Build a Web API with Hanami (ConFoo Montreal 2017)

Today, when building a web application, you very likely need to provide a web API. In Ruby, both web frameworks Rails or Sinatra are common options.

If you need something simpler and lighter than Rails but that doesn't require to reimplement a lot of common pieces, Hanami is a convenient and trendy option.

I'll present the reasons that pushed me to pick Hanami to develop a web API, and how to test and develop a web API with it.

https://github.com/toch/confoomontreal2017-jsonapi

Transcript

1. Build a Web API with Hanami
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 confoo \ --database=postgres \ --application-name=api
21. . ├── apps ├── config ├── db ├── lib ├── public └── spec
22. Gemfile
23. gem 'rake' gem 'hanami', '~> 1.0.0.beta2' gem 'hanami-model', '~> 1.0.0.beta2' gem 'pg'
24. $ bundle viz -W "test development"
27. Container Architecture
28. apps └── api ├── application.rb ├── config ├── controllers ├── templates └── views
29. # config/environment.rb Hanami::Container.configure do mount Api::Application, at: '/api' end
30. # config/environment.rb Hanami::Container.configure do mount Api1::Application, at: '/api/v1' mount Api2::Application, at: '/api/v2' end
31. Business logic
32. lib ├── confoo │ ├── entities │ ├── mailers │ └── repositories └── confoo.rb
33. Test First
34. # 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
35. it 'is empty by default' do header 'Content-Type', 'application/json;' get '/api/speakers' expect(last_response.body).must_equal '[]' end end
36. $ rake # Running: FF 2 runs, 0 assertions, 2 failures, 0 errors, 0 skips
37. Default Content & Accept type
38. # apps/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
39. One Route
40. # apps/api/config/routes.rb get '/speakers', to: 'speakers#list'
41. One Action
42. $ hanami generate action api speakers#list
43. # apps/api/controllers/speakers/list.rb module Api::Controllers::Speakers class List include Api::Action accept :json def call(params) end end end
44. No Template One View
45. # apps/api/views/speakers/list.rb module Api::Views::Speakers class List include Api::View layout false def render "[]" end end end
46. $ rake # Running: .. 2 runs, 3 assertions, 0 failures, 0 errors, 0 skips
47. Test First
48. # spec/api/features/list_speakers_spec.rb #... describe 'List speakers' do # ... describe 'When speakers are recorded' do let(:repository) { SpeakerRepository.new } before do repository.clear repository.create(Speaker.new(name: 'Christophe Philemotte', twitter: '_toch', talk: 'Build a Web API with Hanami')) end
49. 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
50. $ rake # Running: EEE 3 runs, 0 assertions, 0 failures, 3 errors, 0 skips
51. Entity & Repository
52. $ hanami generate model speaker $ hanami generate migration \ create_speakers
53. # 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
54. $ hanami db create $ hanami db migrate
55. # lib/confoo/entities/speaker.rb class Speaker < Hanami::Entity end
56. # lib/confoo/entities/speaker_repository.rb class SpeakerRepository < Hanami::Repository end
57. Retrieve & Expose
58. # apps/api/controllers/speakers/list.rb module Api::Controllers::Speakers class List include Api::Action accept :json expose :speakers def call(params) @speakers = SpeakerRepository.new.all end end end
59. Serialize & View
60. # 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
61. $ rake # Running: … 3 runs, 5 assertions, 0 failures, 0 errors, 0 skips
62. Lessons
63. Stable They played the game
64. Read The Code Luke
65. Ruby FTW
66. Very Friendly Community
67. More Code But Clear Intent
68. ❓ toch/confoo2017-jsonapi toch _toch ibakesoftware.com career@euranova.eu