在 Create-React-App 应用程序中,index.html 和 index.js 之间的联系在哪里? [英] Where's the connection between index.html and index.js in a Create-React-App application?
问题描述
我开始使用 Create React App,但我无法理解 index.js
是如何加载到 index.html
中的.这是html代码:
I'm starting to play with the Create React App, but I can't understand how the index.js
is loaded inside index.html
. This is the html code:
<!doctype html>
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico">
<!--
Notice the use of %PUBLIC_URL% in the tag above.
It will be replaced with the URL of the `public` folder during the build.
Only files inside the `public` folder can be referenced from the HTML.
Unlike "/favicon.ico" or "favicon.ico", "%PUBLIC_URL%/favicon.ico" will
work correctly both with client-side routing and a non-root public URL.
Learn how to configure a non-root public URL by running `npm run build`.
-->
<title>React App</title>
</head>
<body>
<div id="root"></div>
<!--
This HTML file is a template.
If you open it directly in the browser, you will see an empty page.
You can add webfonts, meta tags, or analytics to this file.
The build step will place the bundled scripts into the <body> tag.
To begin the development, run `npm start`.
To create a production bundle, use `npm run build`.
-->
</body>
</html>
但是我在任何地方都看不到 index.js
的导入.连接在哪里?我错过了什么?
But I can't see anywhere the import of the index.js
. Where is the connection? What am I missing?
推荐答案
在幕后,Create React App 使用带有 html-webpack-plugin.
Under the hood, Create React App uses Webpack with html-webpack-plugin.
我们的配置 指定 Webpack 使用 src/index.js
作为 入口点".所以这是它读取的第一个模块,然后它会跟随其他模块将它们编译成单个包.
Our configuration specifies that Webpack uses src/index.js
as an "entry point". So that’s the first module it reads, and it follows from it to other modules to compile them into a single bundle.
当 webpack 编译资产时,它会生成一个(或多个,如果您使用代码拆分)包.它使所有插件都可以使用它们的最终路径.我们正在使用一个这样的插件将脚本注入 HTML.
When webpack compiles the assets, it produces a single (or several if you use code splitting) bundles. It makes their final paths available to all plugins. We are using one such plugin for injecting scripts into HTML.
我们已启用 html-webpack-plugin 来生成 HTML 文件.在我们的配置中,我们 指定它应该读取 public/index.html
作为模板.我们还将 inject
option 设置为 真的
.使用该选项,html-webpack-plugin
添加一个 和 Webpack 提供的路径到最终的 HTML 页面.这最后一页是您在运行
npm run build
后在 build/index.html
中获得的页面,以及在 /
中获得的页面你运行 npm start
.
We have enabled html-webpack-plugin to generate the HTML file. In our configuration, we specified that it should read public/index.html
as a template. We have also set inject
option to true
. With that option, html-webpack-plugin
adds a <script>
with the path provided by Webpack right into the final HTML page. This final page is the one you get in build/index.html
after running npm run build
, and the one that gets served from /
when you run npm start
.
希望这有帮助!Create React App 的美妙之处在于你实际上不需要考虑它.
Hope this helps! The beauty of Create React App is you don’t actually need to think about it.
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