Using a system supplied NSValueTransformer on a transformable Core Data attribute

2
votes

When trying to use a system supplied NSValueTransformer in Core Data I get the following warning:

Warning: no NSValueTransformer with class name 'NSKeyedUnarchiveFromDataTransformerName' was found for attribute 'someAttribute' on entity 'SomeEntity'

How come the NSKeyedUnarchiveFromDataTransformer is not recognized?

1
cocoacore-data

1 Answers

6
votes

Turns out that the actual string that the NSKeyedUnarchiveFromDataTransformer points too for this transformer is NSKeyedUnarchiveFromData. But even more importantly: if you specify this, the transformer will be used in the wrong direction. Leave the transformer name field empty to use NSKeyedUnarchiveFromDataTransformer correctly.