Is it possible to store the array safely?

[noppefoxwolf]

I made a FieldCoderType because I want to save an array of NSCoding. Is the following implementation safe? I want to receive feedbacks about this. (I'm a beginner for CoreData.)

import Foundation
import CoreStore

extension FieldCoders {
    public struct NSArray<C: Foundation.NSObject & Foundation.NSCoding>: FieldCoderType {
        public typealias FieldStoredValue = Array<C>

        public static func encodeToStoredData(_ fieldValue: FieldStoredValue?) -> Data? {

            guard let fieldValue = fieldValue else {

                return nil
            }
            return try! NSKeyedArchiver.archivedData(
                withRootObject: fieldValue,
                requiringSecureCoding: self.requiresSecureCoding
            )
        }

        public static func decodeFromStoredData(_ data: Data?) -> FieldStoredValue? {

            guard let data = data else {

                return nil
            }
            return try! NSKeyedUnarchiver.unarchivedObject(
                ofClasses: [Foundation.NSArray.self, FieldStoredValue.Element.self],
                from: data
            ) as? FieldStoredValue
        }

        private static var requiresSecureCoding: Bool {

            switch FieldStoredValue.Element.self {

            case let valueType as NSSecureCoding.Type:
                return valueType.supportsSecureCoding

            default:
                return false
            }
        }
    }
}

[JohnEstropia]

No need to implement your own. CoreStore implements FieldCoders.DefaultNSSecureCoding and FieldCoders.DefaultNSCoding for NSArrays, or you can use FieldCoders.Json directly for swift Arrays:

@Field.Coded("values", coder: FieldCoders.Json.self)
var values: [MyCodableType] = []

[noppefoxwolf]

DefaultNSSecureCoding looks not supports typed array. How to serialize to element that cannot encode json value?

@Field.Coded("images", coder: FieldCoders.DefaultNSSecureCoding.self)
public var images: [UIImage] = []

Referencing initializer 'init(wrappedValue:_:versionHashModifier:previousVersionKeyPath:coder:customGetter:customSetter:affectedByKeyPaths:)' on 'FieldContainer.Coded' requires that '[UIImage]' conform to 'FieldOptionalType'

[JohnEstropia]

Your original code used KeyedArchiver and KeyedUnarchiver, which DefaultNSSecureCoding uses internally so your code wouldn't work either if DefaultNSSecureCoding doesn't. You need to have Codable types to use the built-in coders, otherwise you have to create your own way to convert to and from Data without using KeyedArchiver/Unarchiver.