A Protocol-Oriented NotificationCenter which is type safe, thread safe and with memory safety.

• Type Safe

  No more userInfo dictionary and Downcasting, just deliver the concrete type value to the observer.

• Thread Safe

  You can register, notify, unregister in any thread without crash and data corruption.

• Memory Safety

  SwiftNotificationCenter store the observer as a zeroing-weak reference. No crash and no need to unregister manually.

It's simple, safe, lightweight and easy to use for one-to-many communication.

Usage

Define protocol and observer:

protocol Update {
    func updateTitle(title: String)
}

extension ViewController: Update {
  func updateTitle(title: String) {
  		self.titleLabel.text = title
  }
}
let vc = ViewController()

Register:

Broadcaster.register(Update.self, observer: vc)

Broadcast:

Broadcaster.notify(Update.self) {
    $0.updateTitle("new title")
}

Unregister:

Broadcaster.unregister(Update.self, observer: self)

Compare with NSNotificationCenter :

For example, handle UIKeyboardWillShowNotification

@objc func handleKeyboardNotification(notification: NSNotification) {
    guard notification.name == NSNotification.Name.UIKeyboardWillShow
        else { return }
    
    guard let beginFrame = (notification
        .userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue
        else { return }
    
    guard let endFrame = (notification
        .userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue
        else { return }
    // use beginFrame, endFrame
}

SwiftNotificationCenter way:

/*
If you want to observe the system built in notifications like this.
You can declare a protocol and the relevant method, and use a singleton as a mediator to observe system's notification, then notify our observers.
Please check the refactor example in SwiftNotificationCenterExample Project.
*/
func UIKeyboardWillShow(beginFrame: CGRect, endFrame: CGRect) {
}

Installation

CocoaPods:

pod 'SwiftNotificationCenter'

Carthage:

github "100mango/SwiftNotificationCenter"

Manually:

Just copy source files in the SwiftNotificationCenter folder into your project.

License

SwiftNotificationCenter is under the MIT license.