Framework Oriented Programming

Have you ever tried to reuse code from your mobile apps and you haven’t been able to? Did you start using frameworks only when Apple suggested it for Watch Extensions? With more platforms coming out, there's a clear need of bundling logic that can be reused and shared in multiple platforms. Frameworks will help us with that and will benefit our application code bases in many ways. Learn how to do it, with or without dependency manager involved, recommendations and some caveats you must keep in mind. Start building your own Foundation frameworks, reusable, well designed, and with single responsibilities.

Transcript

1. Framework Oriented Programming Pedro Piñera @pepibumur ⌚"#$
2. Hello It's me (From the other side London)
3. iOS Developer at SoundCloud @pepibumur
4. Framework Oriented Programming • Started with GitDo • Applying principles to SoundClound • Ideas/Principles together in a repository (Reference) • Feedback is welcome !
5. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
6. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
7. Context Before 2008 OSX == 1 Bundle* *Xcode project target
8. Context 2008 Apple launches iPhone Software Development Kit ! (Developers move to iOS. New platform, frameworks,... New exciting area)
9. Context After 2008 iOS == 1 Bundle* OSX == 1 Bundle* *Xcode project target
11. Context 2011 CocoaPods released Dependency Resolving + Integration + Community !
12. Context After 2011 iOS == 1 Bundle* OSX == 1 Bundle* X Bundles (External Dependencies) *Xcode project target
13. Context 2015 ⌚ "
14. OMG That's Awesome
15. Trying to reuse ! your code base
16. Context 2015 iOS == 1 Bundle* OSX == 1 Bundle* tvOS == 1 Bundle* watchOS == 1 Bundle*
17. How to reuse code? (across platforms) Frameworks
18. Swift ❤ Dynamic Frameworks (OSX, iOS, watchOS, tvOS) • Allow embedded resources (images, fonts, ...) • Dynamically linked (No duplicated symbols) • Swift code
19. Framework Oriented Programming Coding your apps organizing your code base in reusable & multiplatform code bundles Best Practices, Principles, Advices.. github.com/pepibumur/framework-oriented-programming
20. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
21. Frameworks Stack SoundCloud Approach
22. 1. Single Responsibility SOLID inspired
23. 1. Single Responsibility SOLID inspired
24. Responsibility? CoreData access layer?
25. Responsibility? CoreData access layer? Storage access layer?
26. Responsibility? CoreData access layer? Storage access layer? Keychain access layer?
27. Responsibility? CoreData access layer? Storage access layer? Keychain access layer? Models?
28. Responsibility? CoreData access layer? Storage access layer? Keychain access layer? Models? !
29. 1. Single Responsibility Start from a high level
30. 1. Single Responsibility Slice them progressively
31. 1. Single Responsibility Slice them progressively
32. 2. Vertical dependencies (Over Horizontal)
33. 3. Lower in the stack Fewer external dependencies
34. 4. One Step Dependencies
35. 4. One Step Dependencies
36. 5. Internal by default
37. 6. Final SOLID inspired (open/closed)
38. 6. Final SOLID inspired (open/closed)
39. 6. Final SOLID inspired (open/closed)
40. 6. Final SOLID inspired (open/closed) final class Person { let name: String } class Alien: Person { // Compiler complains }
41. 7. Framework models Don't share lower frameworks models upwards
42. 7. Framework models Don't share lower frameworks models upwards
43. 7. Framework models Don't share lower frameworks models upwards // Persistence class Author: NSManagedObjectModel { let name: String } class Track: NSManagedObjectModel { let author: Author } // ListenersKit struct StreamTrackEntity { let name: String let authorName: String }
44. 7. Framework models Don't share lower frameworks models upwards struct StreamTrackEntityAdapter { func adapt(track: Track) -> StreamTrackEntity { return StreamTrackEntity(name: track.name, authorName: track.author.name) } }
45. 8. Platform Abstraction SOLID inspired (DI)
46. But... There's platform specific logic Examples - No NSFetchedResultsController in macOS - NSIndexPath is slightly different for watchOS.
47. 8. Platform Abstraction Macros! #if os(OSX) // OSX logic #else // Other platforms logic #endif
48. 9. Protocol Oriented Interfaces SOLID inspired (DI)
49. 9. Protocol Oriented Interfaces SOLID inspired (DI)
50. 9. Protocol Oriented Interfaces SOLID inspired (DI)
51. 9. Protocol Oriented Interfaces SOLID inspired (DI)
52. 9. Protocol Oriented Interfaces SOLID inspired (DI)
53. 10. Core/Testing (aka your project Foundation frameworks)
54. 10. Core/Testing Accessible from all the Frameworks • Extensions • Logging • Analytics • Architectural components (e.g. Reactive)
55. Index • Context • Principles • Advantages ! • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
56. Multiplatform apps Only working on the UI ⌚"#$
57. Multiplatform apps Only working on the UI ⌚"#$
58. Experimentation import MyAppKit • Prototyping • Playgrounds
59. New products With similar core needs Because you want to reuse code, right?
60. New products With similar core needs Because you want to reuse code, right?
61. Open Source And benefit from the community Build pieces of code that you'd be proud of open sourcing
62. Specialized teams From UI lovers to Core Data experts (clearly defined team boundaries)
63. Specialized teams From UI lovers to Core Data experts (clearly defined team boundaries)
64. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
65. How to? There are multiple options (I'll show you some)
66. How to? CocoaPods
67. How to? CocoaPods • ✅ Easy setup (each Framework .podspec) • ✅ You don't have to worry about Xcode Frameworks configuration • ✅ Same setup for local/external dependencies • ❌ .podspec cannot point to another local .podspecs • ❌ CocoaPods sucks if you don't version.
68. How to? Local podspec discovery # Networking ~> Core dependency not found pod 'Networking' pod 'Core' pod 'AppKit'
69. How to? Local podspec discovery pod 'Core' pod 'Networking' # Core has already been resolved pod 'AppKit'
70. How to? Manual • ✅ More control over the workspace • ❌ Cumbersome setup (Build Settings) • External dependencies can be checked out with Carthage/Git Submodules.
71. How to? Hybrid
72. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
73. Open Questions External Dependencies? RECOMMENDATION ⾠ • If CocoaPods for local: Use it also for external. • If manual setup: Use Carthage for checking out external dependencies carthage update • With the binary. • Adding the project to the workspace: --no-build
74. Open Questions Versioning? Git repo per framework? RECOMMENDATION ⾠ 1. Keep it in the same repository (fast iterations) 2. Move it once it consolidates. (sporadic changes) 3. Then version it! (snapshots in time)
75. Open Questions Static or Dynamic? RECOMMENDATION ⾠ - Objective-C & not shared ~> Static - Objective-C && shared ~> Dynamic - Swift && .* ~> Dynamic The more dynamic the worse load time
76. Open Questions Migrate existing project RECOMMENDATION ⾠ - Start with Core/Testing - Move Foundation components down. - Continue building layers progressively. You'll figure out how couple your code is !
77. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
78. We failed at our first try Why?
79. 1. We didn't version with CocoaPods I'm not against CocoaPods! Local Pods + No versioning + Team = It Sucks
80. 2. Too many frameworks • No clear responsibilities • Crossed dependencies • Messy dependency tree • Very small responsibilities
84. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
85. Lack of documentation (Targets Configuration) Tip: Use CocoaPods and copy the configuration
86. Storyboards/Xibs in Frameworks Sucks ! Tip 1: Keep them in the application target Tip 2: Reuse UI only if it's in code
87. Frameworks code recognition Sucks even more !
88. Index • Context • Principles • Advantages • How to? • Open Questions • SoundCloud attempt • Downsides • Conclusions
89. Very time-saver for multi-platform projects
90. Helps with less coupled code (defined boundaries)
91. Setup requires some Xcode Build Settings knowledge Unless you use CocoaPods
92. Minimize external dependencies (KISS) (avoid more than 2 levels)
93. Use your commonsense When deciding the Frameworks you need (don't get inspired from Javascript) • Try to have only those that you really need.
94. Configuration depends on your project • New project? • Existing project to migrate? • Many external dependencies? • Not that many? • Already using CocoaPods? • How many people in your team?
95. References • Library Oriented Programming: Justin Spahr-Summers • The Unofficial Guide to xcconfig files • CocoaPods • Carthage • pepibumur/framework-oriented-programming • Static & Dynamic libraries • Creating your first iOS Framework
96. Thanks Questions? ! SpeakerDeck Slides: http:/ /bit.ly/22m4lwi