iCloud & NSFileWrapper: Showing as 2 different files in Settings

Question

I have an app that uses a UIDocument that is NSFileWrapper based. My file wrapper is a directory named "XXX.cp", with two sub-files "photo.data" and "photo.metadata". It seems to save and load documents fine, however when I go to Settings\Manage Storage\Unknown the sub-files are listed separately:

I was expecting it to show "XXX.cp" instead of these two sub-files. I think I have the document UTI set up and exported properly:

And I think I am creating the file wrappers correctly (especially since it reads/writes fine):

- (void)encodeObject:(id<NSCoding>)object toWrappers:(NSMutableDictionary *)wrappers preferredFilename:(NSString *)preferredFilename {    
    @autoreleasepool {                
        NSMutableData * data = [NSMutableData data];    
        NSKeyedArchiver * archiver = [[NSKeyedArchiver alloc] initForWritingWithMutableData:data];    
        [archiver encodeObject:object forKey:@"data"];    
        [archiver finishEncoding];   
        NSFileWrapper * wrapper = [[NSFileWrapper alloc] initRegularFileWithContents:data];    
        [wrappers setObject:wrapper forKey:preferredFilename];    
    }    
}        

- (id)contentsForType:(NSString *)typeName error:(NSError *__autoreleasing *)outError {        
    if (self.captionedPhotoMetadata == nil || self.captionedPhoto == nil) {    
        *outError = [[NSError alloc] initWithDomain:CaptionedPhotoErrorDomain code:CaptionedPhotoInvalidDocument userInfo:[NSDictionary dictionaryWithObjectsAndKeys:NSLocalizedString(@"Invalid document!", @""), NSLocalizedDescriptionKey, nil]];    
        return nil;        
    }    
    NSMutableDictionary * wrappers = [NSMutableDictionary dictionary];    
    [self encodeObject:self.captionedPhotoMetadata toWrappers:wrappers preferredFilename:METADATA_FILENAME];    
    [self encodeObject:self.captionedPhoto toWrappers:wrappers preferredFilename:DATA_FILENAME];       
    NSFileWrapper * fileWrapper = [[NSFileWrapper alloc] initDirectoryWithFileWrappers:wrappers];    
    return fileWrapper;        
}

But still no cigar. Anyone know what the problem is? Thanks!

Answer 1

Figured this out. The problem was you need to have a filename extension of 3 letters. Mine had only 2 letters: ".cp". I switched it to ".cap" and it worked :P