addObserver(of:for:using:)
Adds an observer to a center for messages delivered on the main actor with a given subject and message type.
Declaration
func addObserver<Message>(of subject: Message.Subject? = nil, for messageType: Message.Type, using observer: @escaping @MainActor (Message) -> Void) -> NotificationCenter.ObservationToken where Message : NotificationCenter.MainActorMessage, Message.Subject : AnyObjectParameters
- subject:
The subject to be observed. Specify a metatype to observe all values for a given type.
- messageType:
The message type to be observed.
- observer:
A closure to execute when receving a message.
Return Value
A token representing the observation registration with the given notification center.