AVAudioSession Swift

For Swift 3:

let session = AVAudioSession.sharedInstance()
    if (session.responds(to: #selector(AVAudioSession.requestRecordPermission(_:)))) {
        AVAudioSession.sharedInstance().requestRecordPermission({(granted: Bool)-> Void in
            if granted {
                Linphone.manager.callUser(username: username)

                print("granted")

                do {
                    try session.setCategory(AVAudioSessionCategoryPlayAndRecord)
                    try session.setActive(true)
                }
                catch {

                    print("Couldn't set Audio session category")
                }
            } else{
                print("not granted")
            }
        })
    }

Since iOS 7 you need check if it responds to selector requestRecordPermission:

I've tested this code using an iPhone 5S with iOS 8 Beta and it works perfectly. Once you grant permission, the system won't ask for it again.

It's worth saying that it didn't ask for permission when using the Simulator.

This is the code I've tried and is working:

if (session.respondsToSelector("requestRecordPermission:")) {
    AVAudioSession.sharedInstance().requestRecordPermission({(granted: Bool)-> Void in
        if granted {
            println("granted")
            session.setCategory(AVAudioSessionCategoryPlayAndRecord, error: nil)
            session.setActive(true, error: nil)
            self.recorder ()
        } else{
            println("not granted")
        }
     })

}