react+webpack4构建项目（1webpack4开发环境搭建）

1、新建目录e: md react-demo
2、初始化工程 E://react-demo 打开cmd命令行 ，执行 npm init -y， 生产 package.json 文件
3、建立工程目录
--app
--component react组件目录
--index 首页目录
--public 公共目录
--js
--css
--img
--devBuild webpack开发环境下，打包输入目录
--config 打包配置目录
--webpack webpack配置目录
--entryBuild webpack 打包入口文件目录
4，安装react ，react-dom
npm i -S react react-dom
-S 意思是保存 到 package.json dependencies 字段
5.安装webpack,babel依赖
npm i -D [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected] [email protected]
-D 意思是保存 到 package.json devDependencies字段
注意复制的时候要是一行的，不能换行！
6.在 app/component/index目录下建立 index.jsx文件，内容
import React from 'react';
class Index extends React.Component {
render() {
return (

这是首页

);
}
}

export default Index;
7.在devBuild目录下建立index.html文件

8.在entryBuild目录下建立index.js文件
import React from 'react';
import ReactDOM from 'react-dom';
import Index from '../app/component/index/Index.jsx';
ReactDOM.render(,document.getElementById('app'));
9.配置webpack
基础配置 config/webpack/webpack.base.conf.js
let config = {
entry: {
'index':'./entryBuild/index.js'
},
resolve: {
extensions: [".js", ".json", ".jsx", ".css",".pcss"],
}
};
module.exports = config;
文件配置：config/webpack/webpack.file.conf.js
module.exports = {
devDirectory:'devBuild',/开发目录/
proDirectory:'dist',/发布目录/
resource:'resource',/静态资源/
};
开发环境配置：config/webpack/webpack.dev.conf.js
const webpack = require('webpack');//引入webpack
const opn = require('opn');//打开浏览器
const merge = require('webpack-merge');//webpack配置文件合并
const path = require("path");
const baseWebpackConfig = require("./webpack.base.conf");//基础配置
const webpackFile = require("./webpack.file.conf");//一些路径配置

let config = merge(baseWebpackConfig, {
/设置开发环境/
mode: 'development',
output: {
path: path.resolve(webpackFile.devDirectory),
filename: 'js/[name].js',
chunkFilename: "js/[name].js",
publicPath: ''
},
plugins: [
/设置热更新/
new webpack.HotModuleReplacementPlugin(),
],
module: {
rules: [
{
test: /.(js|jsx)$/,
use: [
'babel-loader',
],
include: [
path.resolve(__dirname, "../../app"),
path.resolve(__dirname, "../../entryBuild")
],
exclude: [
path.resolve(__dirname, "../../node_modules")
],
}

    ]
},
/*设置api转发*/
devServer: {
    host: '0.0.0.0',
    port: 8080,
    hot: true,
    inline: true,
    contentBase: path.resolve(webpackFile.devDirectory),
    historyApiFallback: true,
    disableHostCheck: true,
    proxy: [
        {
            context: ['/api/**', '/u/**'],
            target: 'http://192.168.12.100:8080/',
            secure: false
        }
    ],
    /*打开浏览器 并打开本项目网址*/
    after() {
        opn('http://localhost:' + this.port);
    }
}

});
module.exports = config;
10.配置babel
根目录下建立 .babelrc文件
{
"presets":["react","env"],
"env":{
"development": {
"presets":["react-hmre"]
}
}
}
11.配置npm 命令 ，在package.json文件中配置 scripts字段
"dev": "webpack-dev-server --devtool eval --progress --colors --profile --config config/webpack/webpack.dev.conf.js"
12.命令行执行npm run dev