Webpack scaffolding usage optimization-JS Tutorial-php.cn

This time I will bring you the optimization of webpack scaffolding. What are the precautions for webpack scaffolding optimization? The following is a practical case, let's take a look.

In the previous article, I learned about the characteristics of webpack v4. Now I put the knowledge into practice and optimize the packaging performance of a react scaffold I wrote before.

Optimization category

Style separation
Separation of third-party resources
Differentiate development environment
Hot update
Extract public code

1. CSS separation

npm install extract-text-webpack-plugin -D

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webpack.config.js

Separate css, less, and sass files separately from the packaged file

+ let cssExtract = new ExtractTextWebpackPlugin({
+ filename: 'css.css',
+ allChunks: true
+ });
+ let sassExtract = new ExtractTextWebpackPlugin('sass.css')
+ let lessExtract = new ExtractTextWebpackPlugin('less.css')

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In webpack.config.js Add a separate rule,

test:
regular expression # that matches the extension of the
processed file

{
 test: /\.css$/,
 use: cssExtract.extract({
 fallback: "style-loader",
 use: ['css-loader?minimize','postcss-loader'],
 publicPath: "/dist"
 }),
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
},
{
 test: /\.scss$/,
 use: sassExtract.extract({
 fallback: "style-loader",
 use: ["css-loader?minimize","sass-loader"],
 publicPath: "/dist"
 }),
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
},
{
 test: /\.less$/,
 loader: lessExtract.extract({
 use: ["css-loader?minimize", "less-loader"]
 }),
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
},

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compilation. mainTemplate.applyPluginsWaterfall is not a function

Use Chunks.groupsIterable and filter by instanceof Entrypoint instead

The research concluded that the reason why webpack was upgraded to v4 but the corresponding plug-in was not upgraded.

Solution: Install the specified version of dependencies

"html-webpack-plugin": "^3.0.4"
"extract-text-webpack-plugin": "^4.0.0-beta.0"

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resolve

After specifying the extension, you don’t need to add the file extension when requiring or importing , will try to add extensions in order to match

resolve: {
 //引入模块的时候，可以不用扩展名
 extensions: [".js", ".less", ".json"],
 alias: {//别名
 "bootstrap": "bootstrap/dist/css/bootstrap.css"
 }
}

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Listen to file modification

Used in webpack mode, not used in webpack-dev-server mode, you can change watch to false

watchOptions: {
 ignored: /node_modules/,
 aggregateTimeout: 300, //监听到变化发生后等300ms再去执行动作，防止文件更新太快导致编译频率太高
 poll: 1000 //通过不停的询问文件是否改变来判断文件是否发生变化，默认每秒询问1000次
}

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Extract public code

optimization: {
 splitChunks: {
 cacheGroups: {
 commons: {
  chunks: "initial",
  minChunks: 2,
  maxInitialRequests: 5, // The default limit is too small to showcase the effect
  minSize: 0 // This is example is too small to create commons chunks
 },
 vendor: {
  test: /node_modules/,
  chunks: "initial",
  name: "vendor",
  priority: 10,
  enforce: true
 }
 }
 }
 }

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Separate react react-dom ant public code

Method 1: externals

Introduce a third-party resource library to the page, and then use externals to prevent certain imported packages from being packaged into the bundle. Instead, obtain these external dependencies from the outside at runtime. .

<script src="https://cdn.bootcss.com/react/16.4.0-alpha.0911da3/cjs/react.production.min.js"></script>
<script src="https://cdn.bootcss.com/react-dom/16.4.0-alpha.0911da3/cjs/react-dom-server.browser.production.min.js"></script>
externals: { 'react': 'React', 'react-dom': 'ReactDOM', // 提出ant design的公共资源, }

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Method 2: DLL

DLL was written in the previous article, but it kept appearing after packaging.

I later found out that it was There are no resources introduced on the page. . . . (I always thought webpack would automatically generate it on the page....)

Introduced

<script src="./vendor/react.dll.js"></script>

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into the index.html file and the separation was successful! Up code

webpack.base.js

var path = require('path');
var webpack = require('webpack');
var ExtractTextWebpackPlugin = require("extract-text-webpack-plugin");
const HtmlWebpackPlugin = require("html-webpack-plugin");
const CleanWebpackPlugin = require('clean-webpack-plugin');
const CopyWebpackPlugin = require('copy-webpack-plugin')
let cssExtract = new ExtractTextWebpackPlugin({
 filename: 'css.css',
 allChunks: true
});
let sassExtract = new ExtractTextWebpackPlugin('sass.css')
let lessExtract = new ExtractTextWebpackPlugin('less.css')
module.exports = {
 entry:'./src/index.js',
 output: {
 path: path.resolve(dirname, './dist'),
 filename: 'bundle.[hash:8].js',
 publicPath: ''
 },
 resolve: {
 //引入模块的时候，可以不用扩展名
 extensions: [".js", ".less", ".json"],
 alias: {//别名
 "bootstrap": "bootstrap/dist/css/bootstrap.css"
 },
 modules: [path.resolve(dirname, 'node_modules')]
 },
/* externals: {
 'react': 'React',
 'react-dom': 'ReactDOM',
 // 提出ant design的公共资源
 //'antd': 'antd',
 },*/
 devtool: 'source-map',
 devServer: {
 contentBase:path.resolve(dirname,'dist'),
 publicPath: '/',
 port: 8080,
 hot:true,
 compress:true,
 historyApiFallback: true,
 inline: true
 },
 watch: false, //只有在开启监听模式时，watchOptions才有意义
 watchOptions: {
 ignored: /node_modules/,
 aggregateTimeout: 300, //监听到变化发生后等300ms再去执行动作，防止文件更新太快导致编译频率太高
 poll: 1000 //通过不停的询问文件是否改变来判断文件是否发生变化，默认每秒询问1000次
 },
 optimization: {
 splitChunks: {
 cacheGroups: {
 commons: {
  chunks: "initial",
  minChunks: 2,
  maxInitialRequests: 5, // The default limit is too small to showcase the effect
  minSize: 0 // This is example is too small to create commons chunks
 },
 vendor: {
  test: /node_modules/,
  chunks: "initial",
  name: "vendor",
  priority: 10,
  enforce: true
 }
 }
 }
 },
 module: {
 rules:[
 {
 test: /\.js$/,
 use: {
  loader:'babel-loader',
  options: {
  presets: ['env','es2015', 'react'],
  }
 },
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
 },
 {
 test: /\.css$/,
 use: cssExtract.extract({
  fallback: "style-loader",
  use: ['css-loader?minimize','postcss-loader'],
  publicPath: "/dist"
 }),
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
 },
 {
 test: /\.scss$/,
 use: sassExtract.extract({
  fallback: "style-loader",
  use: ["css-loader?minimize","sass-loader"],
  publicPath: "/dist"
 }),
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
 },
 {
 test: /\.less$/,
 loader: lessExtract.extract({
  use: ["css-loader?minimize", "less-loader"]
 }),
 include:path.join(dirname,'./src'),
 exclude:/node_modules/
 },
 {
 test: /\.(html|htm)/,
 use: 'html-withimg-loader'
 },
 {
 test: /\.(png|jpg|gif|svg|bmp|eot|woff|woff2|ttf)/,
 use: {
  loader:'url-loader',
  options:{
  limit: 5 * 1024,
  //指定拷贝文件的输出目录
  outputPath: 'images/'
  }
 }
 }
 ]
 },
 plugins: [
 //定义环境变量
 new webpack.DefinePlugin({
 development: JSON.stringify(process.env.NODE_ENV)
 }),
 new CleanWebpackPlugin(['dist']),
 cssExtract,
 lessExtract,
 sassExtract,
 new HtmlWebpackPlugin({
 title: 'React Biolerplate by YuanYuan',
 template: './src/index.html',
 filename: `index.html`,
 hash: true
 }),
 new webpack.DllReferencePlugin({
 manifest: path.join(dirname, 'vendor', 'react.manifest.json')
 }),
 new CopyWebpackPlugin([{
 from: path.join(dirname,'vendor'),//静态资源目录源地址
 to:'./vendor' //目标地址，相对于output的path目录
 }]),
/* new webpack.optimize.CommonsChunkPlugin({
 name: 'common' // 指定公共 bundle 的名称。
 + })*/
 new webpack.HotModuleReplacementPlugin(), // 热替换插件
 new webpack.NamedModulesPlugin() // 执行热替换时打印模块名字
 ]
};

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webpack.config.js

const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');//用来合并配置文件
const base = require('./webpack.base');
let other = '';
//console.log(process.env.NODE_ENV )
if (process.env.NODE_ENV == 'development') {
 other = require('./webpack.dev.config');
} else {
 other = require('./webpack.prod.config');
}
//console.log(merge(base, other));
module.exports = merge(base, other);
webpack.prod.config.js
const path = require('path');
const webpack = require('webpack');
const UglifyJSPlugin = require('uglifyjs-webpack-plugin')
module.exports = {
 output: {
 filename: 'bundle.min.js',
 },
 plugins: [
 new UglifyJSPlugin({sourceMap: true})
 ]
}

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Original scaffolding address

After optimization, the scaffold address is

The packaging speed is optimized, the packaging file is refined, and the transformation is successful~

I believe you have mastered the method after reading the case in this article, and more How exciting, please pay attention to other related articles on php Chinese website!