An operation used to fetch existing subscriptions from iCloud.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 6.0+
CKFetch object retrieves
CKSubscription objects (whose IDs you already know) from iCloud and can fetch all subscriptions associated with the current user.
You might fetch subscription objects so you can examine or modify their parameters; for example, to adjust the delivery options for push notifications generated by the subscription.
If you assign a completion block to the
completion property of the operation object, the completion block is called after the operation executes and returns its results to you. You can use a completion block to perform housekeeping chores related to the operation, but do not use it to process the results of the operation itself. Any completion block you specify should be prepared to handle the failure of the operation to complete its task, whether due to an error or an explicit cancellation.