rework

What is rework?

Rework is a plugin framework for CSS preprocessing. It allows you to manipulate CSS using JavaScript, providing a way to transform stylesheets with various plugins.

What are rework's main functionalities?

CSS Parsing

Rework can parse CSS strings into an Abstract Syntax Tree (AST), which can then be manipulated programmatically.

const rework = require('rework');
const css = 'body { color: red; }';
const ast = rework(css).toString();
console.log(ast);

CSS Transformation

Rework allows you to transform CSS using plugins. For example, the rework-npm plugin lets you import CSS from npm packages.

const rework = require('rework');
const reworkNPM = require('rework-npm');
const css = '@import "normalize.css";';
const output = rework(css).use(reworkNPM()).toString();
console.log(output);

Vendor Prefixing

Rework can automatically add vendor prefixes to CSS properties using plugins like rework-plugin-prefix.

const rework = require('rework');
const reworkPrefix = require('rework-plugin-prefix');
const css = 'body { display: flex; }';
const output = rework(css).use(reworkPrefix('webkit')).toString();
console.log(output);

Other packages similar to rework

postcss

PostCSS is a tool for transforming CSS with JavaScript plugins. It is more modern and widely used compared to Rework, offering a larger ecosystem of plugins and better performance.

less

Less is a CSS pre-processor that extends the CSS language, adding features like variables, mixins, and functions. Unlike Rework, Less is a full-fledged pre-processor rather than a plugin framework.

sass

Sass is another CSS pre-processor that provides advanced features like variables, nested rules, and mixins. Sass is more feature-rich and has a larger community compared to Rework.

README

rework

CSS manipulations built on css, allowing you to automate vendor prefixing, create your own properties, inline images, anything you can imagine! Also works in the browser as a component.

Installation

with node:

$ npm install rework

or in the browser with component:

$ component install visionmedia/rework

or in the browser with the stand-alone build ./rework.js referencing the rework global.

Links

• rework mixins
• significant whitespace - nested and indented syntax like Stylus and SASS
• third-party plugins

Built with rework

• styl - CSS preprocessor built on Rework
• autoprefixer - prefixer based on the Can I Use database

API

rework(css)

Return a new Rework instance for the given string of css.

Rework#vendors(prefixes)

Define vendor prefixes that plugins may utilize, however most plugins do and should accept direct passing of vendor prefixes as well.

Rework#use(fn)

Use the given plugin fn. A rework "plugin" is simply a function accepting the stylesheet object and Rework instance, view the definitions in ./lib/plugins for examples.

Rework#toString(options)

Return the string representation of the manipulated css. Optionally you may compress the output with .toString({ compress: true })

Plugins

The following plugins are bundled with rework:

• extend — add extend: selector support
• ease — several additional easing functions
• at2x — serve high resolution images
• prefix — add vendor prefixes to properties
• prefixValue — add vendor prefixes to values
• prefixSelectors — add prefixes to selectors
• keyframes — add @keyframe vendor prefixing
• colors — add colour helpers like rgba(#fc0, .5)
• mixin — add custom property logic with mixing
• function — Add user-defined CSS functions
• references — add property references support height: @width etc
• url - rewrite url()s with a given function
• third-party plugins

.extend()

Add support for extending existing rulesets:

button {
  padding: 5px 10px;
  border: 1px solid #eee;
  border-bottom-color: #ddd;
}

.green {
  background: green;
  padding: 10px 15px
}

a.join {
  extend: button;
  extend: .green;
}

a.button,
input[type='submit'],
input[type='button'] {
  extend: button
}

yields:

button,
a.button,
input[type='submit'],
input[type='button'],
a.join {
  padding: 5px 10px;
  border: 1px solid #eee;
  border-bottom-color: #ddd;
}

.green,
a.join {
  background: green;
  padding: 10px 15px
}

Optionally selectors may be prefixed with % to create sass-style "placeholder" selectors, which do not become part of the output. For example:

%dark-button {
  background: black;
}

%dark-button:hover {
  background: rgba(0,0,0,.5);
}

%dark-button:hover .icon {
  color: rgba(255,255,255,.5);
}

button,
.actions a {
  extend: %dark-button;
  padding: 5px 10px;
}

yields:

button,
.actions a {
  background: black
}

button:hover,
.actions a:hover {
  background: rgba(0,0,0,.5)
}

button:hover .icon,
.actions a:hover .icon {
  color: rgba(255,255,255,.5)
}

button,
.actions a {
  padding: 5px 10px
}

This plugin is stored in its own repo at jonathanong/rework-inherit. Please delegate any issues with .extend() to that repository instead of rework.

.ease()

Adds the following list of additional easing functions:

• ease-in-out-back -- cubic-bezier(0.680, -0.550, 0.265, 1.550)
• ease-in-out-circ -- cubic-bezier(0.785, 0.135, 0.150, 0.860)
• ease-in-out-expo -- cubic-bezier(1.000, 0.000, 0.000, 1.000)
• ease-in-out-sine -- cubic-bezier(0.445, 0.050, 0.550, 0.950)
• ease-in-out-quint -- cubic-bezier(0.860, 0.000, 0.070, 1.000)
• ease-in-out-quart -- cubic-bezier(0.770, 0.000, 0.175, 1.000)
• ease-in-out-cubic -- cubic-bezier(0.645, 0.045, 0.355, 1.000)
• ease-in-out-quad -- cubic-bezier(0.455, 0.030, 0.515, 0.955)
• ease-out-back -- cubic-bezier(0.175, 0.885, 0.320, 1.275)
• ease-out-circ -- cubic-bezier(0.075, 0.820, 0.165, 1.000)
• ease-out-expo -- cubic-bezier(0.190, 1.000, 0.220, 1.000)
• ease-out-sine -- cubic-bezier(0.390, 0.575, 0.565, 1.000)
• ease-out-quint -- cubic-bezier(0.230, 1.000, 0.320, 1.000)
• ease-out-quart -- cubic-bezier(0.165, 0.840, 0.440, 1.000)
• ease-out-cubic -- cubic-bezier(0.215, 0.610, 0.355, 1.000)
• ease-out-quad -- cubic-bezier(0.250, 0.460, 0.450, 0.940)
• ease-in-back -- cubic-bezier(0.600, -0.280, 0.735, 0.045)
• ease-in-circ -- cubic-bezier(0.600, 0.040, 0.980, 0.335)
• ease-in-expo -- cubic-bezier(0.950, 0.050, 0.795, 0.035)
• ease-in-sine -- cubic-bezier(0.470, 0.000, 0.745, 0.715)
• ease-in-quint -- cubic-bezier(0.755, 0.050, 0.855, 0.060)
• ease-in-quart -- cubic-bezier(0.895, 0.030, 0.685, 0.220)
• ease-in-cubic -- cubic-bezier(0.550, 0.055, 0.675, 0.190)
• ease-in-quad -- cubic-bezier(0.550, 0.085, 0.680, 0.530)

To view them online visit easings.net.

.at2x([vendors])

Add retina support for images, with optional vendor prefixes, defaulting to .vendors().

.logo {
  background-image: url('component.png');
  width: 289px;
  height: 113px
}

yields:

.logo {
  background-image: url('component.png');
  width: 289px;
  height: 113px
}

@media all and (-webkit-min-device-pixel-ratio: 1.5) {
  .logo {
    background-image: url("[e-mail]");
    background-size: contain
  }
}

.prefix(property|properties, [vendors])

Prefix property or array of properties with optional vendors defaulting to .vendors().

.button {
  border-radius: 5px;
}

yields:

.button {
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  border-radius: 5px;
}

.prefixValue(value, [vendors])

Prefix value with optional vendors defaulting to .vendors().

button {
  transition: height, transform 2s, width 0.3s linear;
}

yields:

button {
  -webkit-transition: height, -webkit-transform 2s, width 0.3s linear;
  -moz-transition: height, -moz-transform 2s, width 0.3s linear;
  transition: height, transform 2s, width 0.3s linear
}

This works with other values as well, such as gradients. For example:

.use(rework.prefixValue('linear-gradient'))
.use(rework.prefixValue('radial-gradient'))

button {
  background: linear-gradient(#eee, #ddd);
}

button.round {
  border-radius: 50%;
  background-image: radial-gradient(#cde6f9, #81a8cb);
}

body {
  background: -webkit-linear-gradient(#fff, #eee);
}

yields:

button {
  background: -webkit-linear-gradient(#eee, #ddd);
  background: -moz-linear-gradient(#eee, #ddd);
  background: linear-gradient(#eee, #ddd)
}

button.round {
  border-radius: 50%;
  background-image: -webkit-radial-gradient(#cde6f9, #81a8cb);
  background-image: -moz-radial-gradient(#cde6f9, #81a8cb);
  background-image: radial-gradient(#cde6f9, #81a8cb)
}

body {
  background: -webkit-linear-gradient(#fff, #eee)
}

.prefixSelectors(string)

Prefix selectors with the given string.

h1 {
  font-weight: bold;
}

a {
  text-decoration: none;
  color: #ddd;
}

yields:

#dialog h1 {
  font-weight: bold;
}

#dialog a {
  text-decoration: none;
  color: #ddd;
}

.mixin(object)

Add user-defined mixins, functions that are invoked for a given property, and passed the value. Returning an object that represents one or more properties.

For example the following overflow mixin allows the designer to utilize overflow: ellipsis; to automatically assign associated properties preventing wrapping etc.

The receiver (this) is the Rework instance, allowing the mixin to reference properties such as the vendor .prefixes array.

var css = rework(css)
  .use(rework.mixin({ overflow: ellipsis }))
  .toString()

function ellipsis(type) {
  if ('ellipsis' == type) {
    return {
      'white-space': 'nowrap',
      'overflow': 'hidden',
      'text-overflow': 'ellipsis'
    }
  }

  return type;
}

Mixins in use look just like regular CSS properties:

h1 {
  overflow: ellipsis;
}

yields:

h1 {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis
}

.function(object)

Add user-defined CSS functions.

For example create black(0.5) shortcut, to replace long rgba(0, 0, 0, 0.5).

var css = rework(css)
  .use(rework.function({ black: black }))
  .toString()

function black(opacity) {
  return 'rgba(0, 0, 0, ' + opacity + ')';
}

User code will receive CSS arguments and replace user-defined function by returned code.

input {
  box-shadow: 0 0 5px black(0.7);
}

yields:

input {
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.7);
}

You may also return array values to expand to several definitions of the property:

function display(type) {
  if ('flex' == type) {
    return {
      display: [
        '-webkit-flex',
        '-moz-flex',
        '-webkit-flexbox',
        'flex'
      ]
    }
  }

  return {
    display: type
  }
}

Would yield:

.myclass {
  display: -webkit-flex;
  display: -moz-flex;
  display: -webkit-flexbox;
  display: flex;
}

.references()

Add property reference support.

button {
  width: 120px;
}

button.round {
  width: 50px;
  height: @width;
  line-height: @height;
  background-size: @width @height;
}

yields:

button {
  width: 120px
}

button.round {
  width: 50px;
  height: 50px;
  line-height: 50px;
  background-size: 50px 50px
}

.colors()

Add color manipulation helpers such as rgba(#fc0, .5).

button {
  background: rgba(#ccc, .5);
}

yields:

button {
  background: rgba(204, 204, 204, .5);
}

.keyframes([vendors])

Prefix @keyframes with vendors defaulting to .vendors(). Ordering with .keyframes() is important, as other plugins may traverse into the newly generated rules, for example the following will allow .prefix() to prefix keyframe border-radius property, .prefix() is also smart about which keyframes definition it is within, and will not add extraneous vendor definitions.

var css = rework(read('examples/keyframes.css', 'utf8'))
  .vendors(['-webkit-', '-moz-'])
  .use(rework.keyframes())
  .use(rework.prefix('border-radius'))
  .toString()

@keyframes animation {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

yields:

@keyframes animation {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@-webkit-keyframes animation {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

.inline(dir)

Inline files from dir directly to CSS. Replace inline(path) to Data URI with base64 encoding of file. It is useful for small images and fonts.

Of course, you can use inline only with node. It is not available in the browser with component.

var css = rework(read(css))
  .use(rework.inline('images/', 'fonts/'))
  .toString()

.logo {
  background: inline(icons/logo.png);
}

yields:

.logo {
  background: url("data:image/png;base64,iVBORw0…");
}

.url(fn)

Map url() calls. Replace all url()s using a given function.

var css = rework(read(css))
  .use(rework.url(function(url){
    return 'http://example.com' + url;
  }))
  .toString()

body {
  background: url(/images/bg.png);
}

yields:

body {
  background: url(http://example.com/images/bg.png);
}

Example

example.js:

var rework = require('rework')
  , read = require('fs').readFileSync
  , str = read('example.css', 'utf8');

var css = rework(str)
  .vendors(['-webkit-', '-moz-'])
  .use(rework.keyframes())
  .use(rework.prefix('border-radius'))
  .toString()

console.log(css);

example.css:

@keyframes animation {
  from { opacity: 0; border-radius: 5px }
  to { opacity: 1; border-radius: 5px }
}

stdout:

@keyframes animation {
  from {
    opacity: 0;
    border-radius: 5px
  }

  to {
    opacity: 1;
    border-radius: 5px
  }
}

@-webkit-keyframes animation {
  from {
    opacity: 0;
    -webkit-border-radius: 5px;
    border-radius: 5px
  }

  to {
    opacity: 1;
    -webkit-border-radius: 5px;
    border-radius: 5px
  }
}

@-moz-keyframes animation {
  from {
    opacity: 0;
    -moz-border-radius: 5px;
    border-radius: 5px
  }

  to {
    opacity: 1;
    -moz-border-radius: 5px;
    border-radius: 5px
  }
}

Example Plugin

Suppose for example you wanted to create your own properties for positions, allowing you to write them as follows:

#logo {
  absolute: top left;
}

#logo {
  relative: top 5px left;
}

#logo {
  fixed: top 5px left 10px;
}

yielding:

#logo {
  position: absolute;
  top: 0;
  left: 0
}

#logo {
  position: relative;
  top: 5px;
  left: 0
}

#logo {
  position: fixed;
  top: 5px;
  left: 10px
}

This is how you could define the plugin:

var rework = require('rework')
  , read = require('fs').readFileSync;

function positions() {
  var positions = ['absolute', 'relative', 'fixed'];

  return function(style){
    style.rules.forEach(function(rule){
      rule.declarations.forEach(function(decl, i){
        if (!~positions.indexOf(decl.property)) return;
        var args = decl.value.split(/\s+/);
        var arg, n;

        // remove original
        rule.declarations.splice(i, 1);

        // position prop
        rule.declarations.push({
          property: 'position',
          value: decl.property
        });

        // position
        while (args.length) {
          arg = args.shift();
          n = parseFloat(args[0]) ? args.shift() : 0;
          rule.declarations.push({
            property: arg,
            value: n
          });
        }

      });
    });
  }
}

var css = rework(read('positions.css', 'utf8'))
  .use(positions())
  .toString()

console.log(css);

License

MIT