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:

$ component install visionmedia/rework

Links

• rework mixins
• significant whitespace

rework(1)

Usage: rework [options]

Options:

  -h, --help            output usage information
  -V, --version         output the version number
  -v, --vendors <list>  specify list of vendors
  -e, --ease            add additional easing functions
  --vars                add css variable support

for example:

$ rework -v webkit,moz < my.css > my.reworked.css

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:

• media macros — define your own @media queries
• 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
• opacity — add IE opacity support
• url — rewrite url()s with a callback function
• vars — add css variable support
• keyframes — add @keyframe vendor prefixing
• colors — add colour helpers like rgba(#fc0, .5)
• references — add property references support height: @width etc
• mixin — add custom property logic with mixing
• extend — add extend: selector support

.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
}

.media(obj)

Define media macros with the given obj.

For example define two contrived custom media types, "phone" and "phone-landscape":

style.use(rework.media({
  'phone': 'only screen and (min-device-width : 320px) and (max-device-width : 480px)',
  'phone-landscape': 'only screen and (min-width : 321px)'
}))

@media phone {
  body {
    background: 'green'
  }
}

@media phone-landscape {
  body {
    background: 'red'
  }
}

yields:

@media only screen and (min-device-width : 320px) and (max-device-width : 480px) {
  body {
    background: 'green'
  }
}

@media only screen and (min-width : 321px) {
  body {
    background: 'red'
  }
}

.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;
}

.opacity()

Add IE opacity support.

ul {
  opacity: 1 !important;
}

yields:

ul {
  opacity: 1 !important;
  -ms-filter: progid:DXImageTransform.Microsoft.Alpha(Opacity=100) !important;
  filter: alpha(opacity=100) !important
}

.url(callback)

Map url() calls, useful for inlining images as data-uris, converting relative paths to absolute etc.

function rewrite(url) {
  return 'http://example.com' + url;
}

rework(str)
  .use(rework.url(rewrite))
  .toString()

.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.

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
}

.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
}

.vars()

Add variable support. Note that this does not cascade like the CSS variable spec does, thus this is not some sort of fallback mechanism, just a useful feature.

:root {
  var-header-color: #06c;
  var-main-color: #c06;
}

div {
  var-accent-background: linear-gradient(to top, var(main-color), white);
}

h1 {
  background-color: var(header-color);
}

.content {
  background: var(accent-background) !important;
}

yields:

:root {
  var-header-color: #06c;
  var-main-color: #c06
}

div {
  var-accent-background: linear-gradient(to top, #c06, white)
}

h1 {
  background-color: #06c
}

.content {
  background: linear-gradient(to top, #c06, white) !important
}

.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;
  }
}

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