The token that identifies the starting point for retrieving changes.
- iOS 10.0–12.0Deprecated
- macOS 10.12–10.14Deprecated
- Mac Catalyst 13.0–13.0Deprecated
- tvOS 10.0–12.0Deprecated
- watchOS 3.0–5.0Deprecated
Each fetch request returns a unique token in addition to any changes. The token is passed as a parameter to your
fetch handler. During a subsequent fetch request, providing the previous token causes the server to return only the changes that have occurred since the last fetch request. Tokens are opaque data objects that you can write to disk safely and reuse later.
Typically, you set the value of this property when you initialize the operation object. If you intend to change the record zone, update the value of the property before executing the operation or submitting it to a queue.