What is the proper way to move a UIDocument to a new location on the file-system

Question

I have a document-based iOS application with a UIDocument subclass. I need to be able to move the file it represents on the file-system. I have considered moving it with an NSFileManager, but this would mess up the UIDocument's fileURL property. Any ideas on how to solve this little conundrum?

Answer 1

This might be old but still relevant.

What you want to do is the following:

For moving: move your file using NSFileCoordinator, inside the coordinator's block, call

[fileCoordinator itemAtURL:URL willMoveToURL:toURL];
[fileManager moveItemAtURL:newURL toURL:toURL error:&moveError];
[fileCoordinator itemAtURL:URL didMoveToURL:toURL];

For deleting: overwrite your UIDocument subclass or implement the file presenter protocol method accommodatePresentedItemDeletionWithCompletionHandler: to close the document.

- (void)accommodatePresentedItemDeletionWithCompletionHandler:(void (^)(NSError *))completionHandler;
{
[self closeWithCompletionHandler:^(BOOL success) {
    NSError *err;
    if (!success)
        err = [NSError error]; // implement your error here if you want

    completionHandler(err);
}];
}

Thus ensuring it will correctly handle being moved.

Answer 2

You can rename a UIDocument by first closing it, and then in the completion handler, moving the file using NSFileManager. Once the file has been successfully moved, initialize a new instance of your UIDocument subclass using the new file URL:

NSURL *directoryURL = [_document.fileURL URLByDeletingLastPathComponent];    
NSFileManager *fileManager = [[NSFileManager alloc] init];    
NSString *filePath = [directoryURL.path stringByAppendingPathComponent:@"NewFileName"];

[_document closeWithCompletionHandler:^(BOOL success) {
    NSError *error;

    if (success)
        success = [fileManager moveItemAtPath:_document.fileURL.path toPath:filePath error:&error];

    if (success) {
        NSURL *url = [NSURL fileURLWithPath:filePath];

        // I handle opening the document and updating the UI in setDocument:
        self.document = [[MyDocumentSubclass alloc] initWithFileName:[url lastPathComponent] dateModified:[NSDate date] andURL:url];
    } else {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:nil message:@"Unable to rename document" delegate:nil cancelButtonTitle:@"Dismiss" otherButtonTitles:nil];
        [alert show];
        NSLog(@"Unable to move document: %@", error);
    }
}];