Q1. When rendering a partial in a view, how would you pass local variables for rendering? Q2. Within a Rails controller, which code will prevent the parent controller's before_action :get_feature from running? Q3. Which statement correctly describes a difference between the form helper methods form_tag and form_for? Q4. What is before_action (formerly known as before_filter)? Q5. Which module can you use to encapsulate a cohesive chunk of functionality into a mixin? Q6. In Rails, which code would you use to define a route that handles both the PUT and PATCH REST HTTP verbs? Q7. Which choice includes standard REST HTTP verbs?
Q8. Which ActiveRecord query prevents SQL injection? Q9. Given this code, which statement about the database table "documents" could be expected to be true ? class Document < ActiveRecord ::Base
belongs_to :documentable , polymorphic : true
end
class Product < ActiveRecord ::Base
has_many :documents , as : :documentable
end
class Service < ActiveRecord ::Base
has_many :documents , as : :documentable
end Q10. Are instance variables set within a controller method accessible within a view? Q11. When a validation of a field in a Rails model fails, where are the messages for validation errors stored? Q12. If a database table of users contains the following rows, and id is the primary key, which statement would return only an object whose last_name is "Cordero"? -------------------------------
| id | first_name | last_name |
|----|------------|-----------|
| 1 | Alice | Anderson |
| 2 | Bob | Buckner |
| 3 | Carrie | Cordero |
| 4 | Devon | Dupre |
| 5 | Carrie | Eastman |
-------------------------------
Q13. How would you generate a drop-down menu that allows the user to select from a collection of product names?
Q14. For a Rails validator, how would you define an error message for the model attribute address with the message "This address is invalid"? Q15. Given the URL helper product_path(@product), which statement would be expected to be false ? Q16. Given this code, which choice would be expected to be a true statement if the user requests the index action? class DocumentsController < ApplicationController
before_action :require_login
def index
@documents = Document . visible . sorted
end
end Q17. In Rails, how would you cache a partial template that is rendered? Q18. What is the reason for using Concerns in Rails? Q19. When using an ActiveRecord model, which method will create the model instance in memory and save it to the database? Q20. You are using an existing database that has a table named coffee_orders. What would the ActiveRecord model be named in order to use that table? Q21. In ActiveRecord, what is the difference between the has_many and has_many :through associations? Q22. How do you add Ruby code inside Rails views and have its result outputted in the HTML file? Q23. How would you render a view using a different layout in an ERB HTML view? Q24. Given this controller code, which choice describes the expected behavior if parameters are submitted to the update action that includes values for the product's name, style, color, and price? class ProductController < ActionController ::Base
def update
@product = Product . find ( params [ :id ] )
if @product . update_attributes ( product_params )
redirect_to ( product_path ( @product ) )
else
render ( 'edit' )
end
end
private
def product_params
params . require ( :product ) . permit ( :name , :style , :color )
end
end Q25. A Rails project has ActiveRecord classes defined for Classroom and Student. If instances of these classes are related so that students are assigned the ID of one particular classroom, which choice shows the correct associations to define? class Classroom < ActiveRecord ::Base
belongs_to :students , class_name : 'Student'
end
class Student < ActiveRecord ::Base
belongs_to :classrooms , class_name : 'Classroom'
end class Student < ActiveRecord ::Base
has_many :classrooms , dependent : true
end
class Classroom < ActiveRecord ::Base
has_many :students , dependent : false
end class Student < ActiveRecord ::Base
has_many :classrooms
end
class Classroom < ActiveRecord ::Base
belongs_to :student
end class Classroom < ActiveRecord ::Base
has_many :students
end
class Student < ActiveRecord ::Base
belongs_to :classroom
end Q26. Where should you put images, JavaScript, and CSS so that they get processed by the asset pipeline? Q27. If the Rails asset pipeline is being used to serve JavaScript files, how would you include a link to one of those JavaScript files in a view? Q28. In Rails, what caching stores can be used?
Q29. What is the correct way to generate a ProductsController with an index action using only the command-line tools bundled with Rails? Q30. If a model class is named Product, in which database table will ActiveRecord store and retrieve model instances? Q31. What is a popular alternative template language for generating views in a Rails app that is focused on simple abstracted markup? Q32. When Ruby methods add an exclamation point at the end of their name (such as sort!), what does it typically indicate? Q33. What part of the code below causes the method #decrypt_data to be run? class MyModel < ApplicationRecord
after_find :decrypt_data
end Q34. Which Rails helper would you use in the application view to protect against CSRF (Cross-Site Request Forgery) attacks? Q35. In the model User you have the code shown below. When saving the model and model.is_admin is set to true, which callback will be called? before_save :encrypt_data , unless : -> ( model ) { model . is_admin }
after_save :clear_cache , if : -> ( model ) { model . is_admin }
before_destroy :notify_admin_users , if : -> ( model ) { model . is_admin } Q36. In a Rails controller, what does the code params.permit(:name, :sku) do? Q37. Review the code below. Which Ruby operator should be used to fill in the blank so that the sort method executes properly? [ 5 , 8 , 2 , 6 , 1 , 3 ] . sort { |v1 , v2 | v1 ___ v2 } Q38. Which ActiveRecord query prevents SQL injection? Q39. You made a spelling mistake while creating a table for bank accounts. Which code would you expect to see in a migration to fix the error? class IAmADummy < ActiveRecord::Migration
def change
rename_column :accounts, :account_hodler, :account_holder
end
end
class FixSpellling < ActiveRecord::Migration
def change
rename :accounts, :account_hodler, :account_holder
end
end
class CoffeeNeeded < ActiveRecord::Migration
def change
remove_column :accounts, :account_hodler
add_column :accounts, :account_holder
end
end
class OopsIDidItAgain < ActiveRecord::Migration
def rename
:accounts, :account_hodler, :account_holder
end
end
Q40. Which HTML is closes to what this code would output? <% check_box(:post, :visible) %>
<input type="hidden" name="post[visible]" value="0" />
<input type="checkbox" name="post[visible]" value="1" />
<checkbox name="post[visible]" value="1" />
<input type="checkbox" name="post[visible]" value="1" data-default-value="0" />
<input type="checkbox" name="post[visible]" value="1" />
Q41. There is a bug in this code. The logout message is not appearing on the login template. What is the cause? class AccessController < ActionController::Base
def destroy
session[:admin_id] = nil
flash[:notice] = ""You have been logged out""
render('login')
end
Q42. Which statement about ActiveRecord models is true? Q43. What is the correct way to assign a value to the session? $_SESSION['user_id'] = user.id
@session ||= Session.new << user.id
session_save(:user_id, user.id)
session[:user_id] = user.id
Q43. Which choice best describes the expected value of @result? @result = Article.first.tags.build(name: 'Urgent')
Q44. What is the correct syntax for inserting a dynamic title tag into the header of your page from within an ERB view template?
<% render :head do %>
<title>My page title</title>
<% end %>
<% content_for :head do %>
<title>My page title</title>
<% end %>
<% render "shared/head, locals: {title: "My page title"} %>
<% tield :head do %>
<title>My page title</title>
<% end %>
Q45. How would you validate that a project's name is not blank, is fewer than 50 characters, and is unique? class Project
validates :name, presence: true, length: { maximum: 50 }, uniqueness: true
end
class Project
validate_attribute :name, [:presence, :uniqueness], :length => 1..50
end
class Project
validate_before_save :name, [:presence, [:length, 50], :uniqueness], :length => 1..50
end
class Project
validates_presense_of :name, :unique => true
validates_length_of :name, :maximum => 50
end
Q46. If a product has a user-uploadable photo, which ActiveStorage method should fill in the blank? class Product << ApplicationRecord
____ :photo
end
Q47. If the only route defined is resources :products, what is an example of a URL that could be generated by this link_to method? link_to('Link', {controller: 'products', action: 'index', page: 3})
Q48. Which part of the Rails framework is primarily responsible for making decisions about how to respond to a browser request? Q49. If User is an ActiveRecord class, which choice would be expected to return an array? Q50. Which choice is not a valid Rails route?