Handling nil exceptions in objective-c

Question

Hey all I'm using a MPMoviePlayerController and trying to catch my exception when there is no movie present.

movies = [movieDictionary objectForKey:@"movieID"];

NSLog(@"callVideoSetting");
CGRect playfram = CGRectMake(0, 0, 320, 500);

stopButton = [UIButton buttonWithType:UIButtonTypeCustom];
[stopButton setFrame:playfram];
[stopButton addTarget:self action:@selector(stopVideo:) forControlEvents:UIControlEventTouchUpInside];

NSURL *movie = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:movies ofType:@"m4v"]];
//path for resource moet id worden 
theMovie = [[MPMoviePlayerController alloc] initWithContentURL:movie];
[theMovie setOrientation:UIDeviceOrientationPortrait animated:NO];

Now I wish to catch the exception when there is nothing behind movies.

-[NSURL initFileURLWithPath:]: nil string parameter'

I know I should have a try catch block.. But I've never handled exceptions in objective-c.

Answer 1

Simply use a variable:

NSString * path = [[NSBundle mainBundle] pathForResource:movies ofType:@"m4v"];

if (!path) {
  // error handling
}

NSURL *movie = [NSURL fileURLWithPath:path];

Answer 2

General try/catch block

@try
{
  // your call that throws the exception
}
@catch (NSException *e)
{
  // handle the exception
}