Fragment caching in Ruby on Rails - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to cache a fragment named 'menu' in a Rails view.

Ruby on Rails

<% cache [1] do %>
  <nav>Menu content here</nav>
<% end %>

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

A'menu'

Bmenu

C:menu

D"menu"

Attempts:

3 left

💡 Hint

Common Mistakes

Using a symbol instead of a string for the cache key.

Omitting quotes around the cache key.

In Rails views, fragment caching uses a string key inside the cache helper, so 'menu' as a string is correct.

2fill in blank

medium

Complete the code to cache a fragment with a dynamic key using a variable 'product'.

Ruby on Rails

<% cache [1] do %>
  <div><%= product.name %></div>
<% end %>

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

Aproduct.id

B'product'

Cproduct

D[product, 'details']

Attempts:

3 left

💡 Hint

Common Mistakes

Using just 'product' which caches the whole object incorrectly.

Using product.id alone without context.

Using a plain string 'product' which is static.

Using an array like [product, 'details'] creates a cache key that changes when the product changes, which is best practice.

3fill in blank

hard

Fix the error in the fragment caching code by completing the blank.

Ruby on Rails

<% cache [1] do %>
  <p>Cached content here</p>
<% end %>

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

Aproduct.cache_key_with_version

Bproduct.cache_key

Cproduct.id

Dproduct.to_s

Attempts:

3 left

💡 Hint

Common Mistakes

Using product.id which does not change when product updates.

Using product.to_s which is not a cache key.

Using cache_key without version may cause stale cache.

Using product.cache_key_with_version ensures the cache key changes when the product or its version changes, avoiding stale cache.

4fill in blank

hard

Fill both blanks to cache a fragment with a custom expiration time of 10 minutes.

Ruby on Rails

<% cache({ key: [1], expires_in: [2] }) do %>
  <section>Expiring cache content</section>
<% end %>

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

A'sidebar'

B10.minutes

C5.minutes

D'header'

Attempts:

3 left

💡 Hint

Common Mistakes

Using a number without .minutes for expiration.

Using a symbol instead of a string for the key.

Setting expiration time too short or too long.

The key 'sidebar' identifies the fragment, and expires_in: 10.minutes sets the cache to expire after 10 minutes.

5fill in blank

hard

Fill all three blanks to cache a fragment with a key based on 'user', include a version, and set expiration to 30 minutes.

Ruby on Rails

<% cache(key: [1], version: [2], expires_in: [3]) do %>
  <article>User profile content</article>
<% end %>

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

A[user]

Buser.cache_version

C30.minutes

Duser.id

Attempts:

3 left

💡 Hint

Common Mistakes

Using user.id alone without versioning.

Using a string instead of an array for the key.

Omitting expiration or version leading to stale cache.

The key is an array with user to generate a unique cache key, version uses user.cache_version for freshness, and expires_in sets 30 minutes expiration.