minifier.rb

module Minifier

  class << self
    attr_accessor :enabled
    attr_accessor :extensions
  end

  self.extensions = ['.js', '.css']

  def self.available?
    @available ||= !`which java`.empty?   # warning: linux only way of checking if java is available
  end

  def self.enabled?(name = nil)
    enabled && available? && (name.nil? || extensions.include?(File.extname(name)))
  end

  def self.minified_name(name)
    if enabled?(name)
      ext = File.extname(name)
      name.sub(ext, ".min#{ext}")
    else
      name
    end
  end

  def self.minify(name)
    if name && enabled?(name) && File.exists?(name)
      minified_name = minified_name(name)
      `java -jar "#{File.dirname(__FILE__)}/yuicompressor-2.4.6.jar" "#{name}" -o "#{minified_name}"`
    end
  end

end