const { resolve } = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const { HotModuleReplacementPlugin } = require('webpack');

module.exports = {
  entry: './src/index.js',//单入口
  output: {
    path: resolve(__dirname, 'dist'),
    filename: '[name].[hash].js'//输出文件添加hash
  },
  optimization: { // 代替commonchunk, 代码分割
    runtimeChunk: 'single',
    splitChunks: {
      cacheGroups: {
        vendor: {
          test: /[\\/]node_modules[\\/]/,
          name: 'vendors',
          chunks: 'all'
        }
      }
    }
  },
  module: {
    rules: [
      {
        test: /\.jsx"htmlcode">

const merge = require('webpack-merge');
const common = require('./webpack.common.js');

module.exports = merge(common, {
  mode: 'development',
  devtool: 'inline-source-map',
  devServer: {
    contentBase: './dist',
    port: 4001,
    hot: true
  }
});


生成模式的 webpack.prod.js 文件，只要定义了 mode:'production' ， webpack 4 打包时就会自动压缩优化代码。


const merge = require('webpack-merge');
const common = require('./webpack.common.js');

module.exports = merge(common, {
 mode: 'production',
 devtool: 'source-map'
});




配置 package.js 中的 scripts


{
 "scripts": {
   "start": "webpack-dev-server --open --config webpack.dev.js",
   "build": "webpack --config webpack.prod.js"
 }
}



Babel 的配置


babel的 .babelrc 文件， css module 包这里推荐 babel-plugin-react-css-modules 。
react-css-modules既支持全局的css(默认 className 属性)，同时也支持局部css module( styleName 属性)，还支持css预编译器，这里使用的是 scss 。


{
  "presets": [
    "@babel/preset-env",
    "@babel/preset-react"
  ],
  "plugins": [
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-transform-runtime",
    [
      "react-css-modules",
      {
        "exclude": "node_modules",
        "filetypes": {
          ".scss": {
            "syntax": "postcss-scss"
          }
        },
        "generateScopedName": "[name]___[local]___[hash:base64:5]"
      }
    ]
  ]
}


React 项目


下面是项目基本的目录树结构，接着从入口开始一步步细化整个项目。


├ package.json
├ src
│ ├ component // 组件目录
│ ├ reducer  // reducer目录
│ ├ action.js
│ ├ constants.js
│ ├ context.js
│ └ index.js
├ public // 静态文件目录
│ ├ css
│ └ index.html
├ .babelrc
├ webpack.common.js
├ webpack.dev.js
└ webpack.prod.js



状态管理组件使用 redux ， react-router 用于构建单页面的项目，因为使用了 hooks API，所以不再需要 react-redux 连接状态 state 。
<Context.Provider value={{ state, dispatch }}>基本代替了 react-redux 的 ** `。


// index.js
import React, { useReducer } from 'react'
import { render } from 'react-dom'
import { HashRouter as Router, Route, Redirect, Switch } from 'react-router-dom'
import Context from './context.js'
import Home from './component/home.js'
import List from './component/list.js'
import rootReducer from './reducer'
import '../public/css/index.css'

const Root = () => {
  const initState = {
    list: [
      { id: 0, txt: 'webpack 4' },
      { id: 1, txt: 'react' },
      { id: 2, txt: 'redux' },
    ]
  };
  // useReducer映射出state，dispatch
  const [state, dispatch] = useReducer(rootReducer, initState);
  return <Context.Provider value={{ state, dispatch }}>
    <Router>
      <Switch>
        <Route exact path="/" component={Home} />
        <Route exact path="/list" component={List} />
        <Route render={() => (<Redirect to="/" />)} />
      </Switch>
    </Router>
  </Context.Provider>
}
render(
  <Root />,
  document.getElementById('root')
)




constants.js， action.js 和 reducer.js 与之前的写法是一致的。


// constants.js
export const ADD_COMMENT = 'ADD_COMMENT'
export const REMOVE_COMMENT = 'REMOVE_COMMENT'
// action.js
import { ADD_COMMENT, REMOVE_COMMENT } from './constants'

export function addComment(comment) {
 return {
  type: ADD_COMMENT,
  comment
 }
}

export function removeComment(id) {
 return {
  type: REMOVE_COMMENT,
  id
 }
}




list.js




import { ADD_COMMENT, REMOVE_COMMENT } from '../constants.js'

const list = (state = [], payload) => {
  switch (payload.type) {
    case ADD_COMMENT:
      if (Array.isArray(payload.comment)) {
        return [...state, ...payload.comment];
      } else {
        return [...state, payload.comment];
      }
    case REMOVE_COMMENT:
      return state.filter(i => i.id != payload.id);
    default: return state;
  }
};
export default list


reducer.js




import { combineReducers } from 'redux'
import list from './list.js'

const rootReducer = combineReducers({
 list,
 //user
});

export default rootReducer




最大区别的地方就是 component 组件，基于 函数式 ，内部的表达式就像是即插即用的插槽，可以很方便的抽取出通用的组件，然后从外部引用。相比之前的 面向对象 方式，我觉得 函数表达式 更受前端开发者欢迎。

  
useContext 获取全局的 state
  
useRef 代替之前的 ref
  
useState 代替之前的 state
  
useEffect则可以代替之前的生命周期钩子函数



//监控数组中的参数，一旦变化就执行
useEffect(() => { updateData(); },[id]);

//不传第二个参数的话，它就等价于每次componentDidMount和componentDidUpdate时执行
useEffect(() => { updateData(); });

//第二个参数传空数组，等价于只在componentDidMount和componentWillUnMount时执行， 
//第一个参数中的返回函数用于执行清理功能
useEffect(() => { 
  initData(); 
  reutrn () => console.log('componentWillUnMount cleanup...'); 
}, []);




最后就是实现具体界面和业务逻辑的组件了，下面是其中的List组件


// list.js
import React, { useRef, useState, useContext } from 'react'
import { bindActionCreators } from 'redux'
import { Link } from 'react-router-dom'
import Context from '../context.js'
import * as actions from '../action.js'
import Dialog from './dialog.js'
import './list.scss'

const List = () => {
  const ctx = useContext(Context);//获取全局状态state
  const { user, list } = ctx.state;
  const [visible, setVisible] = useState(false);
  const [rid, setRid] = useState('');
  const inputRef = useRef(null);
  const { removeComment, addComment } = bindActionCreators(actions, ctx.dispatch);

  const confirmHandle = () => {
    setVisible(false);
    removeComment(rid);
  }

  const cancelHandle = () => {
    setVisible(false);
  }

  const add = () => {
    const input = inputRef.current,
      val = input.value.trim();
    if (!val) return;
    addComment({
      id: Math.round(Math.random() * 1000000),
      txt: val
    });
    input.value = '';
  }

  return <>
    <div styleName="form">
      <h3 styleName="sub-title">This is list page</h3>
      <div>
        <p>hello, {user.name} !</p>
        <p>your email is {user.email} !</p>
        <p styleName="tip">please add and remove the list item !!</p>
      </div>
      <ul> {
        list.map(l => <li key={l.id}>{l.txt}<i className="icon-minus" title="remove item" onClick={() => {
          setVisible(true);
          setRid(l.id);
        }}></i></li>)
      } </ul>
      <input ref={inputRef} type="text" />
      <button onClick={add} title="add item">Add Item</button>
      <Link styleName="link" to="/">redirect to home</Link>
    </div>
    <Dialog visible={visible} confirm={confirmHandle} cancel={cancelHandle}>remove this item "_blank" href="https://github.com/edwardzhong/webpack_react" rel="external nofollow" >https://github.com/edwardzhong/webpack_react

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。