Contents

addObserver(of:for:using:)

Adds an observer to a center for messages delivered asynchronously with a given subject and identifier.

Declaration

func addObserver<Identifier, Message>(of subject: Message.Subject, for identifier: Identifier, using observer: @escaping  @Sendable (Message) async -> Void) -> NotificationCenter.ObservationToken where Identifier : NotificationCenter.MessageIdentifier, Message : NotificationCenter.AsyncMessage, Message == Identifier.MessageType, Message.Subject : AnyObject

Parameters

  • subject:

    The subject to observe. Specify a metatype to observe all values for a given type.

  • identifier:

    An identifier representing a specific message type.

  • observer:

    A closure to execute when receving a message.

Return Value

A token representing the observation registration with the given notification center. Retain this token for as long as you need to receive messages.

See Also

Observing concurrency-safe notifications