How can I copy a file from DocumentPicker to my own application? - swiftui

Question

I'm asking the user to select an image or file in the "Folder" application in iPhone with DocumentPicker. How can I transfer this selected file or image to my own application?
I got this error: Error Domain=GSLibraryErrorDomain Code=3 "Generation not found" UserInfo={NSDescription=Generation not found
Sheet:
.sheet(isPresented: $isOpenDocumentPicker, onDismiss: {
self.isOpenDocumentPicker = false
}, content: {
DocumentPicker(fileContent: $fileContent)
})
DocumentPicker:
struct DocumentPicker: UIViewControllerRepresentable {
#Binding var fileContent: String
func makeCoordinator() -> DocumentPickerCoordinator {
return DocumentPickerCoordinator(fileContent: $fileContent)
}
func makeUIViewController(context: UIViewControllerRepresentableContext<DocumentPicker>) -> UIDocumentPickerViewController {
let controller: UIDocumentPickerViewController
controller = UIDocumentPickerViewController(forOpeningContentTypes: [.text, .pdf, .folder, .jpeg, .png, .gif, .exe, .data], asCopy: true)
return controller
}
func updateUIViewController(_ uiViewController: UIDocumentPickerViewController, context: UIViewControllerRepresentableContext<DocumentPicker>) {
}
}
class DocumentPickerCoordinator: NSObject, UIDocumentPickerDelegate, UINavigationControllerDelegate {
#Binding var fileContent: String
init(fileContent: Binding<String>) {
_fileContent = fileContent
}
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
let fileURL = urls[0]
do {
fileContent = try String(contentsOf: fileURL, encoding: .utf8)
} catch let error {
print("error: \(error)")
}
}
}

Answer 1

According to Apples documentation you have to call startAccessingSecurityScopedResource() before accessing a files content.
In your case I'd update the documentPicker() function as follows:
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
let fileURL = urls[0]
guard fileURL.startAccessingSecurityScopedResource() else {
// Handle denied access
return
}
defer { fileURL.stopAccessingSecurityScopedResource() }
do {
fileContent = try String(contentsOf: fileURL, encoding: .utf8)
} catch let error {
print("error: \(error)")
}
}