def exceptions_to_treat_as_404
      exceptions = [ActiveRecord::RecordNotFound,
                    ActionController::UnknownController,
                    ActionController::UnknownAction]
      exceptions << ActionController::RoutingError if ActionController.const_defined?(:RoutingError)
      exceptions
    end

    def rescue_action_in_public(exception)
      case exception
        when *self.class.exceptions_to_treat_as_404
          render_404

        else
          # render_500
          # dont render_500, do it in application.rb

          deliverer = self.class.exception_data
          data = case deliverer
            when nil then {}
            when Symbol then send(deliverer)
            when Proc then deliverer.call(self)
          end

          ExceptionNotifier.deliver_exception_notification(exception, self,
            request, data)
      end
    end