Lecture presented at The Developer's Conference in Florianópolis. Introduction to ReactiveCocoa and its usage in a sample project.

1. REACTIVE COCOA
Trilha iOS
Carlos Vinícius Real Guilherme Endres
Software Engineer Software Engineer

2. ReactiveCocoa?

3. ISSO NÃO VAI DAR CERTO…

4. RAC
IOS

5. ReactiveCocoa?

7. Functional Reactive
Programming
Reactive Cocoa

8. Reactive Programming
+
Functional Programming
Reactive Cocoa

9. Reactive Programming
+
Functional Programming
Reactive Cocoa

10. Reactive Programming

11. Reactive Programming
+
Functional Programming
Reactive Cocoa

12. Functional Programming
Imperativo vs Declarativo

13. FRP | Imperativo
Como
var strongBeers = [Beer]();
for beer in beers {
if beer.alcohoolPercent > 6 {
strongBeers.append(beer)
}
}

14. FRP | Declarativo
O que
beers.filter{ $0.alcohoolPercent > 6 }

15. SIGNALS
&
SIGNALS PRODUCERS

16. Weiss
map
filter
RedAle

17. http://neilpa.me/rac-marbles

18. EVENTS

19. Events
Next
Completed
Failed
Interrupted

20. CallBack blocks
KVO
Actions
Delegate
NSNOTIFICATION

21. CODE

22. CODE
Swift
ReactiveCocoa4
MVVM

24. BUTTON SIGNAL

25. let buttonSignal: RACSignal = enterButton.rac_signalForControlEvents(
UIControlEvents.TouchUpInside)
USERVIEWCONTROLLER | BUTTON SIGNAL

26. let buttonSignal: RACSignal = enterButton.rac_signalForControlEvents(
UIControlEvents.TouchUpInside)
let buttonSignalProducer: SignalProducer = buttonSignal
.toSignalProducer()
.observeOn(UIScheduler())
USERVIEWCONTROLLER | BUTTON SIGNAL PRODUCER

27. OPERATORS

28. buttonSignalProducer
.flatMap(
transform:)
USERVIEWCONTROLLER | OPERATORS

29. buttonSignalProducer
.flatMap(FlattenStrategy.Latest,
transform: userViewModel.saveUser)
USERVIEWCONTROLLER | OPERATORS

30. buttonSignalProducer
.flatMap(FlattenStrategy.Latest,
transform: userViewModel.saveUser)
.startWithNext { username in
self.performSegueWithIdentifier("beerControllerSegue", sender: self)
}
USERVIEWCONTROLLER | OPERATORS

31. MUTABLE PROPERTY

32. var quantity = MutableProperty<Int>(0)
var userImage = MutableProperty<UIImage?>.init(defaultImage)
BEERVIEWMODEL | MUTABLE PROPERTIES

33. BINDING<~

34. beerViewModel.quantity <~ beerQuantityProducer
BEERVIEWCONTROLLER | BINDING

35. MÉTODOS

36. func imageForBeer(quantity: Int) -> SignalProducer<UIImage?, NoError> {
}
BEERVIEWMODEL | MÉTODOS

37. func imageForBeer(quantity: Int) -> SignalProducer<UIImage?, NoError> {
return SignalProducer { observe, disposable in
}.delay(1, onScheduler: QueueScheduler.mainQueueScheduler)
}
BEERVIEWMODEL | MÉTODOS

38. func imageForBeer(quantity: Int) -> SignalProducer<UIImage?, NoError> {
return SignalProducer { observe, disposable in
guard let image: UIImage = imageForQuantity(quantity) else {
print("Failed to get image for quantity (quantity)")
return
}
}.delay(1, onScheduler: QueueScheduler.mainQueueScheduler)
}
BEERVIEWMODEL | MÉTODOS

39. func imageForBeer(quantity: Int) -> SignalProducer<UIImage?, NoError> {
return SignalProducer { observe, disposable in
guard let image: UIImage = imageForQuantity(quantity) else {
print("Failed to get image for quantity (quantity)")
return
}
observe.sendNext(image)
}.delay(1, onScheduler: QueueScheduler.mainQueueScheduler)
}
BEERVIEWMODEL | MÉTODOS

40. userImage <~ quantity.producer
BEERVIEWMODEL | BINDING

41. userImage <~ quantity.producer
.skipRepeats()
BEERVIEWMODEL | BINDING

42. userImage <~ quantity.producer
.skipRepeats()
.flatMap(FlattenStrategy.Latest, transform: imageForBeer)
BEERVIEWMODEL | BINDING

43. personDrunkImage.rac_image <~ beerViewModel.userImage
BEERVIEWCONTROLLER | BINDING

44. UNIT TEST

45. let userViewModel: UserViewModel = UserViewModel()
UNIT TEST | SUCESSO

46. let userViewModel: UserViewModel = UserViewModel()
userViewModel.username.value = "Skywalker"
UNIT TEST | SUCESSO

47. let userViewModel: UserViewModel = UserViewModel()
userViewModel.username.value = "Skywalker"
userViewModel.saveUser().on(
).start()
UNIT TEST | SUCESSO

48. let userViewModel: UserViewModel = UserViewModel()
userViewModel.username.value = "Skywalker"
userViewModel.saveUser().on(
completed: {
successExpectation.fulfill()
}, failed: { error in
XCTFail()
}).start()
UNIT TEST | SUCESSO

49. let userViewModel: UserViewModel = UserViewModel()
userViewModel.username.value = "Darth Vader"
userViewModel.saveUser().on(
completed: {
XCTFail()
}, failed: { error in
successExpectation.fulfill()
}).start()
UNIT TEST | FALHA

50. PROBLEMAS

52. https://github.com/username/project
Signals
Signal Producer
Map
Functional programming
"Se liga no mestiço, na batida do cavaco"?
Reactive
Reduce

53. Links úteis | Reactive Cocoa
http://reactivecocoa.io/philosophy.html
https://github.com/ReactiveCocoa/ReactiveCocoa
http://www.sprynthesis.com/2014/12/06/reactivecocoa-mvvm-
introduction/
https://nomothetis.svbtle.com/an-introduction-to-reactivecocoa
http://neilpa.me/rac-marbles

54. https://github.com/gfendres/ractdc2016
CVINICIUSREAL@GMAIL.COM
Carlos Vinícius Real Guilherme Endres
GFENDRES@GMAIL.COM