Hi Sanjay,

Mapper Extension is the way to do this. I use one we call our "compiler" extension, it fires events before database insert, datase update and after database load; you can use these events to modify the object as needed. You can probably hack this into what you need:

class CompilerExtension(MapperExtension): """ Allows for "compilation" of sub-items into binary blobs stored on the parent """ def before_insert(self, mapper, connection, instance): instance.oninsert() return EXT_PASS def before_update(self, mapper, connection, instance): instance.onupdate() return EXT_PASS def populate_instance(self, mapper, selectcontext, row, instance, identitykey, isnew): if isnew: mapper.populate_instance(selectcontext, instance, row, identitykey, isnew) instance.onload() return None return EXT_PASS

The code for the "onload" is a bit tangled, because SA does not (yet) provide an "after" db load, just a "before". I've asked Mike for another "after" hook (bump, bump), but I think he may have forgotten (bump) about (bump) it (bump...).

Rick

On 2/28/07, Sanjay <skpa...@gmail.com> wrote: