Adhering to UIDocumentPickerViewController

TableViewController.swift

public func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
    guard let myURL = urls.first else {
       return
    }
    print("import result : \(myURL)")
}

func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
    print("view was cancelled")
    dismiss(animated: true, completion: nil)
}

func selectFile() {
    let importMenu = UIDocumentPickerViewController(documentTypes: [(kUTTypeCommaSeparatedText as String)], in: .import)
    importMenu.delegate = self
    importMenu.modalPresentationStyle = .formSheet
    self.present(importMenu, animated: true, completion: nil)
}