# Usage:
 # referer? :controller => 'beezies', :action => 'holla', :type => 'popozuda'
 # referer? %r|/\d+/edit|

 def referer?(options)
    referer = request.headers["Referer"]
    return (options.blank? ? true : false) if referer.blank?

    if options.is_a?(Regexp)
      referer =~ options
    else
      # Same logic as current_page? in actionpack/lib/action_view/helpers/url_helper.rb
      url_string = CGI.unescapeHTML(url_for(options))
      # We ignore any extra parameters in the referer if the
      # submitted url doesn't have any either.  This lets the function
      # work with things like ?order=asc
      referer = referer.split("?").first unless url_string.index("?")

      if url_string =~ /^\w+:\/\//
        referer == url_string
      else
        referer == "#{request.protocol}#{request.host_with_port}#{url_string}"
      end
    end
  end