# File lib/mongoid/relations/synchronization.rb, line 77 def update_inverse_keys(meta) return unless changes.has_key?(meta.foreign_key) old, new = changes[meta.foreign_key] adds, subs = new - (old || []), (old || []) - new meta.criteria(adds).add_to_set(meta.inverse_foreign_key, id) unless adds.empty? meta.criteria(subs).pull(meta.inverse_foreign_key, id) unless subs.empty? end