URLForUbiquityContainerIdentifier returns nil even if configured correctly

Question

I am having the problem, that URLForUbiquityContainerIdentifier is returning nil in some cases even if the user has set up everything correctly in the settings. My code:

dispatch_async(someQueue, ^{

    if (![[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil]) {
        ErrLog(@"iCloud container not available.");
        return;
    }

    dispatch_async(dispatch_get_main_queue(), ^{
       [...]
    });

});

Does anybody came across the same problem? I am setting nil as the container identifier which should work according to the Apple docs, but I am not so convinced anymore about that. Also this code works fine for the majority of users, but somehow not for everybody.

Answer 1

Check that you have enabled iCloud containers in your entitlement. The containers are not added by default when you enable entitlements. Click the "+" sign in Target/Summary/Entitlements to add your appId.

Answer 2

iPad mini with iOS7. I just have experienced that URLForUbiquityContainerIdentifier suddenly started to return nil. I tried restarting the device, but it didn't help.

Inside the Settings app, under the 'iCloud' menu. I noticed that 'Documents & Data' was set to Off.

Solution was to change 'Documents & Data' to 'On'.

Answer 3

If anyone is having the same problem using the iOS8 Betas, there seems to be a bug with the way the Entitlements are generated in Xcode 6. I was banging my head against this for days until coming across this post in the Apple Developer Forums: https://devforums.apple.com/thread/229509?

Essentially, Xcode generates a key named com.apple.developer.icloud-container-identifiers when it should be com.apple.developer.ubiquity-container-identifiers (ubiquity, not icloud). It may also have the value set as iCloud.$(CFBundleIdentifier) when it should be $(TeamIdentifierPrefix).$(CFBundleIdentifier).

Of course this may get fixed in the next Beta but for anyone as confused as me I hope this helps.