managedObjectContextDidUnregisterObjects(with:)
Indicates that objects identified by a given array of object IDs are no longer being used by a managed object context.
Declaration
func managedObjectContextDidUnregisterObjects(with objectIDs: [NSManagedObjectID])Parameters
- objectIDs:
An array of object IDs.
Discussion
This method is the counterpart to managedObjectContextDidRegisterObjects(with:).
Passing an object ID in the object IDs array of managedObjectContextDidRegisterObjects(with:) is akin to incrementing the object ID’s reference count by 1; passing an object ID in the object IDs array of managedObjectContextDidUnregisterObjects(with:) is akin to decrementing the object ID’s reference count by 1. It is only when an object ID’s reference count is 0 that no contexts indicate that they are using the corresponding managed object. (Object IDs start with a reference count of 0.)
For example, if the register methods is invoked on two occasions when the object IDs array contains a given object ID, and the unregister method is invoked once when the object IDs array contains that object ID, then a context is still using the object with the given ID.