Masks proposal on wiki

[Tim Larson <ti...@keow.org>]

I have been holding back on implementing "choice/case" (the planned
successor to the "union" widget) because of usecases that it does not
support.  Someone emailed me privately wishing for more features, and
the Masks proposal at the bottom of this page is the result:
  http://wiki.cocoondev.org/Wiki.jsp?page=WoodyScratchpad

This is intended to replace both "union" and "choice/case", so I would
really appreciate any feedback before I start implementing this so it
does not need to go through more iterations :)

If the proposal is well received, then we will need to come up with:
* A syntax for the XML representation of the masks.
* A design for the mask builders and mask objects.
* A caching strategy for static (specified in the form model) and
  dynamic (e.g. generated via XSLT) masks. Hopefully we can tie into
  the same strategies as will be used for dynamic forms and for the
  form repositories, a system that knows when not to cache and how
  and when to dump unused entries when there is memory pressure.

Well, what do you think?
--Tim Larson