Swift: use of 'self' in method call before super.init initializes self compile error

Question

I made a custom class that handles audio recording/playback and put a Protocol in that class. I implemented the Protocol in a UIViewController class and called my setDelegate method for my AudioHelper class.

I am getting a compile error that has to do with my init(). Not exactly sure how to get rid of the error:

use of 'self' in method call 'setupAudioSession' before super.init initializes self

override init() {         setupAudioSession()         super.init()     } 

How do I resolve this error? And why do I have to override init()?

My AudioHelper class

import Foundation import AVFoundation  class AudioHelper: NSObject, AVAudioRecorderDelegate {      var audioSession: AVAudioSession?     var audioRecorder: AVAudioRecorder?     var delegate: AudioRecorderProtocol?      class var sharedInstance: AudioHelper {          struct Static {             static var instance: AudioHelper?             static var token: dispatch_once_t = 0         }          dispatch_once(&Static.token) {             Static.instance = AudioHelper()         }          return Static.instance!     }      override init() {         setupAudioSession()         super.init()     }      func setDelegate(delegate: AudioRecorderProtocol) {         self.delegate = delegate     }      func setupAudioSession() {         audioSession = AVAudioSession.sharedInstance()         audioSession?.setCategory(AVAudioSessionCategoryPlayAndRecord, error: nil)         audioSession?.setActive(true, error: nil)     }      func createAudioMessageDirectory() {         let fm = NSFileManager.defaultManager()         if !fm.fileExistsAtPath(GlobalVars.kAudioMessageDirectory) {             var error: NSError?             if !fm.createDirectoryAtPath(GlobalVars.kAudioMessageDirectory, withIntermediateDirectories: true, attributes: nil, error: &error) {                 println("Unable to create audio message directory: \(error)")             }         }     }      // MARK: Recording      func beginRecordingAudio() {         createAudioMessageDirectory()         var filepath =  GlobalVars.kAudioMessageDirectory.stringByAppendingPathComponent("audiofile.aac")         var url = NSURL(fileURLWithPath: filepath)          var recordSettings = [             AVFormatIDKey: kAudioFormatMPEG4AAC,             AVSampleRateKey: 8000.0,             AVNumberOfChannelsKey: 1,             AVEncoderBitRateKey: 12800,             AVLinearPCMBitDepthKey: 16,             AVEncoderAudioQualityKey: AVAudioQuality.Max.rawValue         ]          println("Recorded Audio Message Saved: \(url!)")          var error: NSError?         audioRecorder = AVAudioRecorder(URL: url, settings: recordSettings as [NSObject : AnyObject], error: &error)          if error == nil {             if audioRecorder != nil {                 audioRecorder!.delegate = self                 audioRecorder!.record()             }         }         else {             println(error!.localizedDescription)         }     }      func stopRecordingAudio() {         if audioRecorder != nil {             audioRecorder!.stop()         }     }      func handleRecordAudioButtonLongPressGestureForState(state: UIGestureRecognizerState) {         if state == UIGestureRecognizerState.Ended {             stopRecordingAudio()             delegate?.onRecordAudioStop()         }         else if state == UIGestureRecognizerState.Began {             beginRecordingAudio()             delegate?.onRecordAudioStop()         }     }      func audioRecorderDidFinishRecording(recorder: AVAudioRecorder!, successfully flag: Bool) {         println("Record Audio Success: \(flag)")         delegate?.onRecordAudioFinished()     }      func audioRecorderEncodeErrorDidOccur(recorder: AVAudioRecorder!, error: NSError!) {         println("Record Audio Encode Error: \(error.localizedDescription)")     }      // MARK: Playback      func playAudioMessageFromUrl(messageId: String) {         if let url = NSURL(string: GlobalVars.kUrlAudioMessage + messageId) {             if let data = NSData(contentsOfURL: url) {                 var error: NSError? = nil                 let audioPlayer = AVAudioPlayer(data: data, error: &error)                  if error == nil {                     if audioPlayer != nil {                         audioPlayer.numberOfLoops = 0                         audioPlayer.volume = 1.0                         audioPlayer.prepareToPlay()                         audioPlayer.play()                     }                 }                 else {                     println("Audio playback error: \(error?.localizedDescription)")                 }             }         }     }  }  protocol AudioRecorderProtocol {     func onRecordAudioStart()     func onRecordAudioStop()     func onRecordAudioFinished() } 

My UIViewController that implements the protocol (cut out extraneous code)

class ChatViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, AudioRecorderProtocol {      let audioHelper = AudioHelper.sharedInstance      let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate      override func viewDidLoad() {         super.viewDidLoad()  //        addDemoMessages()          setupGestureRecognizer()         setupKeyboardObserver()         setupViews()         setupTableView()         audioHelper.setDelegate(self)     }      override func viewWillAppear(animated: Bool) {         super.viewWillAppear(animated)         getUsersFromDb()         getMessagesFromDb()     }      override func viewDidAppear(animated: Bool) {         super.viewDidAppear(animated)         setCurrentVC()         tableView.reloadData()          if partnerUserId != nil && !db.doesUserExist(partnerUserId!) {             HttpPostHelper.profileGet(userId: partnerUserId!)         }          requestMessagesFromServer()     }      override func viewDidLayoutSubviews() {         super.viewDidLayoutSubviews()         ViewHelper.scrollTableViewToBottom(tableView)     }      override func didReceiveMemoryWarning() {         super.didReceiveMemoryWarning()         // Dispose of any resources that can be recreated.     }      func handleRecordAudioButtonHold(sender: UILongPressGestureRecognizer) {         audioHelper.handleRecordAudioButtonLongPressGestureForState(sender.state)     }      func onRecordAudioStart() {         dispatch_async(dispatch_get_main_queue(), {             ViewHelper.showToast(NSLocalizedString("RECORDING", comment: ""))             self.recordAudioButton.imageView!.image = UIImage(named: "RecordAudioClicked")         })     }      func onRecordAudioStop() {         dispatch_async(dispatch_get_main_queue(), {             self.recordAudioButton.imageView!.image = UIImage(named: "RecordAudio")         })     }      func onRecordAudioFinished() {         HttpPostHelper.messageAudio(partnerUserId: partnerUserId)     }      func playAudioFromUrl(sender: UIButton) {         let messageId = messages[sender.tag].id         audioHelper.playAudioMessageFromUrl(messageId)     }  } 

Answer 1

Just place it under super.init().

The object needs to be initialized first by the super class and then you can do your custom initialization.

override init() {     super.init()     setupAudioSession() }