[RailsConf 2023 Opening Keynote] The Magic of Rails

Today we're going to explore the magic of Rails. We'll look at the philosophy behind the framework as well as the overall structure of the components. We'll explore some of the common patterns that Rails uses to build agnostic and beautiful interfaces, and the techniques it implements to hide complexity so you can focus building your application. By the end of this talk you'll feel more confident navigating the Rails codebase and better understand the patterns it uses to create the framework we all know and love. But Rails is so much more than its design and architecture. We'll dive into my motivations for working on the framework and why the community is so important to the long term success of Rails.

Transcript

1. The Magic of Rails exploring the principles & techniques behind the framework
3. Hello RailsConf! I'm Eileen M. Uchitelle @eileencodes @eileencodes@ruby.social
6. The Magic of Rails exploring the principles & techniques behind the framework
7. What is Ruby on Rails?
8. Rails is modular, but 
 not fractured
9. Rails is designed to have agnostic interfaces
10. Rails is extracted from applications
11. Rails is made of 
 simple and aesthetic APIs
12. Rails is a framework that takes on complexity to empower you
13. How Rails components are structured
14. RUBY ON RAILS Active Record Active Support Active Model Active Job Active Storage Action Mailer Action Pack Action View Action Cable Action Text Action Mailbox Railties
15. Naming Convention Active vs Action
16. Active Record Active Support Active Model Active Job Active Storage BACKEND NAMING CONVENTION
17. USER FACING Active Record Active Support Active Model Active Job Active Storage BACKEND NAMING CONVENTION Action Mailer Action Pack Action View Action Cable Action Text Action Mailbox USER FACING
18. Active Record Active Support Active Model Active Job Active Storage Action Mailer Action Pack Action View Action Cable Action Text Action Mailbox BACKEND USER FACING Railties GLUE NAMING CONVENTION
19. Architeture & Patterns of Rails components
20. Architecture & Patterns the role of Railties
21. 👩💻 Application
22. 👩💻 Application Register hooks
23. 👩💻 Application Register hooks Load components
24. 👩💻 Application Register hooks Load components Run hooks
25. # railtie.rb initializer "initializer.name" do # do something at initialization end
26. # railties/lib/rails/application.rb def initializer(name, opts = {}, &block) self.class.initializer(name, opts, &block) end
27. # railtie.rb initializer "initializer.name" do |app| app.do_something app.config.do_something end
28. # railtie.rb initializer "initializer.name" do ActiveSupport.on_load(:active_record) do # do something at initialization end end
29. # activerecord/lib/active_record/railtie.rb initializer "active_record.initialize_database" do ActiveSupport.on_load(:active_record) do self.configurations = Rails.application.config.database_configuration establish_connection end end
30. # activerecord/lib/active_record/railtie.rb initializer "active_record.initialize_database" do ActiveSupport.on_load(:active_record) do self.configurations = Rails.application.config.database_configuration establish_connection end end
31. # activerecord/lib/active_record/railtie.rb initializer "active_record.initialize_database" do ActiveSupport.on_load(:active_record) do self.configurations = Rails.application.config.database_configuration establish_connection end end
32. # activejob/lib/active_job/railtie.rb initializer "active_job.logger" do ActiveSupport.on_load(:active_job) { self.logger = ::Rails.logger } end
33. # activejob/lib/active_job/railtie.rb initializer "active_model.deprecator", before: :load_environment_config do |app| app.deprecators[:active_model] = ActiveModel.deprecator end
34. # activejob/lib/active_job/railtie.rb initializer "active_model.deprecator", before: :load_environment_config do |app| app.deprecators[:active_model] = ActiveModel.deprecator end
35. • Railties are the core of the framework
36. • Railties are the core of the framework • Railties control load order and when hooks should be run
37. • Railties are the core of the framework • Railties control load order and when hooks should be run • Enables components to work together without adding dependencies
38. Architecture & Patterns Agnostic interfaces
39. if connection.is_a?(PostgresqlAdapter) # ... elsif connection.is_a?(Mysql2Adapter) # ... elsif connection.is_?(Sqlite3Adapter) # ... else # ... end
40. if connection.is_a?(PostgresqlAdapter) # ... elsif connection.is_a?(Mysql2Adapter) # ... elsif connection.is_?(Sqlite3Adapter) # ... else # ... end ❌
41. module ActiveRecord module ConnectionAdapters class AbstractAdapter # define interface end end end
42. module ActiveRecord module ConnectionAdapters class AbstractAdapter # define interface end end end module ActiveRecord module ConnectionAdapters class PostgresqlAdapter < AbstractAdapter # inherit or redefine interface end end end
43. connection.supports_foreign_keys? => true
44. class AbstractAdapter def supports_foreign_keys? false end end
45. class AbstractAdapter def supports_foreign_keys? false end end class PostgresqlAdapter < AbstractAdapter def supports_foreign_keys? true end end
46. # activestorage/lib/active_storage/service.rb module ActiveStorage class Service def delete(key) raise NotImplementedError end end end
47. # activestorage/lib/active_storage/service/gcs_service.rb class ActiveStorage class Service::GCSService < Service def delete(key) instrument :delete, key: key do file_for(key).delete rescue Google::Cloud::NotFoundError # Ignore files already deleted end end end end
48. @service.delete(key)
49. • Consistent interface for all supported libraries
50. • Consistent interface for all supported libraries • Simpli fi es Rails code to avoid using `is_a?`
51. • Consistent interface for all supported libraries • Simpli fi es Rails code to avoid using `is_a?` • Makes it easy for apps to swap out adapters / services
52. • Consistent interface for all supported libraries • Simpli fi es Rails code to avoid using `is_a?` • Makes it easy for apps to swap out adapters / services • Lowers the maintenance burden
53. Migrating Shopify's Core Rails Monolith to Trilogy Adrianna Chang Monday, April 24 @ 3pm
54. Architecture & Patterns Metaprogramming
55. class Post < ApplicationRecord has_many :comments end class Comment < ApplicationRecord belongs_to :post end
56. post = Post.first post.comments => [#<Comment:0x000000010e353838...>, #<Comment:0x000000010e3530e0>]
57. post = Post.first post.method(:comments).source_location
58. post = Post.first post.method(:comments).source_location => ["rails/activerecord/lib/ active_record/associations/builder/ association.rb", 103]
59. # activerecord/lib/active_record/associations/builder/ association.rb class ActiveRecord::Associations::Builder class Association def self.define_readers(mixin, name) mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1 def #{name} association(:#{name}).reader end CODE end end end
60. # activerecord/lib/active_record/associations/builder/ association.rb class ActiveRecord::Associations::Builder class Association def self.define_readers(mixin, name) mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1 def #{name} association(:#{name}).reader end CODE end end end
61. # activerecord/lib/active_record/associations/builder/ association.rb class ActiveRecord::Associations::Builder class Association def self.define_readers(mixin, name) mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1 def #{name} association(:#{name}).reader end CODE end end end
62. Post::GeneratedAssociationMethods
63. # activerecord/lib/active_record/associations/builder/ association.rb class ActiveRecord::Associations::Builder class Association def self.define_readers(mixin, name) mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1 def #{name} association(:#{name}).reader end CODE end end end
64. # activerecord/lib/active_record/associations/builder/ association.rb class ActiveRecord::Associations::Builder class Association def self.define_writers(mixin, name) mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1 def #{name}=(value) association(:#{name}).writer(value) end CODE end end end
65. # activerecord/lib/active_record/associations/builder/ association.rb class ActiveRecord::Associations::Builder class Association def self.define_writers(mixin, name) mixin.class_eval <<-CODE, __FILE__, __LINE__ + 1 def #{name}=(value) association(:#{name}).writer(value) end CODE end end end
66. • Powerful tool that enables us to build beautiful, simple APIs
67. • Powerful tool that enables us to build beautiful, simple APIs • Hides complexity from your application
68. • Powerful tool that enables us to build beautiful, simple APIs • Hides complexity from your application • Where "Rails Magic" comes from
69. Maintaining Rails Why I work on it
70. 2010 Introduced to Rails
71. 2010 Introduced to Rails 2011 Big Nerd Ranch
72. 2010 Introduced to Rails 2011 Big Nerd Ranch 2014 1st conference 1st contribution
73. 2010 Introduced to Rails 2011 Big Nerd Ranch 2014 1st conference 1st contribution 2015 First RailsConf
74. 2010 Introduced to Rails 2011 Big Nerd Ranch 2014 1st conference 1st contribution 2015 First RailsConf 2017 Join Rails Core
75. 2010 Introduced to Rails 2011 Big Nerd Ranch 2014 1st conference 1st contribution 2015 First RailsConf 2017 Join Rails Core 2023 This RailsConf
76. I work on Rails to advance the framework
77. I work on Rails to ensure applications can stay on Rails
78. I work on Rails to build a stronger community
79. I work on Rails to have an impact on the future
80. Rails is so much more than just a framework
81. Rails is inspiring
82. Rails is empowering
83. Rails is imperfect
84. Rails is the applications we build
85. Rails is the team behind it
86. Rails is the community
87. Rails is magic
88. Thank You!