Core Data Error when segueing: Failed to call designated initializer on NSManagedObject class - ios

Question

I have a view controller that segues to another view controller when a pin on the mapView is tapped. "Pin" is an NSManagedObject that gets populated with latitude and longitude before being sent to the second view controller (where a function populates it with actual images).
I am getting the error "CoreData: error: Failed to call designated initializer on NSManagedObject class 'Pin'" after my didSelect function is completed and before my performSegue function is called.
#nonobjc public class func fetchRequest() -> NSFetchRequest<Pin> {
return NSFetchRequest<Pin>(entityName: "Pin")
}
#NSManaged public var latitude: Double
#NSManaged public var longitude: Double
#NSManaged public var images: NSSet?
This is the class:
convenience init(latitude: Double, longitude: Double, context: NSManagedObjectContext) {
if let entity = NSEntityDescription.entity(forEntityName: "Pin", in: context) {
self.init(entity: entity, insertInto: context)
self.latitude = latitude
self.longitude = longitude
} else {
fatalError("Unable to find entity name")
}
}
I have tried declaring pin as an optional and force declaring it with "!". None of these two options works. Based on what I've learned and read on many posts online I will need to initialize the pin variable using the designated initializer. This is my attempt at the top of the view controller class, but it's not working either.
var pin = Pin.init(entity: NSEntityDescription.entity(forEntityName: "Pin", in: CoreDataStack.sharedInstance().context)!, insertInto: CoreDataStack.sharedInstance().context)
Creating the pin:
// Create the annotation
let touchPoint = gestureRecognizer.location(in: mapView)
let newCoordinate = self.mapView.convert(touchPoint, toCoordinateFrom:self.mapView)
let annotation = MKPointAnnotation()
annotation.coordinate = newCoordinate
pin = Pin(latitude: annotation.coordinate.latitude, longitude: annotation.coordinate.longitude, context: CoreDataStack.sharedInstance().context)
let pinAnnotation = PinAnnotation(objectID: pin.objectID, title: nil, subtitle: nil, coordinate: annotation.coordinate)
// Add the annotation
mapView.addAnnotation(pinAnnotation)
CoreDataStack.sharedInstance().saveContext()
Selecting the pin in didSelect:
do {
let pinAnnotation = view.annotation as! PinAnnotation
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Pin")
let predicate = NSPredicate(format: "latitude == %# AND longitude == %#", argumentArray: [pinAnnotation.coordinate.latitude, pinAnnotation.coordinate.longitude])
fetchRequest.predicate = predicate
let pins = try CoreDataStack.sharedInstance().context.fetch(fetchRequest) as? [Pin]
pin = pins![0]
} catch let error as NSError {
print("failed to get pin by object id")
print(error.localizedDescription)
return
}
self.performSegue(withIdentifier: "collectionViewSegue", sender: self)
...and performing the segue:
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "collectionViewSegue" {
let controller = segue.destination as! CollectionViewController
print("CoreDataStack context in segue= \(CoreDataStack.sharedInstance().context)")
controller.selectedPin = pin
if let images = pin.images?.allObjects as? [Images] {
controller.photos = images
}
print("PrepareForSegue pin properties are: \n latitude: \(pin.latitude) \n longitude: \(pin.longitude)")
}
}
What am I missing?

Answer 1

I resolved this by making my variable declaration optional in the beginning of my class:
var selectedPin: Pin?
...and initializing differently within my long press gestureRecognizer function:
#objc func handleLongPress(_ gestureRecognizer : UIGestureRecognizer) {
if gestureRecognizer.state != .began { return }
print("Tap gesture recognized")
// Create the annotation
let touchPoint = gestureRecognizer.location(in: mapView)
let newCoordinate = self.mapView.convert(touchPoint, toCoordinateFrom:self.mapView)
let annotation = MKPointAnnotation()
annotation.coordinate = newCoordinate
// Initialize NSManagedObject 'Pin' with properties
selectedPin = Pin(context: CoreDataStack.sharedInstance().context)
selectedPin?.latitude = annotation.coordinate.latitude
selectedPin?.longitude = annotation.coordinate.longitude
if let selectedPin = selectedPin {
let pinAnnotation = PinAnnotation(objectID: selectedPin.objectID, title: nil, subtitle: nil, coordinate: annotation.coordinate)
// Add the annotation
mapView.addAnnotation(pinAnnotation)
}
CoreDataStack.sharedInstance().saveContext()
print("This is what the ole save looks like: \(CoreDataStack.sharedInstance().context)")
}