Post xml data to BI server with rest client

Hi all

I've created a report and xml data source - xmlDS in report designer
Report will be generated each time using rest client from web app server

I would like to call pentaho server with post method and xml as payload, payload should be used as xmlDs

according to :
http://infocenter.pentaho.com/help/t...g_biserver.pdf

it is possible to send parameters with post, but can I send xml and use it as data source ?

Thanks