# Tracking Your File Provider’s Changes Create an enumerator to track changes to your file provider’s content. ## Discussion While an enumerator is active, it also tracks any changes to its contents. The system only tracks changes to a document or folder while it has an active enumerator for that item (for example, while a document is open or a folder is being browsed). > Note: > The system always tracks changes to the working set. If it doesn’t have an active enumerator for the working set, it creates a new one.  When your file provider app or extension identifies a change to its content: - Call the [`NSFileProviderManager`](/documentation/FileProvider/NSFileProviderManager) class’s [`signalEnumerator(for:completionHandler:)`](/documentation/FileProvider/NSFileProviderManager/signalEnumerator(for:completionHandler:)) method to notify the system of the change. Pass the item’s identifier as the `containerItemIdentifier` property. - If the change affects the working set, call [`signalEnumerator(for:completionHandler:)`](/documentation/FileProvider/NSFileProviderManager/signalEnumerator(for:completionHandler:)) a second time. Pass the [`workingSet`](/documentation/FileProvider/NSFileProviderItemIdentifier/workingSet) constant as the `containerItemIdentifier` property. This tells the system to update the working set. After the system is alerted to the change, it calls [`enumerateChanges(for:from:)`](/documentation/FileProvider/NSFileProviderEnumerator/enumerateChanges(for:from:)) on any affected, active enumerations and updates the browser’s user interface as needed. This method is asynchronous. When it’s called, the enumerator gathers information about the items (perhaps from a remote server) in the background, and returns the results to the specified observer (an object that adopts the [`NSFileProviderChangeObserver`](/documentation/FileProvider/NSFileProviderChangeObserver) protocol). ## Topics ### Tracking Document Changes [Tracking Changes to Documents](/documentation/FileProvider/tracking-changes-to-documents) Track and report changes to open documents. ### Signaling Changes with Push Notifications [Using push notifications to signal changes](/documentation/FileProvider/using-push-notifications-to-signal-changes) Send push notifications to a device to signal changes from your server. --- 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)