shabib87

protocol CanDisplayHeroDetailsScreen {
    func displayHeroDetailsScreen(presenter aPresenter: Presenter)
}

extension CanDisplayHeroDetailsScreen where Self: UIViewController {
    
    func displayHeroDetailsScreen(presenter aPresenter: Presenter) {
        let detailsVC = HeroDetailsViewController.instantiateFromStoryboard(presenter: aPresenter)
        navigationController?.pushViewController(detailsVC, animated: true)
    }

shabib87

final class HeroListPresenter: Presenter {
    
    private let service: HeroService
    weak private var view : HeroListView?
    ...
    init(service: HeroService) {
        self.service = service
    }
    
    func attachView(view: HeroListView) {

shabib87

protocol HeroListView: NSObjectProtocol {
    func startLoading()
    func finishLoading()
    func reloadHeroList()
    func showEmptyListMessage()
    func gotoHeroDetails(presenter aPresenter: HeroDetailsPresenter)
}

shabib87

final class HeroDetailsViewController: RootViewController {

    override class func instantiateFromStoryboard(presenter aPresenter: Presenter) -> UIViewController {
        let vc = UIStoryboard(name: "Hero", bundle: nil)
            .instantiateViewController(withIdentifier: "HeroDetailsViewController")
            as! HeroDetailsViewController
        vc.presenter = aPresenter as? HeroDetailsPresenter
        return vc
    }
}

shabib87

class RootViewController: UIViewController, StoryboardInitializable {
    
    class func instantiateFromStoryboard(presenter aPresenter: Presenter) -> UIViewController {
        fatalError("Override failed. Dependency injection not processed. Presenter injection hampered.")
    }
    
    // Preventing segue to support dependency injection
    override func shouldPerformSegue(withIdentifier identifier: String, sender: Any?) -> Bool {
        fatalError("Segues should not be used. Presenter injection hampered.")
    }

shabib87

class Presenter {}
protocol StoryboardInitializable {
    static func instantiateFromStoryboard(presenter aPresenter: Presenter) -> UIViewController
}

shabib87

class Person {
  ...
}

class Apartment {
    ...
    weak var person: Person?
    ...
}

shabib87

var person: Person? = Person(name: "John Doe")
var apartment: Apartment? = Apartment(number: 123)
person?.apartment = apartment
apartment?.person = person
person = nil
apartment = nil

// output:
//

shabib87

class Person {
    ...
}

class Apartment {
    ...
    weak var person: Person?
    ...
}

shabib87

class HTMLElement {
    
    let name: String
    let text: String?
    
    lazy var asHTML: () -> String = {
        return "<\(self.name)>\(self.text)</\(self.name)>"
    }
    
    init(name: String, text: String? = nil) {