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Tracking Attribute Changes

#109 Tracking Attribute Changes

May 21, 2008 | 7 minutes | Rails 2.1, Active Record
Rails 2.1 keeps track of the changes you make to a model's attributes. It also allows you to see what the previous value was. But watch out for the gotcha! See this episode for details.
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Update: Partial updates are no longer enabled by default in Rails 2.1 as you can see in this commit Now you can set them in your environment config if you want.

Resources

config/initializers/active_record_settings.rb 
ActiveRecord::Base.partial_updates = true

# change tracking methods
p.changed?
p.changed
p.changes
p.name_changed?
p.name_was
p.name_change
p.name_will_change!