Windy City Rails 2017 - Beyond Active Record

https://windycityrails.com/schedule/#beyond-active-record

Active Record models can quickly become bloated messes that combine persistence logic, validations, callbacks, and business logic into god objects. These models slowly become dependencies of almost all other objects in our code base.

Several months ago, Strava confronted this situation in their mature 8 year old Rails application. In this talk, Pan will walk through the new architecture and object conventions that Strava is migrating to as a solution to unwieldy Active Record models. We’ll explore the reasoning behind each design decision so that you can decide for yourself if a similar approach is right for you. And we’ll walk through some of the benefits of this alternative architecture.

Transcript

1. @panthomakos beyond active record Pan Thomakos @panthomakos
2. @panthomakos
3. @panthomakos @panthomakos
4. @panthomakos The Golden Gate Bridge... / David Ball / Creative Commons @panthomakos
5. @panthomakos rails
6. @panthomakos 8 years ago ruby 1.8.6 rails 1.x
7. @panthomakos today ruby 2.3.3 rails 3/4 400k LOC
8. @panthomakos services
9. @panthomakos @panthomakos Railway / SplitShire / Creative Commons
10. @panthomakos @panthomakos Railway tracks in the sunset / Arne Hückelheim / Creative Commons
11. @panthomakos International space station view / skeeze / Creative Commons @panthomakos global objects
12. @panthomakos ZRAID at PCI-X / Mixabest / Public Domain @panthomakos difficult upgrades
13. @panthomakos ActiveRecord
14. @panthomakos The archive of the Danish Broadcasting Corporation / DRs Kulturarvsprojekt / Creative Commons @panthomakos persistence
15. @panthomakos class Bike < ApplicationRecord
16. @panthomakos belongs_to :athlete has_many :rides, dependent: :nullify has_many :components, dependent: :destroy has_one :picture, dependent: :destroy
17. @panthomakos validates :name, presence: true, message: ... validates :weight, in: ... validates :frame_type, in: ...
18. @panthomakos after_save :calculate_weight after_create :create_frame_component, if: -> ... after_destroy :delete_bike_total, if: -> ...
19. @panthomakos scope :active, -> { where(retired: false) } scope :retired, -> { where(retired: true) } scope :default, -> { where(default: true) }
20. @panthomakos athletes.includes(:bikes).limit(100).to_a
21. @panthomakos athlete.bikes.create(params)
22. @panthomakos def retire! self.retire = true save! end def frame Bikes::Frames[frame_type] end def mountain_bike? Bikes::Frames.mtb?(frame) end ... continues for 200 more lines
23. @panthomakos persistence validation callbacks scopes helpers relationships
24. @panthomakos > Bike.methods.count - Object.methods.count => 448 > Bike.new.methods.count - Object.new.methods.count => 412
25. @panthomakos > Athlete.methods.count - Object.methods.count => 1110 > Athlete.new.methods.count - Object.new.methods.count => Athlete.new: 2650
26. @panthomakos Goats Competition Dispute / hbieser / Creative Commons @panthomakos deadlock
27. @panthomakos noAR
28. @panthomakos no active record
29. @panthomakos persistence validation callbacks scopes helpers relationships
30. @panthomakos persistence validation callbacks scopes helpers relationships
31. @panthomakos persistence validation callbacks scopes helpers relationships
32. @panthomakos persistence validation callbacks scopes helpers relationships
33. @panthomakos persistence validation callbacks scopes helpers relationships
34. @panthomakos Persistence.create(attributes)
35. @panthomakos Validation.validate!(attributes)
36. @panthomakos EventLogging.log(:new_bike, id) AthleteCache.bump(athlete_id)
37. @panthomakos persistence validation callback(s)
38. @panthomakos persistence validation callbacks scopes helpers relationships
39. @panthomakos athlete = Athlete.find(athlete_id) bikes = athlete.bikes
40. @panthomakos athlete = Athlete.find(athlete_id) bikes = Bike.all_by_athlete(athlete_id)
41. @panthomakos athlete.includes(:bikes).limit(100).to_a
42. @panthomakos Bike.all_by_athlete(athlete.id, limit: 100)
43. @panthomakos persistence validation callbacks scopes helpers relationships
44. @panthomakos Waiter Beverages Bottles Alcohol / Alexas Fotos / Creative Commons @panthomakos service
45. @panthomakos Strava::<Service>
46. @panthomakos Strava::Bikes
47. @panthomakos Strava::Bikes::Actions
48. @panthomakos Strava::Bikes::Actions::Creator
49. @panthomakos Strava::Bikes::Actions::Reader
50. @panthomakos Strava::Bikes::Actions::Updater
51. @panthomakos Strava::Bikes::Actions::Destroyer
52. @panthomakos Strava::Bikes::Actions.create
53. @panthomakos Strava::Bikes::Actions::Reader.find(id) Strava::Bikes::Actions::Reader.by_athlete_id(id)
54. @panthomakos Strava::Bikes::Actions::Creator.create
55. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(athlete_id, attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
56. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
57. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
58. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
59. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
60. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
61. @panthomakos Puppy / Public Domain @panthomakos small APIs
62. @panthomakos athlete.bikes.create(params)
63. @panthomakos Strava::Bikes::Actions::Creator.create( athlete.id, params )
64. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = ::Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
65. @panthomakos module Strava::Bikes::Actions::Reader def self.find(id) Bike.find(id) end def self.by_athlete_id(athlete_id) Bike.where(athlete_id: athlete_id).to_a end end
66. @panthomakos module Strava::Bikes::Actions::Reader def self.find(id) Bike.find(id) end def self.by_athlete_id(athlete_id) Bike.where(athlete_id: athlete_id).to_a end end
67. @panthomakos bike = Strava::Bikes::Actions::Reader.find(id) bike.name = ‘Green Commute Fixie’ bike.save!
68. @panthomakos A Pair of Ceremonial Objects or Musical Instruments / LACMA / Public Domain @panthomakos simple objects
69. @panthomakos Strava::Bikes::Bike
70. @panthomakos class Strava::Bikes::Bike < BasicEntity table :bikes columns :id, :athlete_id, :name, :frame_type, :weight primary :id end
71. @panthomakos Strava::Bikes::Bike.methods - Object.methods => [:db_table, :db_columns, :db_primary_key]
72. @panthomakos Strava::Bikes::Bike.new.methods - Object.new.methods => [:name, :id, :athlete_id, :frame_type, :weight]
73. @panthomakos > Strava::Bikes::Bike.new.id = 5 NoMethodError: private method `id=' called for #<Strava::Bikes::Bike:0x00006c99871558> Did you mean? id
74. @panthomakos Strava::Bikes::Db
75. @panthomakos Strava::Bikes::Db::Creator Strava::Bikes::Db::Reader Strava::Bikes::Db::Updater Strava::Bikes::Db::Destroyer
76. @panthomakos class Strava::Bikes::Db::Reader < EntityReader def initialize super(Strava::Bikes::Bike) end end
77. @panthomakos class Strava::Bikes::Db::Reader < EntityReader def initialize super(Strava::Bikes::Bike) end end
78. @panthomakos class Strava::Bikes::Db::Reader < EntityReader def initialize super(Strava::Bikes::Bike) end end
79. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
80. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
81. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
82. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
83. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
84. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
85. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
86. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
87. @panthomakos class EntityReader def initialize(entity, engine = DefaultEngine) @entity = entity @table = ::Arel::Table.new(@entity.db_table) @engine = engine end def find(pk) query = @table.where(@table[@entity.db_primary_key].eq(pk)) select(query).first end private def project(query) query.project(@entity.db_columns.map { |c| @table[c] }) end def select(query) @engine.connection.select_all(project(query).to_sql).map do |row| @entity.new(row) end end end
88. @panthomakos class Strava::Bikes::Db::Reader < EntityReader def initialize super(Strava::Bikes::Bike) end def by_athlete_id(id) select(@table.where(@table[:athlete_id].eq(id))) end end
89. @panthomakos class Strava::Bikes::Db::Reader < EntityReader def initialize super(Strava::Bikes::Bike) end def by_athlete_id(id) select(@table.where(@table[:athlete_id].eq(id))) end end
90. @panthomakos class Strava::Bikes::Db::Creator < EntityCreator def initialize super(Strava::Bikes::Bike) end def create(attrs) t = Time.now attrs = attrs.merge(created_at: t, updated_at: t) super(attrs) end end
91. @panthomakos class Strava::Bikes::Db::Creator < EntityCreator def initialize super(Strava::Bikes::Bike) end def create(attrs) t = Time.now attrs = attrs.merge(created_at: t, updated_at: t) super(attrs) end end
92. @panthomakos class Strava::Bikes::Db::Creator < EntityCreator def initialize super(Strava::Bikes::Bike) end def create(attrs) t = Time.now attrs = attrs.merge(created_at: t, updated_at: t) super(attrs) end end
93. @panthomakos class Strava::Bikes::Db::Creator < EntityCreator def initialize super(Strava::Bikes::Bike) end def create(attrs) t = Time.now attrs = attrs.merge(created_at: t, updated_at: t) super(attrs) end end
94. @panthomakos class Strava::Bikes::Db::Creator < EntityCreator def initialize super(Strava::Bikes::Bike) end def create(attrs) t = Time.now attrs = attrs.merge(created_at: t, updated_at: t) super(attrs) end end
95. @panthomakos Strava::Bikes::Bike Strava::Bikes::Db::[CRUD]er
96. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
97. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) bike = Bike.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) bike.id end end
98. @panthomakos module Strava::Bikes::Actions::Creator def self.create(athlete_id, attrs) Validator.validate!(attrs) id = Db::Creator.create(attrs) ::EventLogging.log(:bike_create, id) ::AthleteCache.bump(athlete_id) id end end
99. @panthomakos module Strava::Bikes::Actions::Reader def self.find(id) Bike.find(id) end def self.by_athlete_id(athlete_id) Bike.where(athlete_id: athlete_id).to_a end end
100. @panthomakos module Strava::Bikes::Actions::Reader def self.find(id) Bike.find(id) end def self.by_athlete_id(athlete_id) Bike.where(athlete_id: athlete_id).to_a end end
101. @panthomakos module Strava::Bikes::Actions::Reader def self.find(id) Db::Reader.new.find(id) end def self.by_athlete_id(athlete_id) Db::Reader.new.by_athlete_id(athlete_id) end end
102. @panthomakos module Strava::Bikes::Actions::Reader def self.find(id) Db::Reader.new.find(id) end def self.by_athlete_id(athlete_id) Db::Reader.new.by_athlete_id(athlete_id) end end
103. @panthomakos Produce / Public Domain @panthomakos local
104. @panthomakos Wall made of hole bricks / Xauxa / Creative Commons @panthomakos framework isolation
105. @panthomakos Water bubbles under the sea / MartinSr / Creative Commons @panthomakos service readiness
106. @panthomakos persistence validation callbacks scopes helpers relationships
107. @panthomakos class Bike < ApplicationRecord def retire! self.retire = true save! end def frame Bikes::Frames[frame_type] end def mountain_bike? Bikes::Frames.mtb?(frame) end end
108. @panthomakos class Bike < ApplicationRecord def retire! self.retire = true save! end def frame Bikes::Frames[frame_type] end def mountain_bike? Bikes::Frames.mtb?(frame) end end
109. @panthomakos Strava::Bikes::Actions::Updater.retire(id)
110. @panthomakos class Bike < ApplicationRecord def retire! self.retire = true save! end def frame Bikes::Frames[frame_type] end def mountain_bike? Bikes::Frames.mtb?(frame) end end
111. @panthomakos BikeFrame[bike.frame_type].mountain_bike?
112. @panthomakos BikeFrame[bike.frame_type].mountain_bike?
113. @panthomakos Strava::Bikes::Actions::Updater.retire(id) BikeFrame[bike.frame_type].mountain_bike?
114. @panthomakos Puppy Sleeping / alexramos10 / Creative Commons @panthomakos services
115. @panthomakos persistence validation callbacks scopes helpers relationships
116. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
117. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
118. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
119. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
120. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
121. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
122. @panthomakos ::Strava Bikes Actions Creator Reader Updater Destroyer Db Creator Reader Updater Destroyer Bike Validator AdminValidator ::EventLogging ::AthleteCache ::BikeFrame
123. @panthomakos Dock Jumping Golden Retriever / Jerry Reynolds / Creative Commons @panthomakos challenges and wins
124. @panthomakos Excavator / cav78au / Public Domain @panthomakos refactoring ActiveRecord
125. @panthomakos class Bike < ApplicationRecord def initialize(*args) StatsD.increment(‘ar.bike.create’) logger.info(‘bike initialized’, caller: caller) super end end
126. @panthomakos includes(:bikes)
127. @panthomakos Dog Thinking / Public Domain @panthomakos more thinking
128. @panthomakos Duck Ducklings / apefrance / Public Domain @panthomakos one:many
129. @panthomakos Caterpillar Butterfly Animal / Public Domain @panthomakos incremental improvement
130. @panthomakos # controller def show @bike = Bike.find(params[:id]) unless BikePermissions.editable?(@bike, current_athlete) permission_denied return false end # view @bike.athlete @bike.components
131. @panthomakos # controller def show @bike = Strava::Bikes::Actions::Reader.find(params[:id]) unless BikePermissions.editable?(@bike, current_athlete) permission_denied return false end @athlete = Athlete.find(@bike.athlete_id) @components = Component.where(bike_id: @bike.id).all
132. @panthomakos # controller def show @bike = Strava::Bikes::Actions::Reader.find(params[:id]) unless BikePermissions.editable?(@bike, current_athlete) permission_denied return false end @athlete = Strava::Athletes::Actions::Reader.find(@bike.athlete_id) @components = Strava::Bikes::Actions::Reader.components(@bike.id)
133. @panthomakos Freedom Jumping / Hany Sadek / Creative Commons @panthomakos
134. @panthomakos STRAVA Pan Thomakos @panthomakos