Using RubyMotion to Build Something Useful

RubyMotion enables developers to write native iOS apps using the Ruby language. So what? Why can't we just continue writing apps in Objective-C, the Apple way?

Maybe RubyMotion is "the other Apple way" because it is the brainchild of Laurent Sansonetti, creator of MacRuby and a former Apple engineer. Both RubyMotion and Objective-C use LLVM-based tools to compile source files into native code that runs on Apple hardware. There is no performance difference between apps developed in Objective-C and those built with RubyMotion.

However, the two platforms rely on different developer tools. This talk will demonstrate some of the more popular RubyMotion libraries/gems while highlighting a few of the "gotchas". The first eight minutes will introduce RubyMotion for those who are unfamiliar with it. The remainder of the talk will feature demos of RubyMotion in action. To get the most out of the talk, the audience member should have some experience with Objective-C, Ruby, or both.

Transcript

1. Using RubyMotion to Build Something Useful Chicago RubyMotion User Group November 19, 2013 Chicago, IL USA
3. Demos What & Why Q & A
4. Demo: iOS
6. 126 def start_game_timer 127 @game_timer = NSTimer.scheduledTimerWithTimeInterval(0.01, 128 target: self, 129 selector: "move_ball", 130 userInfo: nil, 131 repeats: true) 132 end
7. 78 def move_ball 79 # If ball exits right, +1 for the left player 80 if (@ball_view.center.x > self.view.frame.size.width) 81 increment_left_score 82 @direction_x *= -1 83 self.reset_ball 84 end 85 86 # If ball exits left, +1 for the right player 87 if (@ball_view.center.x < 0) 88 increment_right_score 89 @direction_x *= -1 90 self.reset_ball 91 end 92 93 # If ball hits top or bottom wall, bounce y in the opposite direction. x-direction remains unchanged. 94 if ((@ball_view.center.y + @ball_view.frame.size.height > ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! self.view.frame.size.height) || @ball_view.frame.origin.y < 0) 95 @direction_y *= -1 96 end 97 98 # If the ball didn't hit anything, keep on moving... 99 @ball_view.center = [@ball_view.center.x + @direction_x, @ball_view.center.y + @direction_y] 100 101 # If ball collides with a paddle, change direction. 102 check_paddle_collision 103 104 end
8. Demo: OS X
13. Code: OS X
14. def ejectThreeDisks alert = NSAlert.alloc.init response = %x(/usr/sbin/diskutil eject SiiGBlack) + "\n" response += %x(/usr/sbin/diskutil eject Ultra3TB) + "\n" response += %x(/usr/sbin/diskutil eject WDSilver) + "\n" alert.setMessageText response alert.addButtonWithTitle "OK" alert.runModal ! !end
15. @TwitterAPI http://www.businessweek.com/articles/2013-11-07/the-hidden-technology-that-makes-twitter-huge
16. @TwitterAPI v1.1 JSON only. Authentication required.
18. What?
19. RubyMotion Objective-C ARM x86 LLVM logo by Teresa Chang http://llvm.org/Logo.html
20. RubyMotion Objective-C ARM x86 Without LLVM: Extra work.
21. Xcode RubyMotion Editor
22. Why?
23. Mobile MVP. Now.
24. Learn more Ruby.
25. Why not?
26. Ruby’s future on iOS & OS X.
27. Demo: REPL
28. ~/Code/Ruby/RubyMotion$ motion create helloruby Create helloruby Create helloruby/.gitignore Create helloruby/Rakefile Create helloruby/app Create helloruby/app/app_delegate.rb Create helloruby/resources Create helloruby/spec Create helloruby/spec/main_spec.rb ~/Code/Ruby/RubyMotion$
29. ~/Code/Ruby/RubyMotion/helloruby$ rake Build ./build/iPhoneSimulator-6.0-Development Compile ./app/app_delegate.rb Compile ./app/home_controller.rb Link ./build/iPhoneSimulator-6.0-Development/helloruby.app/helloruby Create ./build/iPhoneSimulator-6.0-Development/helloruby.dSYM Simulate ./build/iPhoneSimulator-6.0-Development/helloruby.app (main)>
30. ~/Code/Ruby/RubyMotion$ cd helloruby/ ~/Code/Ruby/RubyMotion/helloruby$ tree . !"" Rakefile !"" app # $"" app_delegate.rb !"" resources $"" spec $"" main_spec.rb 3 directories, 3 files ~/Code/Ruby/RubyMotion/helloruby$
31. ~/Code/Ruby/RubyMotion$ cd helloruby/ ~/Code/Ruby/RubyMotion/helloruby$ tree . !"" Rakefile !"" app # $"" app_delegate.rb !"" resources $"" spec $"" main_spec.rb 3 directories, 3 files ~/Code/Ruby/RubyMotion/helloruby$
32. 1 class AppDelegate 2 def application(application, didFinishLaunchingWithOptions:launchOptions) 3 @window = UIWindow.alloc.initWithFrame(UIScreen.mainScreen.bounds) 4 @window.rootViewController = HomeController.new 5 @window.makeKeyAndVisible 6 @window.backgroundColor = UIColor.grayColor 7 true 8 end 9 end
33. 1 class AppDelegate 2 def application(application, didFinishLaunchingWithOptions:launchOptions) 3 @window = UIWindow.alloc.initWithFrame(UIScreen.mainScreen.bounds) 4 @window.rootViewController = HomeController.new 5 @window.makeKeyAndVisible 6 @window.backgroundColor = UIColor.grayColor 7 true 8 end 9 end
34. 1 class AppDelegate 2 def application(application, didFinishLaunchingWithOptions:launchOptions) 3 @window = UIWindow.alloc.initWithFrame(UIScreen.mainScreen.bounds) 4 @window.rootViewController = HomeController.new 5 @window.makeKeyAndVisible 6 @window.backgroundColor = UIColor.grayColor 7 true 8 end 9 end
35. 1 class AppDelegate 2 def application(application, didFinishLaunchingWithOptions:launchOptions) 3 @window = UIWindow.alloc.initWithFrame(UIScreen.mainScreen.bounds) 4 @window.rootViewController = HomeController.new 5 @window.makeKeyAndVisible 6 @window.backgroundColor = UIColor.grayColor 7 true 8 end 9 end
36. 1 class AppDelegate 2 def application(application, didFinishLaunchingWithOptions:launchOptions) 3 @window = UIWindow.alloc.initWithFrame(UIScreen.mainScreen.bounds) 4 @window.rootViewController = HomeController.new 5 @window.makeKeyAndVisible 6 @window.backgroundColor = UIColor.grayColor 7 true 8 end 9 end
37. 3 @window = UIWindow.alloc.initWithFrame(UIScreen.mainScreen.bounds) Resource Raw Object Allocation Initialization Object Source: Object Creation, https://developer.apple.com
38. Human Interface Guidelines (HIG)
39. Interface Builder .xib files
40. FizzBuzz
41. view.viewWithTag 1 Object ID = 1 1
42. ~/Code/Ruby/RubyMotion$ cd helloruby/ ~/Code/Ruby/RubyMotion/helloruby$ tree . !"" Rakefile !"" app # $"" app_delegate.rb !"" resources $"" spec $"" main_spec.rb 3 directories, 3 files ~/Code/Ruby/RubyMotion/helloruby$
43. resources/fbib.xib
44. 1 class FizzBuzzViewController < UIViewController 2 3 def loadView 4 views = NSBundle.mainBundle.loadNibNamed "fbib", owner:self, options:nil 5 self.view = views[0] 6 @counter = 0 7 @view_handle = self.view 8 end
45. 10 def viewDidLoad 11 @label = view.viewWithTag 1 12 plus_button = view.viewWithTag 2 13 minus_button = view.viewWithTag 3 14 reset_button = view.viewWithTag 4 15 end
46. FizzBuzz
47. TDD MacBacon, Guard, & rm-redgreen
48. ~/Code/Ruby/RubyMotion/fizzbuzzrm[master]$ tree . !"" Gemfile !"" Gemfile.lock !"" Guardfile !"" Rakefile !"" app # !"" app.rb # !"" app_delegate.rb # !"" fizzbuzz_view_controller.rb # !"" home_controller.rb # !"" kernel.rb # !"" rm-ansiterm.rb # $"" string.rb !"" interfaces !"" resources $"" spec !"" 00-redgreen.rb !"" home_controller_spec.rb $"" main_spec.rb
49. 1 describe "FizzBuzz Calculator Function" do 2 before do 3 @this_number = 38 4 end ... 17 18 (1..10).each do |this_number| 19 if this_number % 15 == 0 20 it 'should return buzz for multiples of 15' do 21 HomeController.fizzbuzz_calc(this_number).should == 'fizzbuzz' 22 end 23 elsif this_number % 3 == 0 24 it 'should return fizz for multiples of 3' do 25 HomeController.fizzbuzz_calc(this_number).should == 'fizz' 26 end 27 elsif this_number % 5 == 0 28 it 'should return buzz for multiples of 5' do 29 HomeController.fizzbuzz_calc(this_number).should == 'buzz' 30 end 31 else 32 it 'should return the original number' do 33 HomeController.fizzbuzz_calc(this_number).should == this_number 34 end 35 end 36 end 37 end home_controller_spec.rb
50. describe "FizzBuzz Calculator Function" do before do @this_number = 38 end ... (1..10).each do |this_number| if this_number % 15 == 0 it 'should return buzz for mults of 15' do HomeController.fizzbuzz_calc(this_number) .should == 'fizzbuzz' end home_controller_spec.rb
51. Ruby Version Manager (RVM)
52. $ gem install formotion
53. 1 $:.unshift("/Library/RubyMotion/lib") 2 require 'motion/project/template/ios' 3 require "bundler/gem_tasks" 4 require "bundler/setup" 5 6 $:.unshift("./lib/") 7 require './lib/formotion' 8 9 Motion::Project::App.setup do |app| 10 # Use `rake config' for project settings. 11 app.name = 'Formotion' 12 end Rakefile Source: http://clayallsopp.com
54. 1 class LoginController < Formotion::FormController 2 def init 3 form = Formotion::Form.new({ 4 title: "Login", 5 sections: [{ 6 rows: [{ 7 title: "User Name", 8 type: :string, 9 placeholder: "name", 10 key: :user 11 }, { 12 ... Source: http://clayallsopp.com
55. Source: http://clayallsopp.com
56. $ gem install bubble-wrap $ gem install sugarcube
57. Source: Ben Scheirman of http://nsscreencast.com/
58. ~/Code/Ruby/RubyMotion$ ios profiles:list +----------------------------------+--------------+---------+ | Profile | App ID | Status | +----------------------------------+--------------+---------+ | WisdomGroup iOS Development | ABCDEFGHIJ.* | Active | | WisdomGroup RubyMotion | ABCDEFGHIJ.* | Active | | ChicagoRubyRubyMotion iPad | ABCDEFGHIJ.* | Active | | iOS Team Provisioning Profile: * | ABCDEFGHIJ.* | Active | | RTHiPhone4S | ABCDEFGHIJ.* | Active | +----------------------------------+--------------+---------+ ~/Code/Ruby/RubyMotion$ ios help $ gem install cupertino
59. $ gem install cocoapods $ pod setup $ gem install motion-cocoapods
60. $ rake ctags
61. Resources http://rubymotion-tutorial.com Multi-page tutorial by Clay Allsopp. Also see http://clayallsopp.com http://pragmaticstudio.com/screencasts/rubymotion Pragmatic Studio’s intro to RubyMotion (free) plus a paid intro to Ruby. http://chicagoruby.org/videos/archives/2012/09/04/rubymotion-for-rubyists/ Bill Svec builds a simple RubyMotion weather app in about 90 minutes. http://motioncasts.tv Tutorial videos by Michael Erasmus and Hendrik Swanepoel. http://nshipster.com Mattt Thompson's weekly journal of Objective-C and Cocoa. http://nsscreencast.com/ Ben Scheirman’s Objective-C screencasts, plus a short one on RubyMotion.
62. Thanks!