Natasha Murashev: Practical Protocol-Oriented Programming

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1. @NatashaTheRobot
2. Protocol-Oriented Programming in Swift Dave Abrahams Professor of Blowing-Your-Mind
3. –- Professor of Blowing-Your-Mind "Swift Is a Protocol-Oriented Programming Language"
5. Practical POP • View • (UITable)ViewController • Networking
6. POP Views
9. // FoodImageView.swift import UIKit class FoodImageView: UIImageView { func shake() { let animation = CABasicAnimation(keyPath: "position") animation.duration = 0.05 animation.repeatCount = 5 animation.autoreverses = true animation.fromValue = NSValue(CGPoint: CGPointMake(self.center.x - 4.0, self.center.y)) animation.toValue = NSValue(CGPoint: CGPointMake(self.center.x + 4.0, self.center.y)) layer.addAnimation(animation, forKey: "position") } }
10. // ViewController.swift import UIKit class ViewController: UIViewController { @IBOutlet weak var foodImageView: FoodImageView! @IBAction func onShakeButtonTap(sender: AnyObject) { foodImageView.shake() } }
13. // ShakeableButton.swift import UIKit class ActionButton: UIButton { func shake() { let animation = CABasicAnimation(keyPath: "position") animation.duration = 0.05 animation.repeatCount = 5 animation.autoreverses = true animation.fromValue = NSValue(CGPoint: CGPointMake(self.center.x - 4.0, self.center.y)) animation.toValue = NSValue(CGPoint: CGPointMake(self.center.x + 4.0, self.center.y)) layer.addAnimation(animation, forKey: "position") } }
14. // ViewController.swift class ViewController: UIViewController { @IBOutlet weak var foodImageView: FoodImageView! @IBOutlet weak var actionButton: ActionButton! @IBAction func onShakeButtonTap(sender: AnyObject) { foodImageView.shake() actionButton.shake() } }
16. // UIViewExtension.swift import UIKit extension UIView { func shake() { let animation = CABasicAnimation(keyPath: "position") animation.duration = 0.05 animation.repeatCount = 5 animation.autoreverses = true animation.fromValue = NSValue(CGPoint: CGPointMake(self.center.x - 4.0, self.center.y)) animation.toValue = NSValue(CGPoint: CGPointMake(self.center.x + 4.0, self.center.y)) layer.addAnimation(animation, forKey: "position") } }
17. class FoodImageView: UIImageView { // other customization here } class ActionButton: UIButton { // other customization here } class ViewController: UIViewController { @IBOutlet weak var foodImageView: FoodImageView! @IBOutlet weak var actionButton: ActionButton! @IBAction func onShakeButtonTap(sender: AnyObject) { foodImageView.shake() actionButton.shake() } }
19. // Shakeable.swift import UIKit protocol Shakeable { } extension Shakeable where Self: UIView { func shake() { // implementation code } }
20. class FoodImageView: UIImageView, Shakeable { } class ActionButton: UIButton, Shakeable { }
21. class FoodImageView: UIImageView, Shakeable, Dimmable { }
22. class FoodImageView: UIImageView, Dimmable { }
23. Transparent View Controllers and Dim Backgrounds totem.training
25. POP (UITable)ViewControllers
27. // FoodLaLaViewController override func viewDidLoad() { super.viewDidLoad() let foodCellNib = UINib(nibName: "FoodTableViewCell", bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: "FoodTableViewCell") }
28. let foodCellNib = UINib(nibName: String(FoodTableViewCell), bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: String(FoodTableViewCell))
29. protocol ReusableView: class {} extension ReusableView where Self: UIView { static var reuseIdentifier: String { return String(self) } }
30. extension UITableViewCell: ReusableView { } FoodTableViewCell.reuseIdentifier // FoodTableViewCell
31. let foodCellNib = UINib(nibName: "FoodTableViewCell", bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: FoodTableViewCell.reuseIdentifier)
32. protocol NibLoadableView: class { } extension NibLoadableView where Self: UIView { static var nibName: String { return String(self) } }
33. extension FoodTableViewCell: NibLoadableView { } FoodTableViewCell.nibName // "FoodTableViewCell"
34. let foodCellNib = UINib(nibName: FoodTableViewCell.nibName, bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: FoodTableViewCell.reuseIdentifier)
35. extension UITableView { func register<T: UITableViewCell where T: ReusableView, T: NibLoadableView>(_: T.Type) { let nib = UINib(nibName: T.nibName, bundle: nil) registerNib(nib, forCellReuseIdentifier: T.reuseIdentifier) } }
36. let foodCellNib = UINib(nibName: "FoodTableViewCell", bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: "FoodTableViewCell")
37. tableView.register(FoodTableViewCell)
38. extension UITableView { func dequeueReusableCell<T: UITableViewCell where T: ReusableView>(forIndexPath indexPath: NSIndexPath) -> T { guard let cell = dequeueReusableCellWithIdentifier(T.reuseIdentifier, forIndexPath: indexPath) as? T else { fatalError("Could not dequeue cell with identifier: \(T.reuseIdentifier)") } return cell } }
39. guard let cell = tableView.dequeueReusableCellWithIdentifier(“FoodTableViewCell", forIndexPath: indexPath) as? FoodTableViewCell else { fatalError("Could not dequeue cell with identifier: FoodTableViewCell") }
40. let cell = tableView.dequeueReusableCell(forIndexPath: indexPath) as FoodTableViewCell
41. if indexPath.row == 0 { return tableView.dequeueReusableCell(forIndexPath: indexPath) as DesertTableViewCell } return tableView.dequeueReusableCell(forIndexPath: indexPath) as FoodTableViewCell
42. iOS Cell Registration & Reusing with Swift Protocol Extensions and Generics medium.com/@gonzalezreal
43. Protocol-Oriented Segue Identifiers in Swift natashatherobot.com
45. POP Networking
46. struct FoodService { func get(completionHandler: Result<[Food]> -> Void) { // make asynchronous API call // and return appropriate result } }
47. enum Result<T> { case Success(T) case Failure(ErrorType) }
48. struct FoodService { func get(completionHandler: Result<[Food]> -> Void) { // make asynchronous API call // and return appropriate result } }
49. // FoodLaLaViewController var dataSource = [Food]() { didSet { tableView.reloadData() } } override func viewDidLoad() { super.viewDidLoad() getFood() } private func getFood() { FoodService().getFood() { [weak self] result in switch result { case .Success(let food): self?.dataSource = food case .Failure(let error): self?.showError(error) } } }
50. View Controller Tests?!!!
51. // FoodLaLaViewController var dataSource = [Food]() { didSet { tableView.reloadData() } } override func viewDidLoad() { super.viewDidLoad() getFood() } private func getFood() { FoodService().getFood() { [weak self] result in switch result { case .Success(let food): self?.dataSource = food case .Failure(let error): self?.showError(error) } } }
52. // FoodLaLaViewController func getFood(fromService service: FoodService) { service.getFood() { [weak self] result in // handle result } }
53. // FoodLaLaViewControllerTests func testFetchFood() { viewController.getFood(fromService: FoodService()) // now what? }
54. struct FoodService { func get(completionHandler: Result<[Food]> -> Void) { // make asynchronous API call // and return appropriate result } }
55. protocol Gettable { associatedtype T func get(completionHandler: Result<T> -> Void) }
56. struct FoodService: Gettable { func get(completionHandler: Result<[Food]> -> Void) { // make asynchronous API call // and return appropriate result } }
57. // FoodLaLaViewController override func viewDidLoad() { super.viewDidLoad() getFood(fromService: FoodService()) } func getFood<S: Gettable where S.T == [Food]>(fromService service: S) { service.get() { [weak self] result in switch result { case .Success(let food): self?.dataSource = food case .Failure(let error): self?.showError(error) } } }
58. // FoodLaLaViewControllerTests class Fake_FoodService: Gettable { var getWasCalled = false func get(completionHandler: Result<[Food]> -> Void) { getWasCalled = true completionHandler(Result.Success(food)) } }
59. // FoodLaLaViewControllerTests func testFetchFood() { let fakeFoodService = Fake_FoodService() viewController.getFood(fromService: fakeFoodService) XCTAssertTrue(fakeFoodService.getWasCalled) XCTAssertEqual(viewController.dataSource.count, food.count) XCTAssertEqual(viewController.dataSource, food) }
60. Update: View Controller Data Injection with Storyboards and Segues in Swift natashatherobot.com
61. Protocols with Associated Types Alexis Gallagher 2015.funswiftconf.com
63. Practical POP • View • (UITable)ViewController • Networking
64. Beyond Crusty: Real-World Protocols Rob Napier thedotpost.com
65. Blending Cultures: The Best of Functional, Protocol-Oriented, and Object-Oriented Programming Daniel Steinberg realm.io
66. @NatashaTheRobot