How to skip a tag in get_elem

I have a YANG model, and some leafs can hold values (in the “backend”), while some not.
From a client I am calling get on my configuration.
WIth my get_elem function I am doing as in the examples i.e.
switch (CONFD_GET_XMLTAG(&(keypath->v[0][0])))
Then all the leafs in the YANG model are queried, but for some I may not have values and I want to skip them from the returned XML config.
What is the way of doing it?
Basically I do not want to call confd_data_reply_value(tctx, &v), as I have no value for some leafs.