This document discusses the challenges of building a Swift framework called Realm that provides object-oriented database functionality. It addresses how to interface Swift and C++, distribute the framework via CocoaPods and Carthage, generate API documentation, support multiple Swift versions, and set up continuous integration testing. Maintaining the framework across evolving Swift versions is an ongoing challenge.

1. CHALLENGES
BUILDING A
SWIFT
FRAMEWORK

4. REALM
> Object-oriented
> Fully ACID transactions
> Well-defined threading model
> Native links
> Zero-copy
> Cross-Platform

7. BUT WHAT ABOUT
?

8. HOW TO INTERFACE
C++ FROM SWIFT?

11. CLANG MODULEMAP
framework module Realm {
umbrella header "Realm.h"
export *
module * { export * }
explicit module Private {
header "RLMArray_Private.h"
header "RLMObject_Private.h"
// …
}
}

12. FIND A VIABLE WAY
TO DISTRIBUTE A FRAMEWORK
WHICH VENDORS ANOTHER

14. !
APPSTORE

16. CARTHAGE EXPECTS ONLY
1 FRAMEWORK
PER REPO

17. WORKAROUND:
SERVE !
VIA GITHUB

18. MAKING
COCOAPODS
use_framework!
READY FOR PRIME TIME

19. Pod::Spec.new do |s|
s.name = 'Realm'
# …
s.module_map = 'Realm/module.modulemap'
end
Pod::Spec.new do |s|
s.name = 'RealmSwift'
# …
s.dependency 'Realm', "= #{s.version}"
end

20. !
READY TO SHIP

21. !
BUT WHAT ELSE IS NEEDED?

22. DOCS

23. API
DOCS

24. APPLEDOC
FOR OBJECTIVE-C
/**
Lorem ipsum dolor sit amet.
@param bar Consectetur adipisicing elit.
@return Sed do eiusmod tempor.
*/
func foo(bar: String) -> AnyObject { ... }

25. RESTRUCTURED TEXT (REST)
UNTIL SWIFT 1.2
/**
Lorem ipsum dolor sit amet.
:param: bar Consectetur adipisicing elit.
:returns: Sed do eiusmod tempor.
*/
func foo(bar: String) -> AnyObject { ... }

26. MARKDOWN
FOR SWIFT 2.0
/**
Lorem ipsum dolor sit amet.
- parameter bar: Consectetur adipisicing elit.
- returns: Sed do eiusmod tempor.
*/
func foo(bar: String) -> AnyObject { ... }

28. GET'S THE AST
VIA
SOURCEKITTEN

30. !

32. ☺

33. ⚠
VERIFY CODE EXAMPLES

34. SWIFT IS EVOLVING FAST

35. IT'S HARD TO
KEEP UP WITH THE PACE
!
WHEN WRITING ACTUAL APPS

36. TO MANY OTHER THINGS TO DELIVER
> Extensions
> Watch Extensions
> Watch Apps
> 3D Touch
> …

37. SWIFT 1.2 !
IS STILL RELEVANT

38. ! IN THE
ROOM

39. CI

40. HOW TO SUPPORT
MULTIPLE SWIFT VERSIONS
AT ONCE?

41. MULTIPLE BRANCH MODEL
> master
> swift-1.2
> swift-2.1
> …

42. $ tree -L 2 | !
.
!"" RealmSwift -> RealmSwift-swift2.0
!"" RealmSwift-swift1.2
# !"" Object.swift
# !"" …
# $"" Tests
#
!"" RealmSwift-swift2.0
# !"" Object.swift
# !"" …
# $"" Tests
#
!"" RealmSwift-swift2.1 -> RealmSwift-swift2.0
#
!"" …

43. CI DOESN'T
NEED TO STOP
AT TESTS

44. TEST ALL
INTEGRATION
SCENARIOS

45. pod lib lint

46. STYLEGUIDE

47. ESTABLISH CONVENTIONS

48. ENFORCE CONVENTIONS

50. try! questions.map { try $0.answer() }

51. THANKS FOR YOUR
ATTENTION!
@MRACKWITZ
MR@REALM.IO