find_template_extension_for

# File actionpack/lib/action_view/base.rb, line 382
      def find_template_extension_for(template_path)
        if match = delegate_template_exists?(template_path)
          match.first.to_sym
        elsif erb_template_exists?(template_path):        :rhtml
        elsif builder_template_exists?(template_path):    :rxml
        elsif javascript_template_exists?(template_path): :rjs
        else
          raise ActionViewError, "No rhtml, rxml, rjs or delegate template found for #{template_path}"
        end
      end