alerta.swift

fileprivate func alerta(titulo: String, mensaje: String) {

    // REF: How to use UIAlertController in Swift: https://medium.com/ios-os-x-development/how-to-use-uialertcontroller-in-swift-70143d7fbede
    let alertController = UIAlertController(title: titulo, message: mensaje, preferredStyle: .alert)

    let accion = UIAlertAction(title: "Ok", style: .default) { (action: UIAlertAction) in
        // Acciones cuando se pulsa en OK
    }

    alertController.addAction(accion)

    self.present(alertController, animated: true, completion: nil)
}