# File lib/action_view/helpers/url_helper.rb, line 76
      def url_for(options = {})
        options ||= {}
        url = case options
        when String
          escape = true
          options
        when Hash
          options = { :only_path => options[:host].nil? }.update(options.symbolize_keys)
          escape  = options.key?(:escape) ? options.delete(:escape) : true
          @controller.send(:url_for, options)
        when :back
          escape = false
          @controller.request.env["HTTP_REFERER"] || 'javascript:history.back()'
        else
          escape = false
          polymorphic_path(options)
        end

        escape ? escape_once(url) : url
      end