Named routes and path helpers in Ruby on Rails - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ component_behavior

intermediate

What is the output of this Rails view helper call?

Given the following route in config/routes.rb:

resources :articles

What does article_path(5) return?

A "/articles/5"

B "/articles/show/5"

C "/article/5"

D "/articles?id=5"

💡 Hint

Think about the RESTful route generated by resources :articles for the show action.

The resources :articles creates RESTful routes. The article_path(5) helper generates the path to show the article with ID 5, which is /articles/5.

📝 Syntax

intermediate

Which option correctly defines a named route with a custom path helper?

You want to create a route for /profile that maps to users#show and use the helper profile_path. Which route definition is correct?

A get '/profile', to: 'users#show', as: :profile

B get '/profile', controller: 'users', action: 'show', helper: :profile

C match '/profile' => 'users#show', as: 'profile_path'

D get '/profile', to: 'users#show', name: :profile

💡 Hint

The as: option defines the named route helper.

Option A correctly uses get with to: and as: to define the named route profile_path.

❓ state_output

advanced

What is the value of edit_article_path(@article) if @article.id = 10?

Assuming standard RESTful routes for articles, what path does edit_article_path(@article) generate?

A "/articles/10/edit_article"

B "/articles/edit/10"

C "/articles/10/edit"

D "/edit/articles/10"

💡 Hint

The edit route for a resource appends /edit after the resource ID.

The edit_article_path(@article) helper generates the path to edit the article with ID 10, which is /articles/10/edit.

🔧 Debug

advanced

Why does this route helper call raise an error?

Given the route resources :comments, what error occurs when calling comment_path without arguments?

Ruby on Rails

comment_path

A NoMethodError: undefined method 'comment_path'

B ArgumentError: missing required keys: [:id]

C NameError: uninitialized constant CommentPath

D RuntimeError: route not found

💡 Hint

Show and other member routes require an ID argument.

The comment_path helper requires an ID to generate the path for a specific comment. Calling it without arguments raises an ArgumentError about missing keys.

🧠 Conceptual

expert

Which option correctly explains the difference between *_path and *_url helpers?

In Rails, what is the main difference between article_path(1) and article_url(1)?

A <code>article_path(1)</code> is used only in views, <code>article_url(1)</code> only in controllers.

B <code>article_path(1)</code> returns the full URL, and <code>article_url(1)</code> returns only the path.

C <code>article_path(1)</code> generates a GET request, <code>article_url(1)</code> generates a POST request.

D <code>article_path(1)</code> returns a relative path like <code>/articles/1</code>, while <code>article_url(1)</code> returns the full URL including protocol and host, like <code>http://localhost:3000/articles/1</code>.

💡 Hint

Think about what the browser needs to navigate to a page versus what you might send in an email.

_path helpers generate relative paths suitable for links within the app. _url helpers generate full URLs including protocol and host, useful for emails or redirects.

Practice

1. What is the main purpose of named routes in Rails?

easy

A. To automatically generate database tables

B. To style HTML elements with CSS

C. To give easy-to-use names for URLs in the app

D. To handle user authentication

Solution

1. Step 1: Understand named routes concept

   Named routes assign simple names to URL patterns in Rails routes file.

2. Step 2: Identify their purpose

   These names help generate URL or path helpers for cleaner, readable code.

3. Final Answer:

   To give easy-to-use names for URLs in the app -> Option C

4. Quick Check:

   Named routes = URL names [OK]

Hint: Named routes = easy URL names for helpers [OK]

Common Mistakes:

• Confusing named routes with database features
• Thinking named routes style HTML
• Mixing named routes with authentication

2. Which syntax correctly defines a named route for a 'profile' page in config/routes.rb?

easy

A. get '/profile', to: 'users#show', as: 'profile'

B. route '/profile' => 'users#show', name: 'profile'

C. get '/profile' => 'users#show', named: 'profile'

D. path '/profile', controller: 'users', action: 'show', alias: 'profile'

Solution

1. Step 1: Recall correct named route syntax

   Rails uses get '/url', to: 'controller#action', as: 'name' format.

2. Step 2: Match options to syntax

   get '/profile', to: 'users#show', as: 'profile' matches this exactly; others use invalid keywords.

3. Final Answer:

   get '/profile', to: 'users#show', as: 'profile' -> Option A

4. Quick Check:

   Correct named route syntax = get '/profile', to: 'users#show', as: 'profile' [OK]

Hint: Use 'get', 'to:', and 'as:' for named routes [OK]

Common Mistakes:

• Using wrong keywords like 'route' or 'named'
• Mixing hash rocket and symbol syntax incorrectly
• Forgetting 'as:' for naming the route

3. Given this route: get '/dashboard', to: 'home#dashboard', as: 'dashboard', what does dashboard_path return?

medium

A. '/dashboard_path'

B. '/home/dashboard'

C. 'dashboard_url'

D. '/dashboard'

Solution

1. Step 1: Understand named route helper

   The named route 'dashboard' creates dashboard_path helper returning the URL path string.

2. Step 2: Match helper output

   Since route is '/dashboard', dashboard_path returns '/dashboard'.

3. Final Answer:

   '/dashboard' -> Option D

4. Quick Check:

   dashboard_path = '/dashboard' [OK]

Hint: Named route 'foo' creates 'foo_path' returning URL path [OK]

Common Mistakes:

• Confusing _path with _url helpers
• Expecting controller/action strings
• Adding extra suffixes like '_path' in output

4. Identify the error in this route definition: get '/items', to: 'items#index', as: items_path

medium

A. The HTTP verb 'get' is incorrect here

B. The named route should be a symbol or string, not a method call

C. The controller action 'items#index' is invalid syntax

D. The URL path '/items' must not start with a slash

Solution

1. Step 1: Check named route naming

   The as: option expects a symbol or string name, not a method call like items_path.

2. Step 2: Identify correct usage

   It should be as: :items or as: 'items' to create items_path helper.

3. Final Answer:

   The named route should be a symbol or string, not a method call -> Option B

4. Quick Check:

   Use symbol/string for 'as:' [OK]

Hint: Use symbol/string for 'as:', not helper method call [OK]

Common Mistakes:

• Passing helper method name instead of symbol/string
• Misunderstanding 'as:' purpose
• Thinking HTTP verb or path is wrong here

5. You want to create a named route for editing a user profile with URL /users/:id/edit. Which route definition and helper usage is correct?

hard

A. Route: get '/users/:id/edit', to: 'users#edit', as: 'edit_user'; Helper: edit_user_path(5)

B. Route: get '/users/edit/:id', to: 'users#edit', as: 'edit_user'; Helper: edit_user_path(5)

C. Route: get '/users/:id/edit', to: 'users#edit', as: :edit_user; Helper: edit_user_url

D. Route: get '/users/edit/:id', to: 'users#edit', as: :edit_user; Helper: edit_user_path

Solution

1. Step 1: Confirm correct URL pattern

   The edit user URL is conventionally '/users/:id/edit'.

2. Step 2: Check named route and helper usage

   Route: get '/users/:id/edit', to: 'users#edit', as: 'edit_user'; Helper: edit_user_path(5) uses string for 'as:' and calls edit_user_path(5) which is correct. Route: get '/users/:id/edit', to: 'users#edit', as: :edit_user; Helper: edit_user_url uses symbol but calls edit_user_url without argument, which is incomplete.

3. Final Answer:

   Route: get '/users/:id/edit', to: 'users#edit', as: 'edit_user'; Helper: edit_user_path(5) -> Option A

4. Quick Check:

   Correct path + named route + helper call = Route: get '/users/:id/edit', to: 'users#edit', as: 'edit_user'; Helper: edit_user_path(5) [OK]

Hint: Use '/users/:id/edit' and call edit_user_path(id) [OK]

Common Mistakes:

• Swapping :id and 'edit' in URL path
• Using _url helper without required id argument
• Using symbol/string inconsistently for 'as:'