微前端-portal项目

jiezi

5 年前

微前端 —— 理论篇
上一篇介绍了微前端的理念，本片将开始介绍 portal 项目。

        portal 项目包括两个功能：
        1. 路由分发与应用加载；
        2. 抽离公共依赖；

目录结构如下：

新建一个文件夹，命名随便，我的是 portal
        执行 npm init -y 初始化package.json
        现在我们要做什么呢？肯定是先引入依赖包啊
        webpack 打包相关和 babel 和简单几个需要的 loader 就行了
        npm i webpack webpack-cli webpack-dev-server style-loader css-loader copy-webpack-plugin clean-webpack-plugin babel-loader babel-core @babel/preset-env @babel/plugin-syntax-dynamic-import @babel/core -D
        由于我们还需要同时运行公共依赖引入和应用加载两个服务，所以再 npm i concurrently -D

在引入所需的依赖之后，开始实现相关功能。先实现公共依赖的引入吧。在上一步我们没有引入 single-spa 的依赖包，是因为 single-spa 的依赖包是作为公共依赖导入的。
先创建一个公共依赖的文件夹，这个文件夹在任何地方都可以，因为我们是通过远程链接引入的，要是你认为的 single-spa.js 文件可以通过远程 cdn 或者其他链接取到，可以跳过这一步了，下面是我创建的公共依赖库文件夹。

里面全是我的公共依赖文件

在 portal 下新建 src 文件夹，新建文件index.html，作为我们整个项目的页面文件。代码如下

      <!DOCTYPE html>
          <html>
            <head>
              <meta charset="utf-8" />
              <meta name="viewport" content="width=device-width" />
              <title></title>
            </head>
            <body>
              // 此处为从远程导入各个项目的 js 文件
              //（react、vue 项目打包和运行都会产生一个 js 文件，此文件就是动态渲染页面用的）// config.js 是 portal 项目产生的，用来进行路由分发与组件状态管理等
              <script type="systemjs-importmap">
                {
                  "imports": {
                    "@portal/config": "http://localhost:8233/config.js",
                    "@portal/menu": "http://localhost:8235/menu.js",
                    "@portal/project1": "http://localhost:8236/project1.js",
                    "@portal/project2": "http://localhost:8237/project2.js"
                  }
                }
              </script>
              <!-- 这里是引入我们的 systemjs，在公共依赖文件夹中，通过 http-server 开启的本地服务，进行远程访问 -->
              <script src='http://localhost:8000/systemjs/system.js'></script>
              <script src='http://localhost:8000/systemjs/amd.js'></script>
              <script src='http://localhost:8000/systemjs/named-exports.js'></script>
              <script src='http://localhost:8000/systemjs/use-default.js'></script>
              
              <!-- 执行 common-deps.js-->
              <!-- Load the common deps-->
              <script src="http://localhost:8234/common-deps.js"></script>
          
              <!-- Load the application -->
              <script>
                  // 执行 config.js，进行页面的动态渲染
                System.import('@portal/config')
              </script>
          
              <!-- Static navbar -->
              <!-- 引入样式文件 -->
              <link rel="stylesheet" href="http://localhost:8233/styles.css">
              <link href="https://fonts.googleapis.com/css?family=Roboto" rel="stylesheet">
              <!-- 菜单容器 -->
              <div id='menu'></div>
              <div id='content'>
                  <!-- react 应用容器 -->
                <div id="react"></div>
                  <!-- vue 应用容器 -->
                <div id="vue"></div>
              </div>
            </body>
          </html>

接下来实现common-deps.js，将我们所有的公共依赖文件统一引入，并命名

      window.SystemJS = window.System

      function insertNewImportMap(newMapJSON) {const newScript = document.createElement('script')
        newScript.type = 'systemjs-importmap'
        newScript.text = JSON.stringify(newMapJSON)
        const allMaps = document.querySelectorAll('script[type="systemjs-importmap"]')
      
        allMaps[allMaps.length - 1].insertAdjacentElement(
          'afterEnd',
          newScript
        )
      }
      
      const devDependencies = {
        imports: {
          react: 'http://localhost:8000/react.development.js',
          'react-dom': 'http://localhost:8000/react-dom.development.js',
          'react-dom/server': 'http://localhost:8000/react-dom-server.browser.development.js',
          'single-spa': 'http://localhost:8000/single-spa.min.js',
          lodash: 'http://localhost:8000/lodash.js',
          rxjs: 'http://localhost:8000/rxjs.umd.js',
        }
      }
      
      const prodDependencies = {
        imports: {
          react: 'http://localhost:8000/react.production.min.js',
          'react-dom': 'http://localhost:8000/react-dom.production.min.js',
          'react-dom/server': 'http://localhost:8000/react-dom-server.browser.production.min.js',
          'single-spa': 'http://localhost:8000/single-spa.min.js',
          lodash: 'http://localhost:8000/lodash.min.js',
          rxjs: 'http://localhost:8000/rxjs.umd.min.js',
        }
      }
      
      const devMode = true // you will need to figure out a way to use a set of production dependencies instead
      if (devMode) {insertNewImportMap(devDependencies)
      } else {insertNewImportMap(prodDependencies)
      }

公共依赖的抽取代码已经实现了，下面就配置 webpack，将这些依赖进行打包，在项目根目录创建 webpack.common-deps.config.js、webpack.common-deps.config.dev.js

webpack.common-deps.config.js

  const path = require('path')
  const CleanWebpackPlugin = require('clean-webpack-plugin')
  const CopyWebpackPlugin = require('copy-webpack-plugin');
  
  module.exports = {
    entry: './src/common-deps.js',
    output: {
      filename: 'common-deps.js',
      path: path.resolve(__dirname, 'build/common-deps'),
      chunkFilename: '[name].js',
    },
    mode: 'production',
    node: {fs: 'empty',},
    resolve: {
      modules: [
        __dirname,
        'node_modules',
      ],
    },
    devtool: 'sourcemap',
    plugins: [new CleanWebpackPlugin(['build/common-deps/']),
      CopyWebpackPlugin([{from: path.resolve(__dirname, 'src/common-deps.js')}
      ]),
    ],
    module: {
      rules: [{parser: {System: false}},
        {
          test: /\.js$/,
          exclude: /(node_modules|bower_components)/,
          use: {loader: 'babel-loader',}
        }
      ]
    }
  }

webpack.common-deps.config.dev.js

  /* eslint-env node */
  const config = require('./webpack.common-deps.config.js');
  const webpack = require('webpack');
  
  config.plugins.push(new webpack.NamedModulesPlugin());
  config.plugins.push(new webpack.HotModuleReplacementPlugin());
  config.devServer = {
    headers: {"Access-Control-Allow-Origin": "*",},
  }
  
  config.mode = 'development'
  
  module.exports = config;

上面配置 dev-server 跨域，很重要！！！否则会因为无法跨域，访问不到 js 文件

最后在 package.json 的scripts中添加命令

  "scripts": {
      "test": "echo \"Error: no test specified\"&& exit 1",
      "start:common-deps": "webpack-dev-server --config ./webpack.common-deps.config.dev.js --port 8234",
      "build:common-deps": "webpack --config ./webpack.common-deps.config.js -p"
    },

至此，公共依赖的抽取已经完成，执行 npm run start:common-deps，公共依赖就被打包到了 portal 项目下的build/common-deps/ 目录，通过 import 也可以正常导入使用（归功于 system）

公共依赖抽取实现、配置完毕之后，开始利用 single-spa 构建我们的路由分发系统

在 src 中创建文件activityFns.js，实现路由的正确匹配，内容如下：

  export function prefix(location, ...prefixes) {
      return prefixes.some(
        prefix => (location.href.indexOf(`${location.origin}/${prefix}`) !== -1
        )
      )
    }
    // return true 则加载 false 则不加载
    // 这里的 menu 是菜单，按理应该一直加载出来的，因此 return true
    export function menu(location) {return true}
  
    export function project1(location) {return prefix(location, '','page1','page2')
    }
  
    export function project2(location) {return prefix(location, 'page3', 'page4')
    }

在 src 中创建文件 config.js，通过single-spa 实现路由的注册

  import * as isActive from './activityFns.js'
  import * as singleSpa from 'single-spa'
  
  singleSpa.registerApplication('menu', () => SystemJS.import('@portal/menu'), isActive.menu)
  singleSpa.registerApplication('project1', () => SystemJS.import('@portal/project1'), isActive.project1)
  singleSpa.registerApplication('project2', () => SystemJS.import('@portal/project2'), isActive.project2)
  singleSpa.start()

配置 webpack 打包，在项目根目录创建文件webpack.config.config.js，内容如下：

  /* eslint-env node */
  const webpack = require('webpack')
  const path = require('path');
  const CleanWebpackPlugin = require('clean-webpack-plugin');
  const CopyWebpackPlugin = require('copy-webpack-plugin');
  
  module.exports = {
    entry: './src/config.js',
    output: {
      filename: 'config.js',
      library: 'config',
      libraryTarget: 'amd',
      path: path.resolve(__dirname, 'build'),
    },
    mode: 'production',
    module: {
      rules: [{parser: {System: false}},
        {
          test: /\.js?$/,
          exclude: [path.resolve(__dirname, 'node_modules')],
          loader: 'babel-loader',
        },
        {
          test: /\.css$/,
          exclude: [path.resolve(__dirname, 'node_modules'), /\.krem.css$/],
          use: [
            'style-loader',
            {
              loader: 'css-loader',
              options: {localIdentName: '[path][name]__[local]',
              },
            },
            {
              loader: 'postcss-loader',
              options: {plugins() {
                  return [require('autoprefixer')
                  ];
                },
              },
            },
          ],
        },
        {
          test: /\.css$/,
          include: [path.resolve(__dirname, 'node_modules')],
          exclude: [/\.krem.css$/],
          use: ['style-loader', 'css-loader'],
        },
      ],
    },
    resolve: {
      modules: [
        __dirname,
        'node_modules',
      ],
    },
    plugins: [
      CopyWebpackPlugin([{from: path.resolve(__dirname, 'src/index.html')},
        {from: path.resolve(__dirname, 'src/styles.css')},
      ]),
      new CleanWebpackPlugin(['build']),
    ],
    devtool: 'source-map',
    externals: [
      /^lodash$/,
      /^single-spa$/,
      /^rxjs\/?.*$/,
    ],
  };

上面的配置中，最后的externals 属性值配置不需要 webpack 打包的依赖，因为这些在公共依赖中已经打包好了，不需要单独打包

在项目根目录创建文件webpack.config.config.dev.js，内容如下：

  const config = require('./webpack.config.config.js')
  const webpack = require('webpack')
  
  config.plugins.push(new webpack.NamedModulesPlugin());
  config.plugins.push(new webpack.HotModuleReplacementPlugin());
  config.devServer = {
    contentBase: './build',
    historyApiFallback: true,
    headers: {"Access-Control-Allow-Origin": "*",},
    proxy: {
      "/common/": {
        target: "http://localhost:8234",
        pathRewrite: {"^/common" : ""}
      }
    }
  }
  
  config.mode = 'development'
  
  module.exports = config;

同样配置跨域
在package.json 中添加命令，最终内容如下

  {
    "name": "portal",
    "version": "1.0.0",
    "description": "","main":"index.js","scripts": {"test":"echo \"Error: no test specified\" && exit 1","start":"concurrently \"npm run start:config\" \"npm run start:common-deps\"",
      "start:config": "webpack-dev-server --config ./webpack.config.config.dev.js --port 8233",
      "start:common-deps": "webpack-dev-server --config ./webpack.common-deps.config.dev.js --port 8234",
      "build": "npm run build:config && npm run build:common-deps",
      "build:config": "webpack --config ./webpack.config.config.js -p",
      "build:common-deps": "webpack --config ./webpack.common-deps.config.js -p"
    },
    "keywords": [],
    "author": "","license":"ISC","devDependencies": {"@babel/core":"^7.4.3","@babel/plugin-syntax-dynamic-import":"7.0.0","@babel/preset-env":"^7.4.3","babel-core":"6.26.3","babel-loader":"8.0.0","clean-webpack-plugin":"0.1.19","concurrently":"^4.1.1","copy-webpack-plugin":"4.5.2","css-loader":"1.0.0","style-loader":"0.23.0","webpack":"4.17.1","webpack-cli":"3.1.0","webpack-dev-server":"^3.1.14"}
  }

至此，整个 portal 项目就搭建完毕了，下一篇，我们实现 menu 项目和 project1 项目

项目源码
Portal 源码

        微前端 —— 理论篇
        微前端 —— menu&&project1（React）
        微前端 —— project2 项目（VUE）

微前端-portal项目

前言

portal 项目介绍

具体实现