Taking Swift 2 for a spin

One year after Swift has been released, Apple introduced with Swift 2.0 the programming language of the future. Rather than just running only in an Apple environment, it will also run on an Unix environment and will be open sourced later this year. This years Github survey already placed Swift on the first place of programmers favourite languages. This talk will take the attendees (beginner to expert) for a spin through the new language features, as well as Xcode 7.0 IDE features. We will give a lot of hands on tipps and tricks, from our experience (> 1 year) with Swift in a production environment.

Transcript

1. Taking  Swi*  2  for  a   spin @jriehn     @lukasingelheim
3. Back  to  last  year
5. many  more
9. Produc>on  ready  under   certain  circumstances.
10. Back  to  the  future!
13. Open  Source.
14. Opera>ng  on  Linux.
16. Bindings
17. Bindings  -­‐  ObjC  Style func bindingObjC(x: Int?) { if x == nil || x <= 0 { return } x!.description }
18. func bindingObjC(x: Int?) { // Checking for a condition that you don’t want if x == nil || x <= 0 { return } x!.description } Bindings  -­‐  ObjC  Style
19. func bindingObjC(x: Int?) { if x == nil || x <= 0 { // Value requirements not met, do something return } x!.description } Bindings  -­‐  ObjC  Style
20. func bindingObjC(x: Int?) { if x == nil || x <= 0 { return } // Force unwrap the optional value x!.description } Bindings  -­‐  ObjC  Style
21. func bindingsWithIfLet(x: Int?) { if let x = x where x > 0 { x.description } } Bindings  -­‐  Swi*  1.2
22. func bindingsWithIfLet(x: Int?) { if let x = x where x > 0 { // Putting your desired code within all the conditions x.description } } Bindings  -­‐  Swi*  1.2
23. func getJsonResponse(response: NSObject?) { if let response = response { if let dict = response as? [String: NSObject] { if let user = dict["user"] as? [String : NSObject] { if let address = user["address"] as? [String: NSObject] { if let country = address["country"] as? String { print(country) } } } } } } Bindings  -­‐  Pyramid  of  Doom
24. func bindingsWithIfLet(x: Int?) { if let x = x where x > 0 { x.description } // Value requirements not met, do something } Bindings  -­‐  Swi*  1.2
25. func bindingsWithGuard(x: Int?) { guard let x = x where x > 0 else { return } x.description } Bindings  -­‐  Swi*  2.0
26. func bindingsWithGuard(x: Int?) { // Checking for the condition you do want guard let x = x where x > 0 else { return } x.description } Bindings  -­‐  Swi*  2.0
27. func bindingsWithGuard(x: Int?) { guard let x = x where x > 0 else { // Exit early return } x.description } Bindings  -­‐  Swi*  2.0
28. func bindingsWithGuard(x: Int?) { guard let x = x where x > 0 else { return } // Optional variables are autom. unwrapped x.description } Bindings  -­‐  Swi*  2.0
29. Defer
30. func printFile(fileName: String) { let file = File.openFile(fileName) while let fileLine = file.readline() { print(fileLine, appendNewline: true) } closeFile(file) } Defer  -­‐  Swi*  2.0
31. func printFile(fileName: String) { let file = File.openFile(fileName) defer { closeFile(file) } while let fileLine = file.readline() { print(fileLine, appendNewline: true) } } Defer  -­‐  Swi*  2.0
32. func printFile(fileName: String) { let file = File.openFile(fileName) //defer declaration defer { closeFile(file) } while let fileLine = file.readline() { print(fileLine, appendNewline: true) } //defer execution shortly before scope ends } Defer  -­‐  Swi*  2.0
33. func deferAll() { defer { print("A") } defer { print("B") } defer { print("C") } } // C, B, A deferAll() Defer  -­‐  Swi*  2.0  -­‐  LIFO
34. func shuffleData() { defer { close(inputFile) } defer { close(outputFile) break // or return, or throwing an error } // do something } Defer  -­‐  Swi*  2.0  -­‐  DON’Ts
35. Error  Handling
36. public enum Result { case Success(AnyObject) case Failure(String) } Error  Handling  -­‐  Swi*  1.0
37. public enum WeekendError: ErrorType { case WorkAllWeekend case Overtime(hoursWorked:Int) } Error  Handling  -­‐  Swi*  2.0  -­‐  ErrorType
38. func haveAWeekend(extraWork:Int) throws { guard (extraWork == 0) else { throw WeekendError.Overtime(hoursWorked: extraWork) } print("Let's have a weekend!!") } try haveAWeekend(1) Error  Handling  -­‐  Swi*  2.0  -­‐     Error  Propaga>on
39. // throws indicates something can go wrong here func haveAWeekend(extraWork:Int) throws { guard (extraWork == 0) else { throw WeekendError.Overtime(hoursWorked: extraWork) } print("Let's have a weekend!!") } try haveAWeekend(1) Error  Handling  -­‐  Swi*  2.0  -­‐     Error  Propaga>on
40. func haveAWeekend(extraWork:Int) throws { guard (extraWork == 0) else { // throwing the exception throw WeekendError.Overtime(hoursWorked: extraWork) } print("Let's have a weekend!!") } try haveAWeekend(1) Error  Handling  -­‐  Swi*  2.0  -­‐     Error  Propaga>on
41. func haveAWeekend(extraWork:Int) throws { guard (extraWork == 0) else { throw WeekendError.Overtime(hoursWorked: extraWork) } print("Let's have a weekend!!") } // presence of throws requires a try try haveAWeekend(1) Error  Handling  -­‐  Swi*  2.0  -­‐     Error  Propaga>on
42. do { try haveAWeekend(4) } catch { print("Gulping the weekend exception") } Error  Handling  -­‐  Swi*  2.0  -­‐     Catching  Errors
43. do { try haveAWeekend(4) } catch WeekendError.WorkAllWeekend { print("You worked 48 hours :-0") } Error  Handling  -­‐  Swi*  2.0  -­‐     Catching  Errors
44. do { try haveAWeekend(4) } catch WeekendError.Overtime(let hoursWorked) { print("You worked \(hoursWorked) more than you should") } Error  Handling  -­‐  Swi*  2.0  -­‐     Catching  Errors
45. Protocol  Extensions
46. extension String { var textualDescription: String { return "this is an extension \(self) " } } Protocol  Extensions  -­‐  Swi*  1.0
47. struct Dice { var sides: Int } Protocol  Extensions  -­‐  Swi*  1.0
48. protocol TextRepresentable { var textualDescription: String { get } } Protocol  Extensions  -­‐  Swi*  1.0
49. extension Dice: TextRepresentable { var textualDescription: String { return "A \(sides)-sided dice" } } Protocol  Extensions  -­‐  Swi*  2.0
50. //"A 5-sided dice" Dice(sides: 5).textualDescription Protocol  Extensions  -­‐  Swi*  2.0
51. extension Friend: TextRepresentable { var textualDescription: String { return "Share a Coke with \(name) " } } Protocol  Extensions  -­‐  Swi*  2.0
52. Protocol  Extensions  -­‐  Swi*  2.0 Object oriented Protocol oriented super class class Data Data Behaviour Behaviour struct Data protocol Behaviour Behaviour
53. protocol Creatable { var uid: NSUUID { get } var data: [String:String] { get } } Let’s  build  a  persistency  framework!
54. extension Creatable { func save() throws { AwesomeFrameWork.save(uid: uid, data: data) } } Let’s  build  a  persistency  framework!
55. protocol Updateable { var uid: NSUUID { get } var data: [String:String] { get } } protocol Deleteable { var uid: NSUUID { get } } Let’s  build  a  persistency  framework!
56. struct AccountEntity: Creatable,Updateable,Deleteable { let uid: NSUUID let data: [String:String] } try AccountEntity(uid: NSUUID(), data: ["name" : "Jan"]).save() Let’s  build  a  persistency  framework!
57. @testable
58. test code production code access level: public Produc>on  vs  Test  Target
59. @testable import MyApp func testMyApp() { // access internal properties, methods, and classes } @testable  -­‐  Swi*  2.0
60. func testLogin() { let app = XCUIApplication() app.textFields["username"].typeText("username") app.textFields["password"].typeText("password") app.buttons["login"].tap() } UI  Test  -­‐  Swi*  2.0
61. @available
62. if ((NSClassFromString("WKWebView")) != nil) { print("WKWebView is available") } else { print("WKWebView is notavailable") } Availability  Checking  -­‐  Swi*  1.0
63. @available(iOS 8.0, *) func newFancyFeature() { … } if #available(iOS 8.0, OSX 10.10, watchOS 2, *) { newFancyFeature() } Availability  Checking  -­‐  Swi*  2.0
64. Xcode  7
65. Xcode  7  -­‐  Built-­‐in  test  coverage
66. Xcode  7  -­‐  Markdown  Support
67. Xcode  7  -­‐  Playground  Pages
68. Xcode  7  -­‐  Generated  Interfaces
69. • Control  flow  with  repeat   • Migrator  to  Swift  2.0   • … And  there  is  s>ll  more
70. What  they  forgot!
71. It’s  coding  >me!
72. Danke! @jriehn     @lukasingelheim