Of checkboxes and lists of objects

Hi--

I have a slot in an object that holds a list of objects of a
particular type.  I want to be able to select a subset of all these
objects for any instance of the containing object.

I've subclassed checkboxes-parser to provide a parser called 'object-
ids-parser', which is designed to take a list of ids, and instantiate
the correct objects to pop in the slot of the containing object.  I've
also written an :around method for 'parse-view-field-value' which
turns the list of ids into the list of objects.

If this would be of general use, then let me know and I'll make it
properly available.

Code here: http://paste.lisp.org/display/129156

There is a bit of problem.  All of the above is working well: the
checkboxes are presented correctly, when selected they create the
right object list.  Hunky dory.  However, I can't get the checkboxes
for the objects that have already been chosen to be selected.

I think I'll need to mess around with render-view-field-value but
can't think how.  I need selected-values as presented to 'render-
checkboxes' to contain the list of object ids.

Anyone been here before?

all the best