This document discusses navigation in mobile applications using an advanced architecture. It proposes handling navigation through presenters rather than views to decouple events from semantics. Storyboards are presented as an implementation that is not required. Modular navigation allows passive views and independence from any implementation. Clear benefits include testability, modifying dependency injection, and enabling A/B testing through different navigation implementations in presenters.

1. Fly Me to the
View
Jorge D. Ortiz-Fuentes
@jdortiz

2. A Canonical
Examples
Production

3. #AdvArchMobile
Agenda
★ Architecture & Responsibilities
★ A modular solution
• Storyboards
• XIBs only
★ Benefits
★ Recap

4. Persistance FW
View
Network
LocationFW
Presenter
Entity Gateway
Clean Architecture
Interactor
Entity

5. Where’s the beef?
navigation

7. #AdvArchMobile
Navigation
★ Events vs Semantics
★ Storyboard vs Decoupled VC
★ And without storyboards?
★ Dependency Injection
★ Memory Management

8. Responsibili
ties

9. MVP

10. #AdvArchMobile
View
★ Known by its beautiful face
and its passivity
★ Receives the events and
passes them to the presenter
★ Knows how to navigate

11. #AdvArchMobile
Presenter
★ Provides meaning to the user
events
★ Tells the view what to update
★ Knows when and where to
navigate

12. #AdvArchMobile
Connector
★ Knows the dependencies and
how to connect them
★ Takes you to the next
connector

13. What about MVVM?

14. #AdvArchMobile
No worries
★ MVP Tells
★ MVVM Notifies
★ Feel free to embrace & extend

15. A modular
solution

16. Decoupling

17. #AdvArchMobile
View controller
★ Separate event from semantics
★ Still, navigation is done here

18. A new VC
View (VC) Presenter Interactor
Entity
Gateway
Connector
View (VC) Presenter Interactor
Entity
Gateway
Connector
1 23
4

19. Segue from VC

20. #AdvArchMobile
View Controller: Events
@IBAction func add(_ sender: UIBarButtonItem) {
presenter.addButtonTapped()
}
override func tableView(_ tableView: UITableView,
didSelectRowAt indexPath: IndexPath) {
presenter.select(row: indexPath.row)
}

21. #AdvArchMobile
Presenter: Navigation
Semantics
func addButtonTapped() {
view.navigateToAddProgrammer()
}
func select(row: Int) {
if row < 0 !|| row !>= programmers.count {
selectedId = nil
} else {
let programmer = programmers[row]
selectedId = programmer.id
view.navigateToProgrammerDetail()
}
}

22. #AdvArchMobile
View Controller:
Navigation
func navigateToAddProgrammer() {
performSegue(withIdentifier:
SegueIdentifier.addProgrammer, sender: self)
}
func navigateToProgrammerDetail() {
performSegue(withIdentifier:
SegueIdentifier.showProgrammer, sender: self)
}

23. #AdvArchMobile
View Controller:
Delegate DI
override func prepare(for segue: UIStoryboardSegue, sender:
Any?) {
let identifier = try! segueIdentifier(for: segue)
switch identifier {
case .addProgrammer:
connector.prepareAddProgrammer(viewController:
segue.destination)
case .showProgrammer:
connector.prepareProgrammerDetail(viewController:
segue.destination, presenter: presenter)
}
}

24. #AdvArchMobile
Child Connector:
Assemble
func assembleModule(view:
ProgrammerEditViewController) {
let presenter =
ProgrammerEditPresenter(otherDep: depencency)
view.presenter = presenter
view.connector = self
presenter.view = view
}

25. #MobAppArch
Implementing navigation
and back
★ Navigation destination is NOT decided by
the view event
★ When presented modally, navigation back
requires Unwind segue
★ In a navigation controller things happen
naturally

26. Memory
Management

27. Dismiss a VC
View (VC) Presenter Interactor
Entity
Gateway
Connector
View (VC) Presenter Interactor
Entity
Gateway
Connector
1 2

28. Passing parameters

29. #AdvArchMobile
Having the Information
★ Perform segue & prepare for segue are
disconnected
★ Information for injection:
• Use sender: DON’T
• State in View Controller
• State in Presenter (preferred)

30. XIBs only

31. #AdvArchMobile
Differences
★ Easier to pass the information
★ Easier to do the injection: Initializer instead
of property
★ Presentation is done by the source
★ No “big picture” or unwind segues

32. #AdvArchMobile
VC Injection
via Initializer
var presenter: ProgrammerEditPresenter
init(presenter: ProgrammerEditPresenter,
nibName: String? = nil, bundle: Bundle? =
nil) {
self.presenter = presenter
super.init(nibName: nil, bundle: nil)
presenter.view = self
}

33. #AdvArchMobile
Passing Information &
Presentation
func navigateToDetail(parameter: String) {
let detailViewController =
connector.prepareProgrammerDetail(paramete
r: parameter)
navigationController!?.pushViewController(d
etailViewController, animated: true)
}

34. Benefits

35. Modify Dependency
Injection

36. #AdvArchMobile
Dependencies Change
★ Create them in the connector
★ Pass them from one connector to the next

37. Testable

38. #AdvArchMobile
Test Everything
func testSegueToAddProgrammerInvokesConnectorToNavigate() {
let connectorMock = ProgrammersListConnectorMock(some
Dep: DepTestDummy())
sut.connector = connectorMock
sut.performSegue(withIdentifier:
ProgrammersTableViewControllerMock.SegueIdentifier.addProgr
ammer, sender: sut)
XCTAssertEqual(1,
connectorMock.prepareAddProgrammerInvoked)
}

39. A/B Testing

40. #AdvArchMobile
Presenter
func addButtonTapped() {
if abSelector.isA {
view.navigateToAddProgrammerA()
} else {
view.navigateToAddProgrammerB()
}
}

41. #AdvArchMobile
Recap
★ Navigation is a key part of an advanced
architecture:
• Modular
• Allows passive view
• Not bound to implementation (storyboards)
★ Easy to implement & maintain
★ Clear benefits

42. – Anonymous iOS developer
“Fly me to the View
Let me play among the Apps”

43. Thank
You!

44. 谢谢

45. Terima
kasih!

46. ந"#

47. @jdortiz
#AdvArchMobile