pub unsafe static NSFileProviderWorkingSetContainerItemIdentifier: &'static NSFileProviderItemIdentifierNSFileProviderItem only.Expand description
The item identifier of the working set, a synthetic container used by the extension to communicate changes to the system even when the parent directories of these items aren’t actively being enumerated. Items in this set should have their parentItemIdentifier set to the identifier of their parent directory.
The working set is the set of files and directories that should be made available to the system regardless of the local browsing history. Files listed in the working set are indexed in the local Spotlight index and appear in offline search results. They contribute to the Recents view of the Files app, sorted by lastUsedDate, and it is therefore important to provide a consistent experience across devices by including in the working set all the documents recently used, trashed, favorited, shared or tagged.
The Spotlight index and the Recents view will show outdated information unless the file provider extension keeps the working set up to date with local and remote changes. When an item in the working set is remotely modified, the extension calls -signalEnumeratorForContainerItemIdentifier: on the identifier of the working set; the system will then enumerate changes and update its caches.
Starting in iOS 12 and macOS 10.15, the system maintains a cache on the local file system of files and directories previously enumerated. The working set is the container used to update that set of files. The extension may know whether an item is in that set by checking whether its parentItemIdentifier is listed in the materialized containers, see the documentation on -materializedItemsDidChangeWithCompletionHandler:.
See also Apple’s documentation