willAccessValue(forKey:)
Provides support for key-value observing access notification.
Declaration
func willAccessValue(forKey key: String?)Parameters
- key:
The name of one of the receiver’s properties.
Discussion
See didAccessValue(forKey:) for more details. You can invoke this method with the key value of nil to ensure that a fault has been fired, as illustrated by the following example.
[aManagedObject willAccessValueForKey:nil];