# File lib/action_view/base.rb, line 302
    def template_format
      return @template_format if @template_format

      if controller && controller.respond_to?(:request)
        parameter_format = controller.request.parameters[:format]
        accept_format    = controller.request.accepts.first

        case
        when parameter_format.blank? && accept_format != :js
          @template_format = :html
        when parameter_format.blank? && accept_format == :js
          @template_format = :js
        else
          @template_format = parameter_format.to_sym
        end
      else
        @template_format = :html
      end
    end