Swift, meet Objective-C

Transcript

1. ! Swift, meet Objective-C ! Twitter: @DanToml Email: Dan@Tomlinson.io
2. !
3. In the sharp, square bracketed embrace of Objective-C — @AndrewJClark
4. All objective-c written now is technical debt
5. ...but so is all of your Swift.
6. You can use them together
7. A whole bunch of new developers are going to be Swift only.
8. Starting out
9. Starting out Bridging Header // // Use this file to import your target's public headers that you would like to expose to Swift. // #import "Person.h" #import "PersonController.h" #import "CoreDataController.h"
10. Objective-C -> Swift
11. The bridging header // ReactiveCocoa-Bridging-Header.h // // Use this file to import your target's public headers that you would like to expose to Swift. // #import "RACCommand.h" #import "RACDisposable.h" #import "RACEvent.h" #import "RACScheduler.h" #import "RACTargetQueueScheduler.h" #import "RACSignal.h" #import "RACSignal+Operations.h" #import "RACStream.h" #import "RACSubscriber.h"
12. Method Names // Objective-C - (instancetype)initWithArray:(NSArray *)array title:(NSString *)title; // Swift init!(array: [AnyObject]!, title: String!)
13. Method Names // Objective-C - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions; // Swift func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool
14. Nullability • __nullable • __nonnull • __null_resettable // Properties only. • null_unspecified // Default.
15. Nullability Before // Objective-C @interface XYZList : NSObject <NSCoding, NSCopying> - (XYZListItem *)itemWithName:(NSString *)name; @property (copy, readonly) NSArray *allItems; @end // Swift class XYZList : NSObject, NSCoding, NSCopying { func itemWithName(name: String!) -> XYZListItem! @NSCopying var allItems: [AnyObject]! { get } }
16. Nullability After // Objective-C @interface XYZList : NSObject <NSCoding, NSCopying> - (XYZListItem * __nullable)itemWithName:(NSString * __nonnull)name; @property (copy, readonly) NSArray * __nonnull allItems; @end // Swift class XYZList : NSObject, NSCoding, NSCopying { func itemWithName(name: String) -> AAPLListItem? @NSCopying var allItems: [AnyObject] { get } }
17. Swift -> Objective-C
18. What can be bridged? • Classes
19. Classes // Swift @objc class MySwiftNSObject { var array: [String] init(array: [String]) { self.array = array; } } // Objective-C @interface MySwiftNSObject @property (nonatomic, copy) NSArray * __nonnull array; - (instancetype)initWithArray:(NSArray * __nonnull)array OBJC_DESIGNATED_INITIALIZER; @end
20. What can be bridged? • Classes • Protocols
21. Protocols @objc protocol Edible { func eat() } @protocol Edible { - (void)eat; }
22. What can be bridged? • Classes • Protocols • Methods
23. Methods func genericFunction<T>(param: T) // Not bridged func defaultParameterFunction(param: String = "Hi") // Not bridged func function(param: String) - (void)function:(NSString * __nonnull)param;
24. What can be bridged? • Classes • Protocols • Methods • Properties
25. Properties // Swift let forname: String var surname: String // Objective-C @property (nonatomic, readonly, copy) NSString * __nonnull forname; @property (nonatomic, copy) NSString * __nonnull surname;
26. Properties KVO (Key Value Observing) dynamic var name: String object.addObserver(self, forKeyPath: "name", options: .New, context: &myContext)
27. What can be bridged? • Classes • Protocols • Methods • Properties • Enums
28. Enums @objc enum MyEnum : Int { case SomeValue = 0 case AnotherValue = 1 } typedef NS_ENUM(NSInteger, MyEnum) { MyEnumSomeValue = 0, MyEnumAnotherValue = 1 };
29. Bridging limitations !!! No: - Structs - Functions - Operators - Generics - Subclassing Swift classes in objective-c
30. Roundup
31. Further Resources Apple • WWDC Session 406 (Integrating Swift with Objective-C) • WWDC Session 407 (Swift Interoperability in Depth) Blog Posts • https://mikeash.com/pyblog/friday-qa-2014-08-15-swift- name-mangling.html
32. Questions? Twitter: @DanToml Email: Dan@Tomlinson.io