Build a Web API with Hanami

Today, building a web app usually includes building a web API. In Ruby, you can pick one of common options, Rails or Sinatra, or a new interesting one: Hanami. I'll present in the talk the reasons that pushed me to pick Hanami to develop a web API, a quick tour of the framework and its basics, and how to use it to develop a web API.

code example: https://github.com/toch/takeoffconf2016-jsonapi

Transcript

1. Build a Web API with Hanami
2. Bonjour, Je m'appelle Christophe.
3. pullreview.com rubybelgium.be euranova.eu
5. toch _toch ibakesoftware.com
6. Hanami?
7. A Ruby Web Framework
8. Light & Simple
9. Modular
10. Non Intrusive
11. Test Friendly ✅
12. Thread Safe ☂
13. Why Hanami?
14. What do we need?
15. Sinatra?
16. Rails?
17. Hanami!
18. A Web API
19. GET /api/speakers
20. $ hanami new takeoffconf \ --database=postgres \ --application-name=api
21. . ├── apps ├── config ├── db ├── lib ├── public └── spec
22. Gemfile
23. gem 'bundler' gem 'rake' gem 'hanami', '~> 0.8' gem 'hanami-model', '~> 0.6' gem 'pg'
25. Container Architecture
26. apps └── api ├── application.rb ├── config ├── controllers ├── templates └── views
27. # config/environment.rb Hanami::Container.configure do mount Api::Application, at: '/api' end
28. Business logic
29. lib ├── takeoffconf │ ├── entities │ ├── mailers │ └── repositories └── takeoffconf.rb
30. Test First
31. # spec/api/features/list_speakers_spec.rb require 'api_helper' describe 'List speakers' do it 'is successful' do header 'Content-Type', 'application/json;' get '/api/speakers' expect(last_response).must_be :ok? expect(last_response.content_type) .must_include "application/json" end
32. it 'is empty by default' do header 'Content-Type', 'application/json;' get '/api/speakers' expect(last_response.body).must_equal '[]' end end
33. Default Content & Accept type
34. # api/application.rb module Api class Application < Hanami::Application configure do # ... default_request_format :json default_response_format :json body_parsers :json end end end
35. One Route
36. # apps/api/config/routes.rb get '/speakers', to: 'speakers#list'
37. One Action
38. $ hanami generate action api speakers#list
39. # apps/api/controllers/speakers/list.rb module Api::Controllers::Speakers class List include Api::Action accept :json def call(params) end end end
40. No Template One View
41. # apps/api/views/speakers/list.rb module Api::Views::Speakers class List include Api::View layout false def render "[]" end end end
42. Test First
43. # spec/api/features/list_speakers_spec.rb #... describe 'List speakers' do # ... describe 'When speakers are recorded' do before do SpeakerRepository.clear SpeakerRepository.create(Speaker.new(name: 'Christophe Philemotte', twitter: '_toch', talk: 'Build a Web API with Hanami')) end
44. it 'returns an array of those speakers' do header 'Content-Type', 'application/json;' get '/api/speakers' expect(last_response.body).must_include "\"name\":\"Christophe Philemotte\",\"twitter\":\"_toch\",\"talk\":\"Build a Web API with Hanami\"" end end end
45. Entity & Repository
46. $ hanami generate model speaker $ hanami generate migration \ create_speakers
47. # db/migrations/20161019092946_create_speakers.rb Hanami::Model.migration do change do create_table :speakers do primary_key :id column :name, String, null: false column :twitter, String column :talk, String, null: false end end end
48. $ hanami db create $ hanami db migrate
49. # lib/takeoffconf/entities/speaker.rb class Speaker include Hanami::Entity attributes :name, :twitter, :talk end
50. # lib/takeoffconf/entities/speaker_repository.rb class SpeakerRepository include Hanami::Repository end
51. # lib/takeoffconf.rb # ... mapping do collection :speakers do entity Speaker repository SpeakerRepository attribute :id, Integer attribute :name, String attribute :twitter, String attribute :talk, String end end # ...
52. Retrieve & Expose
53. # apps/api/controllers/speakers/list.rb module Api::Controllers::Speakers class List include Api::Action accept :json expose :speakers def call(params) @speakers = SpeakerRepository.all end end end
54. Serialize & View
55. # apps/api/views/speakers/list.rb require 'json' module Api::Views::Speakers class List include Api::View layout false def render _raw JSON.dump(speakers.map{ |speaker| speaker.to_h }) end end end
56. Lessons
57. Not yet stable But play the game
58. Read The Code Luke
59. Ruby FTW
60. Very Friendly Community
61. More Code But Clear Intent
62. ❓ toch/takeoffconf2016-jsonapi toch _toch ibakesoftware.com