# postcss-lang-optimizer

**Repository Path**: mirrors_linkedin/postcss-lang-optimizer

## Basic Information

- **Project Name**: postcss-lang-optimizer
- **Description**: PostCSS plugin to extract language specific CSS rulesets to their own CSS files to optimize stylesheet delivery.
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-08-09
- **Last Updated**: 2026-03-21

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# PostCSS Lang Optimizer

Extract rulesets that are language specific into their own file so they
can be served at runtime in a more optimal way.

The AST is walked only once and language specific rulesets are collected
along the way. After processing, the language specific selectors can be
written out to their own files or re-combined in various ways according
to how you desire to send the locale specific CSS over the wire.

If a single selector has more than one lang or is combined with
non-lang-specific selectors, then the ruleset is duplicated and the
language specific selectors are removed.

### API

```js
langOptimizer = require("postcss-lang-optimizer");
postcss = require("postcss");

var optimizerOptions = {};
var input = ".foo { font-size: 14px; } .foo:lang(zh) { font-size: 18px; }"
var result = postcss(langOptimizer(optimizerOptions)).process(input);
// language agnostic CSS stripped of all language specific rulesets
result.css; // => ".foo { font-size: 14px; }"
// zh-specific CSS
langOptimizer.extract(result, "zh"); // => " .foo:lang(zh) { font-size: 18px; }"
```

### Control Comments

You can disable and re-enable the language optimizer for portions of the
CSS file by using control comments. When these comments are encountered,
it will change the enabled state of the optimizer until the end of the
file or until another control comment is encountered.

```
/* lang-optimizer: disable */
```

```
/* lang-optimizer: enable */
```

### Options:

* `subtags` - When set to true, then any language selectors will be
extracted to their own file. That is `de`, `de-DE` and `de-DE-1996`
would each be extracted to their own file.

### The following `:lang` features are not well supported:

* Wildcard language matching E.g. `:lang(*-CH)` - These will be left in
  the base file.

### Known Issues:

* Sourcemaps will not work with language specific output files.

### Ember Addon

There is an ember addon for this plugin. You can find it in the
[`ember-addon` branch](https://github.com/linkedin/postcss-lang-optimizer/tree/ember-addon).