wrapper around UserDefaults

SimplePersistence.swift

protocol PersistenceKey {
	var key:String { get }
}

enum User:String, PersistenceKey {

	var key: String {
		return self.rawValue
	}

	case login
	case data
}

final class Persistence {

	private let defaults: UserDefaults

	static private var shared: Persistence = Persistence()
	init(defaults: UserDefaults = .standard) {
		self.defaults = defaults
	}

		static subscript(key: PersistenceKey) -> String? {
		get {
			return self.shared.defaults.string(forKey: key.key)
		}

		set {
			self.shared.defaults.set(newValue, forKey: key.key)
			#if DEBUG
			print("Persistence \(key.key) has changed to : \(String(describing: newValue))")
			#endif
		}
	}

	static subscript(key: PersistenceKey) -> Data? {
		get {
			return self.shared.defaults.data(forKey: key.key)
		}

		set {
			self.shared.defaults.setValue(newValue, forKey: key.key)
		}
	}
	
	static subscript(key: PersistenceKey) -> [Any]? {
		get {
			return self.shared.defaults.array(forKey: key.key)
		}

		set {
			self.shared.defaults.setValue(newValue, forKey: key.key)
		}
	}
}

/*
// set
Persistence[User.login] = "Disconnect me. I’d rather be nothing"

// get
print(Persistence[User.login])
*/