Don't let the Cocoa Api Crush your Ruby Code - Inspect2014

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1. Don't Let the Cocoa API Crush Your Ruby Code Alex Rothenberg
2. ! McKinsey Digital Labs ! @alexrothenberg alex@alexrothenberg.com https://github.com/alexrothenberg !
6. Xcode Objective-C Cocoa Cocoa
7. Ruby Cocoa My Editor
8. theseReallyLongCocoaMethodsThatAreHardToRead
9. Cocoa &
10. Cocoa &
11. Cocoa &
13. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! end! ! end!
14. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! itemTitle = UILabel.alloc! .initWithFrame [[30,100],! [300,22]]! itemTitle.text = 'Alex Rothenberg'! view.addSubview itemTitle! end! ! end
15. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! itemTitle = UILabel.alloc! .initWithFrame [[30,100],[300,22]]! itemTitle.text = 'Alex Rothenberg'! view.addSubview itemTitle! ! itemTitle = UILabel.alloc! .initWithFrame [[30,130],[300,22]]! itemTitle.text = 'Rubyist'! view.addSubview itemTitle! end! ! end
16. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! ! itemTitle = UILabel.alloc! .initWithFrame [[30,100],[300,22]]! itemTitle.text = 'Alex Rothenberg'! view.addSubview itemTitle! ! ! itemTitle = UILabel.alloc! .initWithFrame [[30,130],[300,22]]! itemTitle.text = 'Rubyist'! view.addSubview itemTitle! ! ! itemTitle = UILabel.alloc! .initWithFrame [[30,160],[300,22]]! itemTitle.text = 'alex@alexrothenberg.com'! view.addSubview itemTitle! end! ! end!
17. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! # The name! itemTitle = UILabel.alloc! .initWithFrame [[30,100],[300,22]]! itemTitle.text = 'Alex Rothenberg'! view.addSubview itemTitle! ! # The title! itemTitle = UILabel.alloc! .initWithFrame [[30,130],[300,22]]! itemTitle.text = 'Rubyist'! view.addSubview itemTitle! ! # Email! itemTitle = UILabel.alloc! .initWithFrame [[30,160],[300,22]]! itemTitle.text = 'alex@alexrothenberg.com'! view.addSubview itemTitle! end! ! end!
18. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! # The name! nameLabel = UILabel.alloc! .initWithFrame [[30,100],[300,22]]! nameLabel.text = 'Alex Rothenberg'! view.addSubview nameLabel! ! # The title! titleLabel = UILabel.alloc! .initWithFrame [[30,130],[300,22]]! titleLabel.text = 'Rubyist'! view.addSubview titleLabel! ! # Email! emailLabel = UILabel.alloc! .initWithFrame [[30,160],[300,22]]! emailLabel.text = 'alex@alexrothenberg.com'! view.addSubview emailLabel! ! # Phone! phoineLabel = UILabel.alloc! .initWithFrame [[30,190],[300,22]]! phoineLabel.text = '555-1212'! view.addSubview phoineLabel! end! ! end!
19. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! # The name! nameLabel = UILabel.alloc.initWithFrame [[30,100],[300,22]]! nameLabel.text = 'Alex Rothenberg'! view.addSubview nameLabel! ! # The title! titleLabel = UILabel.alloc.initWithFrame [[30,130],[300,22]]! titleLabel.text = 'Rubyist'! view.addSubview titleLabel! ! # Email! emailLabel = UILabel.alloc.initWithFrame [[30,160],[300,22]]! emailLabel.text = 'alex@alexrothenberg.com'! view.addSubview emailLabel! ! # Mobile Phone! phoineLabel = UILabel.alloc.initWithFrame [[30,190],[300,22]]! phoineLabel.text = '555-1212'! view.addSubview phoineLabel! ! # Office Phone! phoineLabel = UILabel.alloc.initWithFrame [[30,220],[300,22]]! phoineLabel.text = '555-7890'! view.addSubview phoineLabel! ! # Office Address! phoineLabel = UILabel.alloc.initWithFrame [[30,250],[300,22]]! phoineLabel.text = '123 Office Drive'! view.addSubview phoineLabel! end! ! end!
20. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! # The name! caption = UILabel.alloc.initWithFrame [[20,100],[90,22]]! caption.text = 'Name'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! nameLabel = UILabel.alloc.initWithFrame [[110,100],[300,22]]! nameLabel.text = 'Alex Rothenberg'! view.addSubview nameLabel! ! # The title! caption = UILabel.alloc.initWithFrame [[20,130],[90,22]]! caption.text = 'Title'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! titleLabel = UILabel.alloc.initWithFrame [[110,130],[300,22]]! titleLabel.text = 'Rubyist'! view.addSubview titleLabel! ! # Email! caption = UILabel.alloc! .initWithFrame [[20,160],[90,22]]! caption.text = 'Email'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! emailLabel = UILabel.alloc.initWithFrame [[110,160],[300,22]]! emailLabel.text = 'alex@alexrothenberg.com'! view.addSubview emailLabel! ! # Mobile Phone! caption = UILabel.alloc.initWithFrame [[20,190],[90,22]]! caption.text = 'Mobile'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! phoineLabel = UILabel.allocinitWithFrame [[110,190],[300,22]]! phoineLabel.text = '555-1212'! view.addSubview phoineLabel! ! # Office Phone! caption = UILabel.alloc.initWithFrame [[20,220],[90,22]]! caption.text = 'Office'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! phoineLabel = UILabel.allocinitWithFrame [[110,220],[300,22]]! phoineLabel.text = '555-1212'! view.addSubview phoineLabel! ! # Office Address! caption = UILabel.alloc.initWithFrame [[20,250],[90,22]]! caption.text = 'Address'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! phoineLabel = UILabel.allocinitWithFrame [[110,250],[300,22]]! phoineLabel.text = '123 Office Drive'! view.addSubview phoineLabel! end! ! end!
24. 1. Your class can be no longer than 100 lines of code.
 2. Your methods can be no longer than five lines of code.
 3. You can pass no more than four parameters and you can’t just make it one big hash. Sandi Metz Rules
25. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! ! # The name! caption = UILabel.alloc.initWithFrame [[20,100],[90,22]]! caption.text = 'Name'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! nameLabel = UILabel.alloc.initWithFrame [[110,100],[300,22]]! nameLabel.text = 'Alex Rothenberg'! view.addSubview nameLabel! ! # The title! caption = UILabel.alloc.initWithFrame [[20,130],[90,22]]! caption.text = 'Title'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! titleLabel = UILabel.alloc.initWithFrame [[110,130],[300,22]]! titleLabel.text = 'Rubyist'! view.addSubview titleLabel! ! # Email! caption = UILabel.alloc! .initWithFrame [[20,160],[90,22]]! caption.text = 'Email'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! emailLabel = UILabel.alloc.initWithFrame [[110,160],[300,22]]! emailLabel.text = 'alex@alexrothenberg.com'! view.addSubview emailLabel! ! # Mobile Phone! caption = UILabel.alloc.initWithFrame [[20,190],[90,22]]! caption.text = 'Mobile'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! phoineLabel = UILabel.allocinitWithFrame [[110,190],[300,22]]! phoineLabel.text = '555-1212'! view.addSubview phoineLabel! ! # Office Phone! caption = UILabel.alloc.initWithFrame [[20,220],[90,22]]! caption.text = 'Office'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! phoineLabel = UILabel.allocinitWithFrame [[110,220],[300,22]]! phoineLabel.text = '555-1212'! view.addSubview phoineLabel! ! # Office Address! caption = UILabel.alloc.initWithFrame [[20,250],[90,22]]! caption.text = 'Address'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! phoineLabel = UILabel.allocinitWithFrame [[110,250],[300,22]]! phoineLabel.text = '123 Office Drive'! view.addSubview phoineLabel! end! ! end!
26. Extract Method
27. class MyViewController < UIViewController! ! def viewDidLoad! view.backgroundColor = UIColor.whiteColor! add_name! add_title! add_email! add_mobile_phone! add_office_phone! add_office_address! end! ! end!
28. def add_name! caption = UILabel.alloc! .initWithFrame [[20,100],[90,22]]! caption.text = 'Name'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! name_label = UILabel.alloc! .initWithFrame [[110,100],[300,22]]! name_label.text = 'Alex Rothenberg'! view.addSubview name_label! end!
30. def add_name! caption = UILabel.alloc! .initWithFrame [[20,100],[90,22]]! caption.text = 'Name'! caption.font = UIFont.boldSystemFontOfSize(20)! view.addSubview caption! name_label = UILabel.alloc! .initWithFrame [[110,100],[300,22]]! name_label.text = 'Alex Rothenberg'! view.addSubview name_label! end! Text Caption
31. def add_name(frame)! subview = RowView.alloc.initWithFrame(frame)! subview.caption = 'Name'! subview.text = 'Alex Rothenberg'! view.addSubview subview! end
32. class RowView < UIView! ! end!
33. class RowView < UIView! attr_reader :caption_label, :text_label! ! def initWithFrame(frame)! super! addSubview caption_label! addSubview text_label! self! end! ! end!
34. def text_label! @text_label ||= UILabel.alloc! ! ! .initWithFrame([[100, 0],[200,22]])! end!
35. def caption_label! if @caption_label.nil?! @caption_label = UILabel.alloc! .initWithFrame([[0, 0],[ 90,22]])! @caption_label.font = ! UIFont.boldSystemFontOfSize(20)! end! @caption_label! end!
36. def caption=(caption)! caption_label.text = caption! end! ! def text=(text)! text_label.text = text! end!
37. def add_name(frame)! subview = RowView.alloc.initWithFrame(frame)! subview.caption = 'Name'! subview.text = 'Alex Rothenberg'! view.addSubview subview! end
38. Value Clarity & Small Code
40. struct CGRect {! CGPoint origin;! CGSize size;! };! typedef struct CGRect CGRect;!
41. CGRect CGRectMake(! CGFloat x,! CGFloat y,! CGFloat width,! CGFloat height! );!
42. view.frame = [ [x, y], [width, height] ] view.frame = [! [x, y], ! [width, height]! ]!
43. view.frame.origin.x! view.frame.origin.y! view.frame.size.width! view.frame.size.height
44. view.left! view.top! view.width! view.height
45. Ruby Classes are open
46. class UIView! def top! frame.origin.y! end! end!
47. view.frame.origin.x = 0
48. view.frame = [ [0, view.frame.origin.y], view.frame.size ]
49. view.frame = [ [0, view.frame.origin.y], view.frame.size ]
50. class UIView! def left=(new_left)! self.frame = [[new_left, top], ! ! ! ! ! ! ! ! ! ! frame.size]! end! end!
51. class UIView! def top! def left! def height! def width! def bottom! def right! ! def top=(new_top)! def left=(new_left)! def height=(new_height)! def width=(new_width)! end!
52. We love DSLs
54. ABAddressBook Class
56. ABAddressBook Framework
57. first_name = ABRecordCopyValue(! person,! KABPersonFirstNameProperty! )! ! # CFTypeRef
58. person.first_name!
59. http://rubymotion-wrappers.com
60. gem install motion-addressbook
61. ab = AddressBook::AddrBook.new! person = ab.people.first! person.first_name!
62. Jason May ! @jmay
63. Cocoa &
64. Cocoa
65. RubyMotion
67. Thank You