From Ruby to Objective-C

because Ruby and Objective-C has the same ancestor, they have many things in common, and in this talk I mainly talk about what I learned in Ruby, borrow those experiences and move to Objective-C :)

Ruby Tuesday #27 @Taiwan

Transcript

2. from Ruby to Objective-C
4. I’m a Ruby guy (≈ 5 years) I’m a iOS app guy (≈ 3 years) I’m a Flash guy (≈ 9 years) I’m a Python guy (≈ 3 years)
5. Ruby > Rails
6. Current Status
   80% iOS app, 20% Ruby/Rails
7. 100% Ruby Lover!
8. Rails Girls Taipei
9. Rails Girls Taipei
10. WebConf Taiwan 2014
11. Today, I’m NOT talking about.. how to use Ruby to write iOS app!
12. I’m going to talk about..
13. what I learned in Ruby…
14. and move to Objective-C
15. after all, our life, time and resources are limited
17. what about Objective-C?
18. “it has god dame long method name and weird parameters!” Objective-C … NSArray* languages = [NSArray arrayWithObjects:@"Ruby", @"PHP", @"Objective-C", nil]; ! [languages enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) { NSLog(@"language = %@", obj); }];
19. “what the hell is the square bracket!” Objective-C … NSString* myName = @"eddie kao"; NSLog(@"%@", [myName uppercaseString]);
20. “WTF! my app crashed again!!” Objective-C …
21. Introduction
22. Ruby was born on 1993 Objective-C was born on 1983
23. they have the same ancestor
24. Smalltalk photo by Marcin Wichary
25. Ruby is general-purpose Objective-C mainly used in Mac/iOS app development
26. Ruby != Rails Objective-C != Cocoa Framework
27. they have something in common..
28. both Ruby and Objective-C are Object-Oriented
29. both Ruby and Objective-C are strongly typed language.
30. Ruby is a dynamic language Objective-C is a dynamic language
31. both Ruby and Objective-C are Dynamic Typing
32. Type checking.. - (void) makeSomeNoise:(id) sender { if ([sender isKindOfClass:[RobberDuck class]]) { RobberDuck* duck = (RobberDuck *) sender; [duck quack]; } }
33. or you can do this.. - (void) makeSomeNoise:(id) sender { if ([sender respondsToSelector:@selector(quack)]) { [sender quack]; } }
35. id
36. Objective-C is superset of C
37. Objective-C is still C
38. NSString, NSArray, NSNumber…
39. NextSTEP
40. CF… = Core Foundation CG… = Core Graphic CL… = Core Location CA… = Core Animation UI… = User Interface
41. OOP
42. everything in Ruby is an object…
43. and almost everything in Objective-C is an objects..
44. there’re still some primitive data types in Objective-C
45. object model class Animal end ! class Dog < Animal end
46. object model dog = Dog.new ! puts "class of dog is #{dog.class}” # Dog puts "superclass of dog is #{dog.class.superclass}” # Animal puts "super superclass of dog is #{dog.class.superclass.superclass}” # Object puts "super super superclass of dog is #{dog.class.superclass.superclass.superclass}” # BasicObject ! puts "class of Dog is #{Dog.class}” # Class puts "class class of Dog is #{Dog.class.class}” # Class puts "class of Animal is #{Animal.class}” # Class puts "class of Object is #{Object.class}” # Class
47. object model @interface Animal : NSObject @end ! @implementation Animal @end ! @interface Dog : Animal @end ! @implementation Dog @end
48. object model Dog* dog = [[Dog alloc] init]; ! NSLog(@"class of dog is %@", [dog class]); # Dog ! NSLog(@"superclass of dog is %@", [dog superclass]); # Animal ! NSLog(@"super superclass of dog is %@", [[dog superclass] superclass]); # NSObject ! NSLog(@"super super superclass of dog is %@", [[[dog superclass] superclass] superclass]); # null
49. Object Model reference: http://goo.gl/wYL6gT
50. method & message
51. method definition - (void) sayHello:(id)someOne withMessage:(NSString *)message { NSLog(@"Hello %@, %@", someOne, message); } def say_hello(someone, message) puts "Hello #{someone}, #{message}" end
52. sending message [dog walk]; dog.walk() # or you can omit the parentheses
53. [fox saySomething:@"hi, Ruby"]; fox.say_something "hi, Ruby" # what does the fox say? sending message
54. sending message puts 1 + 2 puts 1.+(2) puts 1.send(:+, 2)
55. sending message class Bank def save(money) puts "you just saved #{money} dollars" end end ! bank = Bank.new bank.save 20 # you just saved 20 dollars bank.send(:save, 20) # you just saved 20 dollars
56. sending message @interface Bank : NSObject - (void) save:(NSNumber *) money; @end ! @implementation Bank - (void)save:(NSNumber *)money { NSLog(@"you just saved %@ dollars", money); } @end ! Bank* bank = [[Bank alloc] init]; [bank save:@20]; [bank performSelector:@selector(save:) withObject:@20];
57. block
58. block p1 = Proc.new { puts "Hello, Proc Block" } p1.call ! p2 = lambda { puts "Hello, Lambda Block" } p2.call
59. block ^{ };
60. block typedef void (^MyBlock)(void); int age = 18; MyBlock theBlock = ^{ NSLog(@"Hello, Objective-C Block, your age = %d", age); }; ! theBlock(); # Hello, Objective-C Block, your age = 18 ! age = 38; theBlock(); # guess what’s the age?
61. block 3.times { |i| puts i } NSArray* list = @[@1, @2, @3]; [list enumerateObjectsUsingBlock:^(NSNumber* num, NSUInteger idx, BOOL *stop) { NSLog(@"%@", num); }];
62. iteration
63. iteration list = [1, 2, 3, 4, 5] ! sum = 0 ! list.each { |num| sum += num } ! puts "sum = #{sum}"
64. iteration NSArray* list = @[@1, @2, @3, @4, @5]; ! __block int sum = 0; ! [list enumerateObjectsUsingBlock:^(NSNumber* num, NSUInteger idx, BOOL *stop) { sum += [num intValue]; }]; ! NSLog(@"sum = %d", sum);
65. iteration class Fox def say puts "what does the fox say?" end end ! fox1 = Fox.new fox2 = Fox.new fox3 = Fox.new foxes = [fox1, fox2, fox3] ! foxes.map { |fox| fox.say } # what does the fox say?
66. iteration @interface Fox : NSObject - (void) say; @end ! @implementation Fox - (void) say { NSLog(@"what does the fox say?!"); } @end
67. iteration Fox* fox1 = [[Fox alloc] init]; Fox* fox2 = [[Fox alloc] init]; Fox* fox3 = [[Fox alloc] init]; ! NSArray* foxes = @[fox1, fox2, fox3]; ! [foxes makeObjectsPerformSelector:@selector(say)];
68. add methods at runtime
69. Open class class String def is_awesome? return true if self == "Ruby Tuesday" end end ! puts "Ruby Tuesday".is_awesome?
70. Category @interface NSString(RubyTuesday) - (BOOL) isAwesome; @end ! @implementation NSString(RubyTuesday) - (BOOL) isAwesome { if ([self isEqualToString:@"Ruby Tuesday"]){ return YES; } return NO; } @end
71. Category NSString* meetup = @"Ruby Tuesday"; if ([meetup isAwesome]) { NSLog(@"AWESOME!"); }
72. <objc/runtime.h> Working with Classes class_getName class_getSuperclass class_getInstanceVariable class_getClassVariable class_addIvar class_copyIvarList class_addMethod class_getInstanceMethod class_getClassMethod class_replaceMethod class_respondsToSelector .. reference: http://goo.gl/BEikIM
73. Working with Instances object_copy object_dispose object_setInstanceVariable object_getInstanceVariable object_getIndexedIvars object_getIvar object_setIvar object_getClassName object_getClass object_setClass .. reference: http://goo.gl/BEikIM <objc/runtime.h>
74. reflection - (BOOL) isKindOfClass:(Class) aClass - (BOOL) isMemberOfClass:(Class) aClass - (BOOL) respondsToSelector:(SEL) aSelector - (BOOL) conformsToProtocol:(Protocol *) aProtocol .. reference: http://goo.gl/fgmJcg
75. ecosystem
76. open source projects on Github Ruby : 76,574 Objective-C : 22,959
77. Ruby : bundler source 'https://rubygems.org' ! gem 'rails', '3.2.8' gem 'mysql2' ! group :assets do gem 'sass-rails', '~> 3.2.3' gem "bootstrap-sass" end ! gem "kaminari" gem "simple_form" gem "carrierwave" gem 'unicorn'
78. Objective-C : cocoapods platform :ios, '6.0' ! pod 'Facebook-iOS-SDK', '~> 3.5.1’ pod 'JSONKit', '~> 1.5pre' pod 'MagicalRecord', '~> 2.0.7’ pod 'SSKeychain', '~> 0.1.4’ pod 'TestFlightSDK', '~> 1.1' pod 'SMCalloutView', '~> 1.1.2' ! target :UnitTests do link_with 'UnitTests' pod 'OCMock', '~> 2.0.1' pod 'OCHamcrest', '~> 1.9' end
79. IMHO
80. Objective-C is not really hard to learn…
81. the actual difficult part in iOS app development is Cocoa Framework
82. Objective-C would be almost useless without Cocoa Framework
83. Ruby without Rails?!
84. design patterns observer singleton delegation command target-action composite notifications proxy MVC
85. C
86. what else..
87. photoed by JD Hancock
89. reference: http://goo.gl/2mzyMY Flash Display Hierarchy
90. reference: http://goo.gl/xhS7m7 UIKit and AppKit framework Hierarchy
91. Views reference: http://goo.gl/xhS7m7
92. reference: http://goo.gl/xhS7m7 Views
93. and I read Ruby source code..
94. my iOS app dev experience = Ruby + C + Flash/AS3 = +
95. ⾼高⾒見⻯⿓龍 Contacts photo by Eddie Website Blog Plurk Facebook Google Plus Twitter Email Mobile http://www.eddie.com.tw http://blog.eddie.com.tw http://www.plurk.com/aquarianboy http://www.facebook.com/eddiekao http://www.eddie.com.tw/+ https://twitter.com/#!/eddiekao eddie@digik.com.tw +886-928-617-687