As Swift 3.0 and proposal SE-0069, this library is no longer necessary.

Foundation now provides a Notification struct. Unfortunately, it is not generic like the value type provided by this library, Notification<T, U>, but dealing with the trouble/confusion between the namespaces (Foundation.Notification vs. JSQNotificationObserverKit.Notification) makes this library not worth it.

Generic notifications and observers for Cocoa and CocoaTouch, inspired by objc.io

This library aims to provide better semantics regarding notifications and moves the responsibilty of observing and handling notifications to a lightweight, single-purpose object. It also brings type-safety and a cleaner interface to NSNotificationCenter. See objc.io's snippet #16 on Typed Notification Observers for more information.

• Xcode 7.3+
• iOS 8.0+
• OSX 10.10+
• tvOS 9.1+
• watchOS 2.0+
• Swift 2.2

use_frameworks!# For latest release in cocoapodspod'JSQNotificationObserverKit'# Feeling adventurous? Get the latest on developpod'JSQNotificationObserverKit',:git=>'https://github.com/jessesquires/JSQNotificationObserverKit.git',:branch=>'develop'

github "jessesquires/JSQNotificationObserverKit"

Read the docs. Generated with jazzy. Hosted by GitHub Pages. More information on the gh-pages branch.

import JSQNotificationObserverKit

See the included unit tests for more examples and usage.

// Suppose we have a UIView that posts a notification when its size changes letmyView=UIView() // This notification posts a CGSize value from a UIView sender letnotification=Notification<CGSize,UIView>(name:"NewViewSizeNotif", sender: myView) // This observer listens for the notification described above varobserver:NotificationObserver<CGSize,UIView>? // Register observer, start listening for the notification observer =NotificationObserver(notification){(value, sender)in // handle notification // the value and sender are both passed here } // Post the notification with the updated CGSize value notification.post(CGSizeMake(200,200)) // Unregister observer, stop listening for notifications observer =nil

Not all notifications are associated with a specific sender object. Here's how to handle nil sender in JSQNotificationObserverKit. This observer will respond to notifications regardless of the instances sending them.

// This notification posts a string value, the sender is nil letnotification=Notification<String,AnyObject>(name:"StringNotif") // Post the notification notification.post("new string") // Register observer, this handles notifications from *any* sender varobserver:NotificationObserver<String,AnyObject>? observer =NotificationObserver(notification){(value, sender)in // handle notification // the value is passed here, sender is nil } // unregister observer, stop listening for notifications observer =nil

You can optionally pass an NSOperationQueue and NSNotificationCenter. The default values are nil and NSNotificationCenter.defaultCenter(), respectively.

// Initialize an observer and post a notification // with a custom notification center and operation queue letc=NSNotificationCenter.defaultCenter()letq=NSOperationQueue.mainQueue()letobserver=NotificationObserver(n, queue: q, center: c){(value, sender)in // handle notification } notification.post(v, center: c)

Not all notifications are associated with a specific value. Sometimes notifications are used to simply broadcast an event, for example UIApplicationDidReceiveMemoryWarningNotification.

letnotification=Notification<Any?,AnyObject>(name:"MyEventNotification")letobserver=NotificationObserver(notification){(value, sender)in // handle notification // value is nil, sender is nil } // notification value is `Any?`, so pass nil notification.post(nil)

The library can also handle "traditional" notifications that are posted by the OS. Instead of using the (value, sender) handler, use the (notification) handler which passes the full NSNotification object.

letnotification=CocoaNotification(name: UIApplicationDidReceiveMemoryWarningNotification)letobserver=CocoaObserver(notification, handler:{(notification:NSNotification)in // handle the notification }) // the notification will be posted by iOS

There's a suite of unit tests for the JSQNotificationObserverKit.framework. To run them, open JSQNotificationObserverKit.xcodeproj, select the JSQNotificationObserverKit scheme, then ⌘-u.

These tests are well commented and serve as further documentation for how to use this library.

Please follow these sweet contribution guidelines.

Created and maintained by @jesse_squires.

JSQNotificationObserverKit is released under an MIT License. See LICENSE for details.

Copyright © 2014-present Jesse Squires.

Please provide attribution, it is greatly appreciated.