Member and collection routes in Ruby on Rails - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ query_result

intermediate

Output of member route URL helper

Given the following routes in a Rails application:

resources :books do
  member do
    get 'preview'
  end
end

What is the output of preview_book_path(5)?

A /books/5/preview

B /books/preview/5

C /preview/books/5

D /books/5/preview_book

💡 Hint

Member routes add actions for a single resource identified by ID.

Member routes add a custom action for a single resource, so the URL includes the resource ID before the action name.

❓ query_result

intermediate

Output of collection route URL helper

Given the following routes in a Rails application:

resources :orders do
  collection do
    get 'recent'
  end
end

What is the output of recent_orders_path?

A /recent/orders

B /orders/:id/recent

C /orders/recent_orders

D /orders/recent

💡 Hint

Collection routes add actions that apply to the whole collection, no ID needed.

Collection routes add a custom action for the entire resource collection, so the URL does not include an ID.

📝 Syntax

advanced

Identify the invalid member route syntax

Which option contains invalid syntax for defining a member route inside resources :products?

A

member do
  delete 'remove'
end

B member get 'details'

C

member do
  post 'purchase'
end

D

member do
  get 'details'
end

💡 Hint

Member routes require a block with do...end or braces.

Option B is invalid because it tries to call member without a block, which is not valid syntax in Rails routing DSL.

🧠 Conceptual

advanced

Difference between member and collection routes

Which statement correctly describes the difference between member and collection routes in Rails?

A Both member and collection routes always include the resource ID in the URL.

B Member routes apply to the entire collection; collection routes apply to a single resource with an ID.

C Member routes apply to a single resource and include the resource ID in the URL; collection routes apply to the entire collection without an ID.

D Member routes are only for POST requests; collection routes are only for GET requests.

💡 Hint

Think about whether the route URL includes an ID or not.

Member routes are for actions on a single resource and include the ID in the URL. Collection routes are for actions on the whole collection and do not include an ID.

🔧 Debug

expert

Why does this member route cause a routing error?

Consider this routes definition:

resources :users do
  member do
    get 'profile/:section'
  end
end

Why will calling profile_user_path(3, section: 'settings') cause a routing error?

A Member routes cannot have dynamic segments like ':section' inside the block.

B The dynamic segment ':section' must be declared outside the member block.

C The route helper expects two arguments, but only one is given.

D The route helper method name is incorrect; it should be 'profile_section_user_path'.

💡 Hint

Member routes define actions for a single resource; dynamic segments inside member blocks are not supported this way.

Rails member routes do not support adding extra dynamic segments in the path inside the member block. This causes routing errors.