The block to execute with the fetch results.
- iOS 8.0+
- macOS 10.10+
- tvOS 9.0+
- watchOS 3.0+
- Mac Catalyst 13.0+Beta
The block returns no value and takes the following parameters:
An error object containing information about a problem, or
nilif the results are retrieved successfully.
The operation object executes this block only once and it is your only chance to process the operation results. The block is executed before the operation’s completion block. Your block must be capable of executing on a background thread, so any tasks that require access to the main thread must be redirected accordingly.
If you intend to use this block to process results, set it before executing the operation or submitting the operation object to a queue.
This block reports an error of type
CKError when it retrieves only some of the record zones successfully. The
user dictionary of the error contains a
CKPartial key whose value is an
NSDictionary object. The keys of that dictionary are the IDs of the record zones that were not retrieved, and the corresponding values are error objects containing information about what happened.