Make a playlist (start next song) in swift

Question

I have created a sound player in swift with AVFoundation. I am trying to start the next song in array when the playing song is finished. I was trying to implement this code

if (audioPlayer.currentTime >= audioPlayer.duration){
    var recentSong = songPlaylist[selectedSongNumber + 1]
    audioPlayer = AVAudioPlayer(contentsOfURL: NSURL(fileURLWithPath:
            NSBundle.mainBundle().pathForResource(recentSong, ofType: "mp3")!), error: nil)
    audioPlayer.play()
}

but I am not being able to implement this code (I do not know where to implement it).Here is my complete code

import UIKit
import AVFoundation
import AVKit

public var audioPlayer = AVPlayer()
public var selectedSongNumber = Int()
public var songPlaylist:[String] = ["song1", "song2"]
public var recentSong = "song1"
let playImage = UIImage(named: "Play.png") as UIImage!
let pauseImage = UIImage(named: "Pause.png") as UIImage!

class FirstViewController: UIViewController {

@IBOutlet weak var musicSlider: UISlider!

@IBOutlet weak var PlayPause: UIButton!

var audioPlayer = AVAudioPlayer(contentsOfURL: NSURL(fileURLWithPath:
    NSBundle.mainBundle().pathForResource(recentSong, ofType: "mp3")!), error: nil)

override func viewDidLoad() {
    super.viewDidLoad()

    musicSlider.maximumValue = Float(audioPlayer.duration)

    var timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: Selector("updateMusicSlider"), userInfo: nil, repeats: true)


    if (audioPlayer.currentTime >= audioPlayer.duration){

        var recentSong = songPlaylist[selectedSongNumber + 1]

        audioPlayer = AVAudioPlayer(contentsOfURL: NSURL(fileURLWithPath:
            NSBundle.mainBundle().pathForResource(recentSong, ofType: "mp3")!), error: nil)

        audioPlayer.play()

        }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

}
@IBAction func PlayPauseButton(sender: AnyObject) {

    if (audioPlayer.playing == false){
        audioPlayer.play()
        PlayPause.setImage(pauseImage, forState: .Normal)
    }else{
        audioPlayer.pause()
        PlayPause.setImage(playImage, forState: .Normal)
    }
}

@IBAction func StopButton(sender: AnyObject) {
    audioPlayer.stop()
    audioPlayer.currentTime = 0
    PlayPause.setImage(playImage, forState: .Normal)
}

@IBAction func musicSliderAction(sender: UISlider) {
    audioPlayer.stop()
    audioPlayer.currentTime = NSTimeInterval(musicSlider.value)
    audioPlayer.play()

}

func updateMusicSlider(){

    musicSlider.value = Float(audioPlayer.currentTime)

}

}

Answer 1

I am updating my code with something different:

import UIKit
import AVFoundation

class ViewController: UIViewController, AVAudioPlayerDelegate {

    var counter = 0
    var song = ["1","2","3"]
    var player = AVAudioPlayer()

    @IBOutlet weak var musicSlider: UISlider!

    override func viewDidLoad() {
        super.viewDidLoad()
        musicSlider.value = 0.0
    }

    func updateMusicSlider(){

        musicSlider.value = Float(player.currentTime)
    }

    @IBAction func playSong(sender: AnyObject) {

        music()
    }
    @IBAction func sliderAction(sender: AnyObject) {

        player.stop()
        player.currentTime = NSTimeInterval(musicSlider.value)
        player.play()
    }

    func music(){

        var audioPath = NSBundle.mainBundle().pathForResource("\(song[counter])", ofType: "mp3")!
        var error : NSError? = nil
        player = AVAudioPlayer(contentsOfURL: NSURL(string: audioPath), error: &error)
        musicSlider.maximumValue = Float(player.duration)
        var timer = NSTimer.scheduledTimerWithTimeInterval(0.05, target: self, selector: Selector("updateMusicSlider"), userInfo: nil, repeats: true)
        player.delegate = self
        if error == nil {
            player.delegate = self
            player.prepareToPlay()
            player.play()
        }
    }

    func audioPlayerDidFinishPlaying(player: AVAudioPlayer!, successfully flag: Bool)
    {
        println("Called")
        if flag {
            counter++
        }

        if ((counter + 1) == song.count) {
            counter = 0
        }

        music()
    }

}

You can do it this way.

Hope It will help and HERE is sample project for more Info.

Answer 2

You need to implement AVAudioPlayerDelegate Protocol's method:

optional func audioPlayerDidFinishPlaying(_ player: AVAudioPlayer!, successfully flag: Bool)

Documentation link

Play your next music item here.

But I will not recommend, since AVAudioPlayer can only play one item at a time. You need to instantiate again with another music item after completion. I will suggest you to use AVQueuePlayer. Detaled answer has been given here. Hope it helps!