# File lib/action_view/helpers/url_helper.rb, line 92 def url_for(options = {}) options ||= {} url = case options when String options when Hash options = options.symbolize_keys.reverse_merge!(:only_path => options[:host].nil?) super when :back controller.request.env["HTTP_REFERER"] || 'javascript:history.back()' else polymorphic_path(options) end url end