Optional Attributes in XQuery

I have to return some optional attributes in a XQuery.
There are too many of them, so I cannot return a separate XML for each case. Things have to be done dynamically.

This post explains how:

http://forums.oracle.com/forums/thread.jspa?threadID=785203&tstart=1335

It works like a charm! Yet I wish there was a simpler way...in fact there is, just use Groovy XmlBuilder :o)