Swift : Player audio file from another class file - ios

Question

First of all, I just want to let you know I'm a newbie in iOS programming ;)
I would like to know if the following scenario is possible or which way I need to update my code to make it work.
I would like to play an audio file located in the player class file within the ViewController file.
I added the file "test.wav" to the root of project.
My problem
When I play the sound by tapping a button, the program can't find the sound file. I have the following error message:
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb)
Main swift file: ViewController.swift
import UIKit
import AVFoundation
class ViewController: UIViewController {
var player1: Player!
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func playAudio(sender: AnyObject) {
player1.playAudioFile()
}
}
Class file: Player.swift
import Foundation
import AVFoundation
class Player {
// Variables
var vc: ViewController!
var audioFile: AVAudioPlayer!
// Initializer
init (){
}
// Methods
func playAudioFile() {
if audioFile.playing {
audioFile.stop()
} else {
audioFile.play()
}
}
// Intialize ViewController
init (vc:ViewController!) {
// Set path for the attack sound
let audioSnd = NSBundle.mainBundle().pathForResource("test", ofType: "wav")
let audioFileURL = NSURL(fileURLWithPath: audioSnd!)
do {
try audioFile = AVAudioPlayer(contentsOfURL: audioFileURL, fileTypeHint: nil)
audioFile.prepareToPlay()
} catch let err as NSError {
print(err.debugDescription)
}
}
}
More information
My program has a class "Player", with subclasses such as "Human" and "Monster".
By default, my class player has some audio files for attacks, dying, etc.
Under some conditions, the "player" can become a human or a monster and get custom attack and dying sounds.
Thanks a lot for your help! ;)

Answer 1

Why are you initializing you player with a viewController ? You dont need that.
Change the Player class to:
import Foundation
import AVFoundation
class Player {
// Variables
var audioFile: AVAudioPlayer!
// Initializer
init() {
// Set path for the attack sound
let audioSnd = NSBundle.mainBundle().pathForResource("test", ofType: "wav")
let audioFileURL = NSURL(fileURLWithPath: audioSnd!)
do {
try audioFile = AVAudioPlayer(contentsOfURL: audioFileURL, fileTypeHint: nil)
audioFile.prepareToPlay()
} catch let err as NSError {
print(err.debugDescription)
}
}
// Methods
func playAudioFile() {
if audioFile.playing {
audioFile.stop()
} else {
audioFile.play()
}
}
}
And your ViewController.swift to:
import UIKit
import AVFoundation
class ViewController: UIViewController {
var player1: Player!
override func viewDidLoad() {
super.viewDidLoad()
// Note, that you need to initialize the player1 variable
player1 = Player()
}
#IBAction func playAudio(sender: AnyObject) {
player1.playAudioFile()
}
}

Answer 2

Swift is functional programming, so it is way better to separate the audio operation and viewController into different file/class. Then they could be reused in any scenarios.
Audio part
import AVFoundation
class AudioPlayer {
// Singleton to keep audio playing anywhere
static let shared = AudioPlayer()
var player: AVAudioPlayer?
private init() {}
func play(url: URL) {
do {
try AVAudioSession.sharedInstance().setMode(.default)
try AVAudioSession.sharedInstance().setActive(true, options: .notifyOthersOnDeactivation)
player = try AVAudioPlayer(contentsOf: url)
guard let player = player else { return }
player.prepareToPlay()
player.play()
} catch {
print("error occurred")
}
}
}
ViewController
import UIKit
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
}
#IBAction func playAudio(sender: AnyObject) {
let audioSnd = NSBundle.mainBundle().pathForResource("test", ofType: "wav")
// don't use force unwrap
guard let audioFileURL = NSURL(fileURLWithPath: audioSnd) else { return }
// call the shared instance here
AudioPlayer.shared.play(url: url)
}
}