An opaque generation identifier, returned as an
id <NSCopying, NSCoding, NSObject> (read-only)
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+Beta
- tvOS 9.0+
- watchOS 2.0+
The generation identifier can be compared using isEqual: to determine if the data in a document has been modified. For URLs which refer to the same file inode, the generation identifier changes when the data in the file's data fork is changed. Changes to extended attributes or other file system metadata do not change the identifier. For URLs which refer to the same directory inode, the generation identifier changes when direct children of that directory are added, removed or renamed. Changes to the data of the direct children of that directory does not change the generation identifier. The identifier persists across system restarts. It is tied to a specific document on a specific volume and is not transferred when the document is copied to another volume. This property is not supported by all volumes.
Other Resource Keys
static let addedToDirectoryDateKey: URLResourceKey
The time at which the resource’s was created or renamed into or within its parent directory, returned as an
NSDate. Inconsistent behavior may be observed when this attribute is requested on hard-linked items. This property is not supported by all volumes. (read-only)
static let attributeModificationDateKey: URLResourceKey
The time at which the resource’s attributes were most recently modified, returned as an
NSDate object if the volume supports attribute modification dates, or
nil if attribute modification dates are unsupported (read-only).
static let isExecutableKey: URLResourceKey
Key for determining whether the current process (as determined by the EUID) can execute the resource (if it is a file) or search the resource (if it is a directory), returned as a Boolean
NSNumber object (read-only).
This documentation contains preliminary information about an API or technology in development. This information is subject to change, and software implemented according to this documentation should be tested with final operating system software.Learn more about using Apple's beta software