Instance Method

existingObject(with:)

Returns the object for the specified ID or nil if the object does not exist.

Declaration

func existingObject(with objectID: NSManagedObjectID) throws -> NSManagedObject

Parameters

objectID

The object ID for the requested object.

error

If there is a problem in retrieving the object specified by objectID, upon return contains an error that describes the problem.

Return Value

The object specified by objectID. If the object cannot be fetched, or does not exist, or cannot be faulted, it returns nil.

Discussion

If there is a managed object with the given ID already registered in the context, that object is returned directly; otherwise the corresponding object is faulted into the context.

This method might perform I/O if the data is uncached.

Unlike object(with:), this method never returns a fault.

See Also

Registering and Fetching Objects

func fetch(NSFetchRequest<NSFetchRequestResult>) -> [Any]

Returns an array of objects that meet the criteria specified by a given fetch request.

func count(for: NSFetchRequest<NSFetchRequestResult>) -> Int

Returns the number of objects a given fetch request would have returned if it had been passed to executeFetchRequest:error:.

func registeredObject(for: NSManagedObjectID) -> NSManagedObject?

Returns the object for a specified ID, if the object is registered with the context.

func object(with: NSManagedObjectID) -> NSManagedObject

Returns an object for a specified ID even if the object needs to be fetched.

var registeredObjects: Set<NSManagedObject>

The set of objects registered with the context.

func count<T>(for: NSFetchRequest<T>) -> Int

Returns the number of objects a given fetch request would have returned.

func execute(NSPersistentStoreRequest) -> NSPersistentStoreResult

Passes a request to the persistent store without affecting the contents of the managed object context and returns a persistent store result.

func fetch<T>(NSFetchRequest<T>) -> [T]

Returns an array of objects that meet the criteria specified by a given fetch request.

func refreshAllObjects()

Refreshes all currently registered objects that are associated with this context.

var retainsRegisteredObjects: Bool

A Boolean value that indicates whether the context keeps strong references to all registered managed objects.