# wantsIncrementalChangeDetails A Boolean value that determines whether your app receives detailed change information for the objects in the fetch result. ``` var wantsIncrementalChangeDetails: Bool { get set } ``` ## Discussion If you have registered a change observer with the shared [`PHPhotoLibrary`](/documentation/Photos/PHPhotoLibrary) object, fetching assets or collections automatically registers your observer to receive information about later changes to the fetch result and about the objects it contains. For a fetch result, change information (a [`PHFetchResultChangeDetails`](/documentation/Photos/PHFetchResultChangeDetails) object) can include a detailed list of incremental differences from the previous state of the fetch result, such as new photos captured since the original fetch. If `true` (the default), Photos sends detailed incremental changes when such information is available. If `false`, Photos tells your app only when the fetch result has changed (in which case you can perform the fetch again to receive updated results). --- Copyright © 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)