How to Read Data from Text File iOS 15 [duplicate] - swift

Question

This question already has answers here:
UIDocumentPickerViewController is not working when testing with my iPad but fine with simulators
(2 answers)
Closed 12 months ago.
Update: This code works in the simulator, but not on my device. Obviously, I'm needing it to work on both.
I've followed the tutorials, yet I cannot seem to get this feature to work. When the user selects the barButtonItem, DocumentPicker opens allowing the user to select a .txt file. I then take the URL to the selected file and attempt to return a string from it; however, I'm getting the following error: "The file “Test.txt” couldn’t be opened because you don’t have permission to view it." What am I missing? Did I fail to ask for permission somewhere? I've tried cleaning the build folder - didn't work.
#IBAction func importFileBtnTapped(_ sender: Any) {
selectFiles()
}
func selectFiles() {
let types = UTType.types(tag: "txt",
tagClass: UTTagClass.filenameExtension,
conformingTo: nil)
let documentPickerController = UIDocumentPickerViewController(forOpeningContentTypes: types)
documentPickerController.delegate = self
self.present(documentPickerController, animated: true, completion: nil)
}
func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
guard let myURL = urls.first else {
let alert = SCLAlertView()
alert.showError("ERROR", subTitle: "Unable to retrieve document.")
return
}
let text = createStringFromSelectedFile(fileURL: myURL)
if text == "error" {
print("ERROR creating a string from the selected file.")
return
}
let separatedStrings = decipherString(text: text)
if separatedStrings.first == "error" {
print("ERROR deciphering the string in ClaimInfoViewController")
return
}
for string in separatedStrings {
print("\(string)")
}
print("import result: \(myURL)")
}
func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
dismiss(animated: true, completion: nil)
}
func createStringFromSelectedFile(fileURL: URL) -> String {
var text = String()
do {
text = try String(contentsOf: fileURL)
}
catch {
print("ERROR in the createStringFromSelectedFile function in ClaimInfoViewController")
print("The error: \(error.localizedDescription)")
let alert = SCLAlertView()
alert.showError("ERROR", subTitle: "Unable to read the file. Please try again.")
return "error"
}
return text
}
func decipherString(text: String) -> [String]{
let newText = text
let startIndexes = ["<Claim#",
"<File#",
"<DateOfLoss:"
]
var claimNumber = String()
var fileNumber = String()
var dateOfLoss = String()
for indexValue in startIndexes {
guard let index = newText.firstIndex(of: ">") else { return ["error"] }
let newString = String(newText[..<index])
if indexValue == "<Claim#" {
claimNumber = newString
}
else if indexValue == "<File#" {
fileNumber = newString
}
else if indexValue == "<DateOfLoss:" {
dateOfLoss = newString
}
}
let finalText = [claimNumber, fileNumber, dateOfLoss]
return finalText
}

Answer 1

Thanks to matt, who commented above, I was able to find out that it's a security issue. Adding this simple code resolved the issue:
let shouldStopAccessing = pickedFolderURL.startAccessingSecurityScopedResource()
defer {
if shouldStopAccessing {
pickedFolderURL.stopAccessingSecurityScopedResource()
}
}
I added it right before this line of code that can be seen above:
let text = createStringFromSelectedFile(fileURL: myURL)
I got this code from here: StackOverflow Post