postcss-js

PostCSS JS

PostCSS for React Inline Styles, Radium, JSS and other CSS-in-JS.

For example, to use Stylelint, RTLCSS or postcss-write-svg plugins in your workflow.

Usage

Installation

npm i postcss-js

Processing

const postcssJs = require('postcss-js')
const autoprefixer = require('autoprefixer')

const prefixer = postcssJs.sync([ autoprefixer ]);

const style = prefixer({
    display: 'flex'
});

style //=> { display: ['-webkit-box', '-webkit-flex', '-ms-flexbox', 'flex'] }

Compile CSS-in-JS to CSS

const postcss = require('postcss')
const postcssJs = require('postcss-js')

const style = {
    top: 10,
    '&:hover': {
        top: 5
    }
};

postcss().process(style, { parser: postcssJs }).then( (result) => {
    result.css //=> top: 10px;
               //   &:hover { top: 5px; }
})

Compile CSS to CSS-in-JS

const postcss = require('postcss')
const postcssJs = require('postcss-js')

const css  = '@media screen { z-index: 1 }'
const root = postcss.parse(css);

postcssJs.objectify(root) //=> { '@media screen': { zIndex: '1' } }

API

sync(plugins): function

Create PostCSS processor with simple API, but with only sync PostCSS plugins support.

Processor is just a function, which takes one style object and return other.

async(plugins): function

Same as sync, but also support async plugins.

Returned processor will return Promise.

parse(obj): Root

Parse CSS-in-JS style object to PostCSS Root instance.

It converts numbers to pixels and parses [Free Style] like selectors and at-rules:

{
    '@media screen': {
        '&:hover': {
            top: 10
        }
    }
}

This methods use Custom Syntax name convention, so you can use it like this:

postcss().process(obj, { parser: postcssJs })

objectify(root): object

Convert PostCSS Root instance to CSS-in-JS style object.

Troubleshoot

Webpack may need some extra config for some PostCSS plugins.

Module parse failed

Autoprefixer and some other plugins need a json-loader to import data.

So, please install this loader and add to webpack config:

loaders: [
    {
        test: /\.json$/,
        loader: "json-loader"
    }
]