Switch View Controller From TableViewCell Class in Swift

Question

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?

Answer 1

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
}