One Year with Hanami

Have you ever heard of Hanami? Have you considered using it for your new project, but you don’t know what to expect? This talk will clear your doubts - my team has been using Hanami for more than a year and I’m going to share our experience with the framework.

1. ONE YEAR WITH HANAMI @ A R N V A L D , P U N E , 2 0 1 8
2. GRZEGORZ
3. GRZEGORZ
5. 5 WHAT IS HANAMI • long-standing Japanese tradition of welcoming spring • web framework written in Ruby image source: https://hanamirb.org
6. 6 BRIEF INTRODUCTION Hanami is a full-featured web framework Hanami is modular Hanami is lightweight Hanami promotes good practices
7. 7 Exploration Familiarity WHY WE CHOSE HANAMI? ☼
8. 8 OUR TIMELINE June 2017 R U N N I N G P R O D U C T I O N January 2017 F I R S T C O M M I T July 2017 2 N D A P P L I C A T I O N March 2018 H A N A M I 1 . 1
9. 9 OUTLINE The web part The data part The application part The support part
10. PART 1: THE WEB
11. 11 HANAMI WEB GEMS router controller view helpers
12. 12 Each action is a separate class with call method. Testing controller is as simple as calling Action.new.call(params) one controller action = one class
13. 13 Each action is a separate class with call method. Testing controller is as simple as calling Action.new.call(params) one controller action = one class /apps
 /admin
 /config
 /controllers
 /orders
 /index.rb
 /create.rb
 /customers
 /index.rb
 /create.rb
14. 14 controller actions are magical Hanami Action module wraps around your class’ call method. The value you return from call is ignored, instead you must modify class’ attributes
15. 15 controller actions are magical Hanami Action module wraps around your class’ call method. The value you return from call is ignored, instead you must modify class’ attributes class Index
 include MyApp::Action
 
 def call(params)
 “this is action”
 end
 end Index.new.call({}) [200,
 … a lot of headers,
 []]
16. 16 controller actions are magical Hanami Action module wraps around your class’ call method. The value you return from call is ignored, instead you must modify class’ attributes class Index
 include MyApp::Action
 
 def call(params)
 status 200, “this is action”
 end
 end Index.new.call({}) [200,
 … a lot of headers,
 [“this is action”]]
17. 17 controller actions are magical Hanami Action module wraps around your class’ call method. The value you return from call is ignored, instead you must modify class’ attributes class Index
 include MyApp::Action
 
 def call(params)
 self.body = “this is action”
 self.status = 403
 end
 end Index.new.call({}) [403,
 … a lot of headers,
 [“this is action”]]
18. 18 Views in Hanami are objects that encapsulate logic that is used in the template Templates are representation of the data returned to the user views != templates
19. 19 Views in Hanami are objects that encapsulate logic that is used in the template Templates are representation of the data returned to the user views != templates # view
 class Index
 include MyApp::View
 
 def users_age
 Time.now.year - user.year_of_birth
 end
 end # template
 <div class=“user”>
 <span class=“age”>
 <%= users_age %>
 </span>
 </div>
20. 20 Views in Hanami are objects that encapsulate logic that is used in the template Templates are representation of the data returned to the user built-in helpers are private
21. 21 Views in Hanami are objects that encapsulate logic that is used in the template Templates are representation of the data returned to the user built-in helpers are private # view
 class Index
 include MyApp::View
 
 def total_cost
 format_number(cost)
 end
 end # template
 <div class=“order”>
 <span class=“cost”>
 <%= total_cost %>
 </span>
 </div>
22. PART 2: THE DATA
23. 23 HANAMI DATA GEMS model validations events (experimental)
24. 24 Repository pattern separates the entities (individual objects) from the repository (a collection of objects) It means that queries will be in different class than individual object methods repository pattern
25. 25 Repository pattern separates the entities (individual objects) from the repository (a collection of objects) It means that queries will be in different class than individual object methods repository pattern class OrderRepository < Hanami::Repository
 associations do
 belongs_to :customer
 end 
 
 def future
 orders.where { delivered_at.is(nil() }
 end
 end class Order < Hanami::Entity
 def description
 “#{product.name} #{total_cost}”
 end
 end
26. 26 3 layers around the database Hanami model library relies on Rom-rb which relies on Sequel Sometimes we can’t achieve what we want in Hanami model and we need to go down to another layer of abstraction
27. 27 Validations are a mixin that can be included anywhere - they perfectly fit controllers or service objects validations separated from entities
28. 28 Validations are a mixin that can be included anywhere - they perfectly fit controllers or service objects validations separated from entities class Create
 include MyApp::Action
 
 params do
 required(:title).filled(:str?)
 required(:amount).filled(:int?)
 end
 end
 
 class CreateOrder
 include Hanami::Validations
 
 validations do
 required(:title).filled(:str?)
 end
 end
29. PART 3: APPLICATION
30. 30 HANAMI APPLICATION GEMS hanami cli
31. 31 Starting a new Hanami project creates /apps directory with one application there Having multiple applications in one project is not a special case, but a standard mountable apps are first class citizens
32. 32 Starting a new Hanami project creates /apps directory with one application there Having multiple applications in one project is not a special case, but a standard mountable apps are first class citizens /apps
 /admin
 /config
 /controllers
 /orders
 /customers
 /web
 /config
 /controllers
 /api
 /config
 /controllers
33. 33 not that modular Hanami libraries are independent of each other. However, Hanami application gem relies on most of the gems. Even if you don’t need mailers - you’ll have them in Gemfile.lock
34. 34 Hanami promotes good engineering practices: separating layers of the application, writing code that’s easy to test, making most of the code private emphasis on architecture
35. PART 4: SUPPORT
36. 36 HANAMI SUPPORT GEMS mailer utils
37. 37 Hanami utils do not monkey patch standard Ruby classes. Instead they add their own classes on top of the standard ones no monkey patching
38. 38 Hanami utils gem provides a simple class that helps implementing service objects in a consistent manner interactors
39. 39 magic in interactors Similarly to controller actions, the result is based on instance variables, not on the value you return from your call function
40. 40 magic in interactors class CreateUser
 include Hanami::Interactor
 
 expose :user
 
 def call(params)
 @user = User.new(params)
 end
 end
 
 creator = CreateUser.new
 result = creator.call(params)
 result.user Similarly to controller actions, the result is based on instance variables, not on the value you return from your call function
41. 41 small ecosystem Hanami is still considered a new framework, despite being more than 3 years old. There’s still few resources and libraries that help develop Hanami applications
42. PART 5: SUMMARY
43. 43 YOU CAN USE HANAMI FOR most web applications even non-web applications (model, validations, mailers)
44. 44 YOU MIGHT RECONSIDER IF YOU BUILD application that needs a lot of external libraries project with a lot of complex queries simple CRUD applications
45. WE’RE HIRING
46. GRZEGORZ
47. GRZEGORZ
48. ONE YEAR WITH HANAMI @ A R N V A L D , P U N E , 2 0 1 8 wonderful