iOS UserDefaults Best Practices

1- Extension:

	import Foundation

	enum UserDefaultKeys: String {
	case key1
	case key2
	case key3
	}

	extension UserDefaults {
	func removeObject(forKey key: UserDefaultKeys) {
	removeObject(forKey: key.rawValue)
	}

	subscript<Value>(key: UserDefaultKeys) -> Value? {
	get { object(forKey: key.rawValue) as? Value }
	set { set(newValue, forKey: key.rawValue) }
	}
	}

	func testExtension() {
	let userDefaults = UserDefaults.standard
	userDefaults[.key1] = "Hasancan"
	print(userDefaults[.key1] ?? "nil")
	userDefaults.removeObject(forKey: .key1)
	print(userDefaults[.key1] ?? "nil")
	}

2- Property Wrappers:

	import Foundation

	@propertyWrapper
	public struct UserDefaultsStorage<Value> {
	let key: String

	public init(_ key: String) {
	self.key = key
	}

	public var wrappedValue: Value? {
	get {
	return UserDefaults.standard.object(forKey: key) as? Value
	}
	set {
	if newValue != nil {
	UserDefaults.standard.set(newValue, forKey: key)
	} else {
	UserDefaults.standard.removeObject(forKey: key)
	}
	}
	}
	}

	public struct UserDefaultConfig {
	@UserDefaultsStorage("key1")
	public static var key1: String?

	@UserDefaultsStorage("key2")
	public static var key2: Bool?

	@UserDefaultsStorage("key3")
	public static var key3: Int?
	}

	func testPropertyWrapperExtension() {
	UserDefaultConfig.key1 = "Hasancan"
	print(UserDefaultConfig.key1 ?? "nil")
	UserDefaultConfig.key1 = nil
	print(UserDefaultConfig.key1 ?? "nil")
	}

iOS Tricks