Global Variable

NSKeyValueChangeNotificationIsPriorKey

If the NSKeyValueObservingOptionPrior option was specified when the observer was registered this notification is sent prior to a change.

Declaration

const NSKeyValueChangeKey NSKeyValueChangeNotificationIsPriorKey;

Discussion

The change dictionary contains an NSKeyValueChangeNotificationIsPriorKey entry whose value is an NSNumber object that contains the Boolean value YES.