CloudKit : How to handle account changes with local persistent store?

Question

In my application i have to maintain a local persistent store in sync with cloud kit private database. So I just wanted to know how can I handle account changes that may happen.

Confusion I have is as below: say a set of records belong to user A now if user B log's in to the same phone I can do the following of the 2 things:

1. Ignore user and let data sync to B account too but that way A's data will get sync to B's private account too. Here the record change tag and all get a bit mess up since am saving CKRecord encoded fields to database.

2. I can maintain a user table and link each record to the user that is logged in that way user data will get separated. So should I maintain a user field along with all records ?

How can this be best handled even apart from above 2 things.

Answer 1

Of course in your local persistence store you could add the userID to personalize all records. An other mechanism is to remove all local data and fetch the users data when a change is detected. If you want to keep the users data on the device you could also create separate data stores for each user.

You can detect a changed login by adding the following code in your app delegate or root view controller:

NSNotificationCenter.defaultCenter().addObserverForName(NSUbiquityIdentityDidChangeNotification, object: nil, queue: nil) { _ in
     /// remove local data and fetch user data
}

You should also refresh all user related data in memory and refresh the loaded views.