Rails - the dark side

In this talk we will see how to be careful with the framework, and how and what to use according to some situations. Should we always use Fat Models and Skinny? Should we also stick with the MVC model for everything? Should we use Concerns? What about JS+ERB? Use convention over configuration in Rails is always a good thing to do?

1. R il : t e ar s de
2. @f an ej
3. A en a 4 I 4 C l 4 P s 4 I /P a s n 4 M 4 P s 4 I /P a s n 4 V 4 P s 4 I /P a s n 4 C i
4. T an s, R il !
5. W l ar w th o in on .
6. T is al i n t f r oc -s ar .
7. I'm ot lo e
8. O r ro es io , w a e ik :
10. W n ed o ho se xa tl w at c lo s nd ow o se he
13. B t e nd f he al 4 I e o k r A s n E u 4 E i c e i a c p 4 M r h "p s" c p s o l m a t
14. C nv nt on ve c n g ra io
15. O er im R il b ca e as er nd as er o se.
16. D n t et he ra ew rk ec de ve yt in f r s. D k s ?
17. I d es ak s ns .
18. W c n ur ly ak s me ha ge o R il .
19. R il l ts s ak b d n w th ut iv ng s ny ar in , a d y he im w r al ze t he ha ge w n ed o ak a e os ly. 1 T l R d e
20. "w r al y ee t m ve as t m ke ur ar et ex y ar s w a e ed ci g <s me es gn ct vi y>".
21. D si n ta in H po he is
23. S ar in f om c l
24. I t e M e ou h?
25. T ;D , M yb !
26. O r ey ue ti n
27. H w he c l a d m w rk og th r
28. [C l ]
29. C as ic VC 4 C l c a m l b m n v
30. T e ro le
31. class SomeController < ApplicationController def blah @model = ... @model.perform_side_effects render ... end end class Model < ActiveRecord::Base def perform_side_effects self.some_association.perform_side_effects end end class SomeAssociation < ActiveRecord::Base def perform_side_effects do_the_actual_work end private def do_the_actual_work update_attributes(...) end end e f : h ://j e .c /p /r -v -p -m /
32. class SomeController < ApplicationController def blah @model = ... @model.perform_side_effects render ... end end class Model < ActiveRecord::Base def perform_side_effects self.some_association.perform_side_effects end end class SomeAssociation < ActiveRecord::Base def perform_side_effects do_the_actual_work end private def do_the_actual_work update_attributes(...) end end e f : h ://j e .c /p /r -v -p -m /
33. class SomeController < ApplicationController def blah @model = ... @model.perform_side_effects render ... end end class Model < ActiveRecord::Base def perform_side_effects self.some_association.perform_side_effects end end class SomeAssociation < ActiveRecord::Base def perform_side_effects do_the_actual_work end private def do_the_actual_work update_attributes(...) end end e f : h ://j e .c /p /r -v -p -m /
34. class SomeController < ApplicationController def blah @model = ... @model.perform_side_effects render ... end end class Model < ActiveRecord::Base def perform_side_effects self.some_association.perform_side_effects end end class SomeAssociation < ActiveRecord::Base def perform_side_effects do_the_actual_work end private def do_the_actual_work update_attributes(...) end end e f : h ://j e .c /p /r -v -p -m /
35. class SomeController < ApplicationController def blah @model = ... @model.perform_side_effects render ... end end class Model < ActiveRecord::Base def perform_side_effects self.some_association.perform_side_effects end end class SomeAssociation < ActiveRecord::Base def perform_side_effects do_the_actual_work end private def do_the_actual_work update_attributes(...) end end e f : h ://j e .c /p /r -v -p -m /
36. class SomeController < ApplicationController def blah @model = ... @model.perform_side_effects render ... end end class Model < ActiveRecord::Base def perform_side_effects self.some_association.perform_side_effects end end class SomeAssociation < ActiveRecord::Base def perform_side_effects do_the_actual_work end private def do_the_actual_work update_attributes(...) end end e f : h ://j e .c /p /r -v -p -m /
37. P ob em 4 I o c a h c l c 4 C l o r h g d e e 4 M c a m (a t ) n i a d e e 4 H u a 4 H t
38. class CheckoutsController < ApplicationController ... def checkout cart = Cart.new(params[:cart]) if current_user.default_payment_method.pay(cart.amount) line_items = cart.line_items line_items = line_items.map do |line_item| amount = line_item.product.price * line_item.quantity LineItem.new(product: line_item.product, quantity: line_item.quantity, amount: amount) end Order.create(user: current_user, line_items: line_items) Invoice.create(user: current_user, line_items: line_items) CheckoutMailer.with(user: current_user, line_items: line_items).deliver_now Metrics.send(user: current_user, cart: cart) flash.now[:notice] = 'You have just paid' render action: 'success' else flash.now[:error] = 'Could not make checkout' render action: 'payment' end end ... end
39. class CheckoutsController < ApplicationController ... def checkout cart = Cart.new(params[:cart]) if current_user.default_payment_method.pay(cart.amount) line_items = cart.line_items line_items = line_items.map do |line_item| amount = line_item.product.price * line_item.quantity LineItem.new(product: line_item.product, quantity: line_item.quantity, amount: amount) end Order.create(user: current_user, line_items: line_items) Invoice.create(user: current_user, line_items: line_items) CheckoutMailer.with(user: current_user, line_items: line_items).deliver_now Metrics.send(user: current_user, cart: cart) flash.now[:notice] = 'You have just paid' render action: 'success' else flash.now[:error] = 'Could not make checkout' render action: 'payment' end end ... end
40. class CheckoutsController < ApplicationController ... def checkout cart = Cart.new(params[:cart]) if current_user.default_payment_method.pay(cart.amount) line_items = cart.line_items line_items = line_items.map do |line_item| amount = line_item.product.price * line_item.quantity LineItem.new(product: line_item.product, quantity: line_item.quantity, amount: amount) end Order.create(user: current_user, line_items: line_items) Invoice.create(user: current_user, line_items: line_items) CheckoutMailer.with(user: current_user, line_items: line_items).deliver_now Metrics.send(user: current_user, cart: cart) flash.now[:notice] = 'You have just paid' render action: 'success' else flash.now[:error] = 'Could not make checkout' render action: 'payment' end end ... end
41. I ea /P te ti l ol ti ns
42. L t's ee g od xa pl o c nt ol er
43. Y u ig t on id r nc rp ra e om o t es i ea
44. H na i S mp e ub f am wo k 4 T u h "R b " 4 T o l R
45. I r/L S R Y o M t H E J é V P r R R D B p P F r C M D d H L G ---
46. # apps/web/controllers/home/index.rb module Web module Controllers module Home class Index include Web::Action def call(params) end end end end end E a H d n a s c , w m s t
47. S ng e es on ib li y ri ci le A od le ha c mp le a d ri ts r po t. 4 T c c c 4 T f c c O s t c , n n c c. T ey av t o es on ib it es, a d he t ey ho ld e n wo ep ra e la se .
48. A i te es in e am le f si g VC
49. T e ho ni F am wo k
50. P oe ix VC 4 S y d e 4 S d e e 4 S e e v h c l
51. C nt ol er i P oe ix
52. defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end 4 T c l e a c n h h d e e 4 T c l d 't o a o r a n h d
53. defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end 4 T c l e a c n h h d e e 4 T c l d 't o a o r a n h d
54. defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end 4 T c l e a c n h h d e e 4 T c l d 't o a o r a n h d
55. defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end 4 T c l e a c n h h d e e 4 T c l d 't o a o r a n h d
56. defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end 4 T c l e a c n h h d e e 4 T c l d 't o a o r a n h d
57. defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end 4 T c l e a c n h h d e e 4 T c l d 't o a o r a n h d
58. W w ll ee om s lu io s n m me t
59. [M ]
60. M de s n ai s
61. F t od ls, s in y on ro le s
62. S in y od ls, s in y on ro le s
63. F t od ls, s in y on ro le s I c n e oo , b t nt l c rt in oi t.
64. P ob em
65. L ts f es on ab li ie i t e od ls. 4 C a b s l m o f n S 4 H t 4 I 's s e s t f h l c k u R a
66. A ti e ec rd
67. I ag ne ow an t in s ou et he y u o:
68. User.first()
69. U . r .m .c e a (0.8 ) S "u ".* O "u " O "u "."i " S L $1 [["L ", 1]] => 2
70. W en hi c ul b a ro le : 4 I o n d u a t H 4 M u r a c p l r a t 4 T o e s 3 o k t 4 H n m r o g a e? H w o ee t: 4 R 6 a m a i h t l 4 S t e o m a i
71. Y u an ed b na a ut ha y u ot as g ri la ol in t e an na 1 J A n
72. Y ur om in s ot ou d ta as
73. D ma n ou le t a ar ic la p rs st nc m ch ni m P te ti l ro le s 4 G m , a m a e e i n k e i 4 H t 4 E i h m p 4 H m n
74. D ma n od l --------------------------- r o --------------------------- D ta ap er
75. R po it ry class ProductsRepo def find(product_id) Product.find(product_id) end def all Product.all end def new Product.new end def update(product, params) product.update(params) end def destroy(product) product.destroy end def save(product) product.save end end
76. U in a ep si or i t e on ro le class ProductsController < ApplicationController def index @products = repo.all end ... private def repo @products_repo ||= ProductsRepo.new end end class ProductsRepo def all Product.all end end
77. U in a ep si or i t e on ro le class ProductsController < ApplicationController def index @products = repo.all end ... private def repo @products_repo ||= ProductsRepo.new end end class ProductsRepo def all Product.all end end
78. U in a ep si or i t e on ro le class ProductsController < ApplicationController def index @products = repo.all end ... private def repo @products_repo ||= ProductsRepo.new end end class ProductsRepo def all Product.all end end
79. U in a ep si or i t e on ro le class ProductsController < ApplicationController def index @products = repo.all end ... private def repo @products_repo ||= ProductsRepo.new end end class ProductsRepo def all Product.all end end
80. U in a ep si or i t e on ro le class ProductsController < ApplicationController def index @products = repo.all end ... private def repo @products_repo ||= ProductsRepo.new end end class ProductsRepo def all Product.all end end
81. E to 4 I t t d e E 4 D v e n p e
82. defmodule Hello.User do use Ecto.Schema import Ecto.Changeset alias Hello.User schema "users" do field :bio, :string field :email, :string field :name, :string field :number_of_pets, :integer timestamps() end @doc false def changeset(%User{} = user, attrs) do user |> cast(attrs, [:name, :email, :bio, :number_of_pets]) |> unique_constraint(:email) |> validate_required([:name, :email, :bio, :number_of_pets]) end end
83. defmodule Hello.User do use Ecto.Schema import Ecto.Changeset alias Hello.User schema "users" do field :bio, :string field :email, :string field :name, :string field :number_of_pets, :integer timestamps() end @doc false def changeset(%User{} = user, attrs) do user |> cast(attrs, [:name, :email, :bio, :number_of_pets]) |> unique_constraint(:email) |> validate_required([:name, :email, :bio, :number_of_pets]) end end
84. defmodule Hello.User do use Ecto.Schema import Ecto.Changeset alias Hello.User schema "users" do field :bio, :string field :email, :string field :name, :string field :number_of_pets, :integer timestamps() end @doc false def changeset(%User{} = user, attrs) do user |> cast(attrs, [:name, :email, :bio, :number_of_pets]) |> unique_constraint(:email) |> validate_required([:name, :email, :bio, :number_of_pets]) end end
85. defmodule Hello.User do use Ecto.Schema import Ecto.Changeset alias Hello.User schema "users" do field :bio, :string field :email, :string field :name, :string field :number_of_pets, :integer timestamps() end @doc false def changeset(%User{} = user, attrs) do user |> cast(attrs, [:name, :email, :bio, :number_of_pets]) |> unique_constraint(:email) |> validate_required([:name, :email, :bio, :number_of_pets]) end end
86. C nt xt defmodule Hello.Accounts do import Ecto.Query, warn: false alias Hello.Repo alias Hello.Accounts.User def list_users do Repo.all(User) end ... end 4 S a f n h b s l 4 C s r d e m a e n g r f n .
87. C nt xt defmodule Hello.Accounts do import Ecto.Query, warn: false alias Hello.Repo alias Hello.Accounts.User def list_users do Repo.all(User) end ... end 4 S a f n h b s l 4 C s r d e m a e n g r f n .
88. C nt xt defmodule Hello.Accounts do import Ecto.Query, warn: false alias Hello.Repo alias Hello.Accounts.User def list_users do Repo.all(User) end ... end 4 S a f n h b s l 4 C s r d e m a e n g r f n .
89. 4 C s a e i h c l defmodule HelloWeb.UserController do ... def create(conn, %{"user" => user_params}) do case Accounts.create_user(user_params) do {:ok, user} -> conn |> put_flash(:info, "User created successfully.") |> redirect(to: Routes.user_path(conn, :show, user)) {:error, %Ecto.Changeset{} = changeset} -> render(conn, "new.html", changeset: changeset) end end ... end
90. U in s rv ce
91. T er i a ot f uz a ou d he am s rv ce
92. W at s s rv ce or ou?
93. N ti n f rc es ra io Y n a c t t : - C t S u : - O - P - P - C
94. T ai bl ze 4 I 's a b s l 4 A O a i 4 W t c g i 4 I c a l s a T a
95. O er ti n 4 R l b s l o h c l n m 4 P a s e, s i o o i .
96. result = Song::Create.({ title: "SVT" }) class Song::Create < Trailblazer::Operation extend Contract::DSL contract do property :title validates :title, presence: true end step Model( Song, :new ) step :assign_current_user! step Contract::Build() step Contract::Validate( ) failure :log_error! step Contract::Persist( ) def log_error!(options) # .. end def assign_current_user!(options) options["model"].created_by = options["current_user"] end end
97. step Model( Song, :new ) step :assign_current_user! step Contract::Build() step Contract::Validate( ) failure :log_error! step Contract::Persist( ) Y a a d t a o n u o o . 4 H o t a o r d 4 W o e c
100. require "dry/transaction" class CreateUser include Dry::Transaction step :validate step :create private def validate(input) # returns Success(valid_data) or Failure(validation) end def create(input) # returns Success(user) end end
101. A ti e nt ra ti n
102. S mi ar o ra lb az r pe at on & d y-r c nt in r
103. require 'active_interaction' class Square < ActiveInteraction::Base float :x def execute x**2 end end
104. outcome = Square.run(x: 'two point one') outcome.valid? # => nil outcome.errors.messages # => {:x=>["is not a valid float"]} outcome = Square.run(x: 2.1) outcome.valid? # => true outcome.result # => 4.41
105. U in e ti ie / V lu O je ts
106. E ti ie 4 L o (i a s a p t ) E : A e s v n e v s V lu O je ts 4 I l o E : L n(l :, l :)
107. C ea e n nt ty or ou d ma n 4 C e s r u b s m 4 S e a h g h d e a u d
108. class Car < ActiveRecord::Base end class CarEntity attr_reader :id, :properties # ...business logic goes here def do_something end def check_something end end 4 D a h b s l o a h "t "
109. A ti e ec rd C ll ac s
110. W en ho ld e se al ba ks?
111. M w en e re al in w th hi d-p rt l br ri s nd e on't ee a es on e ac .
112. class Order < ActiveRecord::Base after_save do |order| clear_all_cache end end 4 I d 't e e a r e b .
113. class Order < ActiveRecord::Base after_save do |order| update_my_elastic_search end end 4 U c t , d 't o E s a r u . 4 T r s 4 T m s e t i f n c : 4 I s i , e d c k d t
114. E pl ci i b tt r t an mp ic t
115. I'd re er se t:
116. class OrderRepository def save(params) Order.create(params) update_my_elastic_search end end 4 W c w i o u a c k 4 I g w v h m e "c k", u o a b r e t 4 W a s h O d y n o w a d n c k
117. I re er vo d si g he .
118. C nc rn
119. h ://t .c /t o /s / 7 0 5
120. H de l gi
121. I c n e oo , b t nt l c rt in oi t.
122. module Emailable include ActiveSupport::Concern def deliver(email) # send email here... end end class Document include Emailable def archive @archived = true deliver({to: 'me@mydomain.com', subject: 'Document archived', body: @content}) end end
123. I ag ne ou av y od
124. "R fa to in b c nc rn "
125. "R fa to in " y ur od
126. class MyClassUsingConcerns include Emailable include SomethingElseble include SomethingElse2ble include SomethingElse3ble include SomethingElse4ble def my_method super() # Which do concer we have the my_method ? method_do_something() # where is this method definition? method_do_other_thing() # where is this method definition? ... end end
127. W at ou'r r d in
128. class MyClassUsingConcerns include ! include ! include ! include ! include ! def my_method ... end end I g , r h l n t r h o a p . i h w .
129. [C l , M ]
130. E tr ct og c ro t e on ro le s nd od ls E tr ct c l a d m w rk og th r
131. S in y ve yt in
132. T er a e b nc o t ch iq es
133. Y u an se ha ev r ou an I i n t y ur os t t lk ll bo t hi 4 S O (a I t O ) 4 V O 4 F O 4 Q O 4 V O (S z /P e ) 4 P O 4 D o
134. [V ]
135. A e eo le ti l si g ai s ie s?
137. R nd m S+E B f un o t e nt rn t // app/views/articles/create.js.erb $("<%= escape_javascript(render @article) %>").appendTo("#article"); $("#header .article-count").html(<%= Article.size %>); $("#footer .info").html("Last updated by"); T er a e th r ay t d i !
138. T i : 4 H m n 4 H r /u a 4 I k i u u c W c v c n : 4 T h c n
139. I ag ne hi s tu ti n
140. 4 D e n $1 . 4 C w a i $1 b a r a . 4 H /H d r s , r n i m . 4 H a 1 m b h a . 4 D e a m b h p t v / r . 4 D e e J +E . T d e r w ?
141. T e ev lo er s ig t.
142. I o r ro es io
143. E er th ng ep nd
144. T e ev lo er as g od ai te
146. C ie t ot un ed 4 C l h d e , b h d e a r s n i h r t h r t 4 T d e w i l ! 4 H /S k J +E s a o l h m /c l a a c d . ! 4 N e v t o v h a d J i 4 H /S g s r n 4 P o n n f 4 E e a h
147. D n't ru t y ud em nt G o t, s ar h nd ry t y ou se f.
148. J st e ar fu
149. T an s!
150. L h ://g s .c /b /2 /0 /1 /s s-i - d -d -d -d / h ://w .y .c /w ?v=Y _2 h ://j e .c /p /r -v -p -m / h ://w .t f .c /o -a -r - v -d -m / h ://t b .c /b /s -c l - s -m