xxf:event( $attribute-name as xs:string ) as item()*
xxf:event() works like the XForms 1.1
event() function, except that when using XBL components,
xxf:event() returns event information from the original event instead of the retargeted event.
This function is deprecated since Orbeon Forms 4.0 and is just an alias for the standard
xf:if() / xxf:if()
This function implements the semantic of the XForms 1.0
Prefer the XPath 2
if(...) then ... else ... construct.