<!--
{
  "availability" : [
    "iOS: 15.0.0 -",
    "iPadOS: 15.0.0 -",
    "macCatalyst: 15.0.0 -",
    "macOS: 12.0.0 -",
    "tvOS: 15.0.0 -",
    "visionOS: -",
    "watchOS: 8.0.0 -"
  ],
  "documentType" : "symbol",
  "framework" : "CloudKit",
  "identifier" : "/documentation/CloudKit/CKModifySubscriptionsOperation/perSubscriptionSaveBlock-8y9zn",
  "metadataVersion" : "0.1.0",
  "role" : "Instance Property",
  "symbol" : {
    "kind" : "Instance Property",
    "modules" : [
      "CloudKit"
    ],
    "preciseIdentifier" : "s:So30CKModifySubscriptionsOperationC8CloudKitE24perSubscriptionSaveBlockySS_s6ResultOySo14CKSubscriptionCs5Error_pGtcSgvp"
  },
  "title" : "perSubscriptionSaveBlock"
}
-->

# perSubscriptionSaveBlock

The closure to execute when CloudKit saves a subscription.

```
var perSubscriptionSaveBlock: ((CKSubscription.ID, Result<CKSubscription, any Error>) -> Void)? { get set }
```

## Discussion

This property is a closure that returns no value and has the following parameters:

- The ID of the subscription that CloudKit saves.
- A <doc://com.apple.documentation/documentation/Swift/Result> that contains either
  - The subscription that CloudKit saves
  - An error that provides information about a failure saving the subscription.

The closure executes once for each subscription in the [`subscriptionsToSave`](/documentation/CloudKit/CKModifySubscriptionsOperation/subscriptionsToSave) property. Each time the closure executes, it executes serially with respect to the other subscription completion blocks of the operation.

If you intend to use this closure to process results, set it before you execute the operation or submit the operation to a queue.

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)