Brew Your Own Cocoa Framework

In this session, I will discuss how to design, implement, distribute, and use a Cocoa Frameworks. The talk would start describing the different options available (Cocoa touch frameworks, static frameworks and development Cocoapods), following a set of guidelines to (re)architect the code into a modular design and finalizing with some recommendations about swift integration, version management, code documentation and testing; including unit and code coverage. I'm planning to illustrate the talk with a small project that refactor some code, wrap it in a framework and later is used in another application.

Transcript

1. Brew your own Cocoa Framework Billy Tobon AltCONF 2015
2. Agenda: » How to create frameworks IRL » We will live code* * famous last words
3. What is this talk about
4. What is this NOT about
5. What is a framework? “A software framework is a universal, reusable software environment that provides particular functionality as part of a larger software platform to facilitate development of software applications, products and solutions...” -- wikipedia
6. Why do I want one?
9. bonus points » (Re)learn your code » Pay your technical debt » Opportunity to start or improve Unit tests » A chance to document your code
10. What options do we have? » Share source files » Cocoa Touch Library (Static) » Cocoa Touch Framework (Dynamic)
11. Cocoa Touch Framework » New in XCode 6 and iOS 8 » Easy setup » Same look and feel as Apple frameworks » Bundle, not source code
12. What goes in a framework? » Classes [.h | .m | .swift] » Assets (Images, fonts, icons) » Custom UI elements @IBDesignable
13. How to Brew a framework
14. Step 1: The what
15. Step 2: REFACTOR
16. Think in Patterns
17. Without Dependecy Injection -(void) doSomething { NSArray *tshirts = [ShirtService sharedInstance].tshirts Dlog(@"We have %d designs",[tshirts count]); } With Dependecy Injection -(void) doSomething:ShirtService *shirtService { NSArray *tshirts = shirtService.tshirts Dlog(@"We have %d designs",[tshirts count]); }
18. façade pattern //RENTKit.h @interface RENTKit:NSObject +(BOOL) rentDressWithSKU:(NSString *)sku; @end //RENTKit.m @implementation +(BOOL) rentDressWithSKU:(NSString *)sku{ [[RTRKit sharedInstance] rentWithSKU:sku]; } -(BOOL) rentWithSKU:(NSString *)sku{ //some business logic return true; } @end //Framework use [RENTKit rentDressWithSKU:@"31415"];
19. Follow a style guide
20. Examples » Google Style Guide » New York Times Style Guide » raywenderlich.com » GitHub
21. Add default behaviors
22. Untangle your headers
23. Step 3: HANDLE VERSIONS
24. Versioning » Coredata » NSKeyedArchiver » NSUserDefaults
25. Versioning » Ask for respondToSelector if ([anObject respondsToSelector:@selector(aMethod)]) { [anObject aMethod]; }
26. Versioning » Check with NSSClassfromString Class dictionaryClass = NSClassFromString(@"NSMutableDictionary");
27. Versioning » Deprecate -(void) anOldMethod __deprecated_msg("use aNewMethod instead.");
28. Step 4: Honor both languages » Nullability NEW » Lightweight generics NEW
29. Step 5: TEST
30. Testining » Test Driven Development » Have code coverage » Also share the tests
31. Step 6: Document
32. Documenting » VVDocumenter XCode Plugin » AppleDoc » Jazzy » Swift playgrounds
33. Step 7: Distribute
34. Cocoapods
35. Carthage
36. Distribution blues: » Need a framework per architecture (sim/device): » Simulator i386 x86_64 » Device armv7 armv7s arm64 » use lipo tool to create a fat binary » Decide the framework depending the build configuration and Architecture
37. Step 8: Use it:
38. Importing Objective-C #import <myLittleFramework/MYObject.h> MYObject *anObject = [MYObject new]; Swift import RentKit let anObject = MYObject()
39. Assets Objective-C NSBundle *aBundle = [NSBundle bundleWithIdentifier:@"altconf.MyLittleFramework"]; UIImage *im = [UIImage imageNamed:@"nice_image" inBundle:aBundle compatibleWithTraitCollection:nil]; Swift let image = UIImage(named: "nice_image", inBundle: NSBundle(forClass: MyLittleFramework.self), compatibleWithTraitCollection: nil)
40. Let's try it!* github.com/billyto/CocoaFrameworks-Demo * famous last words
41. Gracias » Q&A » no corgis were harmed in the making of this demo
42. Images attribution » Hot Cocoa lanielderts - flickr.com/photos/ lanielderts/ » Cocoapods Icon - cocoapods.org » Carthage Icon - github.com/Carthage/Carthage » Apple Watch - clockmaker-jp flickr.com/photos/ clockmaker-jp/ » Wishbone jamesjordan - flickr.com/photos/ jamesjordan/