AVPlayer video disappears when navigating 'back' in Swift - ios

Question

When navigating to a subview, I have set it up so that a video plays automatically. At the bottom of the video, there is a group of links that go to related content. When clicking one of them, a new view is pushed onto the stack and a different video starts playing.
The problem happens when using the automatically generated '< Back' button to go back to the prior view (which had a different video). This original view can be operated using the player controls, but nothing shows up on the screen.
I've tried to update the CGRect frame, use onAppear to reinitialize the video player, and also followed the advice here.
So far nothing seems to work. Here is the code I am using for the actual video player (adapted from Chris Mash's website):
import SwiftUI
import AVKit
import UIKit
import AVFoundation
let playerLayer = AVPlayerLayer()
class PlayVideo: UIView {
init(frame: CGRect, url: URL) {
super.init(frame: frame)
// Create the video player using the URL passed in.
let player = AVPlayer(url: url)
player.volume = 100 // Will play audio if you don't set to zero
player.play() // Set to play once created
// Add the player to our Player Layer
playerLayer.player = player
playerLayer.videoGravity = .resizeAspectFill // Resizes content to fill whole video layer.
playerLayer.backgroundColor = UIColor.black.cgColor
layer.addSublayer(playerLayer)
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
override func layoutSubviews() {
super.layoutSubviews()
playerLayer.frame = bounds
}
static func pauseVideo() {
playerLayer.player?.pause()
}
}
struct ViewVideo: UIViewRepresentable {
var videoURL:URL
var previewLength:Double?
func makeUIView(context: Context) -> UIView {
return PlayVideo(frame: .zero, url: videoURL)
}
func updateUIView(_ uiView: UIView, context: Context) {
}
}
This is called from the main view using:
ViewVideo(videoURL: videoURL)
The only work around I can think of is to disable the back button and force the user to go back to the main view every time. That's a terrible option and I'm hoping someone will have some helpful advice here. Thanks -

Answer 1

If I understand this correctly, you play a different video, when you navigate to the new view. So you create a new PlayVideo view?
Then the problem is that your playerLayer is a static property. The new view will set a new player into the playerLayer and replace the old one. Similarly, if you pause one player, both are paused. Additionally, adding the player as a sublayer to the new view will remove it from the old view.
You need the playerLayer as a local property to your view. Or at least a AVPlayerLayer for every video you want to play. Then you need a mechanism for pausing/restarting each video, when it becomes visible. For example by implementing the viewWillAppear. This method gets always called, when you navigate back to a view/ the view becomes visible.

Answer 2

Thank you to #dominik-105 for helping with this question. I was able to fix the problem using the suggestions that were made.
Specifically, I removed the global definition of playerLayer and instead placed it as a local variable in my main view call:
var playerLayer = AVPlayerLayer()
I then call ViewVideo with the playerLayer: playerLayer tag, and the ViewVideo then calls PlayVideo with playerLayer:AVPlayerLayer as part of the init.
Interestingly, this leads to problems with the override layout function I was using to define the size of the video box. I define the frame directly in the init now and removed the old override function code. The full code is now:
import SwiftUI
import AVKit
import UIKit
import AVFoundation
class PlayVideo: UIView {
init(frame: CGRect, url: URL, playerLayer: AVPlayerLayer, width: CGFloat, height: CGFloat) {
super.init(frame: frame)
// Create the video player using the URL passed in.
let player = AVPlayer(url: url)
player.volume = 100 // Will play audio if you don't set to zero
player.play() // Set to play once created
// Add the player to our Player Layer
playerLayer.player = player
playerLayer.videoGravity = .resizeAspectFill // Resizes content to fill whole video layer.
playerLayer.backgroundColor = UIColor.black.cgColor
playerLayer.player?.actionAtItemEnd = .pause
layer.addSublayer(playerLayer)
playerLayer.frame = CGRect(x: 0, y: 0, width: width, height: height)
}
required init?(coder: NSCoder) {
super.init(coder: coder)
}
}
struct ViewVideo: UIViewRepresentable {
var videoURL:URL
var playerLayer: AVPlayerLayer
var width: CGFloat
var height: CGFloat
func makeUIView(context: Context) -> UIView {
return PlayVideo(frame: .zero, url: videoURL, playerLayer: playerLayer, width: width, height: height)
}
func updateUIView(_ uiView: UIView, context: Context) {
}
}
I use GeometryReader to define the size of the box, and then pass along the width and height to the struct, which passes it along to the class.