Swift Document Picker, can not reach the file

Question

I am writing a project which involves picking a file and getting the content of the file. However, I think it is not reaching the correct url of the file.

Here is the function where it calls the document picker. It is activated by a button.

@IBAction func selectFile(_ sender: Any) {
        let documentPicker = UIDocumentPickerViewController(documentTypes: [kUTTypePlainText as String], in: .import)
        documentPicker.delegate = self
        documentPicker.allowsMultipleSelection = false
        present(documentPicker, animated: true, completion: nil)
}

And here is the extension to UIDocumentPickerViewController

extension ViewController: UIDocumentPickerDelegate {
    func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        print(urls)
        do {
            let fileContent = try String(contentsOf: urls[0], encoding: .utf8)
            print(fileContent)
        } catch {
            return
        }
    }
}

In the console output, fileContent is not being printed out, instead, here is what it prints out.

Failed to associate thumbnails for picked URL
file:///Users/<user>/Library/Developer/CoreSimulator/Devices/480A2D02-810F-435E-BF44-4B2F6FC614A9/data/Containers/Data/Application/BAA825D0-C4D8-4B33-AFB3-3737ADCA0B29/Documents/test2.txt with the Inbox copy 
file:///Users/<user>/Library/Developer/CoreSimulator/Devices/480A2D02-810F-435E-BF44-4B2F6FC614A9/data/Containers/Data/Application/BAA825D0-C4D8-4B33-AFB3-3737ADCA0B29/tmp/<project>-Inbox/test2.txt: 
Error Domain=QLThumbnailErrorDomain Code=102 "(null)" 
UserInfo={NSUnderlyingError=0x600003348060 
{Error Domain=GSLibraryErrorDomain Code=3 "Generation not found" UserInfo={NSDescription=Generation not found}}}

There aren't many resources about this online, can someone help look at what I did wrong here?

Actually it is for iOS application right? – Joseph Feb 07 '20 at 19:43 — Joseph, Feb 07 '20 at 19:43

score 2 · Answer 1 · answered Feb 07 '20 at 19:54

Actually I made a small change on the UIDocumentPickerViewController initialiser. Adding the updated code below.

@IBAction func selectFile(_ sender: Any) {
    let documentPicker = UIDocumentPickerViewController(documentTypes: ["public.text"], in: .import)
    documentPicker.delegate = self
    documentPicker.allowsMultipleSelection = false
    present(documentPicker, animated: true, completion: nil) }

Rest of the code same, only replaced this ["public.text"] instead of [kUTTypePlainText as String].

May be it resolves your problem. Please let me know the feedback. Credit gose to adrian check this link using-uidocumentpickerviewcontroller-to-import-text-in-swift

How can that change make any difference? `kUTTypePlainText` already has the value `public.text`. — HangarRash, Apr 19 '23 at 18:18

score 2 · Answer 2 · answered Jan 03 '21 at 22:23

I know this is an old question, but if it is of help to anyone, I fixed the console issue by changing the instance type of UIDocumentPickerViewController, entering .open instead of .import

In my case, the behaviour does not change and I can choose a file without losing the expected behaviour.

score -1 · Answer 3 · answered Apr 19 '23 at 18:10

-1

File urls different because its like it said its importing to applications temp files if you choose .import. To get orginal file url you should choose .open

answered Apr 19 '23 at 18:10

Mehmet Karanlık

237
1
10

Please don't post duplicate answers. – HangarRash Apr 19 '23 at 18:18

Swift Document Picker, can not reach the file

3 Answers3