0 Replies
      Latest reply on Sep 14, 2017 3:59 PM by ryanipete+sp
      ryanipete+sp Level 1 Level 1 (0 points)

        When using batch delete to delete a core data object, the object's external binary data is not deleted. Am I doing something wrong? Or is this a bug on Apple's end?


        To reproduce:



        I've set up a simple Core Data project. The data model defines an `ImageProperty` entity with a binary data attribute that "Allows External Storage".


        I don't make any changes to the implementation of the persistentContainer that is provided by Apple:


        lazy var persistentContainer: NSPersistentContainer = {
             let container = NSPersistentContainer(name: "ExternalStorage")
            container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            return container


        On application launch, I create and save an instance of `ImageProperty` with data large enough to be stored externally. I then immediately delete that property using a batch delete:


        let entityName = String(describing: ImageProperty.self)
        // Create property
        let entity = NSEntityDescription.entity(forEntityName: entityName, in: persistentContainer.viewContext)!
        let property = ImageProperty(entity: entity, insertInto: persistentContainer.viewContext)
        property.data = NSData(contentsOfFile: Bundle.main.path(forResource: "sample-house-a", ofType: "jpg")!)
        try! persistentContainer.viewContext.save()
        // Batch-delete property
        let fetch: NSFetchRequest<NSFetchRequestResult> = NSFetchRequest(entityName: entityName)
        let request = NSBatchDeleteRequest(fetchRequest: fetch)
        _ = try! self.persistentContainer.viewContext.execute(request) as! NSBatchDeleteResult
        try! self.persistentContainer.viewContext.save()


        When I check the app's sandbox, the item has been deleted from the database, but the external file still exists. Why?