Callback before items are persisted

[Jim Talbut]

Hi,

I want to modify a couple of persisted columns in an entity based on 
data in other columns (basically caching some stuff from related entities).
I was under the impression that a lifecycle listener on PrePersist would 
make this easy - but that is called from within the call to persist, 
which is before any columns in the new entity have any values at all.

There doesn't seem to be any callback that is called just before an 
object is written the database, is this true?

Thanks.

Jim