Field.Coded implementations for transformable attributes

Sources/FieldCoders.NSCoding.swift

@@ -0,0 +1,91 @@
+//
+//  FieldCoders.NSCoding.swift
+//  CoreStore
+//
+//  Copyright © 2020 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+
+
+// MARK: - FieldCoders
+
+extension FieldCoders {
+
+    // MARK: - NSCoding
+
+    public struct NSCoding<V: NSObject & Foundation.NSCoding>: FieldCoderType {
+
+        // MARK: FieldCoderType
+
+        public typealias FieldStoredValue = V
+
+        public static func encodeToStoredData(_ fieldValue: FieldStoredValue?) -> Data? {
+
+            guard let fieldValue = fieldValue else {
+
+                return nil
+            }
+            if #available(iOS 11.0, macOS 10.13, watchOS 4.0, tvOS 11.0, *) {
+
+                return try! NSKeyedArchiver.archivedData(
+                    withRootObject: fieldValue,
+                    requiringSecureCoding: self.requiresSecureCoding
+                )
+            }
+            else {
+
+                return NSKeyedArchiver.archivedData(withRootObject: fieldValue)
+            }
+        }
+
+        public static func decodeFromStoredData(_ data: Data?) -> FieldStoredValue? {
+
+            guard let data = data else {
+
+                return nil
+            }
+            if #available(iOS 11.0, macOS 10.13, watchOS 4.0, tvOS 11.0, *) {
+
+                return try! NSKeyedUnarchiver.unarchivedObject(ofClass: FieldStoredValue.self, from: data)
+            }
+            else {
+
+                return NSKeyedUnarchiver.unarchiveObject(with: data) as! FieldStoredValue?
+            }
+        }
+
+
+        // MARK: Private
+
+        private static var requiresSecureCoding: Bool {
+
+            switch FieldStoredValue.self {
+
+            case let valueType as NSSecureCoding.Type:
+                return valueType.supportsSecureCoding
+
+            default:
+                return false
+            }
+        }
+    }
+}