Reduce Paperclip processor (loseless opt js, css, jpg, png or gif files)

loseless_reduce.rb

#lib/paperclip_processors/loseless_reduce.rb
require 'reduce'

## LoseLessReduce
# This module is able to reduce js, css, jpg, png or gif files
# thanks to gem reduce by grosser (via yui compressor or punnyPng)
# https://github.com/grosser/reduce

module Paperclip
  class LoselessReduce < Processor
    class InstanceNotGiven < ArgumentError; end

    def compress_asset
      Reduce.reduce(@file.path)
    end    
          
    def initialize(file, options = {})
      super
      @file = file
      @instance = options[:instance]
      @current_format   = File.extname(@file.path)
      @basename         = File.basename(@file.path, @current_format)
    end
    
    def make
      @file.pos = 0
      dst = Tempfile.new([@basename, @format].compact.join("."))
      dst << compress_asset
      dst
    end
  end
end