formats

# File actionpack/lib/action_dispatch/http/mime_negotiation.rb, line 45
      def formats
        accept = @env['HTTP_ACCEPT']

        @env["action_dispatch.request.formats"] ||=
          if parameters[:format]
            Array(Mime[parameters[:format]])
          elsif xhr? || (accept && accept !~ /,\s*\*\/\*/)
            accepts
          else
            [Mime::HTML]
          end
      end