Rails attribute changed?

gistfile1.rb

my_model = MyModel.find(:first)
my_model.changed?  # it will return false

# You can Track changes to attributes with my_model.name_changed? accessor
my_model.name  # returns  "Name"
my_model.name = "New Name"
my_model.name_changed? # returns true

# Access previous value with name_was accessor
my_model.name_was  # "Name"

# You can also see both the previous and the current values, using name_change
my_model.name_change  #=> ["Name", "New Name"]