Clean Swift - Routing without segues - ios

Question

I found Router in Clean Swift architecture is responsible to navigate and pass data between view controllers. Some samples and articles depict that Routers use segue to communicate with view controllers. What would be the convenient design when I don't want to use any segue from Storyboard. Is it possible to pass data without segue in Clean Swift? If you describe with simplest complete example, would be appreciated.

Answer 1

Article says that you can:
// 2. Present another view controller programmatically
You can use this to manually create, configure and push viewController.
Example.
Let's pretend that you have ViewController with button (handle push):
final class ViewController: UIViewController {
private var router: ViewControllerRouterInput!
override func viewDidLoad() {
super.viewDidLoad()
router = ViewControllerRouter(viewController: self)
}
#IBAction func pushController(_ sender: UIButton) {
router.navigateToPushedViewController(value: 1)
}
}
This ViewController has router that implements ViewControllerRouterInput protocol.
protocol ViewControllerRouterInput {
func navigateToPushedViewController(value: Int)
}
final class ViewControllerRouter: ViewControllerRouterInput {
weak var viewController: ViewController?
init(viewController: ViewController) {
self.viewController = viewController
}
// MARK: - ViewControllerRouterInput
func navigateToPushedViewController(value: Int) {
let pushedViewController = PushedViewController.instantiate()
pushedViewController.configure(viewModel: PushedViewModel(value: value))
viewController?.navigationController?.pushViewController(pushedViewController, animated: true)
}
}
The navigateToPushedViewController func can takes any parameter you want (it is good to encapsulate parameters before configure new vc, so you may want to do that).
And the PushedViewController hasn't any specific implementation. Just configure() method and assert (notify you about missing configure() call):
final class PushedViewModel {
let value: Int
init(value: Int) {
self.value = value
}
}
final class PushedViewController: UIViewController, StoryboardBased {
#IBOutlet weak var label: UILabel!
private var viewModel: PushedViewModel!
func configure(viewModel: PushedViewModel) {
self.viewModel = viewModel
}
override func viewDidLoad() {
super.viewDidLoad()
assert(viewModel != nil, "viewModel is nil. You should call configure method before push vc.")
label.text = "Pushed View Controller with value: \(viewModel.value)"
}
}
Note: also, i used Reusable pod to reduce boilerplate code.
Result:

Answer 2

As above article explained you can use option 2/3/4 of navigateToSomewhere method as per your app design.
func navigateToSomewhere()
{
// 2. Present another view controller programmatically
// viewController.presentViewController(someWhereViewController, animated: true, completion: nil)
// 3. Ask the navigation controller to push another view controller onto the stack
// viewController.navigationController?.pushViewController(someWhereViewController, animated: true)
// 4. Present a view controller from a different storyboard
// let storyboard = UIStoryboard(name: "OtherThanMain", bundle: nil)
// let someWhereViewController = storyboard.instantiateInitialViewController() as! SomeWhereViewController
// viewController.navigationController?.pushViewController(someWhereViewController, animated: true)
}

Answer 3

You need pass data across protocols
protocol SecondModuleInput {
// pass data func or variable
var data: Any? { get set }
}
protocol SecondModuleOutput {
// pass data func or variable
func send(data: Any)
}
First presenter
class FirstPresenter: SecondModuleOutput {
var view: UIViewController
var secondModuleInputHandler: SecondModuleInput?
// MARK: SecondModuleInput
func send(data: Any) {
//sended data from SecondPresenter
}
}
Second presenter
class SecondPresenter: SecondModuleInput {
var view: UIViewController
var secondModuleOutputHandler: SecondModuleOutput?
static func configureWith(block: #escaping (SecondModuleInput) -> (SecondModuleOutput)) -> UIViewController {
let secondPresenter = SecondPresenter()
secondPresenter.secondModuleOutputHandler = block(secondPresenter)
return secondPresenter.view
}
// Sending data to first presenter
func sendDataToFirstPresenter(data: Any) {
secondModuleOutputHandler?.send(data: data)
}
// MARK: FirstModuleInput
var data: Any?
}
Router
class FirstRouter {
func goToSecondModuleFrom(firstPresenter: FirstPresenter, with data: Any) {
let secondPresenterView = SecondPresenter.configureWith { (secondPreseter) -> (SecondModuleOutput) in
firstPresenter.secondModuleInputHandler = secondPreseter
return firstPresenter
}
//Pass data to SecondPresenter
firstPresenter.secondModuleInputHandler?.data = data
//Go to another view controller
//firstPresenter.view.present(secondPresenterView, animated: true, completion: nil)
//firstPresenter.view.navigationController.pushViewController(secondPresenterView, animated: true)
}
}