How to write data to end of file using NSFileCoordinator while saving UIDocument to iCloud?

Question

Objective-C

Have your own UIDocument, redefined

writeContents:toURL:forSaveOperation:originalContentsURL:error:

and in it I try to write data to the end of the file using , but it only turns out to overwrite the file, all other options do not work, it gives an error. There is another method[NSFileCoordinator coordinateWritingItemAtURL::::]

coordinateReadingItemAtURL:options:writingItemAtURL:options:error:byAccessor:

but as I understand it, it is for different files, it is not clear how it can be used in my case. There is very little information on this subject. :(

Answer 1

Adding to the file is done through the handler, for example like this:

NSString *dir = [pathCache stringByAppendingPathComponent:[NSString stringWithFormat:@"%@.download", [itemToDownload fileName]]];
    if(data)
        [tmpData appendData:data];
    if(![tmpData length])
        return;
    NSFileHandle *handle = [NSFileHandle fileHandleForWritingAtPath:dir];
    [handle seekToEndOfFile];
    [handle writeData:tmpData];
    [handle closeFile];
    [tmpData setLength:0];

where tmpData is NSData