当前位置:首页 >> 网络编程

webpack中CommonsChunkPlugin详细教程(小结)

本文介绍了webpack中CommonsChunkPlugin详细教程(小结),分享给大家,也给自己留个笔记,具体如下:

1.demo结构:

webpack中CommonsChunkPlugin详细教程(小结)

2.package.json配置:

{
 "name": "webpack-simple-demo",
 "version": "1.0.0",
 "description": "",
 "main": "index.js",
 "scripts": {
  "webpack": "webpack"
 },
 "author": "",
 "license": "ISC",
 "dependencies": {
  "jquery": "^3.1.0",
  "vue": "^1.0.26"
 },
 "devDependencies": {
  "css-loader": "^0.24.0",
  "style-loader": "^0.13.1",
  "webpack": "^1.13.2",
  "webpack-dev-server": "^1.15.1"
 }
}

3.多种打包情况(未使用CommonsChunkPlugin)

(1)单一入口,模块单一引用

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
 },
 output: {
  path:__dirname+'/dist',
  filename: 'build.js'
 },
 plugins: [
  
 ]
};

main.js

require("jquery");

demo目录下运行命令行 webpack或npm run webpack

webpack中CommonsChunkPlugin详细教程(小结)

jquery模块被一起打包到build.js

(2)单一入口,模块重复引用

webpack.config.js不变,main.js:

require("./chunk1");
require("./chunk2");

chunk1.js:

require("./chunk2");
var chunk1=1;
exports.chunk1=chunk1;

chunk2.js:

var chunk2=1;
exports.chunk2=chunk2;

main.js引用了chunk1、chunk2,chunk1又引用了chunk2,打包后:

build.js:

 ...省略webpack生成代码
/************************************************************************/
/******/ ([
/* 0 */
/***/ function(module, exports, __webpack_require__) {

  __webpack_require__(1);
  __webpack_require__(2);


/***/ },
/* 1 */
/***/ function(module, exports, __webpack_require__) {

  __webpack_require__(2);
  var chunk1=1;
  exports.chunk1=chunk1;

/***/ },
/* 2 */
/***/ function(module, exports) {

  var chunk2=1;
  exports.chunk2=chunk2;

/***/ }
/******/ ]);

(3)多入口,模块单一引用,分文件输出

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
  main1:'./main1.js'
 },
 output: {
  path:__dirname+'/dist',
  filename: '[name].js'
 },
 plugins: [
  
 ]
};

打包后文件main.js,main1.js 内容与(2)build.js一致

(4)多入口,模块单一引用,单一文件输出

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
  main1:'./main1.js'
 },
 output: {
  path:__dirname+'/dist',
  filename: 'buid.js'
 },
 plugins: [
  
 ]
};

build.js与(2)一致

(5)多入口,模块重复引用,单文件输出

webpack.config.js与(4)一致

main.js

require("./chunk1");
require("./chunk2");
exports.main=1;

main1.js

require("./chunk1");
require("./chunk2");
require("./main");

报错:ERROR in ./main1.js

Module not found: Error: a dependency to an entry point is not allowed

@ ./main1.js 3:0-17

4.使用CommonsChunkPlugin

(1)单一入口,模块单一引用,分文件输出:

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
 },
 output: {
  path:__dirname+'/dist',
  filename: '[name].js'//不使用[name],并且插件中没有filename,这输出文件中只用chunk.js的内容, 
  main.js的内容不知跑哪里去了
 },
 plugins: [
  new CommonsChunkPlugin({
    name:"chunk",
    filename:"chunk.js"//忽略则以name为输出文件的名字,否则以此为输出文件名字
  })
 ]
};

main.js

require("./chunk1");
require("./chunk2");
require("jquery");

webpack中CommonsChunkPlugin详细教程(小结)

输出文件main.js chunk.js,chunk1.js,chunck2.js,jquery都被打包到main.js里,好像并没有什么卵用,但是页面上使用的时候chunk.js必须在mian.js前引用

将chunk1.js,chunck2.js打包到chunk.js:

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
  chunk: ["./chunk1", "./chunk2"],//插件中name,filename必须以这个key为值
 },
 output: {
  path:__dirname+'/dist',
  filename: '[name].js'//不使用[name],并且插件中没有filename,
  这输出文件中只用chunk.js的内容,main.js的内容不知跑哪里去了
 },
 plugins: [
  new CommonsChunkPlugin({
    name:"chunk",
   // filename:"chunk.js"//忽略则以name为输出文件的名字,否则以此为输出文件名字
  })
 ]
};

webpack中CommonsChunkPlugin详细教程(小结)

(1)单一入口,模块重复引用,分文件输出(单一入口CommonsChunkPlugin能否将多次引用的模块打包到公共模块呢?):

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
  //main1:'./main1.js',
 },
 output: {
  path:__dirname+'/dist',
  filename: '[name].js'//不使用[name],并且插件中没有filename,
这输出文件中只用chunk.js的内容,main.js的内容不知跑哪里去了
 },
 plugins: [
  new CommonsChunkPlugin({
    name:"chunk",
   // filename:"chunk.js"//忽略则以name为输出文件的名字,否则以此为输出文件名字
   minChunks:2
  })
 ]
};

main.js

require("./chunk1");
require("./chunk2");

chunk1.js

require("./chunk2");
var chunk1=1;
exports.chunk1=chunk1;

chunk2模块被引用了两次

打包后,所有模块还是被打包到main.js中

(3)多入口,模块重复引用,分文件输出(将多次引用的模块打包到公共模块)

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
 entry: 
 {
  main:'./main.js',
  main1:'./main1.js',
 },
 output: {
  path:__dirname+'/dist',
  filename: '[name].js'//不使用[name],并且插件中没有filename,
  这输出文件中只用chunk.js的内容,main.js的内容不知跑哪里去了
 },
 plugins: [
  new CommonsChunkPlugin({
    name:"chunk",
   // filename:"chunk.js"//忽略则以name为输出文件的名字,否则以此为输出文件名字
   minChunks:2
  })
 ]
};

main.js,main1.js里都引用chunk1,chunk2.

打包后:

chunk1,chunk2被打包到chunk.js,不再像3(3)chunk1,chunk2分别被打包到mian,mian1中。

5.将公共业务模块与类库或框架分开打包

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
  entry: {
    main: './main.js',
    main1: './main1.js',
    common1: ['jquery'],
    common2: ['vue']
  },
  output: {
    path: __dirname + '/dist',
    filename: '[name].js'//不使用[name],并且插件中没有filename,
    //这输出文件中只用chunk.js的内容,main.js的内容不知跑哪里去了
  },
  plugins: [
    new CommonsChunkPlugin({
      name: ["chunk","common1","common2"],//页面上使用的时候common2
      //必须最先加载
      // filename:"chunk.js"//忽略则以name为输出文件的名字,
        //否则以此为输出文件名字
      minChunks: 2
    })
  ]
};

webpack中CommonsChunkPlugin详细教程(小结)

jquery被打包到common1.js,vue被打包到common2.js,chunk.js打包的是公共的业务模块(webpack用插件CommonsChunkPlugin进行打包的时候,将符合引用次数(minChunks)的模块打包到name参数的数组的第一个块里(chunk),然后数组后面的块依次打包(查找entry里的key,没有找到相关的key就生成一个空的块),最后一个块包含webpack生成的在浏览器上使用各个块的加载代码,所以页面上使用的时候最后一个块必须最先加载)

将webpack.config.js改为

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
  entry: {

    main: './main.js',
    main1: './main1.js',
    jquery:["jquery"],
    vue:["vue"]
  },
  output: {
    path: __dirname + '/dist',
    filename: '[name].js'
  },
  plugins: [
    new CommonsChunkPlugin({
      name: ["common","jquery","vue","load"],

      minChunks:2

    })
  ]
};

main.js

require("./chunk1");
require("./chunk2");
var jq=require("jquery");
console.log(jq);

main1.js

require("./chunk1");
require("./chunk2");
var vue=require("vue");
console.log(vue);
exports.vue=vue;

打包后

webpack中CommonsChunkPlugin详细教程(小结)

common.js

webpackJsonp([4,5],[
/* 0 */,
/* 1 */,
/* 2 */
/***/ function(module, exports, __webpack_require__) {

  __webpack_require__(3);
  var chunk1=1;
  exports.chunk1=chunk1;

/***/ },
/* 3 */
/***/ function(module, exports) {

  var chunk2=1;
  exports.chunk2=chunk2;

/***/ }
]);

相当于公共的业务代码都打包到了common.js里

load.js

/******/ (function(modules) { // webpackBootstrap
/******/   // install a JSONP callback for chunk loading
/******/   var parentJsonpFunction = window["webpackJsonp"];
/******/   window["webpackJsonp"] = function webpackJsonpCallback(chunkIds, moreModules) {
/******/     // add "moreModules" to the modules object,
/******/     // then flag all "chunkIds" as loaded and fire callback
/******/     var moduleId, chunkId, i = 0, callbacks = [];
/******/     for(;i < chunkIds.length; i++) {
/******/       chunkId = chunkIds[i];
/******/       if(installedChunks[chunkId])
/******/         callbacks.push.apply(callbacks, installedChunks[chunkId]);
/******/       installedChunks[chunkId] = 0;
/******/     }
/******/     for(moduleId in moreModules) {
/******/       modules[moduleId] = moreModules[moduleId];
/******/     }
/******/     if(parentJsonpFunction) parentJsonpFunction(chunkIds, moreModules);
/******/     while(callbacks.length)
/******/       callbacks.shift().call(null, __webpack_require__);
/******/     if(moreModules[0]) {
/******/       installedModules[0] = 0;
/******/       return __webpack_require__(0);
/******/     }
/******/   };

/******/   // The module cache
/******/   var installedModules = {};

/******/   // object to store loaded and loading chunks
/******/   // "0" means "already loaded"
/******/   // Array means "loading", array contains callbacks
/******/   var installedChunks = {
/******/     5:0
/******/   };

/******/   // The require function
/******/   function __webpack_require__(moduleId) {

/******/     // Check if module is in cache
/******/     if(installedModules[moduleId])
/******/       return installedModules[moduleId].exports;

/******/     // Create a new module (and put it into the cache)
/******/     var module = installedModules[moduleId] = {
/******/       exports: {},
/******/       id: moduleId,
/******/       loaded: false
/******/     };

/******/     // Execute the module function
/******/     modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);

/******/     // Flag the module as loaded
/******/     module.loaded = true;

/******/     // Return the exports of the module
/******/     return module.exports;
/******/   }

/******/   // This file contains only the entry chunk.
/******/   // The chunk loading function for additional chunks
/******/   __webpack_require__.e = function requireEnsure(chunkId, callback) {
/******/     // "0" is the signal for "already loaded"
/******/     if(installedChunks[chunkId] === 0)
/******/       return callback.call(null, __webpack_require__);

/******/     // an array means "currently loading".
/******/     if(installedChunks[chunkId] !== undefined) {
/******/       installedChunks[chunkId].push(callback);
/******/     } else {
/******/       // start chunk loading
/******/       installedChunks[chunkId] = [callback];
/******/       var head = document.getElementsByTagName('head')[0];
/******/       var script = document.createElement('script');
/******/       script.type = 'text/javascript';
/******/       script.charset = 'utf-8';
/******/       script.async = true;

/******/       script.src = __webpack_require__.p + "" + chunkId + "." + ({"0":"jquery","1":"main","2":"main1","3":"vue","4":"common"}[chunkId]||chunkId) + ".js";
/******/       head.appendChild(script);
/******/     }
/******/   };

/******/   // expose the modules object (__webpack_modules__)
/******/   __webpack_require__.m = modules;

/******/   // expose the module cache
/******/   __webpack_require__.c = installedModules;

/******/   // __webpack_public_path__
/******/   __webpack_require__.p = "";
/******/ })
/************************************************************************/
/******/ ([]);

使用的时候必须最先加载load.js

6.参数minChunks: Infinity

看一下下面的配置会是什么结果

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
  entry: {

    main: './main.js',
    main1: './main1.js',
    jquery:["jquery"]
  },
  output: {
    path: __dirname + '/dist',
    filename: '[name].js'
  },
  plugins: [
    new CommonsChunkPlugin({
      name: "jquery",

      minChunks:2

    })
  ]
};

webpack中CommonsChunkPlugin详细教程(小结)

main.js,main1.js共同引用的chunk1和chunk2会被打包到jquery.js里

minChunks:2修改为minChunks:Infinity后,chunk1和chunk2都打包到main.js,main1.js里

7.参数chunks

webpack.config.js

var CommonsChunkPlugin = require("webpack/lib/optimize/CommonsChunkPlugin");
module.exports = {
  entry: {

    main: './main.js',
    main1: './main1.js',
    jquery:["jquery"]
  },
  output: {
    path: __dirname + '/dist',
    filename: '[name].js'
  },
  plugins: [
    new CommonsChunkPlugin({
      name: "jquery",

      minChunks:2,

      chunks:["main","main1"]

    })
  ]
};

只有在main.js和main1.js中都引用的模块才会被打包的到公共模块(这里即jquery.js)

以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。