這次帶給大家webpack腳手架使用優化，webpack腳手架優化的注意事項有哪些，下面就是實戰案例，一起來看一下。
在先前的文章中了解了webpack v4的特性，現在將知識用於實踐，對先前寫的一個react腳手架進行打包性能的最佳化。
最佳化類別目
樣式分離
#第三方資源分離
#區分開發環境
1. CSS分離
npm install extract-text-webpack-plugin -D
test：符合+ let cssExtract = new ExtractTextWebpackPlugin({ + filename: 'css.css', + allChunks: true + }); + let sassExtract = new ExtractTextWebpackPlugin('sass.css') + let lessExtract = new ExtractTextWebpackPlugin('less.css')登入後複製在webpack.config.js中單獨新增規則，
處理檔案
的副檔名的正規表示式
##include/exclude手動指定必須處理的資料夾或屏蔽不需要處理的資料夾
{
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/
},然後執行webpack命令時報錯誤
compilation. mainTemplate.applyPluginsWaterfall is not a functionUse Chunks.groupsIterable and filter by instanceof Entrypoint instead研究得出結論：webpack升級到v4然而的插件沒有升級的原響應。
解決方法：安裝指定版本的依賴"html-webpack-plugin": "^3.0.4"
"extract-text-webpack-plugin": "^4.0.0-beta.0"
指定extension之後可以不用在require或是import的時候加檔案副檔名,會依序嘗試新增副檔名進行比對
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"
}
}webpack模式下使用，webpack-dev-server模式不用，可以將watch改為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
}提取公用程式碼
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
}
}
}
}分離react react-dom ant公用程式碼
方法一：externals在頁面上引入第三方資源庫，然後使用externals防止將某些import 的套件(package)打包到bundle 中，而是在運行時(runtime)再去從外部獲取這些擴展依賴(external dependencies) 。
<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, }##DLL在上篇文章中寫過，但是打包後一直出現
後來才發現是頁面上沒有引入資源。 。 。 。 （我一直以為會webpack自動生成在頁面上....）
<script src="./vendor/react.dll.js"></script>
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
]
};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})
]
}以上是webpack腳手架使用最佳化的詳細內容。更多資訊請關注PHP中文網其他相關文章！
