ViewControllers: The Right Way

Bottom-up approach to relieve ViewController's from some responsabilities.
The first part is about how we can define a component and then how these components interact between them.

Transcript

1. ViewControllers The right way
2. @FranDepascuali francisco.depascuali@gmail.com Speaker iOS developer (1.5 years) @Wolox Software Engineering @ITBA
3. Content • State of the art • Problem • Solution • Demo • Components • Demo • Questions?
4. State of the art
5. Massive View Controller
6. VC Responsibilities • Model - View binding • Handle user input Ideal world
7. VC Responsabilidades • Model - View binding • Handle user input Ideal World Real World • Model - View binding • Handle user input • Layout • Navigation flow • Data source • Persistance • Data fetching & transformation • Model mutation
8. MVVM • ViewModel - View binding • Handle user input • Layout • Navigation flow View Controller View Model • Data source • Persistance (Services, Repositories) • Data fetching & transformation • Model mutation
9. WWDC example Layout!!!
10. Storyboards Layout!
11. Storyboards Explicitly dereferenced properties
12. Storyboards Mutability!
13. Problem
14. Problem • Layout is ViewController’s responsibility.
 • Can’t inject dependencies on ViewController’s init method: • Inconsistent state of ViewController at initialization. • User needs to call a function. • Mutability: Different semantic meaning.
15. Solution
16. Solution • Layout in ViewController’s view • Inject dependencies in ViewController’s init method
17. Create a component
18. Bind xib with view
19. Add outlets to the VIEW!
20. NibLoadable Represents a component that can be loaded from a nib.
21. NibLoadable Represents a component that can be loaded from a nib. Default implementation for UIViews: Load a view by its name
22. Load the view from the nib in the controller NibLoadable
23. Storyboards way
24. Storyboards way New way
25. Demo
26. Components
27. Components
28. Demo
29. Trade-offs • Storyboards not supported
 • Deep thinking about components relationships
30. Questions?
31. Reference • Simple made easy - Rich Hickey • WWDC session 229: Adv. iOS Application Architecture and Patterns - Andy Matuschak • Let’s Play: Refactor the Mega-Controller - Andy Matuschak • Repo: https://github.com/Wolox/wolmo-core- ios