The block to execute with the contents of a changed record.
- iOS 10.0+
- macOS 10.12+
- Mac Catalyst 13.0+
- tvOS 10.0+
- watchOS 3.0+
The block returns no value and takes the following parameter:
The operation object executes this block once for each record in the zone that changed since the previous fetch request. Each time the block is executed, it is executed serially with respect to the other progress blocks of the operation. If no records changed, the block is not executed.
If you intend to use this block to process results, set it before executing the operation or submitting it to a queue.