Webpack学习笔记

# 七.懒加载

# 1.安装

package.json

{
  "name": "7.lazyload",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "webpack",
    "dev": "webpack-dev-server",
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.4.0",
    "@babel/plugin-syntax-dynamic-import": "^7.2.0",
    "@babel/preset-env": "^7.4.2",
    "@babel/preset-react": "^7.0.0",
    "babel-loader": "^8.0.5",
    "html-webpack-plugin": "^3.2.0",
    "webpack": "^4.29.6",
    "webpack-cli": "^3.3.0",
    "webpack-dev-server": "^3.2.1"
  },
  "dependencies": {
    "jquery": "^3.3.1",
    "moment": "^2.24.0"
  }
}
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# 2.文件

src/index.js

let button = document.createElement("button")
button.innerHTML = "hello"
//vue懒加载 react懒加载都是这样的形式
button.addEventListener("click", function() {
  //es6 草案中的语法 jsonp实现动态加载文件
  import("./source.js").then((data) => {
    console.log(data) //返回一个promise
  })
})
document.body.appendChild(button)
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src/source.js

export default "123"
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# 3.配置

webpack.config.js

let path = require("path")
let HtmlWebpackPlugin = require("html-webpack-plugin")
let webpack = require("webpack")
module.exports = {
  mode: "production",
  entry: {
    index: "./src/index.js",
  },
  output: {
    filename: "[name].js",
    path: path.resolve(__dirname, "dist"),
  },
  plugins: [
    new HtmlWebpackPlugin({
      template: "./public/index.html",
    }),
    new webpack.IgnorePlugin(/\.\/locale/, /moment/),
  ],
  module: {
    noParse: /jquery/, //不去解析jquery中的依赖库
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        include: path.resolve("src"),
        use: {
          loader: "babel-loader",
          options: {
            presets: ["@babel/preset-env", "@babel/preset-react"],
            plugins: ["@babel/plugin-syntax-dynamic-import"],
          },
        },
      },
    ],
  },
}
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# 4.运行

npm run dev
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完整代码 (opens new window)

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