Swift 3 protocol extension using selector error

Question

I have what I thought to be a very simple protocol extension for my UIViewControllers providing the capability to dismiss a keyboard through a tap gesture. Here

Answer 1

Here is a similar use-case, you can call a method through a selector without using @objc as in swift by using the dynamic keyword. By doing so, you are instructing the compiler to use dynamic dispatch implicitly.

import UIKit

protocol Refreshable: class {

    dynamic func refreshTableData()

    var tableView: UITableView! {get set}
}

extension Refreshable where Self: UIViewController {

    func addRefreshControl() {
        tableView.insertSubview(refreshControl, at: 0)
    }

    var refreshControl: UIRefreshControl {
        get {
            let tmpAddress = String(format: "%p", unsafeBitCast(self, to: Int.self))
            if let control = _refreshControl[tmpAddress] as? UIRefreshControl {
                return control
            } else {
                let control = UIRefreshControl()
                control.addTarget(self, action: Selector(("refreshTableData")), for: .valueChanged)
                _refreshControl[tmpAddress] = control
                return control
            }
        }
    }
}

fileprivate var _refreshControl = [String: AnyObject]()

class ViewController: UIViewController: Refreshable {
    @IBOutlet weak var tableView: UITableView! {
        didSet {
            addRefreshControl()
        }
    }

    func refreshTableData() {
        // Perform some stuff
    }
}