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:
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
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");
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 }) ] };
(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 }) ] };
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
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 }) ] };
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安科网。