Unfortunately the new Core Data semantics make me crazy. My previous question had a clean code that didn't work because of incorrect auto generation of header files. Now I continue my work with deleting objects. My code seems to be very simple:
func deleteProfile(withID: Int) {
let fetchRequest: NSFetchRequest<Profile> = Profile.fetchRequest()
fetchRequest.predicate = Predicate.init(format: "profileID==\(withID)")
let object = try! context.fetch(fetchRequest)
context.delete(object)
}
I did a "hard" debug with print(object)
instead of context.delete(object)
and it showed me the right object.
So I need just to delete it.
P.S. there is no deleteObject
. Now NSManagedContext has only public func delete(_ sender: AnyObject?)
The result of a fetch is an array of managed objects, in your case
[Event]
, so you can enumerate the array and delete all matching objects.
Example (using try?
instead of try!
to avoid a crash in the case
of a fetch error):
if let result = try? context.fetch(fetchRequest) {
for object in result {
context.delete(object)
}
}
If no matching objects exist then the fetch succeeds, but the resulting array is empty.
Note: In your code, object
has the type [Event]
and therefore in
context.delete(object)
the compiler creates a call to the
public func delete(_ sender: AnyObject?)
method of NSObject
instead of the expected
public func delete(_ object: NSManagedObject)
method of NSManagedObjectContext
. That is why your code compiles
but fails at runtime.