Check If Particular Attribute Has Changed In A Callback
Posted by Weston Ganger
Sometimes its handy to do a particular task if an attribute has changed in a model.
You probably only want it to run when an instance is updated, so choose your callback accordingly.
class Post < ActiveRecord::Base after_update :notify, :if => :my_attribute_changed? def notify puts "The Attribute 'my_attribute' has been changed!" end end