https://github.com/pascalduez/postcss-apply

PostCSS plugin enabling custom properties sets references
https://github.com/pascalduez/postcss-apply

css postcss

Last synced: 12 days ago
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PostCSS plugin enabling custom properties sets references

• Host: GitHub
• URL: https://github.com/pascalduez/postcss-apply
• Owner: pascalduez
• License: unlicense
• Created: 2015-08-26T15:40:55.000Z (about 9 years ago)
• Default Branch: main
• Last Pushed: 2023-10-13T06:35:29.000Z (about 1 year ago)
• Last Synced: 2024-10-19T12:19:55.440Z (23 days ago)
• Topics: css, postcss
• Language: JavaScript
• Homepage:
• Size: 536 KB
• Stars: 165
• Watchers: 8
• Forks: 12
• Open Issues: 9
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md

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README

        
# postcss-apply

[![CSS Standard Status][css-image]][css-url]

[![npm version][npm-image]][npm-url]

[![Build Status][travis-image]][travis-url]

[![Coverage Status][codecov-image]][codecov-url]

> [PostCSS] plugin enabling custom property sets references

Refer to [`postcss-custom-properties`](https://github.com/postcss/postcss-custom-properties#postcss-custom-properties-) for DOMless limitations.

## Web Platform status

Spec (editor's draft): https://tabatkins.github.io/specs/css-apply-rule  

Browser support: https://www.chromestatus.com/feature/5753701012602880  

:warning: The `@apply` rule and custom property sets most likely won't get any more support from browser vendors as the spec is yet considered deprecated and [alternative solutions](https://tabatkins.github.io/specs/css-shadow-parts) are being discussed.  

Refer to following links for more infos:

  * https://discourse.wicg.io/t/needed-new-champion-for-css-apply-rule/2012

  * https://github.com/w3c/webcomponents/issues/300#issuecomment-276210974  

  * http://www.xanthir.com/b4o00

  * https://github.com/w3c/csswg-drafts/issues/1047

  * https://chromium.googlesource.com/chromium/src/+/5874fca7324e4523a4bdecc8999bdadfdb6c4eff

## Installation

```

npm install postcss-apply --save-dev

```

## Usage

```js

const fs = require('fs');

const postcss = require('postcss');

const apply = require('postcss-apply');

let input = fs.readFileSync('input.css', 'utf8');

postcss()

  .use(apply)

  .process(input)

  .then(result => {

    fs.writeFileSync('output.css', result.css);

  });

```

## Examples

### In CSS declared sets

```css

/* input */

:root {

  --toolbar-theme: {

    background-color: rebeccapurple;

    color: white;

    border: 1px solid green;

  };

}

.Toolbar {

  @apply --toolbar-theme;

}

```

```css

/* output */

.Toolbar {

  background-color: rebeccapurple;

  color: white;

  border: 1px solid green;

}

```

### In JS declared sets

```js

const themes = {

  /* Set names won't be transformed, just `--` will be prepended. */

  'toolbar-theme': {

    /* Declaration properties can either be camel or kebab case. */

    backgroundColor: 'rebeccapurple',

    color: 'white',

    border: '1px solid green',

  },

};

[...]

postcss().use(apply({ sets: themes }))

[...]

```

```css

/* input */

.Toolbar {

  @apply --toolbar-theme;

}

```

```css

/* output */

.Toolbar {

  background-color: rebeccapurple;

  color: white;

  border: 1px solid green;

}

```

## options

### `preserve`

type: `Boolean`  

default: `false`  

Allows for keeping resolved declarations and `@apply` rules alongside.

### `sets`  

type: `{ [customPropertyName: string]: Object | string }`  

default: `{}`  

Allows you to pass an object or string of custom property sets for `:root`.

These definitions will be prepended, in such overridden by the one declared in CSS if they share the same name.

The keys are automatically prefixed with the CSS `--` to make it easier to share sets in your codebase.

## Credits

* [Pascal Duez](https://github.com/pascalduez)

## Licence

postcss-apply is [unlicensed](http://unlicense.org/).

[PostCSS]: https://github.com/postcss/postcss

[css-url]: https://cssdb.org#rejected

[css-image]: https://img.shields.io/badge/cssdb-rejected-red.svg?style=flat-square

[npm-url]: https://www.npmjs.org/package/postcss-apply

[npm-image]: http://img.shields.io/npm/v/postcss-apply.svg?style=flat-square

[travis-url]: https://travis-ci.org/pascalduez/postcss-apply?branch=master

[travis-image]: http://img.shields.io/travis/pascalduez/postcss-apply.svg?style=flat-square

[codecov-url]: https://codecov.io/gh/pascalduez/postcss-apply

[codecov-image]: https://img.shields.io/codecov/c/github/pascalduez/postcss-apply.svg?style=flat-square

[spec]: https://tabatkins.github.io/specs/css-apply-rule