Question

I am making minor edits to a QTMovie in an application using NSDocument architecture (such as adding a track, as shown below). After the edit, I want to save to the original file. However, I keep getting a ‘file is busy’ error. I assume this is due to some oversight I made in the handling of the files, or a failure in how I am using NSDocument. Any tips would be helpful! Here is (some of) the relevant code:

// open file that has the track I want to add to my movie
QTMovie* tempMovie = [QTMovie movieWithURL:outputFileURL error:nil];

// Use old API to add the track 
AddMovieSelection([movie quickTimeMovie], [tempMovie quickTimeMovie]);

// get the filename from the NSDocument
NSString *filename = [[self fileURL] path];
NSLog(@"writing to filename: %@", filename);

// FLATTEN the movie file so I don't get external references
NSMutableDictionary *attributes = [NSMutableDictionary dictionaryWithCapacity:1];
[attributes setObject:[NSNumber numberWithBool:YES] forKey:QTMovieFlatten];

// attempt to write
NSError *error;
//  this is where I get the "file is busy"
if (![movie writeToFile:filename withAttributes:attributes error:&error]) {
    NSLog(@"Error: %@", [error localizedDescription]);
    NSRunAlertPanel(@"Error", [error localizedDescription], nil, nil, nil);
}    

Do I have to first release the movie in my NSDocument? What is the “proper” way to do that? Keep in mind, I am not necessarily finished with this document, I am not closing it. I have just finished this operation, and I want the file on disk to reflect my changes. I would love to use [movie updateMovieFile], but that call doesn’t seem to flatten the movie. I don’t want any external references in my file.

Answer 1

Turns out I just wasn’t using the NSDocument architecture properly. When I changed it to use Save/SaveAs properly, this problem went away.