Vue+express项目优化上线（1）

时间：2020-12-04 09:14:16 收藏：0 阅读：43

Vue+express项目优化上线（1）

Vue+express项目优化上线（1）
- 1.Vue项目优化
- 2.项目上线

1.Vue项目优化

1.1 项目优化策略

生成打包报告
第三方库启用CDN
Element-UI组件按需加载
路由懒加载
首页内容定制

1.2 通过nprogress添加加载进度条

安装运行依赖后，导入并在axios拦截器中使用

//设置request拦截器
axios.interceptors.request.use(config => {
  //展示进度条
  Nprogress.start()
  //为请求头添加一个Authorization的属性，值为sessionStorage中存储的token
  config.headers.Authorization = window.sessionStorage.getItem(‘token‘)
  return config
})
//设置response拦截器
axios.interceptors.response.use(config => {
  //隐藏进度条
  Nprogress.done()
  return config
})

1.3 在发布阶段移除所有console

安装babel-plugin-transform-remove-console开发依赖

使用方法可参考官方文档

babel.config.js文件初步使用

//该文件全局共享，开发阶段和发布阶段都会生效
module.exports = {
  "presets": [
    "@vue/cli-plugin-babel/preset"
  ],
  "plugins": [
    [
      "component",
      {
        "libraryName": "element-ui",
        "styleLibraryName": "theme-chalk"
      }
    ],
    "transform-remove-console"
  ]
}

  
- 只在发布阶段移除所有console

  ```js
  //这是项目发布阶段要用到的 babel 插件
  const prodPlugins = []
  //判断当前所处模式
  if (process.env.NODE_ENV === ‘production‘) {
    prodPlugins.push("transform-remove-console")
  }
  module.exports = {
    "presets": [
      "@vue/cli-plugin-babel/preset"
    ],
    "plugins": [
      [
        "component",
        {
          "libraryName": "element-ui",
          "styleLibraryName": "theme-chalk"
        }
      ],
      //发布产品时候的插件数组(...对象展开符)
      ...prodPlugins
    ]
  }

1.4 生成打包报告

在打包时生成报告有两种方式：

通过命令行参数

//通过 vue-cli 的命令选项可以生成打包报告
// --report 选项可以生成 report.html 以帮助分析包内容
vue-cli-service build --report

通过可视化UI面板直接查看
- 控制台 AND 分析

1.5 通过创建vue.config.js修改webpack的默认配置

在vue.config.js导出的配置对象中，新增 configureWebpack 或 chainWebpack 节点，来自定义 webpack 的打包配置
configureWebpack 和 chainWebpack 的作用相同，唯一区别是它们修改 webpack配置的方式不同
- chainWebpack通过链式编程的形式，来修改默认的webpack配置
- configureWebpack通过操作对象的形式，来修改默认的webpack配置

通过chainWebpack自定义打包入口

将main.js入口文件复制一份，分别命名main-dev.js&main-prod.js

//vue.config.js文件内容
module.exports = {
    chainWebpack: config => {
        //发布模式
        config.when(process.env.NODE_ENV === ‘production‘, config => {
            config.entry(‘app‘).clear().add(‘./src/main-prod.js‘)
        })

        //开发模式
        config.when(process.env.NODE_ENV === ‘development‘, config => {
            config.entry(‘app‘).clear().add(‘./src/main-dev.js‘)
        })
    }
}

1.6 通过 externals 加载外部CDN资源

默认情况下，通过 import 语法导入的第三方依赖包，最终会被打包合并到一个文件中，导致打包成功后，单文件体积过大问题
通过webpack的externals节点，配置并加载外部CDN资源，凡是声明在externals中的第三方依赖包，都不会被打包

在 vue.config.js 中进行配置

module.exports = {
    chainWebpack: config => {
        //发布模式
        config.when(process.env.NODE_ENV === ‘production‘, config => {
            config.
            entry(‘app‘).
            clear().
            add(‘./src/main-prod.js‘)

            config.set(‘externals‘, {
                vue: ‘Vue‘,
                ‘vue-router‘: ‘VueRouter‘,
                axios: ‘axios‘,
                echarts: ‘echarts‘,
                nprogress: ‘NProgress‘,
            })
        })

        //开发模式
        config.when(process.env.NODE_ENV === ‘development‘, config => {
            config.entry(‘app‘).clear().add(‘./src/main-dev.js‘)
        })
    }
}

在index.html文件中导入CDN资源

<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <link rel="icon" href="<%= BASE_URL %>favicon.ico">
    <title><%= htmlWebpackPlugin.options.isProd ? ‘‘ : ‘dev - ‘ %>522人事工资管理后台网站</title>

    <% if(htmlWebpackPlugin.options.isProd){ %>

    <!--nprogress的样式表文件-->
    <link href="https://cdn.bootcdn.net/ajax/libs/nprogress/0.2.0/nprogress.min.css" rel="stylesheet">
    <!--element-ui的样式表-->
    <link href="https://cdn.bootcdn.net/ajax/libs/element-ui/2.9.0/theme-chalk/index.css" rel="stylesheet">

    <!--js文件-->
    <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.11/vue.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/nprogress/0.2.0/nprogress.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/vue-router/3.2.0/vue-router.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/echarts/4.9.0-rc.1/echarts.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/axios/0.20.0/axios.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/element-ui/2.9.0/index.js"></script>

    <% } %>
</head>

优化后进行打包，js文件大小减少了大半，警告减少了一个
此处遇坑：即使使用了项目依赖对应版本的element-ui的cdn，打包后显示也不正常，切换多个版本后解决

1.7 首页内容定制

不同的打包环境下，首页内容可能会有所不同，我们可以通过插件的方式进行定制

在开发与发布环境中为isProd设置不同的值

//为html插件新增自定义属性isProd
            config.plugin(‘html‘).tap(args => {
                args[0].isProd = true
                return args
            })

在index.html中根据isProd展示不同内容

<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width,initial-scale=1.0">
    <link rel="icon" href="<%= BASE_URL %>favicon.ico">
    <title><%= htmlWebpackPlugin.options.isProd ? ‘‘ : ‘dev - ‘ %>title</title>

    <% if(htmlWebpackPlugin.options.isProd){ %>

    <!--nprogress的样式表文件-->
    <link href="https://cdn.bootcdn.net/ajax/libs/nprogress/0.2.0/nprogress.min.css" rel="stylesheet">
    <!--element-ui的样式表-->
    <link href="https://cdn.bootcdn.net/ajax/libs/element-ui/2.4.5/theme-chalk/index.css" rel="stylesheet">

    <!--js文件-->
    <script src="https://cdn.bootcdn.net/ajax/libs/nprogress/0.2.0/nprogress.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/vue/2.6.11/vue.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/vue-router/3.2.0/vue-router.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/echarts/4.9.0-rc.1/echarts.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/axios/0.20.0/axios.min.js"></script>
    <script src="https://cdn.bootcdn.net/ajax/libs/element-ui/2.4.5/index.js"></script>

    <% } %>
</head>

1.8 路由懒加载

打包项目时，js包巨大，影响页面加载，可以把不同路由对应组件分割成不同的代码块，当路由被访问时才加载对应组件，提升效率
安装@babel/plugin-syntax-dynamic-import开发依赖
配置在babel.config.js文件中

改造router/index.js文件

import Vue from ‘vue‘
import VueRouter from ‘vue-router‘

/*
import Login from "@/views/Login";
import Home from "@/views/Home";
import Welcome from "@/views/Welcome";
import Users from "@/views/user/users";
import Rights from "@/views/power/Rights";
import Roles from "@/views/power/Roles";
import Positions from "@/views/staff/Positions";
import Staffs from "@/views/staff/Staffs";
import Events from "@/views/event/Events";
import Attendance from "@/views/staff/Attendance";
import Reports from "@/views/report/Reports";
*/

//路由懒加载
const Login = () => import(/* webpackChunkName: "login_home_welcome" */ ‘../views/Login‘)
const Home = () => import(/* webpackChunkName: "login_home_welcome" */ ‘../views/Home‘)
const Welcome = () => import(/* webpackChunkName: "login_home_welcome" */ ‘../views/Welcome‘)

const Users = () => import(/* webpackChunkName: "users_rights_roles" */ ‘../views/user/Users‘)
const Rights = () => import(/* webpackChunkName: "users_rights_roles" */ ‘../views/power/Rights‘)
const Roles = () => import(/* webpackChunkName: "users_rights_roles" */ ‘../views/power/Roles‘)

const Attendance = () => import(/* webpackChunkName: "attendance_positions_staffs" */ ‘../views/staff/Attendance‘)
const Positions = () => import(/* webpackChunkName: "attendance_positions_staffs" */ ‘../views/staff/Positions‘)
const Staffs = () => import(/* webpackChunkName: "attendance_positions_staffs" */ ‘../views/staff/Staffs‘)

const Events = () => import(/* webpackChunkName: "events" */ ‘../views/event/Events‘)

const Reports = () => import(/* webpackChunkName: "reports" */ ‘../views/report/Reports‘)

Vue.use(VueRouter)

const routes = [
  { path: ‘/‘, redirect: ‘/login‘},//访问根路径时重定向到：/login
  { path: ‘/login‘, component: Login },
  { path: ‘/home‘, component: Home, redirect: ‘/welcome‘, children: [
      { path: ‘/welcome‘, component: Welcome },
      { path: ‘/users‘, component: Users },
      { path: ‘/rights‘, component: Rights },
      { path: ‘/roles‘, component: Roles },
      { path: ‘/positions‘, component: Positions },
      { path: ‘/staffs‘, component: Staffs },
      { path: ‘/events‘, component: Events },
      { path: ‘/attendance‘, component: Attendance },
      { path: ‘/reports‘, component: Reports }
    ]}
]

const router = new VueRouter({
  routes
})

export default router

优化后js大文件被分割成数个小文件

2.项目上线

原文：https://www.cnblogs.com/liutaodashuaige/p/14083349.html