CoreStore-JohnEstropia/Sources/FieldCoders.NSCoding.swift

//
//  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

    /**
     A `FieldCoderType` that implements encoding and decoding of `NSCoding` values
     */
    public struct NSCoding<V: Foundation.NSObject & Foundation.NSCoding>: FieldCoderType {

        // MARK: FieldCoderType

        public typealias FieldStoredValue = V

        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(
                ofClass: FieldStoredValue.self,
                from: data
            )
        }


        // MARK: Private

        private static var requiresSecureCoding: Bool {

            switch FieldStoredValue.self {

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

            default:
                return false
            }
        }
    }
}