Selecting folders with UIDocumentBrowserViewController

Question

I'm developing a new app and I would like the user to be able to select a folder from iCloud or an external drive. How can I allow them to select a folder using a UIDocumentBrowserViewController?

I have tried setting the allowedContentTypes to the UTI of folders, 'public.directory', but the document browser doesn't allow folders to be selected.

UIDocumentBrowserViewController(forOpeningFilesWithContentTypes: ["public.directory"])

Answer 1

Here is an official Apple solution for iOS 13:

let documentPicker = UIDocumentPickerViewController(documentTypes: [kUTTypeFolder as String], in: .open)
documentPicker.delegate = self
documentPicker.directoryURL = startingDirectory
present(documentPicker, animated: true)

The constant kUTTypeFolder comes from import CoreServices.