Alert view controller abstraction

AlertViewControllerImpl.swift

import Foundation

final class AlertViewControllerBuilder {
    
    var title: String?
    var message: String?
    var okHandler: AnonymousActionClosure?
    var cancelHandler: AnonymousActionClosure?

    typealias BuilderClosure = (AlertViewControllerBuilder) -> Void
    
    init(_ buildClosure: BuilderClosure) {
        buildClosure(self)
    }
}

final class AlertViewControllerImpl: AlertViewController {

    private var alert: UIAlertController
    
    init(_ builder: AlertViewControllerBuilder) {
        self.alert = UIAlertController(title: builder.title, message: builder.message, preferredStyle: .alert)
        let okAction = UIAlertAction(title: NSLocalizedString("OK", comment: ""), style: .default) { _ in
            builder.okHandler?()
        }

        self.alert.addAction(okAction)
        
        let cancelAction = UIAlertAction(title: NSLocalizedString("CANCEL", comment: ""), style: .default) { _ in
            builder.cancelHandler?()
        }
        
        self.alert.addAction(cancelAction)
    }
    
    func show(viewControllerPresenting: UIViewController, animated: Bool, completion: (() -> Void)?) {
        viewControllerPresenting.present(alert, animated: animated, completion: completion)
    }
}





// Alert functionality should be limited to AlertViewController, revisit
typealias Alert = AlertViewControllerImpl
typealias AnonymousActionClosure = () -> Void

protocol AlertViewController {

    init(_ builder: AlertViewControllerBuilder)

    func show(viewControllerPresenting: UIViewController, animated: Bool, completion: (() -> Void)?)
}




let alertBuilder = AlertViewControllerBuilder({ builder in
  builder.title = NSLocalizedString("GENERIC_ERROR_TITLE", comment: "")
  builder.message = NSLocalizedString("GENERIC_LOADING_ERROR_MESSAGE", comment: "")
  builder.okHandler = { self?.loadTopics() }
  })
self?.present(alert, animated: true, completion: nil)
Alert(alertBuilder).show(viewControllerPresenting: self!, animated: true, completion: nil)