Trouble Passing Variable Info to First VC Using Closure

Question

I am trying to pass the data of which name was selected by the user in my ShipViewController to my ProfileViewController. I tried using closures to do so, but the title of the button in ProfileViewController (which presents the modal popover to ShipViewController) isn't changing to the name the user selects in ShipViewController.

Should it not be String --> () or is the way I instantiate my view controller incorrect?

(ShipViewController)

var completionHandler:((String) -> ())?

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {

    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "shipCell", for: indexPath) as! ShipViewCell

    if selectedIndex == indexPath.row {
        let result = completionHandler?(shipNames[selectedIndex!])
        self.dismiss(animated: true, completion: nil)
    }
}

(In viewDidLoad of ProfileViewController)
        let vc = storyboard?.instantiateViewController(withIdentifier: "ShipViewController") as! ShipViewController
    vc.completionHandler = { (text) -> ()in
        print(text)
        self.shipButton.setTitle(text, for: .normal)
    }

Why are you dismissing in cellForItemAt indexPath instead of didSelect ? — RajeshKumar R, Mar 26 '19 at 04:30

RajeshKumar R · Accepted Answer · 2019-03-26T04:48:08.400

1

Dismiss ShipViewController in didSelectItemAt

func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
        let result = completionHandler?(shipNames[indexPath.item])
        self.dismiss(animated: true, completion: nil)
}

In ProfileViewController Don't assign to completionHandler in viewDidLoad

Assign to completion handler in prepare for segue

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if segue.identifier == "showShip" {
        if let vc = segue.destination as? ShipViewController {
             vc.completionHandler = { (text) -> ()in
                  print(text)
                  self.shipButton.setTitle(text, for: .normal)
             }
        }
    }
}

edited Mar 26 '19 at 04:48

answered Mar 26 '19 at 04:33

RajeshKumar R

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How are you presenting ShipViewController? Show that code – RajeshKumar R Mar 26 '19 at 04:39
What do you mean by presenting the view controller? I have a popover that gets triggered when user clicks button but it's done through the storyboard. – Aza Mar 26 '19 at 04:42
Do you have identifier for the storyboard segue? – RajeshKumar R Mar 26 '19 at 04:45
Yayyyy!! Thank you. Could you briefly explain why this works? – Aza Mar 26 '19 at 04:54
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/190666/discussion-between-rajeshkumar-r-and-aza). – RajeshKumar R Mar 26 '19 at 05:01

Trouble Passing Variable Info to First VC Using Closure

1 Answers1