Ruby - Write Once, Run Anywhere - Polyconf 2014

Some people say that Ruby is dying.
I wouldn't…
I'd rather claim that Ruby is more alive than ever!
Few years ago we could only envy Javascript programmers while their favorite language was becoming ubiquitous. Currently, thanks to RubyMotion we can write desktop and mobile apps. While Opal can execute Ruby in a browser. With these tools we can finally write cross-platform Ruby apps.
Learn how!

Transcript

1. Ruby - Write Once, Run Anywhere Michal Taszycki @mehowte GunpowderLabs
2. Ruby is dead
3. Ruby is alive
4. Who wants to play a game?
5. Who wants to play a game?
6. 2 Facts about Multiplayer Games • Players expect snappy interface • Players cheat
7. What does it mean? • Game logic required in each client • Game logic required on server
8. It used to mean A lot of redundancy
9. But now… We have the technology!
10. But now… We can write cross-platform applications!
11. Opal.rb
12. Opal.rb • Ruby to Javascript compiler • Performant • Version < 1.0, actively developed • Out of the box Rails integration • Interesting libraries start to show up
13. RubyMotion
14. RubyMotion • Compiles Ruby to ObjectiveC runtime • Android Support available in beta • Native performance • Version > 2.0, actively developed • Widely used in production
15. mruby
16. mruby • Supports ISO ruby standard • Can be embedded into any C application • low memory footprint • Faster than MRI • Works even on Arduino DUE (requires 96KB SRAM) • Promising for Windows desktop applications
17. Is any of them really a Ruby == ? == ? == ?
18. Differences • No require at runtime • No eval at runtime • Methods can have incompatible names • Threads are working • Memory leaks possible
19. Differences • no require at runtime • strings are immutable • symbols are strings • regexps differ • All numbers are floats • no for loop yet ;)
20. Differences • no require at runtime • gems (mrgems) need to be compiled into mruby • no Bignumber support • Regular Expressions unavailable by default • optimized for size (but ofter faster than MRI)
21. Is any of them really a Ruby
22. They’re Ruby enough!
23. Cross Platform Ruby
24. Cross Platform Ruby
25. Interactions
26. Internal interactions Hexagonal Clean Architecture DCI DDD CQRS Cowboy Coding Functional Programming Micro Libraries
27. This is your dreamland! Internal interactions DCI Hexagonal Clean Architecture DCI DDD Cowboy Coding Functional Programming CQRS Micro Libraries
28. Interactions
29. Access From Outside title_label.text = translator.get(:title) <h1><%= translator.get(:title) %></h1>
30. Access From Outside event_logger.save_event(:user_signed_up) event_logger.save_event(:user_tapped_on_top_left_button) event_logger.save_event(:user_bought_an_in_app_purchase, type: "coin", amount: 1000) event_logger.save_event(:user_signed_in) event_logger.save_event(:user_browsed_products) event_logger.save_event(:user_bought_product, name: "beef_jerky", amount: 35)
31. Interactions
32. Driving from inside # toggle panels - same interface # for animation on all platforms ! image_editor_controller.animate_view( brushes_panel, :horizontall_slide, from: 0, to: -90) ! image_editor_controller.animate_view( shapes_panel, :horizontall_slide, from: -90, to: 0)
33. Interactions
34. class TodoItem def mark_as_done self.done = true end end Async interactions
35. ! ! ! # We want to save it afterwards on each platform todo.mark_as_done Async interactions
36. Async interactions Abstract interface Notifications Aspect Oriented Programming
37. class Todo def self.saver=(saver) @saver = saver end ! def mark_as_done self.done = true self.class.saver.save(self) end end Abstract interface
38. Abstract interface Todo.saver = TodoSaver.new(DatabaseAdapter.new) todo.mark_as_done ! # or ! Todo.saver = TodoSaver.new(RestAdapter.new) todo.mark_as_done
39. Abstract interface +Well defined interaction - Core needs to know about use cases +Useful when use cases on each platform are similar
40. Notifications class Todo include Eventable def mark_as_done self.done = true trigger(:marked_as_done, self) end end
41. Notifications todo.on(:marked_as_done) do |todo| save_to_database(todo) end todo.mark_as_done ! # or ! todo.on(:marked_as_done) do |todo| post_to_api(todo) end todo.mark_as_done
42. Notifications +Core doesn’t need to know use cases - Hard to compose interactions !Beware of memory leaks +Useful when use cases on each platform are a bit different
43. AOP class Todo def mark_as_done self.done = true end end
44. AOP class DatabaseTodoSaver include AspectOrientedLibraryOfChoice after Todo, :mark_as_done do |todo| save_to_database(todo) end end
45. AOP class RestTodoSaver include AspectOrientedLibraryOfChoice after Todo, :mark_as_done do |todo| post_to_service(todo) end end
46. AOP +Core is blissfully unaware of surroundings - Platforms need to know about internals !Beware of memory leaks +Useful when use cases on each platform are different
47. Where to keep this logic?
48. Cross Platform Gems But it requires a little bit of work
49. Cross Platform Gems • Tell sprockets where to look for files using Opal.append_path • use require as usual (it is translated into Sprockets directive)
50. Cross Platform Gems • Use require only in the gem’s entry point • Add all required files in rubymotion config block
51. Cross Platform Gems It literally takes 20 lines of code http://blog.crossplatformruby.com/universal-ruby-gems-in-20-lines-of-code
52. Let me show you the code!
53. Ruby is alive
54. Ruby Is taking over the world… … one platform at a time.
55. Want to hear more? twitter.com/mehowte michal@gunpowderlabs.com ! " github.com/mehowte # Michal Taszycki gunpowderlabs crossplatformruby.com