If you ever wondered how to easily develop and manage your own libraries for iOS and OS X seek no further! Watch the presentation and read our blog to find a solution. If you have any questions just drop me an email or tweet :)

1. Building static libraries
for iOS with
kamil.burczyk@sigmapoint.pl

2. • What is CocoaPods?
• Local CocoaPods dependencies.
• Building a distribution library.
• One library - 5 different architectures.
• Avoiding collisions in other projects.
• Final thoughts.
Roadmap:

3. CocoaPods is the dependency manager for
Objective-C projects. It has thousands of
libraries and can help you scale your projects
elegantly. [http://cocoapods.org]

4. Podfile:
pod 'CocoaLumberjack', '~> 1.7.0'
pod 'AFNetworking', '~> 1.3.3'
pod 'UIView+AutoLayout', '~> 1.1.0'
pod 'MagicalRecord', '~> 2.2'
pod 'Reachability', '~> 3.1.1'
pod 'UIAlertView-Blocks', '~> 0.0.1'
Terminal:
$ pod install

5. Semantic versioning:
!
• Major.Minor.Patch -> 2.0.1
• Major - incompatible API changes
• Minor - added features but backward compatible
• Patch - backward compatible bug fixes
int add(int a, int b) { return a-b; } // 1.0.0
double add(int a) { return 3.14+a; }
int add(int a, int b, int c=0) { return a+b+c; }
int add(int a, int b) { return a+b; } // x.y.z

6. CocoaPods project structure

7. Podspec file
Pod::Spec.new do |s|
s.name = "NetworkLib"
s.version = “1.0.0”
s.platform = :ios, '7.0'
s.source_files = 'NetworkLib', 'NetworkLib/**/*.{h,m}'
s.public_header_files = 'NetworkLib/**/*.h'
s.resources = "NetworkLib/*.png"
s.framework = 'SystemConfiguration'
s.requires_arc = true
s.dependency 'AFNetworking'
end

8. Local CocoaPods dependency
$ pod 'NetworkLib', :path => '../NetworkLib'
git fork CocoaPods dependency
$ pod 'WebViewJavascriptBridge', :git =>
‘https://github.com/burczyk/WebViewJavascriptBridge/',
:commit => '5183c4c'

9. Demo #1

10. Building distribution library
xcodebuild
-workspace NetworkLib.xcworkspace
-scheme NetworkLib
-sdk iphonesimulator
-configuration Debug
lipo
-create lib1.a lib2.a
-output libMultipleArch.a

11. Aggregate Lib script

12. Build all supported architectures
$ lipo —info libNetworkingLib-debug-0.1.a
!
!
Architectures in the fat file:
libNetworkLib-debug-0.1.a are:
armv7 armv7s i386 x86_64 arm64

13. Copy files phase & results

14. Demo #2

15. Symbol collisions
What happens if user adds AFNetworking to
his app?

16. Symbols investigation
$ nm libNetworkLib-debug-0.1.a | grep AFN
!
!
000000000000bea0 s -[UIWebView(_AFNetworking)
af_HTTPRequestOperation].eh
!
0000000000000030 t -[UIWebView(_AFNetworking)
af_setHTTPRequestOperation:]
!
000000000000bec8 s -[UIWebView(_AFNetworking)
af_setHTTPRequestOperation:].eh
!
0000000000000190 t ___44-[UIWebView(AFNetworking)
requestSerializer]_block_invoke
!
000000000000bf18 s ___44-[UIWebView(AFNetworking)
requestSerializer]_block_invoke.eh

17. Symbol collisions solutions
• Pretend they don’t exist ;)
• Write in docs which dependencies are required
• Export all dependencies’ headers
• Build library with prefixed symbols

18. Exporting all symbols
http://pdx.esri.com/blog/2013/12/13/namespacing-dependencies/
nm $CODESIGNING_FOLDER_PATH -j | sort | uniq |
grep "_OBJC_CLASS_$_" | grep -v "$_NS" | sed …
//NamespacedDependencies.h:
!
#ifndef AFHTTPSessionManager
#define AFHTTPSessionManager
__NS_SYMBOL(AFHTTPSessionManager)
#endif
AFHTTPSessionManager —> SIGMA_AFHTTPSessionManager

19. Configuring Pods & lib to use prefixed symbols

20. Symbols re-investigation
$ nm libNetworkLib-debug-0.1.a | grep SIGMA
!
!
000000000000b720 s l_OBJC_
$_CATEGORY_SIGMA_AFURLConnectionOperation_$__UIProgressView
!
000000000000b6d8 s l_OBJC_
$_PROP_LIST_SIGMA_AFURLConnectionOperation_
$__UIProgressView
!
U _OBJC_CLASS_$_SIGMA_AFHTTPRequestOperation
!
U _OBJC_CLASS_$_SIGMA_AFHTTPRequestSerializer
!
U _OBJC_CLASS_$_SIGMA_AFHTTPResponseSerializer

21. Demo #3

22. • Easy development
• Clean git repo
• Easy switching from local podspec to static
library
• Shell & classic build script sometimes
necessary
• Only one step to put your lib to global repo
Summary

23. Contact:
kamil.burczyk@sigmapoint.pl @KamilBurczyk
Thank you!
Links:
http://cocoapods.org/
http://pdx.esri.com/blog/2013/12/13/namespacing-dependencies/
http://blog.sigmapoint.pl/