为了前端体验更加友好，减缓用户的焦虑情绪，提升项目质量等，我们在项目里面可以使用骨架屏，提前渲染出来一个跟正式页面相似的页面出来，减小首屏加载时间。

在vue中使用骨架屏

因为我们的代码会使用webpack打包，所以在我们的js下载运行之前，用户是无法在页面上看到信息，所以，我们要把骨架屏相关的代码放到HTML里面，当然，可以把代码直接写在html文件的<div id=’app‘></div>里面，但是为了维护我们进行开发时的体验，我们在开发时可以使用一个webpack插件，来像开发组件一样来开发骨架屏。

1.全局安装@vue/cli（Vue CLI 3的包名称由 vue-cli 改成了 @vue/cli）

npm install -g @vue/cli

2.新建vue-skeleton项目

vue create vue-skeleton

3.添加vue-skeleton-webpack-plugin插件

npm install vue-skeleton-webpack-plugin

4.创建骨架屏文件

在src文件夹下新建skeleton目录，并在这个目录内新建listSkeleton.vue、detailSkeleton.vue，两个文件内的内容如下：

<!--listSkeleton.vue -->
<template>
  <div class="container">
    <div>列表骨架屏</div>
    <img
      src="data:image/svg+xml;base64,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"
    />
    <img
      src="data:image/svg+xml;base64,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"
    />
  </div>
</template>

<script>
export default {
  components: {},
  data () {
    return {}
  },
  mounted () {},
  methods: {}
}
</script>

<style scoped lang="scss">
</style>

<!-- detailSkeleton.vue -->
<template>
  <div class="container">
    详情骨架屏
    <img
      src="data:image/svg+xml;base64,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"
    />
  </div>
</template>

<script>
export default {
  components: {},
  data () {
    return {}
  },
  mounted () {},
  methods: {}
}
</script>

<style scoped lang="scss">
</style>

在这个页面里面我们可以根据需要来编写代码，最好使用样式或者base64的图片，以减少初始的请求。 

5.新建一个Skeleton.js入口文件

在main.js同级新建一个Skeleton.js，内容如下：

// skeleton.js
import Vue from 'vue'
import listSkeleton from './skeleton/listSkeleton'
import detailSkeleton from './skeleton/detailSkeleton'

export default new Vue({
  components: {
    listSkeleton,
    detailSkeleton
  },
  template: `
    <div>
      <listSkeleton id="listSkeleton" style="display:none;" />
      <detailSkeleton id="detailSkeleton" style="display:none;" />
    </div>
  `
})

6.配置打包方案

在项目根目录新建vue.config.js,在里面配置vue-skeleton-webpack-plugin插件，并开启css分离；

根据配置各个路由路径对应的 Skeleton

//vue.config.js
const path = require('path')
const SkeletonWebpackPlugin = require('vue-skeleton-webpack-plugin')

module.exports = {
  configureWebpack: (config) => {
    config.plugins.push(new SkeletonWebpackPlugin({
      webpackConfig: {
        entry: {
          app: path.join(__dirname, './src/Skeleton.js')
        }
      },
      minimize: true,
      quiet: true,
      router: {
        mode: 'hash',
        routes: [
          { path: '/', skeletonId: 'listSkeleton' },
          { path: /^\/detail/, skeletonId: 'detailSkeleton' }
        ]
      }
    }))
  },
  // css相关配置
  css: {
    // 是否使用css分离插件 ExtractTextPlugin
    extract: true,
    // 开启 CSS source maps?
    sourceMap: false,
    // 启用 CSS modules for all css / pre-processor files.
    modules: false
  }
}

vue-skeleton-webpack-plugin插件参数说明

• webpackConfig 必填，渲染 skeleton 的 webpack 配置对象
• insertAfter 选填，渲染 DOM 结果插入位置，默认值为字符串 '<div id="app">'
  • 也可以传入 Function，方法签名为 insertAfter(entryKey: string): string，返回值为挂载点字符串
• quiet 选填，在服务端渲染时是否需要输出信息到控制台
• router 选填 SPA 下配置各个路由路径对应的 Skeleton
  • mode 选填 路由模式，两个有效值 history|hash
  • routes 选填 路由数组，其中每个路由对象包含两个属性：
    • path 路由路径 string|RegExp
    • skeletonId Skeleton DOM 的 id string
• minimize 选填 SPA 下是否需要压缩注入 HTML 的 JS 代码

7.在浏览器中查看效果

因为网络快的时候，我们是不显示骨架屏的，所以要把我们的浏览器网络调慢一点（调整为solw 3G），以方便我们开发和调试；

首页加载时：

detail页面加载时

我们会看到骨架屏先被渲染出来，然后才会有我们的页面渲染出来；