Strange behavior of AVPlayer - ios

Question

I noticed a very odd behavior when working with AVPlayer from AVFoundation framework. I'm trying to stream (play) some mp3 radio file from internet.
So I created a new project in Xcode and added the following code to the default ViewController:
import UIKit
import AVFoundation
class ViewController: UIViewController {
let player: AVPlayer = AVPlayer()
override func viewDidLoad() {
super.viewDidLoad()
let asset = AVAsset(url: URL(string: "https://rfcmedia.streamguys1.com/Newport.mp3")!);
let playerItem = AVPlayerItem(asset: asset);
player.replaceCurrentItem(with: playerItem)
player.play();
}
}
There's nothing particularly interesting going on there. I just create an AVPlayerItem instance with the radio station URL and give it to AVPlayer and then ask the player object to play the song and it works just as expected.
However if I remove the player object instantiation from the class block and put it in the viewDidLoad method the code simply doesn't work (doesn't play anything) yet it doesn't crash or spit out any kinds of errors or warning.
import UIKit
import AVFoundation
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let player: AVPlayer = AVPlayer()
let asset = AVAsset(url: URL(string: "https://rfcmedia.streamguys1.com/Newport.mp3")!);
let playerItem = AVPlayerItem(asset: asset);
player.replaceCurrentItem(with: playerItem)
player.play();
}
}
I can't understand this behavior. Why is that happening? Is it limited to AVPlayer or I should watch out for cases like this?

Answer 1

As Andrea Mugnaini explained in the comments to my post, my second example is going to cause an immediate deallocation by the ARC (Automatic Reference Counting) as we don't keep a strong reference to the AVPlayer object.
This is a common pitfall of developers new to Apple's ecosystem.