How does DreamWeaver make the channelartlist tag support the limit attribute?

$attlist= 'typeid|0,row|20,cacheid|';

$attlist= 'typeid|0,row|20,cacheid|,limit|';

$limit= trim(preg_replace('#limit#is', '', $limit)); if($limit!='') $limitsql= " LIMIT $limit "; else$limitsql= " LIMIT 0,$totalnum";

$dsql->SetQuery("SELECT id,typename,typedir,isdefault,ispart,defaultname,namerule2,moresite, siteurl,sitepath FROM `zmb_arctype` WHERE $tpsqlORDER BY sortrank ASC LIMIT $totalnum");

$dsql->SetQuery("SELECT id,typename,typedir,isdefault,ispart,defaultname,namerule2, moresite,siteurl,sitepath FROM zmb_arctype WHERE $tpsql ORDER BY sortrank ASC $limitsql");

{dede:channelartlist limit='0,1'}{/dede:channelartlist}