The block to execute with progress information for individual records.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 3.0+
The block returns no value and takes the following parameters:
The ID of the record that is being retrieved.
The amount of the record that has been downloaded, represented as a percentage of the total. The range of this value is
0means nothing has been downloaded, and
1means the download is complete.
The operation object executes this block zero or more times for each record ID in the
record property. Each time the block is executed, it is executed serially with respect to the other progress blocks of the operation. You can use this block to track the ongoing progress of the download operation and possibly to provide feedback to the user.
If you intend to use this block to process results, set it before executing the operation or submitting the operation object to a queue.