Question

Could you tell me please how can I get data for an object that is changed.

For example, I have an object @student = {:name => 'xxx', :class => 'yyy'} and a user plays with this object on the site. After the object is saved I notify user about what has been changed, for example, Student #{@student.name} has changed #{@student.class}.

So basically how to get previous data from a model that was there before save?

Note: before_save callback doesn’t do the job.

Answer 1

Check out the paper_trail gem which allows versioning of and tracking changes on your models.