50 Shades of MVC

Video: https://vimeo.com/89377195

We at the Rails world are very proud of embracing the Model-View-Controller design pattern, it is integral to the way we build web applications and there is a general consensus that all of us generally know what we are talking about in regards to it, hell , most of our code files are under a model, controller or views directories! We've got to know what we are doing, right?

Much like Object Orientation the Model-View-Controller pattern is one of the most popular-yet-heavily-altered concepts in modern computer science, what were the original propositions of the pattern? How was it applied back in the 70's, when it was proposed as a part of Smalltalk? How much have we changed it to adapt it to the web application scene? How can we apply this to our day to day work in 2013? is altering the original pattern necessarily a bad thing?

On this talk I present different aspects of the MVC pattern and its changes from its inception to modern day use, what to keep in mind about the pattern as opposed to a single framework's implementation of it and how knowing this should make us all around better programmers.

Transcript

1. 50 Shades
   of MVC
2. Pablo
   Astigarraga
3. ! @poteland
   github.com/pote
4. tarmac.io
5. Surculus Fructum
6. Uruguay
7. Uruguay
8. Argentina
10. ! Thank you RubyConf Ar <3
11. Model
    View
    Controller
12. 2004 - 2005
14. Models
    Data + Behavior
    
15. Views
    User Interface !
16. Controllers
    Glue. (?)
18. Browser GET / HTTP/1.1
19. Web Server
20. Router MyApp::Application.routes.draw do! get '/' => 'sessions#new'! root :to => 'sessions#new' ! end!
21. Router MyApp::Application.routes.draw do! get '/' => 'sessions#new'! root :to => 'sessions#new' ! end!
22. Router MyApp::Application.routes.draw do! get '/' => 'sessions#new'! root :to => 'sessions#new' ! end!
23. Controller class SessionsController < ApplicationController! def new! @model = FictionalModel.last! render :new! end! end!
24. Model class FictionalModel < ActiveRecord::Base! # validations! # other stuff (?)! end!
25. Database SELECT * FROM fictional_models ORDER BY fictional_models.id DESC LIMIT 1
26. Model # => #<FictionalModel id: 221, name: "Derek Zoolander">
27. Controller class SessionsController < ApplicationController! def new! @model = FictionalModel.last! render :new! end! end!
28. Controller class SessionsController < ApplicationController! def new! @model = FictionalModel.last! render :new! end! end!
29. View <div id="sign_in">! <h3>! Our last registeded model is: <%= @model.name %>! </h3>! ! <a href="/auth/google">Sign in with Google</a>! <div>!
30. Browser <div id="sign_in">! <h3>! Our last registeded model is: Derek Zoolander! </h3>! ! <a href="/auth/google">Sign in with Google</a>! <div>!
32. What about Logic?
33. Logic in Views? (›°□°)›ớ sʍǝıᴧ
34. Logic in Controllers? (›°□°)›ớ sɹǝʃʃoɹʇuoↃ
35. Logic in Controllers? Controllers ϊ( ʄ-ʄϊ)
36. Logic in Models? ¯\_(π)_/¯
37. ಠ_ಠ
38. ?
39. ಠ_ಠ
40. 197x - 1988
41. “Everything
    is an Object”
42. Smalltalk
43. Xerox PARC
44. Message
    Passing
45. Integrated
    Development
    Environment
46. Inspired:
47. Graphical Interfaces (pretty much)
48. Graphical Interfaces are why MVC exists.
49. MVC in Smalltalk
50. Interactions
52. Controller Sends commands to its associated view to change the view's presentation ! Sends commands to the model to update the model's state
53. View Requests from the model the information that it needs to generate an output representation to the user.
54. Model Notifies its associated views and controllers when there has been a change in its state.
55. Model
    A passive implementation of MVC omits these notifications, because the application does not require them or the software platform does not support them
57. “Thin Client”
58. We can do this.
59. Websockets
61. “Active” MVC. class Timeline < ActiveRecord::Base! ! after_save :notify_views! ! def websockets_channel! "#{ self.class }#{ self.id }".hash! end! ! private! ! def notify_views! Pusher.trigger(self.websockets_channel, 'update', { self: self.to_json })! end! end!
62. class Timeline < ActiveRecord::Base! ! after_save :notify_views! ! def websockets_channel! "#{ self.class } #{ self.id }".hash! “Active” MVC.
63. “Active” MVC. class Timeline < ActiveRecord::Base! ! after_save :notify_views! ! def websockets_channel! "#{ self.class }#{ self.id }".hash! end! ! private! ! def notify_views! Pusher.trigger(self.websockets_channel,
64. class Timeline < ActiveRecord::B ! after_save :notify_views! ! def websockets_channel! "#{ self.class }#{ self.id } end! ! “Active” MVC.
65. “Active” MVC. end! ! private! ! def notify_views! Pusher.trigger(! self.websockets_channel,! 'update',! { self: self.to_json }! )! end! end!
67. GET /timelines/1 http http
68. PUT /timelines/1 http
69. Web Server
70. Router MyApp::Application.routes.draw do! get '/' => 'sessions#new'! root :to => 'sessions#new' ! end!
71. Controller class TimelinesController < ApplicationController! def update! @timeline = Timeline.find(params[:id])! if @timeline.update_attributes(params[:timeline])! #...! #...! end! end!
72. Model after_save :notify_views
73. Model
    def notify_views! Pusher.trigger(! self.websockets_channel,! 'update',! { self: self.to_json }! )! end!
77. Websockets <3
78. (Never said it was a good idea)
79. 2009 - 2013
80. JavaScript
81. MVC in the browser.
82. Full Circle.
83. View Requests from the model the information that it needs to generate an output representation to the user.
84. Empower your Views
85. Backbone.js
86. Angular.js
88. So what is MVC’s
    purpose?
89. Separation of Concerns
    ! (for graphical interface apps)
90. Guideline.
91. Tailor MVC to your needs.
    
92. You > MVC
93. Gracias! @poteland
95. Questions? @poteland References: