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https://github.com/birdofpreyru/babel-plugin-react-css-modules
Transforms styleName to className using compile time CSS module resolution.
https://github.com/birdofpreyru/babel-plugin-react-css-modules
babel css javascript modules plugin react web
Last synced: 1 day ago
JSON representation
Transforms styleName to className using compile time CSS module resolution.
- Host: GitHub
- URL: https://github.com/birdofpreyru/babel-plugin-react-css-modules
- Owner: birdofpreyru
- License: other
- Fork: true (gajus/babel-plugin-react-css-modules)
- Created: 2020-08-08T13:29:36.000Z (about 4 years ago)
- Default Branch: master
- Last Pushed: 2024-06-05T09:01:46.000Z (4 months ago)
- Last Synced: 2024-09-21T13:02:43.450Z (6 days ago)
- Topics: babel, css, javascript, modules, plugin, react, web
- Language: JavaScript
- Homepage: https://dr.pogodin.studio/docs/babel-plugin-react-css-modules
- Size: 1.78 MB
- Stars: 30
- Watchers: 3
- Forks: 12
- Open Issues: 3
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE.md
Awesome Lists containing this project
README
# Babel Plugin: React CSS Modules
[](https://www.npmjs.com/package/@dr.pogodin/babel-plugin-react-css-modules)
[](https://www.npmjs.com/package/@dr.pogodin/babel-plugin-react-css-modules)
[](https://app.circleci.com/pipelines/github/birdofpreyru/babel-plugin-react-css-modules)
[](https://github.com/birdofpreyru/babel-plugin-react-css-modules)
[](https://dr.pogodin.studio/docs/babel-plugin-react-css-modules)
[Babel] plugin for advanced [CSS modules] support in [React]:
- It transforms `styleName` attribute of JSX components into `className` using
compile-time CSS module resolution, allowing for a cleaner use of CSS modules
in React.
- For server-side rendering (SSR) scenarios it can replace named stylesheet
imports by classname mapping objects, and remove anonymous stylesheet imports.
[](https://github.com/sponsors/birdofpreyru)
## Content
- [Usage examples](#usage-examples)
- [Installation](#installation)
- [React Native](#react-native)
- [Configuration](#configuration)
- [Plugin options](#plugin-options)
- [Configurate syntax loaders]
- [Custom Attribute Mapping]
- [Under the hood](#under-the-hood)
- [How does it work?](#how-does-it-work)
- [Project history](#project-history)
- [Migration from `babel-plugin-react-css-modules`](##migration-from-babel-plugin-react-css-modules)
- [`css-loader` compatibility](#css-loader-compatibility)
## Usage Examples
Assuming `style.css` in the following examples is compiled as CSS Module.
**Without this plugin**
```jsx
import S from './styles.css';
export default function Component() {
return (
Example
Sample text paragraph.
Sample text paragraph with special style.
);
}
```
**With this plugin**
```jsx
import './styles.css';
export default function Component() {
return (
Example
Sample text paragraph.
Sample text paragraph with special style.
);
}
```
**With this plugin and multiple stylesheets**
Assuming:
- Styles `container`, `title`, and `text` are defined in `styles-01.css`.
- Style `special` is defined in `styles-02.css`.
- The plugin's `autoResolveMultipleImports` option is enabled (default).
```jsx
import './styles-01.css';
import './styles-02.css';
export default function Component() {
return (
Example
Sample text paragraph.
Sample text paragraph with special style.
);
}
```
If both files, `styles-01.css` and `styles-02.css` contain styles with the same
names, thus making auto resolution impossible, this plugin allows explicit
stylesheet prefixes:
```jsx
import S1 from './styles-01.css';
import S2 from './styles-02.css';
export default function Component() {
return (
Example
Sample text paragraph.
Sample text paragraph with special style.
);
}
```
**With this plugin and runtime resolution**
```jsx
import './styles-01.css';
import './styles-02.css';
export default function Component({ special }) {
let textStyle = 'text';
if (special) textStyle += ' special';
return (
Example
Sample text paragraph.
Sample text paragraph with special style.
);
}
```
In the case when the exact style value is not known at the compile time, like in
this example, the plugin will inject necessary code to correctly resolve the
`styleName` at runtime (which is somewhat less performant, but otherwise works
fine).
**SSR scenario**
Consider such component, which uses a named stylesheet import in order to use it
in some other ways, beside simple styling, _e.g._ to also display the classname
mapping:
```jsx
import S from './style.css';
export default function Component() {
return (
{JSON.stringify(S)}
)
}
```
While by default this plugin transforms it into (leaving it to the Webpack's
**css-loader** to handle `./style.scss` import for the actual CSS bundling,
and leaving a correct JS in place of it):
```jsx
import S from './style.css';
export default function Component() {
return (
{JSON.stringify(S)}
)
}
```
For server-side environment, if you don't compile server-side code with Webpack,
you'll need to replace `./style.css` with valid JS code. That is exactly what
this plugin does with `replaceImport` option enabled, it outputs:
```jsx
const S = {
container: '12345',
// Other stylesheet keys, if any.
};
export default function Component() {
return (
{JSON.stringify(S)}
)
}
```
**CommonJS require() support**
The plugin works the same with `require('./style.css')` CSS imports.
## Installation
- The core CSS Modules functionality should be enabled and configured elsewhere
in your React project:
- With [Create React App] see
[Adding a CSS Modules Stylesheet](https://create-react-app.dev/docs/adding-a-css-modules-stylesheet).
- With bare [Webpack] see
[`modules` option of `css-loader`](https://webpack.js.org/loaders/css-loader/#modules).
- With other frameworks refer to their documentation.
- Install this plugin as a direct dependency (in edge-cases not allowing for
a compile-time `styleName` resolution, the plugin falls back to the runtime
resolution).
```
npm install --save @dr.pogodin/babel-plugin-react-css-modules
```
- Install Webpack at least as a dev dependency:
```
npm install --save-dev webpack
```
- Add the plugin to Babel configuration:
```js
{
"plugins": [
["@dr.pogodin/react-css-modules", {
// The default localIdentName in "css-loader" is "[hash:base64]",
// it is highly-recommended to explicitly specify the same value
// both here, and in "css-loader" options, including the hash length
// (the last digit in the template below).
"generateScopedName": "[hash:base64:6]"
// See below for all valid options.
}]
]
}
```
- The `generateScopedName` option value MUST match `localIdentName` option of
`css-loader` to ensure both Webpack and this plugin generate matching class
names. The same goes for other options impacting class names
(_e.g._ the default length of hashes generated by Webpack, which is used
if you don't specify the hash length explicitly in `localIdentName` hash
placeholders), and also the actuals version of this plugin and `css-loader`
(see [`css-loader` compatibility]).
- _Optional_. `css-loader` is known for eventual minor updates in their default
class name generation logic that require counterpart upgrades of this plugin
to keep it compatible.
[They denied](https://github.com/webpack-contrib/css-loader/issues/1152)
to expose the default class name generator for re-used by 3rd party libraries,
and suggested to rely on
[`getLocalIdent`](https://webpack.js.org/loaders/css-loader/#getlocalident])
option if unwanted class name changes due to `css-loader` updates are
a problem for a particular project.
To alleviate this issue, this plugin provides stable default implementation
for `getLocalIdent` function (taken from a selected earlier version of
`css-loader`). Consider to use it:
**Within Webpack Config**
```js
const { getLocalIdent } = require('@dr.pogodin/babel-plugin-react-css-modules/utils');
const cssLoaderOptions = {
modules: {
getLocalIdent,
localIdentName: '[path]___[name]__[local]___[hash:base64:6]'
}
};
```
**Within Babel Config**
```js
const { generateScopedNameFactory } = require('@dr.pogodin/babel-plugin-react-css-modules/utils');
module.exports = {
plugins: [
["@dr.pogodin/react-css-modules", {
generateScopedName:
// The classname template MUST match "localIdentName" option value
// you passed to "css-loader".
generateScopedNameFactory("[path]___[name]__[local]___[hash:base64:6]"),
}]
]
};
```
In addition to the standard class name template placeholders mentioned in
[`css-loader` documentation](https://webpack.js.org/loaders/css-loader/#localidentname)
the version of `getLocalIdent()` and `generateScopedName()` provided by this
plugin also support `[package]` placeholder. If used, it looks up from CSS
file for the closest `package.json` file, takes the package name from it,
and inserts it into the class name (this is useful for CSS bundling for
libraries).
### React Native
If you'd like to get this working in React Native, you're going to have to allow
custom import extensions, via a `rn-cli.config.js` file:
```js
module.exports = {
getAssetExts() {
return ["scss"];
}
}
```
Remember, also, that the bundler caches things like plugins and presets. If you
want to change your `.babelrc` (to add this plugin) then you'll want to add the
`--reset-cache` flag to the end of the package command.
## Configuration
### Plugin Options
These are valid plugin options. All are optional, but the overall configuration
should be compatible with that of `css-loader`, thus defaults may not work for
you.
- `context` - **string** - Must match webpack
[`context`](https://webpack.js.org/configuration/entry-context/#context)
configuration. `css-loader` inherits `context` values from webpack. Other CSS
module implementations might use different context resolution logic.
Defaults `process.cwd()`.
- `exclude` - **string** - A RegExp that will exclude otherwise included files
_e.g._, to exclude all styles from node_modules: `exclude: 'node_modules'`.
- `filetypes` - [Configurate syntax loaders] like sugarss, LESS and SCSS,
and extra plugins for them.
- `generateScopedName` - **function | string** - Allows to customize the exact
`styleName` to `className` conversion algorithm. For details see
[Generating scoped names](https://github.com/css-modules/postcss-modules#generating-scoped-names).
Defaults `[path]___[name]__[local]___[hash:base64:5]`.
- `replaceImport` - **boolean** - Replaces / removes stylesheet imports for
server-side rendering purposes. [See details below](#server-side-rendering).
Defaults **false**.
- `webpackHotModuleReloading` - **boolean** | `"commonjs"` - Enables injection
of [Hot Module Reloading] code.
- `handleMissingStyleName` - **string** - Determines what should be done for
undefined CSS modules (using a `styleName` for which there is no CSS module
defined). Valid values: `"throw"`, `"warn"`, `"ignore"`. Setting this option
to `"ignore"` is equivalent to setting `errorWhenNotFound: false` in
[react-css-modules](https://github.com/birdofpreyru/react-css-modules#errorwhennotfound). Defaults `"throw"`.
- `attributeNames` - [Custom Attribute Mapping]
- `skip` - **boolean** - Whether to apply plugin if no matching `attributeNames`
found in the file. Defaults **false**.
- [transform] - **function** - If provided, each CSS source loaded by
the plugin will be passed through this function, alongside its path,
and this plugin's options, and the output of this function will be used
in place of the original CSS.
- `autoResolveMultipleImports` - **boolean** - Allows multiple anonymous imports if
`styleName` is only in one of them. Defaults **true**.
### Deprecated Plugin Options
- ~~`removeImport` - **boolean**~~ - Use `replaceImport` option instead.
### Configurate syntax loaders
To add support for different CSS syntaxes (e.g. SCSS), perform the following
two steps:
1. Add the [postcss syntax loader](https://github.com/postcss/postcss#syntaxes)
as a development dependency:
```bash
npm install postcss-scss --save-dev
```
2. Add a `filetypes` syntax mapping to the Babel plugin configuration.
For example for SCSS:
```json
"filetypes": {
".scss": {
"syntax": "postcss-scss"
}
}
```
And optionally specify extra plugins:
```json
"filetypes": {
".scss": {
"syntax": "postcss-scss",
"plugins": [
"postcss-nested"
]
}
}
```
> NOTE: [`postcss-nested`](https://github.com/postcss/postcss-nested)
is added as an extra plugin for demonstration purposes only. It's not
needed with [`postcss-scss`](https://github.com/postcss/postcss-scss)
because SCSS already supports nesting.
Postcss plugins can have options specified by wrapping the name and an options object in an array inside your config:
```json
"plugins": [
["postcss-import-sync2", {
"path": ["src/styles", "shared/styles"]
}],
"postcss-nested"
]
```
### Hot Module Reloading
If you don't know what is Hot Module Reloading (HMR), refer to the
[Webpack documentation](https://webpack.js.org/concepts/hot-module-replacement).
If you use HMR in your development setup (you probably should), depending on
your particular configuration you might need to enable `webpackHotModuleReloading`
option of this plugin, or you may need to leave it disabled (default), as other
loaders / plugins in your Webpack pipeline for CSS may already inject required
HMR code.
In case you decide to enable it in this plugin, `webpackHotModuleReloading`
option may be set equal:
- **true** - this plugin will inject HMR accept code for each imported CSS
module, using `import.meta.webpackHot` (ESM) syntax
([see for details](https://webpack.js.org/api/hot-module-replacement)).
- `commonjs` string - this plugin will inject HMR accept code using
the legacy `module.hot` syntax.
The default value is **false** - this plugin does not inject HMR accept code.
### transform
```js
function transform(cssSource, cssSourceFilePath, pluginOptions): string
```
The transform function, if provided as the `transform` option of this plugin,
will be called for each loaded CSS source with three arguments:
- `cssSource` - **string** - The loaded CSS code.
- `cssSourceFilePath` - **string** - The path of loaded CSS file.
- `pluginOptions` - **object** - The options set for this plugin.
It should return a string, the actual CSS code to use.
### Custom Attribute
You can set your own attribute mapping rules using the `attributeNames` option.
It's an object, where keys are source attribute names and values are destination
attribute names.
For example, the
[<NavLink>](https://github.com/ReactTraining/react-router/blob/master/packages/react-router-dom/docs/api/NavLink.md)
component from [React Router](https://github.com/ReactTraining/react-router)
has an `activeClassName` attribute to accept an additional class name. You can
set `"attributeNames": { "activeStyleName": "activeClassName" }` to transform it.
The default `styleName` -> `className` transformation **will not** be affected
by an `attributeNames` value without a `styleName` key. Of course you can use
`{ "styleName": "somethingOther" }` to change it, or use `{ "styleName": null }`
to disable it.
### Server-Side Rendering
If `replaceImport` flag is set, this plugin will remove or replace original
stylesheet imports, which is needed for server-side rendering:
```js
// Anonymous imports are removed from the code:
import 'path/to/style.css';
// Default and named imports are replaced in the following manner:
// Before:
import styles, {
className,
otherClassName as alias,
} from 'path/to/style.css';
// After:
const styles = {
className: 'generatedClassName',
otherClassName: 'otherGeneratedClassName',
},
className = 'generatedClassName',
alias = 'otherGeneratedClassName';
// Also this kind of import:
import * as style from 'path/to/style.css';
// is replaced by:
const style = {
className: 'generatedClassName',
otherClassName: 'otherGeneratedClassName',
};
```
## Under the hood
### How does it work?
This plugin does the following:
1. Builds index of all stylesheet imports per file (imports of files with
`.css` or `.scss` extension).
2. Uses [postcss](https://github.com/postcss/postcss) to parse the matching
CSS files into a lookup of CSS module references.
3. Iterates through all
[JSX](https://facebook.github.io/react/docs/jsx-in-depth.html)
element declarations.
4. Parses the `styleName` attribute value into anonymous and named CSS module
references.
5. Finds the CSS class name matching the CSS module reference:
* If `styleName` value is a string literal, generates a string literal value.
* If `styleName` value is a
[`jSXExpressionContainer`](https://babeljs.io/docs/en/next/babel-types.html#jsxexpressioncontainer),
uses a helper function ([`getClassName`](./src/getClassName.js))
to construct the `className` value at the runtime.
6. Removes the `styleName` attribute from the element.
7. Appends the resulting `className` to the existing `className` value
(creates `className` attribute if one does not exist).
### Project history
This plugin is an up-to-date, well-maintained fork of the original
[`babel-plugin-react-css-modules`](https://www.npmjs.com/package/babel-plugin-react-css-modules):
- It generates class names matching current `css-loader` versions (see
[`css-loader` compatibility] for details).
- All dependencies are upgraded to the latest versions.
- Follow-up maintenance and improvements are performed as necessary.
The original `babel-plugin-react-css-modules` plugin is largely abandoned by
its author since March 2019. When an year later updates of `css-loader` and
Webpack broke dependant projects, with no reaction from
`babel-plugin-react-css-modules` author on emerging issue reports in GitHub,
I ([birdofpreyru]) created this fork to ensure stability of my own projects
relying on it.
I am banned from commenting in the original project repo since I tried a little
self-promo, trying to encourage people to switch over to my fork. If you read
this, consider to spread the word to encourage more users to move to this fork.
### Migration from `babel-plugin-react-css-modules`
- Prefix plugin name in your Babel config by `@dr.pogodin/` scope, _i.e._:
`@dr.pogodin/babel-plugin-react-css-modules` or `@dr.pogodin/react-css-moudles` instead of `babel-plugin-react-css-modules` or `react-css-modules`.
- Be sure to have `webpack` installed (it is a must-to-have peer dependency
of this plugin starting from `v6.2.0`).
### `css-loader` compatibility
| `css-loader` versions | this plugin versions |
| ------------------------- | ------------------------- |
| `7.0.0` – `7.1.2` (latest) | `6.13.0` – `6.13.2` (latest) |
| `6.7.1` – `6.11.0` | `6.7.0` – `6.12.0` |
| `6.5.0` – `6.7.0` | `6.5.1` – `6.6.1` |
| `6.4.0` | `6.4.0` – `6.4.1` |
| `6.0.0` – `6.3.0` | `6.2.1` – `6.3.1` |
| `5.2.5` – `5.2.7` | `6.1.1` |
| `5.2.4` | `6.1.0` |
| `5.1.3` – `5.2.3` | `6.0.11` / `6.1.0`(1) |
| `5.0.0` – `5.1.2` | `6.0.7` – `6.0.11` |
| `4.2.0` – `4.3.0` | `6.0.3` – `6.0.6` |
| ≤ `3.6.0` | [original plugin](https://www.npmjs.com/package/babel-plugin-react-css-modules) |
1) There might be some corner-case differences in class name transformation between these versions of `css-loader` and this plugin, but most probably they won't break compatibility for most users.
[Babel]: https://babeljs.io
[birdofpreyru]: https://github.com/birdofpreyru
[CSS modules]: https://github.com/css-modules/css-modules
[Create React App]: https://create-react-app.dev
[React]: https://reactjs.org
[Webpack]: https://webpack.js.org
[Hot Module Reloading]: #hot-module-reloading
[FiletypesConfiguration]: #filetypesconfiguration
[GenerateScopedNameConfiguration]: #generatescopednameconfiguration
[Configurate syntax loaders]: #configurate-syntax-loaders
[Custom Attribute Mapping]: #custom-attribute-mapping
[`css-loader` compatibility]: #css-loader-compatibility
[transform]: #transform