[TYPO3-project-formidable] atstartup renderlet:lister

[Dmitri Pisarev]

As while I do not get an answer how to do it properly, I had to hack it 
the bad way.
I put 
if($this->oDataStream->aCriterias['search_parts.itemnumber']==''){return 
'';}
in function _render(), in class.tx_rdtlister.php.
Please save me from doing such a dirty hacks, and tell me how to do it 
properly:)

Dmitri.