Do you have to manually unregister block-based NotificationCenter observers?
final class NotificationToken {
private let notificationCenter: NotificationCenter
private let token: NSObjectProtocol
init(notificationCenter: NotificationCenter = .default, token: NSObjectProtocol) {
self.notificationCenter = notificationCenter
self.token = token
}
deinit {
notificationCenter.removeObserver(token)
}
func add(to bag: NotificationTokenBag) {
bag.add(token: self)
}
}
final class NotificationTokenBag {
private var tokens: [NotificationToken] = []
func add(token: NotificationToken) {
tokens.append(token)
}
}
protocol Disposable {
func dispose()
}
extension NotificationToken: Disposable {
func dispose() {
notificationCenter.removeObserver(token)
}
}
extension NotificationTokenBag: Disposable {
func dispose() {
tokens.removeAll()
}
}
extension NotificationCenter {
func observe(forName name: NSNotification.Name?, object obj: Any?, queue: OperationQueue?, using block: @escaping (Notification) -> Swift.Void) -> NotificationToken {
let token = addObserver(forName: name, object: obj, queue: queue, using: block)
return NotificationToken(notificationCenter: self, token: token)
}
}
class MyClass {
private var token: NotificationToken?
init() {
token = NotificationCenter.default.observe(forName: nil, object: nil, queue: nil) { (noti) in
}
}
}
class MyClass2 {
private let bag = NotificationTokenBag()
init() {
NotificationCenter.default.observe(forName: nil, object: nil, queue: nil) { (noti) in
}.add(to: bag)
}
}
