Decodable CoreStoreObject subclass implementation

[eraydiler]

Hello,

I'm trying to figure out how to implement a CoreStoreObject subclass that also needs to conform to Decodable protocol. What I came up with is the code below.

`
class TestObject: CoreStoreObject, Decodable {
let title = Value.Optional("title", initial: nil)

 private enum CodingKeys: String, CodingKey {
     case title = "title"
 }

 required init(from decoder: Decoder) throws {
     let values = try decoder.container(keyedBy: CodingKeys.self)

     title.value = try values.decodeIfPresent(String.self, forKey: .title)

     super.init(asMeta: ())
 }

 required init(asMeta: Void) {
     super.init(asMeta: ())
 }

 required init(rawObject: NSManagedObject) {
     super.init(asMeta: ())
 }

}
`

However I'm having error;
❗ [CoreStore: Assertion Failure] Value.swift:373 value
↪︎ Attempted to access values from a 'Test' meta object. Meta objects are only used for querying keyPaths and infering types.

I think issue is related to the init(asMeta:...), init(rawObject:...) methods' implementation.
What is the proper way to implement these methods?
Thanks.

[JohnEstropia]

As mentioned somewhere in the discussion in mogenerator's prototype for Codable support, NSManagedObjects generally do not really play well with Encodable because the init(decoder:) needs to be implemented, while NSManagedObject's init(context:) needs an instance of the NSManagedObjectContext where the object will be added. (Basically you can call init(decoder:) many times without side effects, but init(context:) does)

You are hitting the same limitation with CoreStoreObject here, where it needs the context (via the NSManagedObject in init(rawObject:)).

You can borrow the techniques used in the mogenerator proposal above, but at that point I would recommend you to use ImportableUniqueObjects instead as they are much much more simple.

[eraydiler]

I solved my issue by creating two different objects. They conform CoreStoreObject and Decodable seperately. Added additional methods to make required mapping between them. Thanks for the information.