fn:nilled

fn:nilled() as xs:boolean?

fn:nilled($arg as node()?) as xs:boolean?

The zero-argument form of this function is deterministic, context-dependent, and focus-dependent.

The one-argument form of this function is deterministic, context-independent, and focus-independent.

If the argument is omitted, it defaults to the context item (.). The behavior of the function if the argument is omitted is exactly the same as if the context item had been passed as the argument.

If $arg is the empty sequence, the function returns the empty sequence.

Otherwise the function returns the result of the dm:nilled accessor as defined in [Data Model (XDM) 3.1] (see nilled Accessor).

The following errors may be raised when $arg is omitted:

If the context item is absent, dynamic error [ERRXPDY0002]

If the context item is not a node, type error [ERRXPTY0004].

If $arg is not an element node, the function returns the empty sequence.

If $arg is an untyped element node, the function returns false.

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; the detailed rules, however, are defined in [Data Model (XDM) 3.1].