With Observers officially removed from Rails 4.0, I\'m curious what other developers are using in their place. (Other than using the extracted gem.) While Observers were cer
I have the same probjem! I find a solution ActiveModel::Dirty so you can track your model changes!
include ActiveModel::Dirty
before_save :notify_categories if :data_changed?
def notify_categories
self.categories.map!{|c| c.update_results(self.data)}
end
http://api.rubyonrails.org/classes/ActiveModel/Dirty.html