項目初始化
$ npm init
安裝webpack
本次創(chuàng)建是基于webpack4
$ npm install --save-dev
新建webpack配置文件
在根目錄創(chuàng)建build文件夾，添加一個js文件，命名為webpack.base.conf.js
// webpack.base.conf.js 文件const path = require('path');const DIST_PATH = path.resolve(__dirname, '../dist');module.exports = { entry: { app: './app/index.js' }, output: { filename: "js/bundle.js", path: DIST_PATH }};使用merge的方式來組織webpack基礎配置和不同環(huán)境的配置
先安裝webpack-merge：
$ npm install --save-dev webpack-merge
在build文件夾中再添加一個js文件，命名為 webpack.prod.conf.js
// webpack.prod.conf.js 文件const merge = require('webpack-merge');const baseWebpackConfig = require('./webpack.base.conf');module.exports = merge(baseWebpackConfig, { mode: 'production'});在根目錄下創(chuàng)建app目錄，然后創(chuàng)建index.js文件
var element =document.getElementById('root');element.innerHTML = 'hello, world!';在根目錄創(chuàng)建一個public文件夾，然后新建一個index.html文件
// index.html<!DOCTYPE html><html lang="en"> <head> <meta charset="UTF-8"> <title>從零開始搭建react工程</title> </head> <body> <div id="root"></div> <script src="../dist/js/bundle.js"></script> </body></html>
當前項目目錄樹
|- /app |- index.js |- /node_modules |- /public |- index.html |- /build |- webpack.base.conf.js |- webpack.prod.conf.js |- package.json |- package-lock.json
安裝webpack-cli
webpack 4.0 版本之后的webpack，已經(jīng)將webpack命令工具遷移到webpack-cli模塊了,需要安裝 webpack-cli
$ npm install --save-dev webpack-cli
package.json文件 scripts屬性配置一個build命令
其值為：webpack --config build/webpack.prod.conf.js，以下是scripts的相關代碼
// package.json"scripts": { "build": "webpack --config build/webpack.prod.conf.js", "test": "echo /"Error: no test specified/" && exit 1"},安裝React
$ npm install --save react react-dom
修改app目錄下的index.js的代碼
import React from "react";import ReactDom from "react-dom";ReactDom.render( <h1>hello, world!</h1>, document.getElementById("root"));注意 import 屬于ES6規(guī)范，因此需要轉(zhuǎn)譯ES2015+的語法，安裝并配置 babel 以及相關依賴
$ npm install --save-dev babel-loader babel-core babel-preset-env babel-preset-react
根目錄創(chuàng)建.babelrc文件，配置presets.
{ "presets": [ [ "env", { "targets": { "browsers": [ "> 1%", "last 5 versions", "ie >= 8" ] } } ], "react" ]}修改webpack.base.conf.js文件
// webpack.base.conf.jsconst path = require('path');const APP_PATH = path.resolve(__dirname, '../app');const DIST_PATH = path.resolve(__dirname, '../dist');module.exports = { entry: { app: './app/index.js' }, output: { filename: 'js/bundle.js', path: DIST_PATH }, module: { rules: [ { test: //.js?$/, use: "babel-loader", include: APP_PATH } ] }}; 運行 npm run build
添加插件
public下的index.html本該自動添加到dist目錄，并且引用資源自動加載到該文件，通過html-webpack-plugin實現(xiàn)這一步
$ npm install html-webpack-plugin --save-dev
webpack.prod.conf.js中配置plugins屬性
const merge = require('webpack-merge');const baseWebpackConfig = require('./webpack.base.conf.js');const HtmlWebpackPlugin = require('html-webpack-plugin');module.exports = merge(baseWebpackConfig, { mode: 'production', plugins: [ new HtmlWebpackPlugin({ template: 'public/index.html', inject: 'body', minify: { removeComments: true, collapseWhitespace: true, removeAttributeQuotes: true }, }) ]});刪除 index.html 中手動引入的 script 標簽
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <title>從零開始搭建react工程</title></head><body> <div id="root"></div></body></html>
重新編譯查看 npm run build 瀏覽器打開查看目錄 dist 下的 index.html
以上步驟都成功的前提下繼續(xù)走下一步
生成的文件名添加Hash值，目的是解決緩存問題
修改webpack.prod.conf.js，mode: 'production', 增加以下代碼
// webpack.prod.conf.jsoutput: { filename: "js/[name].[chunkhash:16].js",},生成前需要清理之前項目生成的文件，因為由于文件名的改變?nèi)绻粍h除會一直增加
安裝插件 clean-webpack-plugin
$ npm install --save-dev clean-webpack-plugin
修改 webpack.prod.conf.js
// webpack.prod.conf.jsconst merge = require('webpack-merge');const baseWebpackConfig = require('./webpack.base.conf.js');const HtmlWebpackPlugin = require('html-webpack-plugin');const CleanWebpackPlugin = require('clean-webpack-plugin');module.exports = merge(baseWebpackConfig, { mode: 'production', output: { filename: "js/[name].[chunkhash:16].js", }, plugins: [ new HtmlWebpackPlugin({ template: 'public/index.html', inject: 'body', minify: { removeComments: true, collapseWhitespace: true, removeAttributeQuotes: true }, }), new CleanWebpackPlugin(['../dist'], { allowExternal: true }) ]});公共代碼與業(yè)務代碼分離
修改 webpack.base.conf.js 的 entry 入口屬性，抽出框架代碼
entry: { app: './app/index.js', framework: ['react','react-dom'],},修改webpack.prod.conf.js，增加以下代碼，目的是分離框架代碼和業(yè)務代碼
雖然上面步驟抽出框架代碼生成兩個文件，但是app.js還是包含框架代碼
optimization: { splitChunks: { chunks: "all", minChunks: 1, minSize: 0, cacheGroups: { framework: { test: "framework", name: "framework", enforce: true } } } }cacheGroups對象，定義了需要被抽離的模塊
其中test屬性是比較關鍵的一個值，他可以是一個字符串，也可以是正則表達式，還可以是函數(shù)。如果定義的是字符串，會匹配入口模塊名稱，會從其他模塊中把包含這個模塊的抽離出來
name是抽離后生成的名字，和入口文件模塊名稱相同，這樣抽離出來的新生成的framework模塊會覆蓋被抽離的framework模塊
整合 webpack-dev-server
開發(fā)環(huán)境開啟服務監(jiān)聽文件改動實時更新最新內(nèi)容
$ npm install --save-dev webpack-dev-server
在build中添加webpack.dev.conf.js文件
const path = require('path');const merge = require('webpack-merge');const baseWebpackConfig = require('./webpack.base.conf.js');const HtmlWebpackPlugin = require('html-webpack-plugin');const webpack = require('webpack');module.exports = merge(baseWebpackConfig, { mode: 'development', output: { filename: "js/[name].[hash:16].js", }, plugins: [ new HtmlWebpackPlugin({ template: 'public/index.html', inject: 'body', minify: { html5: true }, hash: false }), new webpack.HotModuleReplacementPlugin() ], devServer: { port: '8080', contentBase: path.join(__dirname, '../public'), compress: true, historyApiFallback: true, hot: true, https: false, noInfo: true, open: true, proxy: {} }});在package.json scripts屬性添加內(nèi)容
"dev": "webpack-dev-server --inline --progress --config build/webpack.dev.conf.js",
npm run dev
自動打開瀏覽器打開入口頁面實時更新
獨立導出 css 文件
安裝css相關依賴
sass less 預處理
$ npm install extract-text-webpack-plugin$ npm install style-loader css-loader postcss-loader autoprefixer --save-dev$ npm install less sass less-loader sass-loader stylus-loader node-sass --save-dev
webpack.base.conf.js 文件修改
// webpack.base.conf.js{ test: //.css$/, use: [ { loader: "style-loader" //在html中插入<style>標簽 }, { loader: "css-loader",//獲取引用資源，如@import,url() }, { loader: "postcss-loader", options: { plugins:[ require('autoprefixer')({ browsers:['last 5 version'] }) ] } } ]},{ test://.less$/, use: [ { loader: "style-loader" }, { loader: "css-loader" }, { loader: "postcss-loader",//自動加前綴 options: { plugins:[ require('autoprefixer')({ browsers:['last 5 version'] }) ] } }, { loader: "less-loader" } ]},{ test://.scss$/, use:[ { loader: "style-loader" }, { loader: "css-loader", }, { loader: "sass-loader" }, { loader: "postcss-loader", options: { plugins:[ require('autoprefixer')({ browsers:['last 5 version'] }) ] } } ]},圖片和路徑處理
$ npm i file-loader url-loader --save-dev
webpack.base.conf.js 文件修改
// webpack.base.conf.js{ test: //.(png|jpg|gif|woff|svg|eot|woff2|tff)$/, use: 'url-loader?limit=8129', //注意后面那個limit的參數(shù)，當你圖片大小小于這個限制的時候，會自動啟用base64編碼圖片 exclude: /node_modules/}build 時報錯
Error: Chunk.entrypoints: Use Chunks.groupsIterable and filter by instanceof Entrypoint instead
at Chunk.get (F:/react/createApp/node_modules/webpack/lib/Chunk.js:824:9)
webpack4.0中使用“extract-text-webpack-plugin”報錯
解決辦法
$ npm install extract-text-webpack-plugin@next
背景圖片路徑問題
由于css文件分離出來的原因，會導致在css文件夾下找images文件夾下的圖片
解決辦法 publicPath屬性改為 '/'，以絕對路徑的方式尋找資源
{ test://.(png|jpg|gif)$/, use:[{ loader:'url-loader', options: { // outputPath:'../',//輸出**文件夾 publicPath: '/', name: "images/[name].[ext]", limit:500 //是把小于500B的文件打成Base64的格式，寫入JS } }]},以上就是本文的全部內(nèi)容，希望對大家的學習有所幫助，也希望大家多多支持VeVb武林網(wǎng)。
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