Perform UIDocumentPickerView in a TableViewCell

Question

I'm trying to open a picker file menu. To perform this, I create a class like so:

class pickerView: UIDocumentPickerViewController, UIDocumentPickerDelegate, LTHM_Pickerable {

func importTapped() {
    //Create a picker specifying file type and mode
    let documentPicker = UIDocumentPickerViewController(documentTypes: [String(kUTTypePNG)], in: .import)
    documentPicker.delegate = self
    documentPicker.allowsMultipleSelection = false
    documentPicker.modalPresentationStyle = .fullScreen
    present(documentPicker, animated: true, completion: nil)
}

public func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
    guard controller.documentPickerMode == .import, let url = urls.first, let image = UIImage(contentsOfFile: url.path) else { return }
    
    controller.dismiss(animated: true)
}

public func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
    controller.dismiss(animated: true)
}

}

I want to call the function "importTapped" in a function with is in a class inheriting from UITableViewCell.

class LTHM_Sticker_Cell: UITableViewCell {
     @IBAction func createStickerOnTAp(_ sender: UIButton, forEvent event: UIEvent) {
         //CALL IMPORTTAPPED HERE
     }
}

can you please help me? I have tried with a protocol, but I'm not sure...

Answer 1

Having a UIDocumentPickerViewController subclass that creates an instance of the regular UIDocumentPickerViewController is a bit confusing, and it's missing a clear means to actually present it. You might want to try this protocol/delegate solution instead:

Define a protocol

protocol PickerPresenter: UIViewController {
    func presentPicker()
}

Create the view controller class that will contain your table view

class MyViewController: UIViewController  {
   // your implementation
}

Conform your view controller to the protocol

extension MyViewController: PickerPresenter {
    
    func presentPicker() {
        let documentPicker = UIDocumentPickerViewController(documentTypes: [String(kUTTypePNG)], in: .import)
        documentPicker.delegate = self
        documentPicker.allowsMultipleSelection = false
        documentPicker.modalPresentationStyle = .fullScreen
        present(documentPicker, animated: true, completion: nil)
    }
}

And to be the picker delegate

extension MyViewController: UIDocumentPickerDelegate {

    public func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
        guard controller.documentPickerMode == .import, let url = urls.first, let image = UIImage(contentsOfFile: url.path) else { return }
        // do something with the selected image
        controller.dismiss(animated: true)
    }

    public func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
        controller.dismiss(animated: true)
    }
}

Pass a reference to the view controller when you're dequeuing the cell

extension MyViewController: UITableViewDataSource {
    
    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        let cell = tableView.dequeueReusableCell(withIdentifier: "myCell") as! LTHM_Sticker_Cell
        cell.delegate = self
        return cell
    }
}

Finally, your cell class has a weak reference to the delegate, and calls it's delegate method when the button is tapped

class LTHM_Sticker_Cell: UITableViewCell {
    
    weak var delegate: PickerPresenter?
    
    @IBAction func createStickerOnTAp(_ sender: UIButton, forEvent event: UIEvent) {
        delegate?.presentPicker()
    }
}