How to determine if any field in a model / nested model changed?

Question

Is there some quick way to find out if any of a model\'s fields or any fields of it\'s nested models (a.k.a. associations) changed?

Answer 1

I know this is old question but recently came across same situation.

You can get all changes for your nested model using previous_changes method even after saving the object.

parent_model_object.nested_model_name.previous_changes

This will list all changes in the nested model along with old and new value.