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

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2. from Ruby to Objective-C
   

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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)
   

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5. Ruby > Rails
   

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6. Current Status
   80% iOS app, 20% Ruby/Rails
   

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7. 100% Ruby Lover!
   

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8. Rails Girls Taipei
   

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9. Rails Girls Taipei
   

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10. WebConf Taiwan 2014
    

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11. Today, I’m NOT talking about..
    how to use Ruby to write iOS app!
    

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12. I’m going to talk about..
    

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13. what I learned in Ruby…
    

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14. and move to Objective-C
    

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15. after all, our life, time and
    resources are limited
    

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17. what about Objective-C?
    

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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);
    }];
    

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19. “what the hell is the square bracket!”
    Objective-C …
    NSString* myName = @"eddie kao";
    NSLog(@"%@", [myName uppercaseString]);
    

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20. “WTF! my app crashed again!!”
    Objective-C …
    

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21. Introduction
    

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22. Ruby was born on 1993
    Objective-C was born on 1983
    

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23. they have the same ancestor
    

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24. Smalltalk
    photo by Marcin Wichary
    

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25. Ruby is general-purpose
    Objective-C mainly used in
    Mac/iOS app development
    

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26. Ruby != Rails
    Objective-C != Cocoa Framework
    

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27. they have something in common..
    

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28. both Ruby and Objective-C are
    Object-Oriented
    

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29. both Ruby and Objective-C are
    strongly typed language.
    

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30. Ruby is a dynamic language
    Objective-C is a dynamic language
    

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31. both Ruby and Objective-C are
    Dynamic Typing
    

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32. Type checking..
    - (void) makeSomeNoise:(id) sender
    {
    if ([sender isKindOfClass:[RobberDuck class]])
    {
    RobberDuck* duck = (RobberDuck *) sender;
    [duck quack];
    }
    }
    

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33. or you can do this..
    - (void) makeSomeNoise:(id) sender
    {
    if ([sender respondsToSelector:@selector(quack)])
    {
    [sender quack];
    }
    }
    

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35. id
    

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36. Objective-C is superset of C
    

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37. Objective-C is still C
    

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38. NSString, NSArray, NSNumber…
    

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39. NextSTEP
    

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40. CF… = Core Foundation
    CG… = Core Graphic
    CL… = Core Location
    CA… = Core Animation
    UI… = User Interface
    

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41. OOP
    

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42. everything in Ruby is an object…
    

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43. and almost everything in
    Objective-C is an objects..
    

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44. there’re still some primitive data
    types in Objective-C
    

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45. object model
    class Animal
    end
    !
    class Dog < Animal
    end
    

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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
    

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47. object model
    @interface Animal : NSObject
    @end
    !
    @implementation Animal
    @end
    !
    @interface Dog : Animal
    @end
    !
    @implementation Dog
    @end
    

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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
    

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49. Object Model
    reference: http://goo.gl/wYL6gT
    

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50. method & message
    

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51. method definition
    - (void) sayHello:(id)someOne withMessage:(NSString *)message
    {
    NSLog(@"Hello %@, %@", someOne, message);
    }
    def say_hello(someone, message)
    puts "Hello #{someone}, #{message}"
    end
    

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52. sending message
    [dog walk];
    dog.walk() # or you can omit the parentheses
    

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53. [fox saySomething:@"hi, Ruby"];
    fox.say_something "hi, Ruby" # what does the fox say?
    sending message
    

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54. sending message
    puts 1 + 2
    puts 1.+(2)
    puts 1.send(:+, 2)
    

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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
    

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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];
    

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57. block
    

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58. block
    p1 = Proc.new { puts "Hello, Proc Block" }
    p1.call
    !
    p2 = lambda { puts "Hello, Lambda Block" }
    p2.call
    

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59. block
    ^{ };
    

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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?
    

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61. block
    3.times { |i| puts i }
    NSArray* list = @[@1, @2, @3];
    [list enumerateObjectsUsingBlock:^(NSNumber* num,
    NSUInteger idx, BOOL *stop) {
    NSLog(@"%@", num);
    }];
    

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62. iteration
    

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63. iteration
    list = [1, 2, 3, 4, 5]
    !
    sum = 0
    !
    list.each { |num|
    sum += num
    }
    !
    puts "sum = #{sum}"
    

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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);
    

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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?
    

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66. iteration
    @interface Fox : NSObject
    - (void) say;
    @end
    !
    @implementation Fox
    - (void) say
    {
    NSLog(@"what does the fox say?!");
    }
    @end
    

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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)];
    

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68. add methods at runtime
    

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69. Open class
    class String
    def is_awesome?
    return true if self == "Ruby Tuesday"
    end
    end
    !
    puts "Ruby Tuesday".is_awesome?
    

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70. Category
    @interface NSString(RubyTuesday)
    - (BOOL) isAwesome;
    @end
    !
    @implementation NSString(RubyTuesday)
    - (BOOL) isAwesome
    {
    if ([self isEqualToString:@"Ruby Tuesday"]){
    return YES;
    }
    return NO;
    }
    @end
    

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71. Category
    NSString* meetup = @"Ruby Tuesday";
    if ([meetup isAwesome])
    {
    NSLog(@"AWESOME!");
    }
    

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72. 
    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
    

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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
    
    

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74. reflection
    - (BOOL) isKindOfClass:(Class) aClass
    - (BOOL) isMemberOfClass:(Class) aClass
    - (BOOL) respondsToSelector:(SEL) aSelector
    - (BOOL) conformsToProtocol:(Protocol *) aProtocol
    ..
    reference: http://goo.gl/fgmJcg
    

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75. ecosystem
    

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76. open source projects on Github
    Ruby : 76,574
    Objective-C : 22,959
    

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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'
    

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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
    

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79. IMHO
    

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80. Objective-C is not really hard to
    learn…
    

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81. the actual difficult part in iOS app
    development is Cocoa Framework
    

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82. Objective-C would be almost
    useless without Cocoa Framework
    

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83. Ruby without Rails?!
    

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84. design patterns
    observer
    singleton
    delegation
    command
    target-action
    composite
    notifications
    proxy
    MVC
    

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85. C
    

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86. what else..
    

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87. photoed by JD Hancock
    

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89. reference: http://goo.gl/2mzyMY
    Flash Display Hierarchy
    

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90. reference: http://goo.gl/xhS7m7
    UIKit and AppKit framework Hierarchy
    

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91. Views
    reference: http://goo.gl/xhS7m7
    

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92. reference: http://goo.gl/xhS7m7
    Views
    

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93. and I read Ruby source code..
    

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94. my iOS app dev experience
    = Ruby + C + Flash/AS3
    = +
    

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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
    

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