I'm creating an app that uses pictures from the camera.
I ask the user to take a picture then save it in my document folder. It appears that it is not deleted when the program exits.
How and where is this best done (appdelegate perhaps)?
If you want to get the files deleted when application exit, I would recommend you to use the /tmp directory instead. Read the documentation of File System.
Also if you just want to delete the files in documents directory, do it from applicationWillTerminate as follows:
NSArray *homePaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *homeDir = [homePaths objectAtIndex:0];
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error=nil;
NSArray *contents = [fileManager contentsOfDirectoryAtPath:homeDir error:nil];
for (NSString *file in contents) {
BOOL success = [fileManager removeItemAtPath:[homeDir stringByAppendingPathComponent:file] error:&error];
if(!success){
NSLog(@"couldn't delete file: %@",error);
}
}