I have an NSAttributedString attribute in an entity marked as Transformable with the transformer set to NSSecureUnarchiveFromDataTransformerName.
I have a Transformer defined as:
class AttributedStringTransformer: NSSecureUnarchiveFromDataTransformer {
override class func allowsReverseTransformation() -> Bool {
return true
}
override class func transformedValueClass() -> AnyClass {
return NSAttributedString.self
}
override class var allowedTopLevelClasses: [AnyClass] {
return [NSAttributedString.self]
}
override func transformedValue(_ value: Any?) -> Any? {
guard let data = value as? Data else {
fatalError("Wrong data type: value must be a Data object; received \(type(of: value))")
}
return super.transformedValue(data)
}
override func reverseTransformedValue(_ value: Any?) -> Any? {
guard let string = value as? NSAttributedString else {
fatalError("Wrong data type: value must be a Reminder object; received \(type(of: value))")
}
return super.reverseTransformedValue(string)
}
}
extension AttributedStringTransformer {
/// The name of the transformer. This is the name used to register the transformer using `ValueTransformer.setValueTrandformer(_"forName:)`.
static let name = NSValueTransformerName(rawValue: String(describing: AttributedStringTransformer.self))
/// Registers the value transformer with `ValueTransformer`.
public static func register() {
let transformer = AttributedStringTransformer()
ValueTransformer.setValueTransformer(transformer, forName: name)
}
}
The transformer is registered on launch.
When I launch the app with the string initialised to an empty attributed string the app fails right away with:
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x6000005679c0> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
2021-08-12 08:53:30.390456+0100 Easiwriter[5985:108985] [error] error: -executeRequest: encountered exception = <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo = (null)
CoreData: error: -executeRequest: encountered exception = <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo = (null)
2021-08-12 08:53:30.391637+0100 Easiwriter[5985:108985] [error] error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600000550a80> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600000550a80> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
2021-08-12 08:53:30.458505+0100 Easiwriter[5985:108985] [error] error: -executeRequest: encountered exception = <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo = (null)
CoreData: error: -executeRequest: encountered exception = <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo = (null)
2021-08-12 08:53:30.459614+0100 Easiwriter[5985:108985] [error] error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600000550a80> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600000550a80> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
2021-08-12 08:53:30.459835+0100 Easiwriter[5985:108985] [error] error: -executeRequest: encountered exception = <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo = (null)
CoreData: error: -executeRequest: encountered exception = <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo = (null)
2021-08-12 08:53:30.471535+0100 Easiwriter[5985:108985] [error] error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x60000056d8c0> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x60000056d8c0> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
I have put break points on the transformer, but it never hits them.
The behaviour of the app gives me the feeling that this is a bug in CoreData, but I can't pin it down.
Can someone please suggest what might be wrong. I am using Xcode 13.0 beta 5 (it failed on beta 4 as well).