automatically update label in Swift by checking the status - ios

Question

I'm new to programming with iOS and Swift. I have a label that should automatically be updated when the status of the StreamingKit Framework changes.
Currently the label only changes when I press a different button (it calls the self.updateView() function again), but I want it to happen automatically when the status has changed, not by pressing a different button.
Here is the code:
func updateView() {
dispatch_async(dispatch_get_main_queue()) {
if let label = self.bufferingLabel, let button = self.playerButton{
if let audioPlayer = self.player{
if(audioPlayer.state == STKAudioPlayerStateBuffering)
{
self.playerState = "Loading"
button.setImage(self.image1, forState: UIControlState.Normal)
}
else(audioPlayer.state == STKAudioPlayerStatePlaying)
{
self.playerState = self.defaultPlayerState
self.playerState = "Playing"
button.setImage(self.image1, forState: UIControlState.Normal)
}
label.text = self.playerState!
}
}
So when I press this button, it gives the first state (which is loading), but after that is done (status changed), the label should change to play, but it doesn't.
#IBAction func pressStart(sender: AnyObject) {
//declare path to streaming
let filePath = "http://mp3.streampower.be/mnm-high.mp3"
if player == nil {
self.player = STKAudioPlayer()
self.player?.delegate = self
}
if let audioPlayer = player{
if (audioPlayer.state == STKAudioPlayerStateReady) ||
(audioPlayer.state == STKAudioPlayerStateStopped){
audioPlayer.play(filePath)
}else{
audioPlayer.stop()
}
}
self.updateView()
}
Some of the delegates I tried as well
func audioPlayer(audioPlayer: STKAudioPlayer!, didStartPlayingQueueItemId queueItemId: NSObject!) {
self.updateView()
}
func audioPlayer(audioPlayer: STKAudioPlayer!, didFinishBufferingSourceWithQueueItemId queueItemId: NSObject!) {
self.updateView()
}
func audioPlayer(audioPlayer: STKAudioPlayer!, stateChanged state: STKAudioPlayerState, previousState: STKAudioPlayerState) {
self.updateView()
}

Answer 1

You should look and use the delegate property of the STKAudioPlayer.
I'm not familiar with it, but generally in the iOS world, that's how you receive events from an object (the object delegates some stuff to the object of your choice).

Answer 2

You can use NSNotifications to send a signal whenever the streaming kit changes. Then you can add an observer to your UI view controller that will trigger a function whenever it receives a signal.
If you want to try out functional reactive programming you can also use The Reactive Cocoa framework to do a similar signal observer pattern. And finally, there is plain old key-value observation. One of these options should be able to help you.