Filtering the left hand combo box for "has_many"
I need a has_many relationship between 2 tables, but the left hand (''foreign") list of the admin combo box really needs to be a filter, based on the id of the candidate table.
So if the foreign table were "schools", and the candidate "authorities" then the left list would be schools with an authority_id of the current authority admin view.
I think this is possible, perhaps with the has_many property definition specifying a method on the foreign table. A form_fields() derived custom field (type 'multi') would do the trick, but with extra post methods I guess.
If the former I'm not sure of the definition. Is is possible?