Nsryjdtyk

I would like to present a new ViewController when user clicks element in tableviewcell. The standard code for launching a VC, however, does not work from a tableview cell or even in a helper class because neither a TVC nor a helper class can present a view controller.

Here is the code in a helper class. Whether placed in the helperclass or the tableview cell, it doesn't have a present method to launch a VC.

class launchVC {

 func launchVCNamed(identifier: String) {

    let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

    let secondVC = storyBoard.instantiateViewController(withIdentifier: "contactDetail")

//FOLLOWING LINE HAS ERROR NO SUCH MEMBER (present)

    self.present(secondVC, animated: true, completion: nil)

    }

 }

How can I modify this to launch a VC?

Generally you should use delegate pattern, or closure to pass a block from cell back to view controller. I prefer using closures to delegates so I'll give such example:

class SomeCell: UITableViewCell {

    var actionBlock = { }



    func someActionOccured() { // some action like button tap in cell occured

        actionBlock()

    }

}

And in cellForRow in view controller you need to assign the closure

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as! SomeCell // replace cell identifier with whatever your identifier is

    cell.actionBlock = { [unowned self] in 

        let storyBoard: UIStoryboard = UIStoryboard(name: "Main", bundle: nil)

        let secondVC = storyBoard.instantiateViewController(withIdentifier: "contactDetail")

        self.present(secondVC, animated: true, completion: nil)

    }

    return cell

}

Add a delegate to your cell and assign it to the presentingVC. See below.

Using Delegation

Create a CustomCell that inherits from UITableViewCell.

class CustomCell: UITableViewCell {

    var cellDelegate : CustomCellDelegate = nil



    @IBAction func elementTapped() {

        cellDelegate?.launchVC()

    }

}

Custom Cell Delegate

protocol CustomCellDelegate {

    func launchVC()

}

MainViewController

class ViewController: UIViewController, UITableViewControllerDataSource, UITableViewDelegate {



    IBOutlet weak var tableView: UITableView!



    override func viewDidLoad() {

        tableView.dataSource = self

        tableView.delegate = self

    }



    func numberOfSections(in: UITableView) -> Int {

        return 1

    }



    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        return 1

    }



    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        if let cell = tableView.dequeueReusableCell(withIdentifier: "Cell") as? CustomCell {



            // important

            cell.delegate = self

            return cell

        }

    }

}

Extend ViewController to implement the protocol

extension ViewContrller: CustomCellDelegate {

    func launchVC() {

        let storyboard = UIStoryboard.init(name: "Main", bundle: nil)

        let vc = storyboard.instantiateViewController(withIdentifier: "SecondViewController")

        self.present(vc, animated: true, completion: nil)

    }

}