Null (query directive)
From WandoraWiki
Description
Returns then null value
Constructor
Null()
Examples
Following example gets the superclass of input topic or null if it does not have a superclass.
importPackage(org.wandora.query2); importPackage(org.wandora.topicmap); new If( new Players(XTMPSI.SUPERCLASS_SUBCLASS,XTMPSI.SUPERCLASS) .whereInputIs(XTMPSI.SUBCLASS), new If.COND(), new Null().as(XTMPSI.SUPERCLASS) )