postcss-functions

PostCSS plugin for exposing JavaScript functions.

Installation

npm install postcss-functions

Usage

var fs = require('fs');
var postcss = require('postcss');
var functions = require('postcss-functions');

var options = {
	//options
};

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

postcss()
  .use(functions(options))
  .process(css)
  .then(function (result) {
    var output = result.css;
  });

Example of a function call:

body {
	prop: foobar();
}

Options

functions

Type: Object

An object containing functions. The function name will correspond with the object key.

Example:

var color = require('css-color-converter');

require('postcss-functions')({
    functions: {
        darken: function (value, frac) {
           var darken = 1 - parseFloat(frac);
           var rgba = color(value).toRgbaArray();
           var r = rgba[0] * darken;
           var g = rgba[1] * darken;
           var b = rgba[2] * darken;
           return color([r,g,b]).toHexString();
        }
    }
});

.foo {
    /* make 10% darker */
    color: darken(blue, 0.1);
}

glob

Type: string|string[]

Loads files as functions based on one or more glob patterns. The function name will correspond with the file name.

Example:

require('postcss-functions')({
	glob: path.join(__dirname, 'functions', '*.js')
});

withNode

Type: string[]

A list of function names for which you'd like the CSS node to be provided as the first argument

Example:

require('postcss-functions')({
  functions: {
    willGetTheNode: function(node, otherArg) {
      // Will receive the node as first argument
    },
    wontGetTheNode: function(arg) {
      // Won't receive it
    }
  },
  withNode: ['willGetTheNode']
});

walk

Type: function

By default, the plugin walks all the nodes of the AST. You can use the walk option to provide your own walking function.

Example:

require('postcss-functions')({
  // Only walk declarations of matching /background/
  walk: function (css, cb) {
    css.walkDecls(/background/,cb);
  }
});