Created by: josephktcheung
This issue and the proposed fix is very similar to https://github.com/thoughtbot/administrate/pull/1176
Right now association search doesn't work for new types of association fields.
Administrate::Search hard-codes the possible types of association fields in a list to determine if association search should be used. This means that new types of fields cannot perform association search and things break.
My proposed solution (see lib/administrate/search.rb) does a programmatic search for field classes that inherit from Administrate::Field::Associative. This allows plugin authors not to worry about adding their new type to a list or any other sort of setup.
A potential problem with this approach is that it includes Administrate::Field::Polymorphic on the list. I don't know if this can cause problems down the line or not.