Functional Web Apps with Webmachine

Speech for RubyMeditation meetup #13

Transcript

1. Ruby Meditation #13 Functional web apps with Webmachine framework Mikhail Bortnyk, Amoniac OÜ
2. Who am I ❖ Mikhail Bortnyk
3. Who am I ❖ Mikhail Bortnyk ❖ github: @vessi
4. Who am I ❖ Mikhail Bortnyk ❖ github: @vessi ❖ twitter: @mikhailbortnyk
5. Who am I ❖ Mikhail Bortnyk ❖ github: @vessi ❖ twitter: @mikhailbortnyk ❖ language researcher
6. Who am I ❖ Mikhail Bortnyk ❖ github: @vessi ❖ twitter: @mikhailbortnyk ❖ language researcher ❖ co-founder of Kottans community school
7. Who am I ❖ Mikhail Bortnyk ❖ github: @vessi ❖ twitter: @mikhailbortnyk ❖ language researcher ❖ co-founder of Kottans community school ❖ 3rd contributor of mruby/c
8. Who am I ❖ Mikhail Bortnyk ❖ github: @vessi ❖ twitter: @mikhailbortnyk ❖ language researcher ❖ co-founder of Kottans community school ❖ 3rd contributor of mruby/c ❖ Ruby developer (not Rails!)
9. Source code ❖ [Link to presentation online]
10. Source code ❖ [Link to presentation online] ❖ [Link to source code on GitHub]
11. Introduction
12. Typical experience of web developer CGI Old school is cool! (Bash, C, Perl, some scripting)
13. Typical experience of web developer CGI Old school is cool! (Bash, C, Perl, some scripting) Servlets I know your pain, bro (PHP, Java)
14. Typical experience of web developer CGI Old school is cool! (Bash, C, Perl, some scripting) Servlets I know your pain, bro (PHP, Java) MVC The thing we all know (Python/Django, Ruby/Rails etc)
16. SPA is a new sexy ❖ No one uses ol’ goo’ ERB
17. SPA is a new sexy ❖ No one uses ol’ goo’ ERB ❖ Javascript rules over the web
18. SPA is a new sexy ❖ No one uses ol’ goo’ ERB ❖ Javascript rules over the web ❖ Web does not work without JS
19. SPA is a new sexy ❖ No one uses ol’ goo’ ERB ❖ Javascript rules over the web ❖ Web does not work without JS ❖ http://tobyho.com/ 2010/03/11/how-much-of-the- web-actually/
20. SPA is a new sexy ❖ No one uses ol’ goo’ ERB ❖ Javascript rules over the web ❖ Web does not work without JS ❖ http://tobyho.com/ 2010/03/11/how-much-of-the- web-actually/ ❖ In fact, you are limited to StackOverflow, Amazon and Google Search
21. SPA is a new sexy ❖ No one uses ol’ goo’ ERB ❖ Javascript rules over the web ❖ Web does not work without JS ❖ http://tobyho.com/2010/03/11/ how-much-of-the-web-actually/ ❖ In fact, you are limited to StackOverflow, Amazon and Google Search ❖ Actually, only paranoids disable JS in 2017
22. We are outdated
23. No more MPA applications
24. Web developers are developing APIs
25. APIs for SPAs, for mobile applications, for another APIs
26. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api)
27. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated.
28. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny
29. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big
30. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY
31. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY - too much to write
32. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY - too much to write ❖ Roda
33. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY - too much to write ❖ Roda - a challenger appears. No one noticed
34. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY - too much to write ❖ Roda - a challenger appears. No one noticed ❖ Rack
35. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY - too much to write ❖ Roda - a challenger appears. No one noticed ❖ Rack - maybe easier to rewrite the whole stack from scratch?
36. Solutions for APIs ❖ Still Rails. Now with API flavor (rails-api). Still Rails. Still boring. Still overbloated. ❖ Sinatra is a new shiny OH WAI~~. A little too big ❖ Microframeworks like Cuba, NYNY - too much to write ❖ Roda - a challenger appears. No one noticed ❖ Rack - maybe easier to rewrite the whole stack from scratch? (And end up with buggy unfinished Rails)
37. If you can’t create it, steal it
38. WebMachine-ruby ❖ Based on Erlang’s web machine
39. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs
40. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs ❖ More than 5 years old
41. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs ❖ More than 5 years old ❖ Still alive!
42. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs ❖ More than 5 years old ❖ Still alive! Last commit - on 30 Jan 2017
43. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs ❖ More than 5 years old ❖ Still alive! Last commit - on 30 Jan 2017 ❖ 13 issues opened and 80 closed
44. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs ❖ More than 5 years old ❖ Still alive! Last commit - on 30 Jan 2017 ❖ 13 issues opened and 80 closed ❖ Author works with Erlang, Ruby and Elixir
45. WebMachine-ruby ❖ Based on Erlang’s web machine ❖ Created by Sean Cribbs ❖ More than 5 years old ❖ Still alive! Last commit - on 30 Jan 2017 ❖ 13 issues opened and 80 closed ❖ Author works with Erlang, Ruby and Elixir ❖ github://webmachine/webmachine-ruby.git
46. Fundamental idea ❖ Each API resource is a typical state machine
47. Fundamental idea ❖ Each API resource is a typical state machine ❖ Each request is a flow through this state machine
48. Fundamental idea ❖ Each API resource is a typical state machine ❖ Each request is a flow through this state machine ❖ Most requests are pretty standard
49. Fundamental idea ❖ Each API resource is a typical state machine ❖ Each request is a flow through this state machine ❖ Most requests are pretty standard ❖ Functional behavior is more suiting case for this
50. Fundamental idea ❖ Each API resource is a typical state machine ❖ Each request is a flow through this state machine ❖ Most requests are pretty standard ❖ Functional behavior is more suiting case for this ❖ Define standards and override only needed things
51. Why state machine? ❖ Typical frameworks: request is running by predefined procedure.
52. Why state machine? ❖ Typical frameworks: request is running by predefined procedure. They are not your bros
53. Why state machine? ❖ Typical frameworks: request is running by predefined procedure. They are not your bros ❖ Webmachine determines facts about requests
54. Why state machine? ❖ Typical frameworks: request is running by predefined procedure. They are not your bros ❖ Webmachine determines facts about requests ❖ Uses finite state machine to determine proper response
55. Why state machine? ❖ Typical frameworks: request is running by predefined procedure. They are not your bros ❖ Webmachine determines facts about requests ❖ Uses finite state machine to determine proper response ❖ Each fact can easily be tested
56. Why state machine? ❖ Typical frameworks: request is running by predefined procedure. They are not your bros ❖ Webmachine determines facts about requests ❖ Uses finite state machine to determine proper response ❖ Each fact can easily be tested ❖ Webmachine is your bro
57. State machine diagram
59. Request to resource flow
60. Validation and authorization
61. Content negotiation
62. Existence and redirection
63. Conditional requests
64. PUT/POST (resource creation)
65. DELETE (resource deletion)
66. render body
67. How it parses your request?
68. Parsing request ❖ Initial request: 
 curl "http://localhost/kudos/1" -H "Accept: application/json" -u test -p test
69. Parsing request ❖ Initial request: 
 curl "http://localhost/kudos/1" -H "Accept: application/json" -u test -p test ❖ Does route /kudos/:id exist?
70. Parsing request ❖ Initial request: 
 curl "http://localhost/kudos/1" -H "Accept: application/json" -u test -p test ❖ Does route /kudos/:id exist? ❖ Does resource with ID 1 exist?
71. Parsing request ❖ Initial request: 
 curl "http://localhost/kudos/1" -H "Accept: application/json" -u test -p test ❖ Does route /kudos/:id exist? ❖ Does resource with ID 1 exist? ❖ Is this user with this password allowed to execute this request on resource?
72. Parsing request ❖ Initial request: 
 curl "http://localhost/kudos/1" -H "Accept: application/json" -u test -p test ❖ Does route /kudos/:id exist? ❖ Does resource with ID 1 exist? ❖ Is this user with this password allowed to execute this request on resource? ❖ Can this method be called for this resource?
73. Parsing request ❖ Initial request: 
 curl "http://localhost/kudos/1" -H "Accept: application/json" -u test -p test ❖ Does route /kudos/:id exist? ❖ Does resource with ID 1 exist? ❖ Is this user with this password allowed to execute this request on resource? ❖ Can this method be called for this resource? ❖ Can this resource be rendered with this content type?
74. Typical resource class KudoResource < Webmachine::Resource def allowed_methods ["GET"] end def content_types_provided [["application/json", :to_json]] end def resource_exists? kudo # Truthy or falsey end def to_json kudo.to_json end private def kudo @kudo ||= Kudo.find(id) end def id request.path_info[:id] end end
75. Little coding session
76. Bonus: request trace
77. Even more
78. Lattice: Webmachine on actors
79. Thank you!
80. Questions?