Handles writing non-Core Data content to the additional content directory in the document’s file package.
- iOS 5.0+
- Mac Catalyst 13.0+
The URL for the additional content directory in the document’s file package.
Upon return, if a problem occurs, contains an error object that describes the problem.
An object that contains the additional content for the document at
nil if there is a problem.
You override this method to perform to manage non-Core Data content to be stored in the additional content directory in the document’s file package.
There is no need to invoke
A return value of
nil indicates an error condition. To avoid generating an exception, you must return a value from this method. If it is not always the case that there will be additional content, you should return a sentinel value (for example, an
NSNull instance) that you check for in
The object returned from this method is passed to
write is executed on a different thread, you must ensure that the object you return is thread-safe. For example, you might return an
NSData object containing an archive of the state you want to capture.
Additional content is not supported on iCloud.