NotificationObserver

public final class NotificationObserver <V, S: AnyObject>

An instance of NotificationObserver is responsible for observing notifications.

Warning

When an observer is initialized, it will immediately begin listening for its specified notification by registering with the specified notification center. To stop listening, dealloc the observer by setting it to nil.

Typealiases


                    
                    
                    NotificationClosure

The closure to be called when an NSNotification is received.

Declaration

Swift

public typealias NotificationClosure = (notification: NSNotification) -> Void

Parameters


                                notification

The notification received.


                    
                    
                    ValueSenderClosure

The closure to be called when a Notification is received.

Declaration

Swift

public typealias ValueSenderClosure = (value: V, sender: S?) -> Void

Parameters

`value`	The data sent with the notification.
`sender`	The object that sent the notification, or `nil` if the notification is not associated with a specific sender.

Initialization


                    
                    
                    init(_:queue:center:handler:)

Constructs a new NotificationObserver instance and immediately registers to begin observing the specified notification.

Warning

To unregister this observer and end listening for notifications, dealloc the object by setting it to nil.

Declaration

Swift

public convenience init(_ notification: Notification<V, S>,
                              queue: NSOperationQueue? = nil,
                              center: NSNotificationCenter = .defaultCenter(),
                              handler: ValueSenderClosure)

Parameters

`notification`	The notification for which to register the observer.
`queue`	The operation queue to which `handler` should be added. If `nil` (the default), the block is run synchronously on the posting thread.
`center`	The notification center from which the notification should be dispatched. The default is `NSNotificationCenter.defaultCenter()`.
`handler`	The closure to execute when the notification is received.

Return Value

A new NotificationObserver instance.


                    
                    
                    init(_:queue:center:handler:)

Constructs a new NotificationObserver instance and immediately registers to begin observing the specified notification.

Warning

To unregister this observer and end listening for notifications, dealloc the object by setting it to nil.

Declaration

Swift

public init(_ notification: Notification<V, S>,
                  queue: NSOperationQueue? = nil,
                  center: NSNotificationCenter = .defaultCenter(),
                  handler: NotificationClosure)

Parameters

`notification`	The notification for which to register the observer.
`queue`	The operation queue to which `handler` should be added. If `nil` (the default), the block is run synchronously on the posting thread.
`center`	The notification center from which the notification should be dispatched. The default is `NSNotificationCenter.defaultCenter()`.
`handler`	The closure to execute when the notification is received.

Return Value

A new NotificationObserver instance.