CSSminify 
CSS minification with YUI compressor, but as native Ruby port.
The CSSminify gem provides CSS compression using YUI compressor. Instead of wrapping around the Java or Javascript version of YUI compressor it uses a native Ruby port of the CSS engine. Therefore this gem has no dependencies.
In basic benchmarks the Ruby version performed about as good as the Java jar. It currently passes all CSS test cases included with the YUI compressor Java source code.
Main motivation for the Ruby port and this gem was to reduce dependencies like Java.
PLEASE NOTE: this project is no longer maintained.
Installation
Install CSSminify from RubyGems:
gem install cssminify
Or include it in your project's Gemfile:
gem 'cssminify'
Usage
require 'cssminify'
CSSminify.compress('/* a comment */ .test { display: block; }')
# => minified CSS
CSSminify.compress(File.read('path/to/styles.css'))
# => minified CSS
CSSminify.compress(File.open('path/to/styles.css'))
# => minified CSS
# Alternatively use instance method...
compressor = CSSminify.new
compressor.compress(File.read("path/to/styles.css"))
# => minified CSS
Files or strings are acceptable as input.
You can pass in a second argument to control the maximum output line length (default 5000 characters):
CSSminify.compress(File.read("path/to/styles.css"), 200)
Note: in most cases line length will only be approximated.
Rails asset pipeline
Rails 3.1 integrated Sprockets to provide asset packaging and minimising out of the box. For CSS compression it relies on the yui-compressor gem which requires Java. To use CSSminify instead, edit your config/application.rb file:
config.assets.css_compressor = CSSminify.new
Compatibility
Tested with Ruby 1.9.2, 1.9.3, jruby-19mode, rbx-19mode
Changelog
See CHANGES.
Copyright
CSSminify gem and documentation
Copyright (c) 2012 Matthias Siegel (matthias.siegel@gmail.com) See LICENSE for details.
YUI compressor
See file.