CocoaPods Frameworks with Marius Rackwitz

The history of CocoaPods frameworks.
Advice on how you can do it.

Transcript

1. 5 Oct 2015 @orta @mrackwitz Marius Rackwitz & Orta Therox CocoaPods Frameworks
3. What is CocoaPods?
4. 5 Oct 2015 @orta @mrackwitz WHAT IS COCOAPODS? A dependency manager A community around mostly open source code 5 years old
5. TERMINOLOGY
6. WORKSPACE
7. TARGETS
8. BUILD PHASE
9. Integration History
10. Static Libraries COMMON DENOMINATOR UNTIL IOS 7.0
11. 5 Oct 2015 @orta @mrackwitz WHAT ARE STATIC LIBRARIES? ”A static library (aka static archive) is a collection of .o files with a table of contents that lists the global symbols in the .o files.
 
 ld will only pull .o files out of a static library if needed to resolve some symbol reference.
 man page of ld
12. 5 Oct 2015 @orta @mrackwitz WHAT ARE STATIC LIBRARIES? ”A static library (aka static archive) is a collection of .o files with a table of contents that lists the global symbols in the .o files.
 
 ld will only pull .o files out of a static library if needed to resolve some symbol reference.
 man page of ld
13. 5 Oct 2015 @orta @mrackwitz ar
 archive BUILDING A STATIC LIBRARY Source Code clang lipo fat binary ar
 archive ranlib o-files o-file o-files o-file table of contents
14. 5 Oct 2015 @orta @mrackwitz INSIDE LD 1 2 3
 4 5 6 7 8 9 10 #BananaKit.h @import monkey; @interface BKBananaTree @property (copy) NSArray *fruits; @end 
 @interface BKBananaFruit @property (weak) MKMonkey *peeledByMonkey; - (void)peel:(MKMonkey *)m;
 @end 1 2 3
 4 5 6 7 8 9 #monkey.h typedef NS_ENUM(NSUInteger, MKSize) { MKSizeSmall, MKSizeBig }
 @interface MKMonkey @property (nonatomic, assign) MKSize size; - (id)init(MKSize)size; @end 1 2 3
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 #main.m @import monkey; @import BananaKit; 
 void main() { id m = [[MKMonkey alloc]
 init:MKMonkeySmall]; id t = [BKBananaTree new]; t.fruits.first.peel(m);
 }

15. COCOAPODS HAS TO BUNDLE RESOURCES
16. Dynamic Frameworks REQUIRED FOR SWIFT
17. 5 Oct 2015 @orta @mrackwitz INSIDE A FRAMEWORK
18. 5 Oct 2015 @orta @mrackwitz COCOA TOUCH FRAMEWORKS Binary
 Dynamic linkable binary Modules Declaration
 Clang Module Map, Swift Module declarations Headers
 Stripped in app Resources
 Prepared like in the app Info.plist
 Meta-data like version, copyright etc. Dependencies
 Can contain further frameworks and dylibs }Necessary for
 import & linking
19. 5 Oct 2015 @orta @mrackwitz WHAT ARE DYNAMIC LIBRARIES? ”A dynamic library (aka dylib or framework) is a final linked image. Putting a dynamic library on the command line causes two things:
 
 1) The generated final linked image will have encoded that it depends on that dynamic library.
 2) Exported symbols from the dynamic library are used to resolve references. 
 the man page of ld
20. 5 Oct 2015 @orta @mrackwitz WHAT ARE DYNAMIC LIBRARIES? ”A dynamic library (aka dylib or framework) is a final linked image. Putting a dynamic library on the command line causes two things:
 
 1) The generated final linked image will have encoded that it depends on that dynamic library.
 2) Exported symbols from the dynamic library are used to resolve references. 
 the man page of ld
21. 5 Oct 2015 @orta @mrackwitz libtool
 -dynam ic MachO BUILDING A DYNAMIC LIBRARY Source Code clang lipo fat binary MachO ld ld o-files o-file
22. 5 Oct 2015 @orta @mrackwitz INSIDE LD 1 2 3
 4 5 6 #main.swift import monkey import BananaKit let m = MKMonkey(.Small) let t = BKBananaTree() t.fruits.first.peel(m) 1 2 3
 4 5 6 7 8 9 10 11 12 #BananaKit.swift import monkey public class BKBananaTree { var fruits: [BKBananaFruit] public struct BKBananaFruit { var peeledByMonkey: MKMonkey? public func peel(m: MKMonkey) { peeledByMonkey = m } } } 1 2 3
 4 5 6 7 8 9 10 #monkey.swift public enum MKSize { case Small case Big } public class MKMonkey { public let size: MKSize public init(_ size: MKSize) { self.size = size } }
23. 5 Oct 2015 @orta @mrackwitz INSIDE LD 1 2 3
 4 5 6 #main.swift import monkey import BananaKit let m = MKMonkey(.Small) let t = BKBananaTree() t.fruits.first.peel(m) MKMonkey MKSize.Small BKBananaTree 1 2 3
 4 5 6 7 8 9 10 11 12 #BananaKit.swift import monkey public class BKBananaTree { var fruits: [BKBananaFruit] public struct BKBananaFruit { var peeledByMonkey: MKMonkey? public func peel(m: MKMonkey) { peeledByMonkey = m } } } BKBananaTree 1 2 3
 4 5 6 7 8 9 10 #monkey.swift public enum MKSize { case Small case Big } public class MKMonkey { public let size: MKSize public init(_ size: MKSize) { self.size = size } } BKBananaTree.peel MKMonkey MKSize MKMonkey.init MKSize.Big MKMonkey MKMonkey.size MKSize.Small BKBananaTree.peel Array Array.first
24. 5 Oct 2015 @orta @mrackwitz DYNAMIC FRAMEWORKS NEED TO BE EMBEDDED
25. 5 Oct 2015 @orta @mrackwitz DYNAMIC FRAMEWORKS NEED TO BE EMBEDDED
26. 5 Oct 2015 @orta @mrackwitz DYNAMIC FRAMEWORKS NEED TO BE EMBEDDED CocoaPods allows different sets of dependencies per build configuration.
 
 pod 'Lookback', :configurations => ['Debug']
27. 5 Oct 2015 @orta @mrackwitz WHAT HAPPENS ON COPY Header Stripping
 Headers are only needed to integrate the library for the compiler and shouldn’t be shipped Code Signing
 Frameworks are all signed individually and excluded from the whole app bundle signature
28. 5 Oct 2015 @orta @mrackwitz FRAMEWORKS IN COMPARISON TO STATIC LIBS Advantages Easier to distribute & integrate if compiled Reduces file size if used for app & extensions Separate resources in distinct bundles Disadvantages Optimization is limited to LTO Limits dead-code stripping Increases load times
29. 5 Oct 2015 @orta @mrackwitz WHAT MEANS THAT FOR COCOAPODS We need to support Clang Modules, too. DSL-extensions for Podfile and Podspec Bundle Resources into Frameworks Workaround issues with swift-stdlib-tool Code Signing
30. Transitioning
31. 5 Oct 2015 @orta @mrackwitz TRANSITIONING FROM STATIC LIBRARIES TO FRAMEWORKS gem install cocoapods-deintegrate pod deintegrate
32. TRANSITIONING FROM STATIC LIBRARIES TO FRAMEWORKS
33. 5 Oct 2015 @orta @mrackwitz TRANSITIONING FROM STATIC LIBRARIES TO FRAMEWORKS Deletes Pods/. Removes the CocoaPods Xcode group. Removes these three build phases: Copy Pods Resources Check Pods Manifest.lock Embed Pods Frameworks
34. 5 Oct 2015 @orta @mrackwitz TRANSITIONING FROM STATIC LIBRARIES TO FRAMEWORKS Add use_frameworks! to Podfile. Run pod install. Run tests.
35. 5 Oct 2015 @orta @mrackwitz COMMON ISSUES Pods depending on static libraries Libraries expecting resources in the main bundle UIFont pods Pods that change behaviour using #defines
36. 1st App With CocoaPods Frameworks github.com/artsy/eidolon/pull/317
37. Simple Transition, old app github.com/artsy/energy/pull/50
38. Large codebase, ~60 pods github.com/artsy/eigen/pull/520
39. App Launch Time Increased github.com/artsy/eigen/issues/586 3rd Party Frameworks have O(N^2) lookup time Could be in library launching Could be in library code sign verification Looking like solution is on app deployment to bundle all framework symbols into one
40. App Launch Time Increased github.com/artsy/eigen/issues/586
41. 5 Oct 2015 @orta @mrackwitz Come help out @mrackwitz / @orta / @CocoaPods cocoapods.org/get-started