Unique Identifier for iCloud / CloudKit User

Question

Is there a better solution (then the possible workaround below) to get an UUID for a iCloud / CloudKit User?
So it's possible to detect if the user already did something (on a different device) with same iCloud account.

Possible workaround:

• Create UUID and store it in the private database
  • Disadvantage: uses extra database requests

Answer 1

I found a possible solution:

Swift 2

CKContainer.default().fetchUserRecordID(completionHandler: { (recordID: CKRecordID?, error: NSError?) in
    print(recordID?.recordName) // UUID String for iCloud user
})

Swift 3

CKContainer.default().fetchUserRecordID(completionHandler: { (recordID: CKRecordID?, error: Error?) in
    print(recordID?.recordName) // UUID String for iCloud user
})

This id is the same across all devices using the same iCloud Account.