如何在Rails中使用观察者gem

Question

It is the first time to interact with observer gem, and after reading the wiki i just cant get it how would it send a message after creating some record in the database here is the code i used from the git hub wiki with changing the names to an existing model name in my project:

  class CommentObserver < ActiveRecord::Observer
      def after_save(comment)
        Notifications.comment("admin@do.com", "New comment was posted", comment).deliver
      end
    end

i dont know what this function do can anyone please explain it to me as it is not clear in the wiki,Thanks.

Answer 1

The after_save callback method is overridden to send a email notification. callbacks are methods which are called at specific points(moment) during the creation of an object. so here the after_save is called when an Object of type Comment is saved. you can read more about callbacks here .