UIManagedDocument doesn't import iCloud changes

Question

When I have a UIManagedDocument (which is inside an ubiquitous container) open on device A, while making changes to that document on device B, the changes are not imported into the CoreData stack on device A.

I see that changes arrive on device A because the method presentedSubitemDidChangeAtURL() is called on the document. If I close and re-open the document, I see those changes.

But I expect that UIManagedDocument automatically merges those changes into the managed object context, while the document is open. Is this not the case? The documentation doesn't say that I have to do that by myself.

---

I create my document with

let document = UIManagedDocument(fileURL:...)
document.persistentStoreOptions = [NSMigratePersistentStoresAutomaticallyOption: true, NSInferMappingModelAutomaticallyOption: true]

and move it to iCloud with

let fileManager = NSFileManager()
fileManager.setUbiquitous(true, itemAtURL: documentURL, destinationURL: url)

Answer 1

After getting help from Apple Developer Technical Support, it turns out that you have to include the NSPersistentStoreUbiquitousContentNameKey when setting up the persistent store.