Parcel 打包示例(React HelloWorld)

2019-11-19 14:31:13

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Parcel 打包特點

極速打包時間

Parcel 使用 worker 進程去啟用多核編譯。同時有文件系統緩存，即使在重啟構建后也能快速再編譯。

將你所有的資源打包

Parcel 具備開箱即用的對 JS, CSS, HTML, 文件及更多的支持，而且不需要插件。

自動轉換

如若有需要，Babel, PostCSS, 和PostHTML甚至 node_modules 包會被用于自動轉換代碼.

配置代碼分拆

使用動態 import() 語法, Parcel 將你的輸出文件束(bundles)分拆，因此你只需要在初次加載時加載你所需要的代碼。

熱模塊替換

Parcel 無需配置，在開發環境的時候會自動在瀏覽器內隨著你的代碼更改而去更新模塊。

友好的錯誤日志

當遇到錯誤時，Parcel 會輸出語法高亮的代碼片段，幫助你定位問題。

使用 Parcel 打包的 React HelloWorld 應用。GitHub 地址: https://github.com/justjavac/parcel-example/tree/master/react-helloworld

0. 新建目錄

mkdir react-helloworldcd react-helloworld

1. 初始化 npm

yarn init -y

或

npm init -y

此時會創建要給 package.json 文件，文件內容：

{ "name": "parcel-example-react-helloworld", "version": "1.0.0", "description": "", "main": "index.js", "scripts": {  "test": "echo /"Error: no test specified/" && exit 1" }, "keywords": [], "author": "", "license": "ISC"}

2. 添加 React

yarn：

yarn add react react-dom

npm:

npm install react react-dom --save

package.json 文件內容：

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {   "test": "echo /"Error: no test specified/" && exit 1"  },  "keywords": [],  "author": "",- "license": "ISC"+ "license": "ISC",+ "dependencies": {+  "react": "^16.2.0",+  "react-dom": "^16.2.0"+ } }

3. 添加 Babel

新建 .babelrc 文件

touch .babelrc

輸入內容：

{ "presets": ["react"]}

添加 babel-preset-react：

yarn：

yarn add babel-preset-react -D

npm:

npm install babel-preset-react --D

此時 package.json 文件內容：

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {   "test": "echo /"Error: no test specified/" && exit 1"  },  "keywords": [],  "author": "",  "license": "ISC",  "dependencies": {   "react": "^16.2.0",   "react-dom": "^16.2.0"-  }+  },+  "devDependencies": {+   "babel-preset-react": "^6.24.1"+  } }

5. 添加 Parcel

yarn：

yarn add parcel-bundler -D

npm:

npm install parcel-bundler --D

此時 package.json 文件內容：

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {   "test": "echo /"Error: no test specified/" && exit 1"  },  "keywords": [],  "author": "",  "license": "ISC",  "dependencies": {   "react": "^16.2.0",   "react-dom": "^16.2.0"  },  "devDependencies": {-   "babel-preset-react": "^6.24.1"+   "babel-preset-react": "^6.24.1",+   "parcel-bundler": "^1.0.3"    } }

6. 新建 index.html 文件

內容

<html><body>  <div id="root"></div>  <script src="./index.js"></script></body></html>

7. 新建 index.js 文件

import React from "react";import ReactDOM from "react-dom";const App = () => { return <h1>Hello World!</h1>;};ReactDOM.render(<App />, document.getElementById("root"));

8. 添加打包命令

 {  "name": "parcel-example-react-helloworld",  "version": "1.0.0",  "description": "",  "main": "index.js",  "scripts": {-  "test": "echo /"Error: no test specified/" && exit 1"+  "start": "parcel index.html"  },  "keywords": [],  "author": "",  "license": "ISC",  "dependencies": {   "react": "^16.2.0",   "react-dom": "^16.2.0"  },  "devDependencies": {    "babel-preset-react": "^6.24.1"    "babel-preset-react": "^6.24.1",    "parcel-bundler": "^1.0.3"    } }

9. 完成

運行