how pass data between view controller and TableViewController when using dismiss page that opened with performSegue in swift 4?

Question

I used this code here to pass data from first view controller to the second view controller

 override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if let vc = segue.destination as? secondViewController {
        vc.showPageType = self.checkEdit
   }

But the problem is that in the second view controller I have text field that when user fill that text field and push the button submit the secondViewController will be dismiss with this method

dismiss(animated: false, completion: nil)

and now I can't use perform segue method to pass textfield text to the first view controller how can I do that in swift4?

Answer 1

Add to your secondViewController source code file:

protocol SecondViewControllerDelegate {

    func submitButtonPushedWithText(_ text: String)
}

Add to class secondViewController property:

var delegate: SecondViewControllerDelegate?

Then conform your first controller to SecondViewControllerDelegate and implement method submitButtonPushedWithText(:):

class FirstViewController: UIViewController, SecondViewControllerDelegate {

    func submitButtonPushedWithText(_ text: String) {
        // use text from textField of second controller 
    }
}

Also setup delegate property of second controller before presenting:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if let vc = segue.destination as? secondViewController {
    vc.showPageType = self.checkEdit
    // setup delegate
    vc.delegate = self
}

Now you can call method submitButtonPushedWithText(_ text: String) in your Second controller just before calling dismiss(animated: false, completion: nil):

func submitButtonPushed() {
    delegate?.submitButtonPushedWithText(textField.text!)
    dismiss(animated: false, completion: nil)
}