NotificationCenter
extension NotificationCenter
-
Adds an entry to the notification center’s dispatch table for a
CheetahNotification
that includes the sender, a notification queue, and a block to add to the queue.This creates a
Notification
using theCheetahNotification.name
, passes it toaddObserver(forName:, object:, queue:, using:)
, and returning its result.Declaration
Swift
public func addObserver(for notification: CheetahNotification, object: Any?, queue: OperationQueue?, using: @escaping (_ notification: Notification) -> Void) -> NSObjectProtocol
Parameters
notification
The notification.
object
The object whose notifications the observer wants to receive; that is, only notifications sent by this sender are delivered to the observer. If you pass nil, the notification center doesn’t use a notification’s sender to decide whether to deliver it to the observer.
queue
The operation queue to which block should be added. If you pass nil, the block is run synchronously on the posting thread.
using
The block to be executed when the notification is received. The block is copied by the notification center and (the copy) held until the observer registration is removed. The block takes one argument:
notification
The notification.
Return Value
An opaque object to act as the observer.