via #iphonedev on irc.freenode.net: AVAudioRecorder failed to initialize by crashing on initialization method

NSURL fileURLWithPathComponents fail

// Problem: AVAudioRecorder failed to initialize by crashing on initialization method
// Diagnosis: NSURL *audioURL was nil at audioRecorder initiliazation point because audioURL's weak declaration
// Solution: Declare NSURL *audioURL as strong to ensure it does not get deallocated prematurelys. 
// *Side note suggestion: Be sure to use [AVAudioRecorder record] instead of prepareToRecord since record will call it implicitly
//  and handle errors appropriately!

// properties
// @property (weak, nonatomic) NSURL *audioURL; /* User's original declaration */
@property (strong, nonatomic) NSURL *audioURL;
@property (strong, nonatomic) AVAudioRecorder *audioRecorder;

@synthesize audioURL = audioURL;
@synthesize audioRecorder = audioRecorder;

// implementation
- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    NSLog(@"FILE PATH :%@", NSTemporaryDirectory());
    
    // set audio file
    NSArray *pathComponents = [NSArray arrayWithObjects:
                               [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject],
                               @"MyAudioMemo.m4a",
                               nil];
    
    audioFileURL = [NSURL fileURLWithPathComponents:pathComponents];
    
    // audio session
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setCategory:AVAudioSessionCategoryPlayAndRecord error:nil];
    [session setActive:YES error:nil];
    NSDictionary *audioSettings = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithFloat:44100],AVSampleRateKey,[NSNumber numberWithInt:kAudioFormatAppleLossless], AVFormatIDKey, [NSNumber numberWithInt:1],AVNumberOfChannelsKey, [NSNumber numberWithInt:AVAudioQualityMedium], AVEncoderAudioQualityKey, nil];
    
    audioRecorder = [[AVAudioRecorder alloc] initWithURL:audioFileURL settings:audioSettings error:nil];
    audioRecorder.delegate = self;
    audioRecorder.meteringEnabled = YES;
    [audioRecorder prepareToRecord];
}