Presenting selected documents
Display user-selected documents over your browser view controller.
Overview
When the user selects one or more documents in the browser view controller, the system calls your delegate’s documentBrowser(_:didPickDocumentURLs:) method.
Display documents with document view controllers
In your implementation of the documentBrowser(_:didPickDocumentURLs:) method, modally present a view controller to display the selected documents by calling the browser’s present(_:animated:completion:) method.
The document view should fill the entire screen, but it can have its own split view controller, navigation controller, or tab controller, as appropriate. It remains onscreen as long as the user is interacting with the documents. To return to the browser, dismiss the document view controller.