Exposing an app's ubiquitous container to iCloud Drive in iOS 8

I was experiencing a similar problem with my application. I was able to make this work by doing the following:

1. Add the NSUbiquitousContainers setting to my Info.plist file according to documentation here https://developer.apple.com/library/prerelease/ios/documentation/General/Conceptual/ExtensibilityPG/FileProvider.html. Here is the relevant code:

   <dict>
       <!-- ... other top-level Info.plist settings ... -->
       <key>NSUbiquitousContainers</key>
       <dict>
           <key>iCloud.com.example.MyApp</key>
           <dict>
               <key>NSUbiquitousContainerIsDocumentScopePublic</key>
               <true/>
               <key>NSUbiquitousContainerSupportedFolderLevels</key>
               <string>Any</string>
               <key>NSUbiquitousContainerName</key>
               <string>MyApp</string>
           </dict>
       </dict>
   </dict>
   

2. Important! I then changed the above NSUbiquitousContainerSupportedFolderLevels string value from Any to One

   <key>NSUbiquitousContainerSupportedFolderLevels</key>
   <string>One</string>
   

3. Next, and last, I had to change CFBundleVersion to a higher version. I also bumped the CFBundleShortVersionString to a new version as well.

Built and ran and after that, the folder with my applications icon appeared properly in iCloud Drive! Hope this helps!

When you edited the Info.plist, maybe you forgot to bump up the bundle version number? This is a requirement as per WWDC session #234.

The catch is to call [[NSFileManager defaultManager] URLForUbiquityContainerIdentifier:nil]; (or with another container identifier if it's not the default one) at least once (not per launch, but presumably per version, or when changing one of the respective PLIST entries) in order to initialize the directory. I reckon this step needs to be combined with an increase of the bundle version number, as suggested in roop's answer.

I notice my question may have been confusing in that respect, as I mentioned being able to look into the documents directory* programmatically using the API in question. However, I removed that code from the app later, maybe before getting the rest of the setup right. I'm not going to write into the documents directory directly, only through the Document Picker. Therefore, there hasn't been any need to get the URL.

If you just need a Document Picker to read/store files from/in iCloud Drive or other apps' document directories, there's no need to call URLForUbiquityContainerIdentifier:. Only if you want your app to have its own ubiquity container (and potentially expose it in iCloud Drive and the Document Picker), the steps mentioned in the original post and the call to URLForUbiquityContainerIdentifier: are necessary.

*When mentioning the documents directory, I'm always referring to the one in the ubiquity container, not the local one.