetcher'

// 2. 安装插件
Vue.use(serverPlugin)

export default async context => {
 const { app, router, store } = createApp()

 router.push(context.url)

 await routerReady(router)

 // 3. 设置 context.rendered 为 serverPlugin.done
 context.rendered = serverPlugin.done

 // 4. app.$$selfStore 是 serverPlugin 插件注入的属性
 context.state = {
  $$stroe: store ? store.state : undefined,
  $$selfStore: app.$$selfStore
 }

 return app
}

function routerReady (router) {
 return new Promise(resolve => {
  router.onReady(resolve)
 })
}

import Vue from 'vue'
import createApp from './createApp'
// 1. 引入插件
import { clientPlugin } from 'vue-ssr-prefetcher'
// 2. 安装插件
Vue.use(clientPlugin)

const { app, router, store } = createApp()

router.onReady(() => {
 // 3. 从 window.__INITIAL_STATE__ 中解构出 $$selfStore
 const { $$selfStore } = window.__INITIAL_STATE__

 // 4. 将数据添加到跟组件实例
 if ($$selfStore) app.$$selfStore = $$selfStore

 app.$mount('#app')
 // 5. 这个非常重要，它用于避免重复获取数据，并且一定要在 $mount() 函数之后
 clientPlugin.$$resolved = true
})

export default {
 name: 'Example',
 data() {
  return { name: 'Hcy' }
 },
 async created() {

  // this.$createFetcher() 函数是 clientPlugin 注入的
  // 接收一个返回 promise 的函数作为参数，例如用于请求 api 函数
  const fetcher = this.$createFetcher(fetchName)

  const res = await fetcher()

  this.name = res.name
 }
}

Vue.prototype.$createFetcher = function(fetcher) {
 const vm = this
 return function(params: any) {
  const p = fetcher(params)
  vm.$$promises.push(p)
  return p
 }
}

export default {
 name: 'Example',
 async created() {
  const fetcher = this.$createFetcher(() => this.$store.dispatch('someAction'))

  fetcher()
 }
}