A Rails Criticism

A deep insight on why Ruby on Rails has revolutionized web development.

This talk will focus its attention on the Rails "Golden Path", the reasons to its success, the most common problems, and how its API can be improved.

We will learn to benefit from a tool as powerful as it is dangerous, how to mitigate architectural, design and testability implications for our applications and how to improve the quality of our code.

Transcript

1. Luca Guidi March 22nd, 2013 A Rails Criticism how i learned to stop worrying about the Golden Path
2. AGENDA intro
3. Luca Guidi Senior Developer at Litmus @jodosha - http//lucaguidi.com
4. litmus Beautiful Email previews Campaign analytics Spam filter tests HTML code analysis And many other..
5. Why Rails has revolutionized web development? (IMHO)
6. Why Rails has revolutionized web development? (IMHO) Convention Over Configuration :)
7. Why Rails has revolutionized web development? (IMHO) Convention Over Configuration Dynamic and innovative ecosystem :)
8. Why Rails has revolutionized web development? (IMHO) Convention Over Configuration Dynamic and innovative ecosystem Productivity and Developer Happiness :)
9. ..but The Framework is almost ten years old
10. ..but The Framework is almost ten years old A Lot of Legacy Code is around
11. ..but The Framework is almost ten years old A Lot of Legacy Code is around Upgrades to a major release are *painful*
12. AGENDA intro problems
13. Active Record Active Record
14. Models != Records Active Record
15. Encapsulation violations Active Record 1 if article.state != 'published' 2 article.update_attribute(state: 'published') 3 end 1 unless article.published? 2 article.publish! 3 end 4 # not completely right...
16. Encapsulation violations Active Record 1 if article.state != 'published' 2 article.update_attribute(state: 'published') 3 end 1 unless article.published? 2 article.publish! 3 end 4 # not completely right...
17. Encapsulation violations Active Record 1 if article.state != 'published' 2 article.update_attribute(state: 'published') 3 end 1 unless article.published? 2 article.publish! 3 end 4 # not completely right...
18. Tell, Don’t Ask violations Active Record 1 unless article.published? 2 article.publish! 3 end 4 # not completely right... 1 article.publish! 2 # push the implementation 3 # into the model
19. Tell, Don’t Ask violations Active Record 1 unless article.published? 2 article.publish! 3 end 4 # not completely right... 1 article.publish! 2 # push the implementation 3 # into the model
20. Tell, Don’t Ask violations Active Record 1 unless article.published? 2 article.publish! 3 end 4 # not completely right... 1 article.publish! 2 # push the implementation 3 # into the model
21. Implicit vs Explicit API Active Record 1 Post.where(state:'published'). 2 order('created_at DESC'). 3 limit(5) 1 Post.most_recent_published 1 class Post < ActiveRecord::Base 2 def self.most_recent_published(limit = 5) 3 published.recent(limit).order('created_at DESC') 4 end 5 6 private 7 scope :published, ->() { where(state: 'published') } 8 scope :recent, ->(n) { limit(n) } 9 end
22. Implicit vs Explicit API Active Record 1 Post.where(state:'published'). 2 order('created_at DESC'). 3 limit(5) 1 Post.most_recent_published 1 class Post < ActiveRecord::Base 2 def self.most_recent_published(limit = 5) 3 published.recent(limit).order('created_at DESC') 4 end 5 6 private 7 scope :published, ->() { where(state: 'published') } 8 scope :recent, ->(n) { limit(n) } 9 end
23. Implicit vs Explicit API Active Record 1 Post.where(state:'published'). 2 order('created_at DESC'). 3 limit(5) 1 Post.most_recent_published 1 class Post < ActiveRecord::Base 2 def self.most_recent_published(limit = 5) 3 published.recent(limit).order('created_at DESC') 4 end 5 6 private 7 scope :published, ->() { where(state: 'published') } 8 scope :recent, ->(n) { limit(n) } 9 end
24. Implicit vs Explicit API Active Record 1 Post.where(state:'published'). 2 order('created_at DESC'). 3 limit(5) 1 Post.most_recent_published 1 class Post < ActiveRecord::Base 2 def self.most_recent_published(limit = 5) 3 published.recent(limit).order('created_at DESC') 4 end 5 6 private 7 scope :published, ->() { where(state: 'published') } 8 scope :recent, ->(n) { limit(n) } 9 end
25. Callbacks abuse Active Record Non-persistence logic is tight to the persistence life cycle. Eg. Sending emails
26. Testability issues Active Record Micheal Feathers
27. Testability issues Active Record A test is not a unit test if it talks to a database. Micheal Feathers
28. Action Controller Action Controller It doesn’t affect too much your architecture, but it has strange OOP design.
29. Frankenstein Controllers Action Controller 1 class PostsController < ApplicationController 2 before_filter :authenticate 3 4 def new 5 end 6 7 def create 8 @post = Post.new(params[:post]) 9 10 if @post.save 11 redirect_to post_url(@post), notice: 'Yay!' 12 else 13 render :new 14 end 15 end 16 end !&
    
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30. Frankenstein Controllers Action Controller 1 class PostsController < ApplicationController 2 before_filter :authenticate 3 4 def new 5 end 6 7 def create 8 @post = Post.new(params[:post]) 9 10 if @post.save 11 redirect_to post_url(@post), notice: 'Yay!' 12 else 13 render :new 14 end 15 end 16 end !&
    
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31. Frankenstein Controllers Action Controller 1 class PostsController < ApplicationController 2 before_filter :authenticate 3 4 def new 5 end 6 7 def create 8 @post = Post.new(params[:post]) 9 10 if @post.save 11 redirect_to post_url(@post), notice: 'Yay!' 12 else 13 render :new 14 end 15 end 16 end !&
    
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41. 1 describe PostsController do 2 it 'assigns @posts' do 3 Post.should_receive(:most_recent_published). 4 and_return(posts = [mock]) 5 get :index 6 7 expect(assigns(:posts)).to eq(posts) 8 end 9 end Testability issues Action Controller 
    
    
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47. Action View Action View
48. Views aren’t views Action View (but templates with logic) Without “real” views (or presenters), we’re tempted to push presentational methods into the models. In an ideal world we shouldn’t test our templates.
49. Helpers are functional programming Action View 1 def user_full_name(user) 2 [ user.first_name, user.last_name ].join(' ') 3 end 4 5 url_for 6 # vs 7 Url.for 8 9 posts_url Half-assed way to solve presentational problems in ActionView.
50. Helpers are functional programming Action View 1 def user_full_name(user) 2 [ user.first_name, user.last_name ].join(' ') 3 end 4 5 url_for 6 # vs 7 Url.for 8 9 posts_url Half-assed way to solve presentational problems in ActionView.
51. Ruby on Rails Ruby on Rails
52. Rails isn’t a framework, but an application template Ruby on Rails
53. Rails is multi-paradigm as Ruby is. Ruby on Rails
54. AGENDA intro problems solutions
55. Decouple your logic from ActiveRecord as much as possible. Solutions AR is focused on data, but OOP is about behavior.
56. Don’t think in ActiveRecord terms. Solutions Database is a detail, forget about associations, scopes, validations..
57. Let your public API to declare intents. Solutions Let your design to emerge via TDD.
58. Keep methods and accessors private as much as possible. Solutions Public APIs are hard to maintain as the codebase and the team grows.
59. Skinny controllers and skinny models. Solutions Use service objects or DCI, they are easier and faster to test.
60. Don’t be afraid to extract ad-hoc classes for specific responsibilities. Solutions Inner classes are your friends, they help you with details, and aren’t part of your public API.
61. Use DIY presenters Solutions They will help you to keep your models clean from presentational logic.
62. Refactor, refactor, refactor. Solutions
63. AGENDA intro problems solutions conclusion
64. Q&A
65. me@lucaguidi.com @jodosha https://speakerdeck.com/jodosha/a-rails-criticism Except where otherwise noted, this work is licensed under: http://creativecommons.org/licenses/by-nc-sa/3.0/
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