vue ssr 指南详读

git clone https://github.com/s249359986/learnssr.git
cd learnssr 
npm install
npm run dev

src
├── components
│  ├── foo.vue
├── views
│  ├── home.vue
├── app.vue
├── app.js 
├── client-entry.js
├── server-entry.js

if (isprod) {
 /**
  生产环境，createrenderer将已经通过webpack打包好的server-bundle.js转化为一个可以操作的renderer对象。
 **/
 renderer = createrenderer(fs.readfilesync(resolve('./dist/server-bundle.js'), 'utf-8'))
 
 /**
 入口模板文件
 **/
 indexhtml = parseindex(fs.readfilesync(resolve('./dist/index.html'), 'utf-8'))
} else {
 /**
  开发环境，createrenderer将已经通过webpack打包好的server-bundle.js转化为一个可以操作的renderer对象。
 **/
 require('./build/setup-dev-server')(app, {
  bundleupdated: bundle => {
   renderer = createrenderer(bundle)
  },
  indexupdated: index => {//index为入口文件及index.html
   indexhtml = parseindex(index)
  }
 })
}

function createrenderer (bundle) {

 return require('vue-server-renderer').createbundlerenderer(bundle, {
  cache: require('lru-cache')({
   max: 1,//1000,
   maxage: 2000//1000 * 60 * 15
  }),
  runinnewcontext: false
 })
}
/*
读取入口文件
*/
function parseindex (template) {
 const contentmarker = '<!-- app -->'
 const i = template.indexof(contentmarker)
 return {
  head: template.slice(0, i),
  tail: template.slice(i + contentmarker.length)
 }
}

const serve = (path, cache) => express.static(resolve(path), {
 maxage: cache && isprod ? 60 * 60 * 24 * 30 : 0
})

app.use('/dist', serve('./dist'))

app.get('*', (req, res) => {
 if (!renderer) {
  return res.end('waiting for compilation... refresh in a moment.')
 }

 res.setheader('content-type', 'text/html')
 res.setheader('server', serverinfo)

 var s = date.now()
 const context = { url: req.url }
 /*
  渲染vue实例，context对象上下文
 */
 const renderstream = renderer.rendertostream(context)

 renderstream.once('data', () => {
  res.write(indexhtml.head)
 })

 renderstream.on('data', chunk => {
  res.write(chunk)
 })

 renderstream.on('end', () => {
  if (context.initialstate) {
   res.write(
    `<script>window.__initial_state__=${
     serialize(context.initialstate, { isjson: true })
    }</script>`
   )
  }
  res.end(indexhtml.tail)
  console.log(`whole request: ${date.now() - s}ms`)
 })

 renderstream.on('error', err => {
  if (err && err.code === '404') {
   res.status(404).end('404 | page not found')
   return
  }
  res.status(500).end('internal error 500')
  console.error(`error during render : ${req.url}`)
  console.error(err)
 })
})

const port = process.env.port || 8080
app.listen(port, () => {
 console.log(`server started at localhost:${port}`)
})

export default context => {
 const s = isdev && date.now()
 router.push(context.url)
 const matchedcomponents = router.getmatchedcomponents()
 if (!matchedcomponents.length) {
  return promise.reject({ code: '404' })
 }
 return promise.all(matchedcomponents.map(component => {
/*
增加服务端数据预处理 start

*/
  if (component.asyncdata) {
     return component.asyncdata({
      store,
      route: router.currentroute
     })
    }

    /*
    增加服务端数据预处理 end

    */
 })).then(() => {
  isdev && console.log(`data pre-fetch: ${date.now() - s}ms`)
  context.initialstate = store.state
  return app
 })
}

/*

第一种方式
 */

vue.mixin({
 beforemount () {
  const { asyncdata } = this.$options
 console.log('beforemount',this.$store)
  if (asyncdata) {

   // 将获取数据操作分配给 promise
   // 以便在组件中，我们可以在数据准备就绪后
   // 通过运行 `this.datapromise.then(...)` 来执行其他任务
   this.datapromise = asyncdata({
    store: this.$store,
    route: this.$route
   })
  }
 },
 beforerouteupdate (to, from, next) {
 const { asyncdata } = this.$options
 console.log('beforerouteupdate',this.$store)
 if (asyncdata) {
 asyncdata({
  store: this.$store,
  route: to
 }).then(next).catch(next)
 } else {
 next()
 }
}
})

/**
更新客户端store，与服务端store同步
**/
// store.replacestate(window.__initial_state__)
if (window.__initial_state__) {
 store.replacestate(window.__initial_state__)
}
// actually mount to dom


router.onready(() => {
/**
挂载实例，客户端激活，所谓激活，指的是 vue 在浏览器端接管由服务端发送的静态 html，使其变为由 vue 管理的动态 dom 的过程。注释掉app.$mount('#app') 可以清楚看到<div id="app" data-server-rendered="true"> 客户端通过data-server-rendered="true"知道该html是vue在服务端渲染的，并且不会在做多余的渲染。由于在服务端无法绑定事件，只有通过客户端vue处理。
**/
 app.$mount('#app')
})