passing data via segue using didSelectRowAt

Question

I want to pass data via segue from UITableViewController to a ViewController. The problem is that the data I want to pass the indexPath.row value (i.e the row selected in the UITableView).

I have declared declared a variable var counter: Int?in the ViewController which is known as foodinfo. This is my code in the UITableView:

var rowselected: Int?

override func viewDidLoad() {
    super.viewDidLoad()

}

//what happens when row is selected
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

    rowselected = indexPath.row

    func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        let destinationVC = segue.destination as! foodinfo
        destinationVC.counter = rowselected
    }

    self.performSegue(withIdentifier: "dayx", sender: self)
    }

for some reason the counter in the ViewController has a value of nil. what am i doing wrong?

Answer 1

Your prepare for segue should not be in inside override func tableView( move it so its like this:

 override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {

rowselected = indexPath.row
self.performSegue(withIdentifier: "dayx", sender: self)

}

also should be override:

   override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
     if segue.identifier == "dayx" {
    let destinationVC = segue.destination as! foodinfo
    destinationVC.counter = rowselected
    }
}

because override func prepareForSegue method is called after self.performSegue. So now you can successfully set the value rowSelected = indexPath.row inside override func tableView( and when self.performSegue is called it will correctly pass the data as set in the override func prepareForSegue