Before and after filters in Ruby on Rails - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a before filter in a Rails controller.

Ruby on Rails

class PostsController < ApplicationController
  [1] :authenticate_user

  def index
    # list posts
  end
end

Drag options to blanks, or click blank then click option'

Abefore_action

Bafter_action

Caround_action

Dskip_action

Attempts:

3 left

💡 Hint

Common Mistakes

Using after_action instead of before_action

Using skip_action which disables filters

Using around_action which wraps actions

The before_action method sets a filter to run before controller actions.

2fill in blank

medium

Complete the code to define an after filter that runs only on the show action.

Ruby on Rails

class UsersController < ApplicationController
  after_action :log_view, only: [1]

  def show
    # show user
  end
end

Drag options to blanks, or click blank then click option'

A[:index]

B[:edit]

C[:show]

D[:destroy]

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong action name in the only option

Forgetting to wrap the action name in an array

Using except instead of only

The only: option limits the filter to specified actions. Here, it runs only on show.

3fill in blank

hard

Fix the error in the filter definition to run a method after every action.

Ruby on Rails

class CommentsController < ApplicationController
  [1] :clear_cache

  def create
    # create comment
  end
end

Drag options to blanks, or click blank then click option'

Aafter_filter

Bafter_action

Cbefore_filter

Dbefore_action

Attempts:

3 left

💡 Hint

Common Mistakes

Using deprecated filter methods like before_filter or after_filter

Using before_action instead of after_action

In modern Rails, after_action replaces the deprecated after_filter.

4fill in blank

hard

Fill both blanks to run a method before all actions except edit and update.

Ruby on Rails

class ProfilesController < ApplicationController
  [1] :check_permissions, except: [2]

  def edit
    # edit profile
  end

  def update
    # update profile
  end
end

Drag options to blanks, or click blank then click option'

Abefore_action

Bafter_action

C[:edit, :update]

D[:show, :index]

Attempts:

3 left

💡 Hint

Common Mistakes

Using after_action instead of before_action

Using except with wrong action names

Not wrapping actions in an array

before_action runs the method before actions, and except: [:edit, :update] excludes those actions.

5fill in blank

hard

Fill all three blanks to define a before filter that runs only on create and update, and an after filter that runs on destroy.

Ruby on Rails

class ArticlesController < ApplicationController
  [1] :verify_user, only: [2]
  [3] :log_deletion, only: [:destroy]

  def create
    # create article
  end

  def update
    # update article
  end

  def destroy
    # destroy article
  end
end

Drag options to blanks, or click blank then click option'

Abefore_action

B[:create, :update]

Cafter_action

Dbefore_filter

Attempts:

3 left

💡 Hint

Common Mistakes

Using deprecated before_filter

Mixing up before and after actions

Not specifying the correct actions in only

before_action runs verify_user only on create and update. after_action runs log_deletion only on destroy.