[cells-devel] observer design question

[Andy Chambers]

My model consists of a family tree of objects all of which have an
xhtml ruled cell.  The client needs to
be updated if the value of this slot has changed.  However, a change
in one would cascade up
the tree so if we were logging these changes, and sending them down to
the client, one of the
things we send would be the entire document which is not what we want.

How do I set up the observer to log the change only if it has not been
accounted for already.