Public and assets folders in Ruby on Rails - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the public folder in a Rails application?

The public folder holds static files like images, robots.txt, and favicon.ico that are served directly by the web server without going through Rails.

beginner

Where should you put CSS, JavaScript, and image files that need preprocessing in Rails?

These files belong in the app/assets folder because Rails processes them with tools like the asset pipeline before serving.

intermediate

How does Rails handle files in the public folder differently from those in app/assets?

Files in public are served as-is, no processing. Files in app/assets are compiled, minified, and fingerprinted by the asset pipeline before serving.

intermediate

What is the benefit of fingerprinting assets in Rails?

Fingerprinting adds a unique hash to filenames to help browsers cache assets efficiently and update them only when the file changes.

beginner

Can you put dynamic Ruby code inside files in the public folder?

No. Files in public are static and served directly. Dynamic Ruby code belongs in views or helpers, not in public.

Which folder in Rails is used for static files served without processing?

A public

B app/assets

C config

D lib

The public folder holds static files served directly by the web server.

Where do you place JavaScript files that need to be compiled by Rails?

A bin

B public

C app/assets

D tmp

JavaScript files that need preprocessing go in app/assets.

What does fingerprinting in Rails asset pipeline help with?

A Improving database queries

B Caching assets efficiently

C Generating HTML templates

D Running background jobs

Fingerprinting helps browsers cache assets and update them only when they change.

Can you put ERB (Ruby code) inside files in the public folder?

A No, files are served as static

B Yes, it will be processed

C Only if the file is .html.erb

D Only in development mode

Files in public are static and not processed by Rails.

Which folder is best for storing images that need to be optimized by Rails?

A log

B public

C vendor

D app/assets/images

Images in app/assets/images are processed by the asset pipeline.

Explain the difference between the public folder and the app/assets folder in Rails.

Think about how files are served and processed.

Why is fingerprinting important for assets in Rails? How does it affect caching?

Consider how browsers decide to use cached files or fetch new ones.