Using fn:nilled()

Question

Hi,
I'm trying to get the "nil" status of some element in request, but I get false no matter what input was.
In xquery editor I tried some simple things, like
fn:nilled(<id xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/>)
but it doesn't work either. I get false, when actually it had to be true.
Some basic things like
fn:not(fn:false())
are working fine, so that's not editor case I suppose.
What could be the problem?
Thanks in advance.
Edited by: frf on 3/11/2010 2:40
Edited by: frf on 3/11/2010 2:40

Answer 1

Hi,
What's your XQuery editor?
According to the specifications, fn:nilled works this way :
In practice, the function returns true only for an element node that has the attribute xsi:nil="true" and that is successfully validated against a schema that defines the element to be nillable;http://www.w3.org/TR/xpath-functions-11/#func-nilled
In short, you need a schema-aware XQuery processor.
Then you can do something like :
import schema default element namespace "" at "http://example.com/schema.xsd";
let $d := validate{ <id xsi:nil="true" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"/> }
return fn:nilled($d)with schema.xsd :
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="id" nillable="true" type="xs:string"/>
</xs:schema>