Downloading files from iCloud

Maybe we can start with #1 and #2 – Would you mind to share the details of how you configure the intents and how you observe the issues?

In the simplest case, if I use coordinate(readingItemAt:options:error:byAccessor:) to coordinated read a file, I always see that the API downloads the file before calling my accessor.

Applying a coordinated read on a folder, however, doesn't necessarily download the folder recursively, and I'm curious if that is the case where you see the issues...

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

I first obtain the directory listing with NSMetadataQuery, which works fine. Once the query is done, I great an array of intents like this:

         for (NSMetadataItem *item in query.results) {
            NSURL *itemURL = [item valueForAttribute:NSMetadataItemURLKey];
            
            if (![allowedExtensions containsObject:itemURL.pathExtension.lowercaseString]) {
                continue;
            }
            NSFileAccessIntent *intent = [NSFileAccessIntent writingIntentWithURL:itemURL
                                                                          options:0];
            [intents addObject:intent];
        }

Then, after stoping the query and removing the notification observer for it, I create a coordinator with the intents array I created and use it:

        NSFileCoordinator *coordinator = [[NSFileCoordinator alloc] initWithFilePresenter:nil];
        
        [coordinator coordinateAccessWithIntents:intents
                                           queue:queue
                                      byAccessor:^(NSError *error) {
            // This gets called with error = nil in Airplane Mode
            for (NSFileAccessIntent *intent in intents) {
                // Sometimes, the file at intent.URL does not exist!
            }
        }];

Note that I use a writing intent because I sometimes need to update some of these files, but using a reading intent instead does not solve the issue.

Any update on this? I can't add iCloud support to my app without being able to safely download and sync files.

OK, I saw that the issue (that coordinateAccessWithIntents:queue:byAccessor: doesn't force a download of an iCloud Documents file) had been reported, which strongly indicates that it is a system bug. I suggest that you file your own feedback report to hopefully get more attentions – If you do so, please share your report ID here.

For a workaround, I am curious if using coordinateWritingItemAtURL:options:error:byAccessor: (or other variants) to do coordinated read or write one by one works. Did you try that? The API is synchronous, so you might want to call it from a global queue.

Best,
——
Ziqiao Chen
 Worldwide Developer Relations.

Unfortunately it seems like coordinateWritingItemAtURL:options:error:byAccessor: suffers from the same issue and calls, but coordinateReadingItemAtURL:options:error:byAccessor: does actually work. It's a bit annoying because it complicates both updating files and syncing multiple files (e.g. bundle-based formats), but it is something I can work around. It's very unfortunate that it's indeed a bug and not some API-misuse, because it seems to affect at least iOS 15 and up, and I'm targeting iOS 13-18.

Thanks for your help!