Object-oriented vs protocol-oriented, czyli o tym jak przełożyć skomplikowany świat na przejrzysty kod

Anna Widera: W czasie prezentacji opowiem o obu paradygmatach, ich zaletach i ograniczeniach. Będą przykłady, będą smoki i tak – będzie też o nazewnictwie (kto nigdy nie poszedł po kawę, bo nie wiedział jak nazwać klasę, niech pierwszy rzuci myszą!).

4. OBJECT ORIENTED
VS
PROTOCOL ORIENTED
czyli o tym jak przełożyć skomplikowany świat
w przejrzysty kod

5. OBJECT ORIENTED
świat jako zbiór odseparowanych obiektów

6. PODOBIEŃSTWA

7. OBJECT ORIENTED
hierarchia

8. DZIEDZICZENIE
inheritance

9. OBJECT ORIENTED
czym jesteś?

10. “
Talk is cheap. Show me the code.
-Linus Torvalds

11. Mateusz Skawiński (2016) / Behance

12. Mateusz Skawiński (2016) / Behance

13. class Creature {
let name: String
init(name: String) {
self.name = name
}
func fight() {
print("!")
}
}

14. deviantart.com/ijkelly/art/Wolf-Link-Transformation-455486791

15. class LandCreature: Creature {
func walk() {
print(""")
}
func run() {
print("#")
}
}

17. deviantart.com/ijkelly/art/Commission-Vorago-497052761

18. class HellCreature: Creature {
func walk() {
print(""")
}
func run() {
print("#")
}
func burn() {
print("$")
}
}

19. class Creature {
let name: String
init(name: String) {
self.name = name
}
func walk() {
print(""")
}
func run() {
print("#")
}
func fight() {
print("!")
}
}

20. class LandCreature: Creature { }
class HellCreature: Creature {
func burn() {
print("$")
}
}

22. Mateusz Skawiński (2016) / Behance

23. class SkyCreature: Creature {
func fly() {
print("%️")
}
}

25. class Creature {
let name: String
init(name: String) {
self.name = name
}
func fight() {
print("!")
}
}

26. class LandCreature: Creature {
func walk() {
print(""")
}
func run() {
print("#")
}
}

27. class HellCreature: Creature {
func walk() {
print(""")
}
func run() {
print("#")
}
func burn() {
print("$")
}
}

29. deviantart.com/cicakkia/art/Meet-a-Dragon-379748899

30. class Dragon: SkyCreature { }

32. PROTOCOL ORIENTED
świat jako zbiór umiejętności

33. PROTOCOL
ORIENTED
obietnica

34. PRZYSTOSOWANIE
conformance

35. PROTOCOL ORIENTED
co potrafisz?

36. …
Protocol Interface~=

37. DOMYŚLNA IMPLEMENTACJA
protocol Running {
func run()
}
extension Running {
func run() {
print("#")
}
}
extension

38. WYBIÓRCZO
extension Running where Self: Walking {

func stepByStep() {
walk()
walk()
}
}
where

39. WŁAŚCIWOŚCI
protocol UserType {
var name: String { get set }
var email: String { get set }
var photo: URL { get }
}

40. Mateusz Skawiński (2016) / Behance

41. Mateusz Skawiński (2016) / Behance

42. class Creature {
let name: String
init(name: String) {
self.name = name
}
}

43. protocol Strikeable {
func fight()
}
extension Strikeable {
func fight() {
print("!")
}
}

44. extension Creature: Strikeable { }

45. deviantart.com/ijkelly/art/Wolf-Link-Transformation-455486791

46. protocol Walking {
func walk()
}
extension Walking {
func walk() {
print(""")
}
}
protocol Running {
func run()
}
extension Running {
func run() {
print("#")
}
}

47. class LandCreature: Creature,
Walking,
Running { }

49. deviantart.com/ijkelly/art/Commission-Vorago-497052761

50. protocol Burning {
func burn()
}
extension Burning {
func burn() {
print("$")
}
}

51. class HellCreature: Creature,
Walking,
Running,
Burning { }

53. Mateusz Skawiński (2016) / Behance

54. protocol Flying {
func fly()
}
extension Flying {
func fly() {
print("%️")
}
}

55. class SkyCreature: Creature, Flying { }

58. deviantart.com/cicakkia/art/Meet-a-Dragon-379748899

59. class Dragon: Creature,
Walking,
Running,
Flying,
Burning { }

61. NICE FEATURES
extension Creature {

var canFly: Bool { return self is Flying }
var canBurn: Bool { return self is Burning }
var canWalk: Bool { return self is Walking }
}

65. NAZEWNICTWO
bzik

66. CAN DO
-able
Hashable 
Comparable
Equatable

67. IS A
-Type
CollectionType
GeneratorType
ErrorType

68. CAN BE
-Convertible
CustomStringConvertible

69. COMMUNICATE
ABILITIES
„can do“

70. protocol Shakeable {
func shake()
}
 
extension Shakeable where Self: UIView {
        
func shake() {
let animation = …
animation.duration = 0.05
animation.repeatCount = 5
animation.fromValue = …
animation.toValue = …
layer.addAnimation(animation, forKey: "position")
}
}

71. class ActionButton: UIButton, Shakeable { }
 
class ViewController: UIViewController {
  
@IBOutlet private weak var actionButton: ActionButton!
        
@IBAction func onShakeButtonTap(sender: AnyObject) {
actionButton.shake()
}
}

72. UNIFICATION
„can do“, „is a“

73. protocol UserType {
var name: String { get }
var uuid: UUID { get }
}
extension ListMember: UserType {
var name: String { return self.nickName }
var uuid: UUID { return UUID(uuidString: self.id) }
}
extension SettlementUser: UserType {
var name: String { return self.login }
var uuid: UUID { return self.uuid }
}

74. protocol InputColorable {

func set(_ color: UIColor)
}
extension UITextField: InputColorable {

func set(_ color: UIColor) {
textColor = color
}
}
extension UISwitch: InputColorable {

func set(_ color: UIColor) {
backgroundColor = color
}
}

75. protocol Colorable {

var inputs: [InputColorable] { get }
func applyColor(_ color: UIColor)
}
extension Colorable {

func applyColor(_ color: UIColor) {
inputs.forEach({ $0.set(color) })
}
}

76. class FormView: UIView, Colorable {

var inputs: [InputColorable] = {
return [loginInput,
passwordInput,
termsSwitch,
newsletterSwitch]
}

func setTheme(to newTheme: Theme) {
applyColor(newTheme.mainColor)
}
}

77. RESTRICT ACCESS
„is a“

78. VIEW
MODEL
VIEW COORDINATOR

79. VIEW
MODEL
protocol
SettingsViewModelViewPart {

func cancelAction()
func logoutAction()
}
protocol
SettingsViewModelCoordinatorPart {

var onAccountDetails: (() -> Void)? { get set }
}

80. VIEW
MODEL
typealias SettingsViewModelType =
SettingsViewModelViewPart &
SettingsViewModelCoordinatorPart
final class SettingsViewModel: SettingsViewModelType { }

81. protocol SettingsViewModelViewPart {

func cancelAction()
func logoutAction()
}
protocol SettingsViewModelCoordinatorPart: class {

var onAccountDetails: (() -> Void)? { get set }
}
typealias SettingsViewModelType =
SettingsViewModelViewPart &
SettingsViewModelCoordinatorPart
final class SettingsViewModel: SettingsViewModelType { }

82. CONVERSION
„can be“

84. class Creature: CustomStringConvertible {

let name: String

init(name: String) {
self.name = name
}

var description: String {
return "\(type(of: self))" + " " + name
}
}

85. DZIĘKI!