Load, parse and cascade CSS rule sets in Ruby.

Install the gem (hosted on GemCutter).

gem sources -a http://gemcutter.org/
gem install css_parser

Done.

require 'css_parser'
include CssParser

parser = CssParser::Parser.new
parser.load_file!('http://example.com/styles/style.css')

# lookup a rule by a selector
parser.find('#content')
#=> 'font-size: 13px; line-height: 1.2;'

# lookup a rule by a selector and media type
parser.find('#content', [:screen, :handheld])

# iterate through selectors by media type
parser.each_selector(:screen) do |selector, declarations, specificity|
  ...
end

# add a block of CSS
css = <<-EOT
  body { margin: 0 1em; }
EOT

parser.add_block!(css)

# output all CSS rules in a single stylesheet
parser.to_s
=> #content { font-size: 13px; line-height: 1.2; }
   body { margin: 0 1em; }

You can run the suite of unit tests using rake test.

The download/import tests use WEBrick. The tests set up a temporary server on port 12000 and pull down files from the test/fixtures/ directory.

By Alex Dunae (dunae.ca, e-mail ‘code’ at the same domain), 2007-09.

Project homepage: github.com/alexdunae/css_parser

Thanks to Tyler Cunnion for the updates leading to 1.0.0.

Made on Vancouver Island.