Identifying which fields have changed before CoreData saves

Question

//set up notifications

[[NSNotificationCenter defaultCenter]
 addObserver:self
 selector:@selector(dataChanged:)
 name:NSManagedObjectContextDidSaveNotification
         


        

Answer 1

The following should do the trick, but you will need to use NSManagedObjectContextWillSaveNotification and access your updated objects through the same NSManagedObjectContext used to save the objects.

for(NSManagedObject *obj in updatedObjects){

   NSDictionary *changes = [obj changedValues];
   // now process the changes as you need

}

See the discussion in the comments.