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@wordpress/babel-plugin-import-jsx-pragma

💡 云策文档标注

概述

@wordpress/babel-plugin-import-jsx-pragma 是一个 Babel 转换插件,用于自动注入 import 语句作为 React JSX Transform 插件的 pragma。它允许开发者在代码中使用 JSX 而无需手动确保转换函数在作用域内,简化了 React 项目中的 JSX 处理。

关键要点

  • 插件自动为 JSX 引入必要的 import,避免手动导入 React 或其他 pragma 函数。
  • 需与 @babel/plugin-transform-react-jsx 插件配合使用,否则遇到 JSX 标记时会报错。
  • 插件尊重现有的 import 语句和作用域变量声明,不会重复导入。
  • 从 v4.0.0 开始,该插件已包含在 @wordpress/babel-preset-default 中,使用预设时可省略配置。
  • 提供选项如 scopeVariable、scopeVariableFrag、source 和 isDefault,以自定义导入行为。

代码示例

// .babelrc.js
module.exports = {
    plugins: [
        '@wordpress/babel-plugin-import-jsx-pragma',
        '@babel/plugin-transform-react-jsx',
    ],
};

注意事项

  • 安装要求 Node.js 长期支持版本,不兼容旧版本。
  • 使用自定义选项时,需确保与 @babel/plugin-transform-react-jsx 插件的 pragma 设置匹配。
  • scopeVariableFrag 用于 Fragment JSX,但命名 <Fragment /> 元素不会自动添加导入。

📄 原文内容

Babel transform plugin for automatically injecting an import to be used as the pragma for the React JSX Transform plugin.

JSX is merely a syntactic sugar for a function call, typically to React.createElement when used with React. As such, it requires that the function referenced by this transform be within the scope of the file where the JSX occurs. In a typical React project, this means React must be imported in any file where JSX exists.

Babel Plugin Import JSX Pragma automates this process by introducing the necessary import automatically wherever JSX exists, allowing you to use JSX in your code without thinking to ensure the transformed function is within scope. It respects existing import statements, as well as scope variable declarations.

Installation

Install the module to your project using npm.

npm install @wordpress/babel-plugin-import-jsx-pragma

Note: This package requires Node.js version with long-term support status (check Active LTS or Maintenance LTS releases). It is not compatible with older versions.

Usage

Refer to the Babel Plugins documentation if you don’t yet have experience working with Babel plugins.

Include @wordpress/babel-plugin-import-jsx-pragma (and @babel/plugin-transform-react-jsx) as plugins in your Babel configuration. If you don’t include both you will receive errors when encountering JSX tokens.

// .babelrc.js
module.exports = {
    plugins: [
        '@wordpress/babel-plugin-import-jsx-pragma',
        '@babel/plugin-transform-react-jsx',
    ],
};

Note: @wordpress/babel-plugin-import-jsx-pragma is included in @wordpress/babel-preset-default (default preset for WordPress development) starting from v4.0.0. If you are using this preset, you shouldn’t include this plugin in your Babel config.

Options

As the @babel/plugin-transform-react-jsx plugin offers options to customize the pragma to which the transform references, there are equivalent options to assign for customizing the imports generated.

For example, if you are using the react package, you may want to use the following configuration:

// .babelrc.js
module.exports = {
    plugins: [
        [
            '@wordpress/babel-plugin-import-jsx-pragma',
            {
                scopeVariable: 'createElement',
                scopeVariableFrag: 'Fragment',
                source: 'react',
                isDefault: false,
            },
        ],
        [
            '@babel/plugin-transform-react-jsx',
            {
                pragma: 'createElement',
                pragmaFrag: 'Fragment',
            },
        ],
    ],
};

scopeVariable

Type: String

Name of variable required to be in scope for use by the JSX pragma. For the default pragma of React.createElement, the React variable must be within scope.

scopeVariableFrag

Type: String

Name of variable required to be in scope for <></> Fragment JSX. Named <Fragment /> elements
expect Fragment to be in scope and will not add the import.

source

Type: String

The module from which the scope variable is to be imported when missing.

isDefault

Type: Boolean

Whether the scopeVariable is the default import of the source module. Note that this has no impact
on scopeVariableFrag.

Contributing to this package

This is an individual package that’s part of the Gutenberg project. The project is organized as a monorepo. It’s made up of multiple self-contained software packages, each with a specific purpose. The packages in this monorepo are published to npm and used by WordPress as well as other software projects.

To find out more about contributing to this package or Gutenberg as a whole, please read the project’s main contributor guide.