[Exist-open] Removing resource question

[TMG <tm...@nc...>]

I could use help from list in trying to figure out the best way to 
remove a document from a collection when it no longer holds any elements 
(or meets some xpath criteria).   For example, if I use xupdate to 
locate and remove a node from within a document, and there are no child 
nodes left in the document as a result, how can I delete the whole document.

For example, if I have the xml:

<?xml version="1.0" encoding="UTF-8"?>
<startElement>
  <childNode>6</childNode>
</startElement>

And I run a xupdate:

<?xml version="1.0"?>
<xu:modifications version="1.0"
     xmlns:xu="http://www.xmldb.org/xupdate">
   <xu:remove select="/startElement/childNode[text() = '6']"/>
</xu:modifications>

The above example is contrived in that it only has one "childNode" 
element, but imagine a resource (xml document) with many childNodes 
being removed one at a time.

I would like to remove the collection's resource if there isn't anymore 
"childNodes" left in the resource.  Any ideas?  What I have been doing 
is running a second query to count how many childNode's are left, and if 
zero then delete the resource, but I am hoping I've missed something in 
the API that crosses the bridge between managing items in a resource 
with the actual resource.

Thanks in advance,

Tom Gordon