init(previousServerChangeToken:)
Creates an operation for fetching database changes.
Declaration
convenience init(previousServerChangeToken: CKServerChangeToken?)Parameters
- previousServerChangeToken:
The change token that CloudKit uses to determine which database changes to return.
Discussion
After creating the operation, assign a handler to the fetchDatabaseChangesCompletionBlock property so that you can process the operation’s results.
If this is your first fetch, or if you want to refetch all zones, pass nil for the change token. If you provide a change token from a previous CKFetchDatabaseChangesOperation, CloudKit returns only the zones with changes since that token. The per-database CKServerChangeToken isn’t the same as the per-record zone CKServerChangeToken from CKFetchRecordZoneChangesOperation.