Aplly transformation to a xml post data

[Sébastien Geindre]

hello all,

I handle a upload request send by cocoon forms with flowscript :
  var uploadWidget = form.lookupWidget("upload");
  var stream = uploadWidget.getValue().getInputStream();

I'd like to transform the upload stream (which is XML) via a pipeline :
 cocoon.processPipelineTo(
      'uri',
      stream,
      ??);

what kind of generator i must use ?

  <map:match pattern="uri">
    <map:generator type ="/*????????*/"/>
   <map:transform src="tranform.xsl"/>
    <map:serialize type="xml"/>
  </map:match>

thanks,
Sébastien.