ActiveRecord::Observer

ActiveRecord::Observer:

Observers will by default be mapped to the class with which they share a name. So CommentObserver will be tied to observing Comment, ProductManagerObserver to ProductManager, and so on. If you want to name your observer differently than the class you’re interested in observing, you can use the ActiveModel::Observer.observe class method which takes either the concrete class (Product) or a symbol for that class (:product):

Full article: http://api.rubyonrails.org/v3.2.13/classes/ActiveRecord/O...