# NSPersistentDocument A document object that can integrate with Core Data. ``` class NSPersistentDocument ``` ## Overview The [`NSPersistentDocument`](/documentation/AppKit/NSPersistentDocument) class is a subclass of [`NSDocument`](/documentation/AppKit/NSDocument) that is designed to easily integrate into the Core Data framework. It provides methods to access a document-wide object, and provides default implementations of methods to read and write files using the persistence framework. In a persistent document, the undo manager functionality is taken over by managed object context. Standard document behavior is implemented as follows: - Opening a document invokes [`configurePersistentStoreCoordinator(for:ofType:modelConfiguration:storeOptions:)`](/documentation/AppKit/NSPersistentDocument/configurePersistentStoreCoordinator(for:ofType:modelConfiguration:storeOptions:)) with the new URL, and adds a store of the default type (XML). Objects are loaded from the persistent store on demand through the document’s context. - Saving a new document adds a store of the default type with the chosen URL and invokes save: on the context. For an existing document, a save just invokes on the context. - Save As for a new document simply invokes save. For an opened document, it migrates the persistent store to the new URL and invokes on the context. - Revert resets the document’s managed object context. Objects are subsequently loaded from the persistent store on demand, as with opening a new document. By default an [`NSPersistentDocument`](/documentation/AppKit/NSPersistentDocument) instance creates its own ready-to-use persistence stack including managed object context, persistent object store coordinator and persistent store. There is a one-to-one mapping between the document and the backing object store. You can customize the architecture of the persistence stack by overriding the [`managedObjectModel`](/documentation/AppKit/NSPersistentDocument/managedObjectModel) property and [`configurePersistentStoreCoordinator(for:ofType:modelConfiguration:storeOptions:)`](/documentation/AppKit/NSPersistentDocument/configurePersistentStoreCoordinator(for:ofType:modelConfiguration:storeOptions:)) method. You might wish to do this, for example, to specify a particular managed object model. > Important: > ``doc://com.apple.appkit/documentation/AppKit/NSPersistentDocument`` does not support some document behaviors: > > - File wrappers. > - ``doc://com.apple.appkit/documentation/AppKit/NSDocument/SaveOperationType/saveToOperation`` operation type. > > Core Data does not support saving changes to a new document while maintaining the unsaved state in the current document. > > - Asynchronous saving. > > ``doc://com.apple.appkit/documentation/AppKit/NSPersistentDocument`` does not support the asynchronous saving API of ``doc://com.apple.appkit/documentation/AppKit/NSDocument`` because that API requires accessing the document’s state on multiple threads and that violates the requirements of the class. Do not override ``doc://com.apple.appkit/documentation/AppKit/NSDocument/canAsynchronouslyWrite(to:ofType:for:)``. ### Undo Support The persistent document uses the managed object context’s undo manager. > Important: Do not override the following properties, their getters, or their setters: > > - ``doc://com.apple.appkit/documentation/AppKit/NSDocument/hasUndoManager`` > - ``doc://com.apple.appkit/documentation/AppKit/NSDocument/undoManager`` The [`isDocumentEdited`](/documentation/AppKit/NSDocument/isDocumentEdited) method returns if the persistent document’s managed object context, or editors registered with the context, have uncommitted changes, otherwise it returns . ## Topics ### Managing the Persistence Objects [`managedObjectContext`](/documentation/AppKit/NSPersistentDocument/managedObjectContext) The managed object context for the document. [`managedObjectModel`](/documentation/AppKit/NSPersistentDocument/managedObjectModel) The managed object model of the document. [`configurePersistentStoreCoordinator(for:ofType:modelConfiguration:storeOptions:)`](/documentation/AppKit/NSPersistentDocument/configurePersistentStoreCoordinator(for:ofType:modelConfiguration:storeOptions:)) Configures the receiver’s persistent store coordinator with the appropriate stores for a given URL. [`persistentStoreType(forFileType:)`](/documentation/AppKit/NSPersistentDocument/persistentStoreType(forFileType:)) Returns the type of persistent store associated with the specified file type. ### Document Content Management [`read(from:ofType:)`](/documentation/AppKit/NSPersistentDocument/read(from:ofType:)) Sets the contents of the receiver by reading from a file of a given type located by a given URL. [`revert(toContentsOf:ofType:)`](/documentation/AppKit/NSPersistentDocument/revert(toContentsOf:ofType:)) Overridden to clean up the managed object context and controllers during a revert. [`write(to:ofType:for:originalContentsURL:)`](/documentation/AppKit/NSPersistentDocument/write(to:ofType:for:originalContentsURL:)) Saves changes in the document’s managed object context and saves the document’s persistent store to a given URL. ### Deprecated [`configurePersistentStoreCoordinatorForURL:ofType:error:`](/documentation/AppKit/NSPersistentDocument/configurePersistentStoreCoordinatorForURL:ofType:error:) Configures the receiver’s persistent store coordinator for a given URL and document type. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)