well I notice it's like 4 months after you asked this question. Maybe this will be help for other seeking souls here.
Basically, on iOS you open a UIDocument first by querying all documents, then by opening what iCloud responds you with.
Here's how you start a query:
NSURL *baseURL = [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil];
if (baseURL)
{
_metadataQuery = [[NSMetadataQuery alloc] init];
[_metadataQuery setSearchScopes:[NSArray arrayWithObject:NSMetadataQueryUbiquitousDocumentsScope]];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"%K like '*'", NSMetadataItemFSNameKey];
[_metadataQuery setPredicate:predicate];
CL_DLog(@"Start query - %d",[_metadataQuery startQuery]);
}
Before doing code above, subscribe to these notifications to receive response
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(queryDidFinish:) name:NSMetadataQueryDidFinishGatheringNotification object:_metadataQuery];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(queryDidFinish:) name:NSMetadataQueryDidUpdateNotification object:_metadataQuery];
Then in your response you can open the document
YourUIDocumentClassName *document = [[YourUIDocumentClassName alloc] initWithFileURL:documentURL];
if ([document documentState] != UIDocumentStateClosed)
{
CL_DLog(@"FYI - metadata document state is not StateClosed.");
}
[document openWithCompletionHandler:^(BOOL success) {
....
You can check Apple's session on icloud and UIDocument https://developer.apple.com/videos/wwdc/2012/?id=218
Hope it helps.