KVO (Key Value Observing)

 

You can generate KVO code from the main interface or via a utility panel that pops up from the Action Menu or Action Panel

When selecting KVO... from the Action Menu or Action Panel, a utility panel appears where you can enter the values you need.

+ (NSSet *)keyPathsForValuesAffectingPerson {

    return [NSSet setWithObjects:@"age", @"weight", @"height", @"firstName", @"lastName", nil];

}

Results