Make a network call when textfield has entered - swift

Question

I have an alertview with textfield, and would like to make call if a user enters something in the text field and confirm it. I am confused how to handle this workflow.
func btnTapped(cell: UICollectionViewCell) {
let indexPath = self.collectionView.indexPath(for: cell)
openAlert()
// I want to move the following part once user enters textfield in the alertview
fetchData(urlString: url, data: data[indexPath.row]) { [weak self] (response, error) in
if error == nil
{
DispatchQueue.main.async {
//do any ui update here!
self?.collectionView.reloadData()
}
}
}
}
func openAlert(){
let alertController = UIAlertController(title: "Alert", message: "", preferredStyle: .alert)
alertController.addTextField { (textField : UITextField!) -> Void in
textField.placeholder = "Enter reason"
}
let saveAction = UIAlertAction(title: "Confirm", style: .default, handler: { alert -> Void in
if let textField = alertController.textFields?[0] {
if textField.text!.count > 0 {
print("Text :: \(textField.text ?? "")")
}
}
})
let cancelAction = UIAlertAction(title: "Cancel", style: .default, handler: {
(action : UIAlertAction!) -> Void in })
alertController.addAction(cancelAction)
alertController.addAction(saveAction)
alertController.preferredAction = saveAction
self.present(alertController, animated: true, completion: nil)
}

Answer 1

You need to work with the text field delegates and use textFieldDidChange, then anytime the text is changed on the alert, call the API. Here is a quick example:
func textFieldDidChange(_ textField: UITextField) {
// Make API call here
}
Then in the completion block for the API call, set whatever data you would like depending on if the API confirmed or did not confirm.