[ios] Swift 4 Singleton inheritance
Swift 4 에서 싱글톤 객체를 사용하는 방법은 여러 가지가 있겠지만 이건 내가 자주 사용하는 두 가지..
# 변수 형태로 사용하기
ex) Singleton.shared.name = "Hello"
클래스를 상속 받아서 확장하기 어려움 ㅠㅠ
import UIKit
class Singleton
{
static let shared: Singleton = {
var instance = Singleton()
instance.name = "default name"
return instance
}()
var name: String = String()
}
class SingletonSubclass: Singleton {
static var sharedSub: SingletonSubclass = {
var instance = SingletonSubclass()
instance.name = "default name"
return instance
}()
var title: String = String()
}
Singleton.shared.name // ""
SingletonSubclass.shared.name // ""
SingletonSubclass.shared.name = "haha"
SingletonSubclass.sharedSub.title = "hello"
Singleton.shared.name // ""
//Singleton.shared.title // (error)
SingletonSubclass.shared.name // "haha"
SingletonSubclass.sharedSub.title // "hello"
# 함수 형태로 사용하기
ex) Singleton.sharedInstance().name = "Hello"
클래스를 상속 받아 확장하기 편함
Sometimes you need to subclass your singleton…
import UIKit
class Singleton
{
class func sharedInstance() -> Singleton {
struct inner { static let instance = Singleton() }
inner.instance
return inner.instance
}
var name: String = String()
}
class SingletonSubclass: Singleton
{
override class func sharedInstance() -> SingletonSubclass {
struct inner { static let instance = SingletonSubclass() }
return inner.instance
}
var title: String = String()
}
Singleton.sharedInstance().name // ""
SingletonSubclass.sharedInstance().name // ""
SingletonSubclass.sharedInstance().name = "haha"
SingletonSubclass.sharedInstance().title = "hello"
Singleton.sharedInstance().name // ""
//Singleton.sharedInstance().title // (error)
SingletonSubclass.sharedInstance().name // "haha"
SingletonSubclass.sharedInstance().title // "hello"
