Migrating from CoreData to SwiftData causes crashes on Watch app

Question

Created Oct ’23

Replies 2

Boosts 0

Participants 2

I'm working on migrating my app from using CoreData to SwiftData. The swift data code generated by Xcode works correctly for the iOS and Mac Catalyst targets but it is causing a crash for the WatchOS target.

It gives me this message **Fatal error: Application must register a ValueTransformer for NSSecureUnarchiveFromDataTransformer **

This attribute is the only one with a .transformable option.

@Attribute(.transformable(by: "NSSecureUnarchiveFromDataTransformer")) 
public var linkedEntities: [UUID] = []

Changing the string NSSecureUnarchiveFromDataTransformer to NSValueTransformerName.secureUnarchiveFromDataTransformerName.rawValue causes a generic crash with no error message.

The app has CloudKit integration as well (not sure if relevant).

Does anyone have a similar issue and can help me on what to do here?

Boost

Answer 1

litkyle OP

Nov ’23

If this was a custom transformer, I would say you need to add ValueTransformer.setValueTransformer(NSSecureUnarchiveFromDataTransformer(), forName: NSValueTransformerName("NSSecureUnarchiveFromDataTransformer")) in your app's init(), but AFAIK UUID is Codable so I'm not sure you need a transformer here. Have you tried just ditching @Attribute(.transformable(by: "NSSecureUnarchiveFromDataTransformer"))?

0

Answer 2

lucas assis OP

Dec ’23

Taking it out worked but I have a worst problem where the SwiftData never syncs to the watch or to the iMessage app. I haven't had time to work on this project lately to try to pinpoint what is causing the issue 😓

0