Ruby - Write Once, Run Anywhere - Arrrrcamp 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 (GunpowderLabs)
2. Who wants to play a game?
3. Who wants to play a game?
4. 2 Facts about Multiplayer Games • Players expect snappy interface • Players cheat
5. What does it mean? • Game logic required in each client • Game logic required on server
6. It used to mean A lot of redundancy
7. But now… We have the technology!
8. Opal.rb
9. Opal.rb • Ruby to Javascript compiler • Performant • Version < 1.0, actively developed • Out of the box Rails integration • Interesting libraries start to show up
10. RubyMotion
11. RubyMotion • Compiles Ruby to ObjectiveC runtime • Android Support available in beta • Native performance • Version > 2.0, actively developed • Widely used in production
12. mruby
13. 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
14. Is any of them really a Ruby == ? == ? == ?
15. Differences • No require at runtime • No eval at runtime • Methods can have incompatible names • Threads are working • Memory leaks possible
16. Differences • no require at runtime • strings are immutable • symbols are strings • regexps differ • All numbers are floats • no for loop yet ;)
17. 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)
18. Is any of them really a Ruby
19. They’re Ruby enough!
20. Cross Platform Ruby
21. Cross Platform Ruby
22. Interactions
23. Internal interactions Hexagonal Clean Architecture DCI DDD CQRS Cowboy Coding Functional Programming Micro Libraries
24. This is your dreamland! Internal interactions DCI Hexagonal Clean Architecture DCI DDD Cowboy Coding Functional Programming CQRS Micro Libraries
25. Interactions
26. Access From Outside title_label.text = translator.get(:title) <h1><%= translator.get(:title) %></h1>
27. 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)
28. Interactions
29. 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)
30. Interactions
31. class TodoItem def mark_as_done self.done = true end end Async interactions
32. ! ! ! # We want to save it afterwards on each platform todo.mark_as_done Async interactions
33. Async interactions Abstract interface Notifications Aspect Oriented Programming
34. 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
35. Abstract interface Todo.saver = TodoSaver.new(DatabaseAdapter.new) todo.mark_as_done ! # or ! Todo.saver = TodoSaver.new(RestAdapter.new) todo.mark_as_done
36. Abstract interface +Well defined interaction - Core needs to know about use cases +Useful when use cases on each platform are similar
37. Notifications class Todo include Eventable def mark_as_done self.done = true trigger(:marked_as_done, self) end end
38. 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
39. 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
40. AOP class Todo def mark_as_done self.done = true end end
41. AOP class DatabaseTodoSaver include AspectOrientedLibraryOfChoice after Todo, :mark_as_done do |todo| save_to_database(todo) end end
42. AOP class RestTodoSaver include AspectOrientedLibraryOfChoice after Todo, :mark_as_done do |todo| post_to_service(todo) end end
43. 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
44. Where to keep this logic?
45. Cross Platform Gems But it requires a little bit of work
46. Cross Platform Gems • Tell sprockets where to look for files using Opal.append_path • use require as usual (it is translated into Sprockets directive)
47. Cross Platform Gems • Use require only in the gem’s entry point • Add all required files in rubymotion config block
48. Cross Platform Gems It literally takes 20 lines of code http://blog.crossplatformruby.com/universal-ruby-gems-in-20-lines-of-code
49. Let me show you the code!
50. Ruby is alive
51. Ruby Is taking over the world… … one platform at a time.
52. Want to hear more? twitter.com/mehowte michal@gunpowderlabs.com ! " github.com/mehowte # Michal Taszycki gunpowderlabs crossplatformruby.com