Building libraries for iOS — Going native

As the iOS community grows, code sharing becomes more and more important thing to discuss. In this presentation I'll share my experience of being a library vendor. I'll give an overview of dependency management approaches. In the "Going Native" part I'll explain why it might be a good idea to stay native and master your libraries manually.

Remarks: One more thing… We are going to talk a bit about mixing Objective-C and C++.

Transcript

1. Building libraries for iOS Going native Alexander Dodatko 2014
3. The standard library saves programmers from having to reinvent the wheel. Bjarne Stroustrup http://bit.ly/1iqZ3JO
5. Code Reuse is Important
7. March 2008
8. http://engt.co/1pOLKH9
9. The fastest code is the code that reaches the market first
10. Nobody Cares
12. August 2011
17. pod install SomeAwesomeLibXYZ
18. Except...
21. Typical Workflow
25. Our own Busyness Logic
27. In-Place Editing
29. Modular Architecture Benefits Code Reuse Test Coverage Easier to Apply Changes
32. Going Native
34. --no-integrate
37. Not Just Library Target
38. #import <AFNetworking/AFNetworking.h> #import "AFHTTPRequestOperation.h" VS
39. #import "AFHTTPRequestOperation.h" For Implementation Files
40. #import <AFNetworking/AFNetworking.h> For Public Headers
41. Incapsulation
43. #import <AFNetworking/AFNetworking.h> #import <Foundation/Foundation.h>
44. Static Framework for iOS
46. <plist version="1.0"> <dict> <key>CFBundleDevelopmentRegion</key> <string>English</string> <key>CFBundleIdentifier</key> <string>org.ocmock</string> <key>CFBundleInfoDictionaryVersion</key> <string>6.0</string> <key>CFBundlePackageType</key> <string>FMWK</string> <key>CFBundleSignature</key> <string>????</string> <key>CFBundleVersion</key> <string>2.2.3</string> </dict> </plist>
47. Drag & Drop
48. Framework Search Path is updated by Xcode
49. Frameworks Reduce Compilation Time
50. CocoaPods Makes you Care about Versioning
51. For Distribution For Development and Unit Testing
52. For You For End Users
53. Library Dependencies and Linker
56. Never Link Libraries into Other Libraries
58. Same Approach for Unit Tests
60. All Testable Code Should be in libraries
61. Use Precompiled Headers
62. // Pure C headers go here #include <math.h> #ifdef __cplusplus // Pure C++ headers go here #include <vector> #endif #ifdef __OBJC__ // Objective-C headers go here #import <Foundation/Foundation.h> #ifdef __cplusplus #import "MyObjectiveCppClass.h" #endif #endif
63. But I do not Need C++
64. NSDictionary* errorMessages; NSLog( @"%@", errorMessages[ @( errorCode ) ] ); Print Message for Low Level Error
65. std::map< NSInteger, NSString* > errorMessages; NSLog( @"%@", errorMessages[ errorCode ] ); C++ ===> No Boxing
66. Scoped Guard
67. void bad(const char* p) { FILE* fh = fopen(p,"r"); // acquire // use f if ( someCondition ) { // Oops! File handle leaks return; } fclose( fh ); // release }
68. void good(const char* p) { FILE* fh = fopen(p,"r"); // acquire // the block to perform cleanup actions GuardCallbackBlock releaseBlock_ = ^void( void ) { fclose( fh ); }; // creating a guard ObjcScopedGuard guard( releaseBlock_ ); if ( someCondition ) { // Now the scoped guard will release the resource return; } }
69. Exception-Safe Resource Deallocation
70. malloc() std::vector<unsigned char> Vector as a Scoped Guard Memory
71. Let's Recap
73. #import <AFNetworking/AFNetworking.h> For Public Headers
74. For Distribution For Development and Unit Testing
75. Native Rulezzz Alexander Dodatko @dodikk88