How to pass data back to ViewController holding Container View and TableViewController that is embedded in the Container? Swift 3

Question

How can I call func checkField when nextButton is tapped? If no field is empty in ManagedTableEleventhViewController, I\'d like to segue to TwelvethViewController.

I hav

Answer 1

Thanks to this answer I have obtained the desired result.

class EleventhViewController: UIViewController {

@IBAction func nextButton(_ sender: Any) {
 var managed: ManagedTable? {
    return self.childViewControllers.last as! ManagedTable?
   //if there is no empty field after checkField(sender:_) is called,    
    // segue to TwelvethViewController
   managed?.checkField(sender: self)
    } 
  }
}



 class ManagedTableEleventhViewController {

 // holds a true value if textField contains a value
  var hasText:Bool!

 //holds a true/false value for each textField after iterating through them    
      //with a for loop
var textValues = [Bool]()

//When nextButton is touched in EleventhViewController, call this method
func checkField(sender:EleventhViewController) {


    for cell in self.tableView.visibleCells{
        for sub in cell.contentView.subviews{

            if sub is UITextField{

let textF = sub as? UITextField
         //if textField is empty, make its border red,else clear
                if textF?.text == "" {
                    self.hasText = false
                    self.textValues.append(self.hasText)
                    textF?.layer.cornerRadius = 8.0
                    textF?.layer.masksToBounds = true
                    textF?.layer.borderColor = UIColor.red.cgColor
                    textF?.layer.borderWidth = 1.0
                } else {
                    self.hasText = true
                    self.textValues.append(self.hasText)

                }
            }// end of if sub is UITextField

        }//end of for sub in cell.contentView

    } //end of  for cell in tableView

   //if no field is empty perform segue to TwelvethViewController, 
       //otherwise reset textValues array
      if !self.textValues.contains(false){
         sender.performSegue(withIdentifier: "eleventhToTwelveth", sender: sender)
        }
     self.textValues.removeAll()
    } //end of checkField(sender:_)
}//end of class