vue ssr+koa2构建服务端渲染的示例代码

yarn global add @vue/cli

const Koa = require('koa')
const path = require('path')

const resolve = file => path.resolve(__dirname, file)
const app = new Koa()
const router = require('./router')
const port = 9000
app.listen(port, () => {
 console.log(`server started at localhost:${port}`)
})
module.exports = app

const fs = require('fs')
const path = require('path')
const send = require('koa-send')
const Router = require('koa-router')
const router = new Router()
// 获取当前文件的绝对路径
const resolve = file => path.resolve(__dirname, file)
const { createBundleRenderer } = require('vue-server-renderer')
const bundle = require('../dist/vue-ssr-server-bundle.json')
const clientManifest = require('../dist/vue-ssr-client-manifest.json')
// 创建一个 BunleRender 实例用于 renderer.renderToString 将 bundle 渲染为字符串
const renderer = createBundleRenderer(bundle, {
 runInNewContext: false,
 template: fs.readFileSync(resolve('../src/index.temp.html'), 'utf-8'),
 clientManifest: clientManifest
})

const handleRequest = async ctx => {
 ctx.res.setHeader('Content-Type', 'text/html')
 // 在 2.5.0+ 版本中，此 callback 回调函数是可选项。在不传递 callback 时，此方法返回一个 Promise 对象，在其 resolve 后返回最终渲染的 HTML。
 ctx.body = await renderer.renderToString(Object.assign({}, ctx.state.deliver, { url }))
}
router.get('/home',handleRequest)
module.exports = router

const { createBundleRenderer } = require('vue-server-renderer')

const renderer = createBundleRenderer(serverBundle, {
 runInNewContext: false, // 推荐
 template, // （可选）页面模板
 clientManifest // （可选）客户端构建 manifest
})

bundleRenderer.renderToString([context, callback]): ?Promise<string>

import Vue from 'vue'
import App from './App.vue'
...
export function createApp() {
 // ...
 const app = new Vue({
 router,
 store,
 render: h => h(App)
 })
 return { app, router, store }
}

import { createApp } from './main.js'
export default context => {
 // 因为有可能会是异步路由钩子函数或组件，所以我们将返回一个 Promise，
 // 以便服务器能够等待所有的内容在渲染前，
 // 就已经准备就绪。
 return new Promise((resolve, reject) => {
 const { app, router, store } = createApp()
 // 设置服务器端 router 的位置
 router.push(context.url)

 // 等到 router 将可能的异步组件和钩子函数解析完
 router.onReady(() => {
  const matchedComponents = router.getMatchedComponents()

  // 匹配不到的路由，执行 reject 函数，并返回 404
  if (!matchedComponents.length) {
  return reject({ code: 404 })
  }
  Promise.all(
  matchedComponents.map(component => {
   if (component.asyncData) {
   return component.asyncData({
    store,
    context,
    route: router.currentRoute
   })
   }
  })
  ).then(() => {
  // 在所有预取钩子(preFetch hook) resolve 后，
  // 我们的 store 现在已经填充入渲染应用程序所需的状态。
  // 当我们将状态附加到上下文，
  // 并且 `template` 选项用于 renderer 时，
  // 状态将自动序列化为 `window.__INITIAL_STATE__`，并注入 HTML。
  // 否则会导致客户端和服务端数据不统一造成渲染错误
  context.state = store.state
  resolve(app)
  }).catch(reject)
 }, reject)
 })
}

import { createApp } from './main'
const { app, router, store } = createApp()

if (window.__INITIAL_STATE__) {
 store.replaceState(window.__INITIAL_STATE__)
}

router.onReady(() => {
 router.beforeResolve((to, from, next) => {
 const matched = router.getMatchedComponents(to)
 const prevMatched = router.getMatchedComponents(from)
 let diffed = false
 const activated = matched.filter((c, i) => {
  return diffed || (diffed = prevMatched[i] !== c)
 })

 if (!activated.length) {
  return next()
 }

 Promise.all(
  activated.map(component => {
  if (component.asyncData) {
   component.asyncData({
   store,
   route: to
   })
  }
  })
 )
  .then(() => {
  next()
  })
  .catch(next)
 })
 app.$mount('#app')
})