keychain/TrustedPeersHelper/SetValueTransformer.swift

   1 import CoreData
   2 import Foundation
   3
   4 @objc(SetValueTransformer)
   5 class SetValueTransformer: ValueTransformer {
   6     override class func transformedValueClass() -> AnyClass {
   7         return NSData.self
   8     }
   9
  10     override class func allowsReverseTransformation() -> Bool {
  11         return true
  12     }
  13
  14     override func transformedValue(_ value: Any?) -> Any? {
  15         do {
  16             guard let value = value else {
  17                 return nil
  18             }
  19             return try NSKeyedArchiver.archivedData(withRootObject: value, requiringSecureCoding: true)
  20         } catch {
  21             os_log("Failed to serialize a Set: %@", log: tplogDebug, type: .default, error as CVarArg)
  22             return nil
  23         }
  24     }
  25
  26     override func reverseTransformedValue(_ value: Any?) -> Any? {
  27         do {
  28             guard let dataOp = value as? Data? else {
  29                 return nil
  30             }
  31             guard let data = dataOp else {
  32                 return nil
  33             }
  34
  35             let unarchiver = try NSKeyedUnarchiver(forReadingFrom: data)
  36             return unarchiver.decodeObject(of: [NSSet.self], forKey: NSKeyedArchiveRootObjectKey)
  37         } catch {
  38             os_log("Failed to deserialize a purported Set: %@", log: tplogDebug, type: .default, error as CVarArg)
  39             return nil
  40         }
  41     }
  42
  43     static let name = NSValueTransformerName(rawValue: "SetValueTransformer")
  44 }