SwiftUI - Audio keeps playing when changing views - swift

Question

I have a problem that's cropped up since I've updated my Xcode... Unless the user hits pause in the audio view. My audio player continues to play when the user changes views however I would like the audio to stop when the user exits the player view (ItemDetail) (for example when the user goes to Content View)
Previously I was using the below at the start of the Content View and that had worked but now it doesn't:
init() { sounds.pauseSounds() }
I've also tried this (which hasn't worked either):
}// end of navigation view .onAppear{sounds.pauseSounds()}
This is my sounds class:
class Sounds:ObservableObject {
var player:AVAudioPlayer?
// let shared = Sounds()
func playSounds(soundfile: String) {
if let path = Bundle.main.path(forResource: soundfile, ofType: nil){
do{
player = try AVAudioPlayer(contentsOf: URL(fileURLWithPath: path))
player?.prepareToPlay()
player?.play()
}catch {
print("Error can't find sound file or something's not working with the sounds model")
}
}
}
// This method used to work at pausing the sound (pre-update)
func pauseSounds() {
player?.pause()
}
// over rides the sound defaulting to bluetooth speaker only and sends it to phone speaker if bluetooth is not available (headset/speaker) however if it is available it'll play through that.
func overRideAudio() {
let audioSession = AVAudioSession.sharedInstance()
do {
try audioSession.setCategory(AVAudioSession.Category.playback, mode: .spokenAudio, options: .defaultToSpeaker)
try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
} catch {
print("error.")
}
}
}
And this is the player view:
struct ItemDetail: View {
#State var isPlaying = false
var item : SessionsItem
#ObservedObject var soundsPlayer = Sounds()
var body: some View {
HStack {
Button(action: {
if self.isPlaying{
// Sounds.player?.pause()
self.isPlaying = false
soundsPlayer.pauseSounds()
}
else{
self.isPlaying = true
soundsPlayer.playSounds(soundfile: "\(self.item.name).mp3")
soundsPlayer.overRideAudio()
}

Answer 1

You are creating another Sound instance so you do not have access to the open audiio instance. You can make Sounds class as single instance or pass the Sounds instance to the detail. Dont create a new one.

Answer 2

onAppear is not a reliable way to do work like this SwiftUI does a lot of preloading (It is very apparent with a List). It depends on the device and its capabilities. Sometimes screens "appear" when they are preloaded not necessarily when the user is looking at it.
With the List example below you can see it in simulator.
On iPhone 8 I get 12 onAppear print statements in the console when I initially load it and on iPhone 12 Pro Max I get 17 print statements.
If the cells are more/less complex you get more/less statements accordingly. You should find another way to do this.
import SwiftUI
struct ListCellAppear: View {
var idx: Int
var body: some View {
HStack{
Text(idx.description)
Image(systemName: "checkmark")
}.onAppear(){
print(idx.description)
}
}
}
struct ListAppear: View {
var body: some View {
List(0..<1000){ idx in
ListCellAppear(idx: idx).frame(height: 300)
}
}
}
struct ListAppear_Previews: PreviewProvider {
static var previews: some View {
ListAppear()
}
}