Generate a bookmarklet from a javascript file

bookmarklet_helper.rb

require 'uglifier'

module BookmarkletHelper

  def get_bookmarklet(file, hash)
    js = File.open( "#{Rails.root}/app/assets/javascripts/#{file}", 'r' ).read
    js = Uglifier.compile(js, :mangle => false, :comments => :none)

    js_vars.each_pair do |k, v|
      js.gsub!("{{#{k.to_s}}}", v)
    end

    "javascript:(function(){#{js}}());"
  end

end