Practial Protocol-Oriented-Programming

@NatashaTheRobot

Protocol-Oriented Programming in Swift Dave Abrahams Professor of Blowing-Your-Mind

–- Professor of Blowing-Your-Mind "Swift Is a Protocol-Oriented Programming Language"

Practical POP • View • (UITable)ViewController • Networking

POP Views

// 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") } }

// ViewController.swift import UIKit class ViewController: UIViewController { @IBOutlet weak var foodImageView: FoodImageView! @IBAction func onShakeButtonTap(sender: AnyObject) { foodImageView.shake() } }

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// 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") } }

// ViewController.swift class ViewController: UIViewController { @IBOutlet weak var foodImageView: FoodImageView! @IBOutlet weak var actionButton: ActionButton! @IBAction func onShakeButtonTap(sender: AnyObject) { foodImageView.shake() actionButton.shake() } }

// 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") } }

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() } }

// Shakeable.swift import UIKit protocol Shakeable { } extension Shakeable where Self: UIView { func shake() { // implementation code } }

class FoodImageView: UIImageView, Shakeable { } class ActionButton: UIButton, Shakeable { }

class FoodImageView: UIImageView, Shakeable, Dimmable { }

class FoodImageView: UIImageView, Dimmable { }

Transparent View Controllers and Dim Backgrounds totem.training

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POP (UITable)ViewControllers

// FoodLaLaViewController override func viewDidLoad() { super.viewDidLoad() let foodCellNib = UINib(nibName: "FoodTableViewCell", bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: "FoodTableViewCell") }

let foodCellNib = UINib(nibName: String(FoodTableViewCell), bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: String(FoodTableViewCell))

protocol ReusableView: class {} extension ReusableView where Self: UIView { static var reuseIdentifier: String { return String(self) } }

extension UITableViewCell: ReusableView { } FoodTableViewCell.reuseIdentifier // FoodTableViewCell

let foodCellNib = UINib(nibName: "FoodTableViewCell", bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: FoodTableViewCell.reuseIdentifier)

protocol NibLoadableView: class { } extension NibLoadableView where Self: UIView { static var nibName: String { return String(self) } }

extension FoodTableViewCell: NibLoadableView { } FoodTableViewCell.nibName // "FoodTableViewCell"

let foodCellNib = UINib(nibName: FoodTableViewCell.nibName, bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: FoodTableViewCell.reuseIdentifier)

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) } }

let foodCellNib = UINib(nibName: "FoodTableViewCell", bundle: nil) tableView.registerNib(foodCellNib, forCellReuseIdentifier: "FoodTableViewCell")

tableView.register(FoodTableViewCell)

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 } }

guard let cell = tableView.dequeueReusableCellWithIdentifier(“FoodTableViewCell", forIndexPath: indexPath) as? FoodTableViewCell else { fatalError("Could not dequeue cell with identifier: FoodTableViewCell") }

let cell = tableView.dequeueReusableCell(forIndexPath: indexPath) as FoodTableViewCell

if indexPath.row == 0 { return tableView.dequeueReusableCell(forIndexPath: indexPath) as DesertTableViewCell } return tableView.dequeueReusableCell(forIndexPath: indexPath) as FoodTableViewCell

iOS Cell Registration & Reusing with Swift Protocol Extensions and Generics medium.com/@gonzalezreal

Protocol-Oriented Segue Identiﬁers in Swift natashatherobot.com

POP Networking

struct FoodService { func get(completionHandler: Result<[Food]> -> Void) { // make asynchronous API call // and return appropriate result } }

enum Result<T> { case Success(T) case Failure(ErrorType) }

// 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) } } }

View Controller Tests?!!! 😱

// 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) } } }

// FoodLaLaViewController func getFood(fromService service: FoodService) { service.getFood() { [weak self] result in // handle result } }

// FoodLaLaViewControllerTests func testFetchFood() { viewController.getFood(fromService: FoodService()) // 🤔 now what? }

protocol Gettable { associatedtype T func get(completionHandler: Result<T> -> Void) }

struct FoodService: Gettable { func get(completionHandler: Result<[Food]> -> Void) { // make asynchronous API call // and return appropriate result } }

// 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) } } }

// FoodLaLaViewControllerTests class Fake_FoodService: Gettable { var getWasCalled = false func get(completionHandler: Result<[Food]> -> Void) { getWasCalled = true completionHandler(Result.Success(food)) } }

// FoodLaLaViewControllerTests func testFetchFood() { let fakeFoodService = Fake_FoodService() viewController.getFood(fromService: fakeFoodService) XCTAssertTrue(fakeFoodService.getWasCalled) XCTAssertEqual(viewController.dataSource.count, food.count) XCTAssertEqual(viewController.dataSource, food) }

Update: View Controller Data Injection with Storyboards and Segues in Swift natashatherobot.com

Protocols with Associated Types Alexis Gallagher 2015.funswiftconf.com

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Practical POP • View • (UITable)ViewController • Networking

Beyond Crusty: Real-World Protocols Rob Napier thedotpost.com

Blending Cultures: The Best of Functional, Protocol-Oriented, and Object-Oriented Programming Daniel Steinberg realm.io

@NatashaTheRobot

Practial Protocol-Oriented-Programming

Natasha Murashev

Practial Protocol-Oriented-Programming