Jekyll plugin to convert Less files to CSS using node.js

jekyll-less-nodejs.rb

# jekyll-less-nodejs.rb
#
# Jekyll plugin to convert Less files to CSS using node.js
# Modified from jekyll-less (https://github.com/zroger/jekyll-less, version 85d6e73dc7)
#
# Twitter: @angusdev
# Released under APL 2.0
#
#
# In windows, there is not easy (or no solution) to install therubyracer, which is a dependency
# of less gem (see http://stackoverflow.com/questions/6356450/therubyracer-gem-on-windows).
# To solve this issue, it will be more simple to run the lessc command line (via node.js)
# to convert the .less to .css
#
# Installation
# ============
#
# 1. Install node.js
# 2. Install less
#      npm install less
# 3. Put this file in _plugins/ folder.
#
# Default Configuration
# =====================
# in _config.yml:
#
# less:
#   compress: true
#   lessc: lessc
#
# With the default configuration, lessc should be in the PATH, otherwise you should specify the
# location of lessc in config.  As the location varies among machine, it is suggested to create
# a _config_local.yml and put the config in this file, then run
#
#   jekyll serve --config _config.yml,_config_local.yml
#
module Jekyll
  module Less

    class LessCssFile < Jekyll::StaticFile
      attr_accessor :compress
      attr_accessor :lessc

      # Obtain destination path.
      #   +dest+ is the String path to the destination dir
      #
      # Returns destination file path.
      def destination(dest)
        File.join(dest, @dir, @name.sub(/less$/, 'css'))
      end

      # Convert the less file into a css file.
      #   +dest+ is the String path to the destination dir
      #
      # Returns false if the file was not modified since last time (no-op).
      def write(dest)
        dest_path = destination(dest)

        return false if File.exist? dest_path and !modified?
        @@mtimes[path] = mtime

        FileUtils.mkdir_p(File.dirname(dest_path))
        begin
          `#{lessc} #{path} #{dest_path} #{compress ? '--compress' : ''}`
          #content = File.read(path)
          #content = ::Less::Parser.new({:paths => [File.dirname(path)]}).parse(content).to_css :compress => compress
          #File.open(dest_path, 'w') do |f|
          #  f.write(content)
          #end
        rescue => e
          STDERR.puts "Less Exception: #{e.message}"
        end

        true
      end

    end

    class LessCssGenerator < Jekyll::Generator
      safe true

      # Initialize options from site config.
      def initialize(config = {})
        @options = config["less"] ||= {"compress" => true, "lessc" => "lessc"}
      end

      # Jekyll will have already added the *.less files as Jekyll::StaticFile
      # objects to the static_files array.  Here we replace those with a
      # LessCssFile object.
      def generate(site)
        site.static_files.clone.each do |sf|
          if sf.kind_of?(Jekyll::StaticFile) && sf.path =~ /\.less$/
            site.static_files.delete(sf)
            name = File.basename(sf.path)
            destination = File.dirname(sf.path).sub(site.source, '')

            less_file = LessCssFile.new(site, site.source, destination, name)
            less_file.compress = @options["compress"]
            less_file.lessc = @options["lessc"]
            site.static_files << less_file
          end
        end
      end
    end

  end
end