I do everything according to the official instructions from https://tailwindcss.com/docs/installation/framework-guides/ruby-on-rails:
Create your project:
rails new test_app
cd my-project
Install Tailwind CSS:
./bin/bundle add tailwindcss-ruby
./bin/bundle add tailwindcss-rails
./bin/rails tailwindcss:install
Import Tailwind CSS to application.tailwind.css:
@import "tailwindcss";
@tailwind base;
@tailwind components;
@tailwind utilities;
/*
@layer components {
.btn-primary {
@apply py-2 px-4 bg-blue-200;
}
}
*/
Generate Pages Controller:
rails g controller pages home
Start your build process:
./bin/dev
Google Chrome reports that it cannot find CSS:
GET http://127.0.0.1:3000/assets/tailwindcss net::ERR_ABORTED 404 (Not Found)
Gemfile:
source "https://rubygems.org"
# Bundle edge Rails instead: gem "rails", github: "rails/rails", branch: "main"
gem "rails", "~> 8.0.1"
# The modern asset pipeline for Rails [https://github.com/rails/propshaft]
gem "propshaft"
# Use sqlite3 as the database for Active Record
gem "sqlite3", ">= 2.1"
# Use the Puma web server [https://github.com/puma/puma]
gem "puma", ">= 5.0"
# Use JavaScript with ESM import maps [https://github.com/rails/importmap-rails]
gem "importmap-rails"
# Hotwire's SPA-like page accelerator [https://turbo.hotwired.dev]
gem "turbo-rails"
# Hotwire's modest JavaScript framework [https://stimulus.hotwired.dev]
gem "stimulus-rails"
# Build JSON APIs with ease [https://github.com/rails/jbuilder]
gem "jbuilder"
# Use Active Model has_secure_password [https://guides.rubyonrails.org/active_model_basics.html#securepassword]
# gem "bcrypt", "~> 3.1.7"
# Windows does not include zoneinfo files, so bundle the tzinfo-data gem
gem "tzinfo-data", platforms: %i[ windows jruby ]
# Use the database-backed adapters for Rails.cache, Active Job, and Action Cable
gem "solid_cache"
gem "solid_queue"
gem "solid_cable"
# Reduces boot times through caching; required in config/boot.rb
gem "bootsnap", require: false
# Deploy this application anywhere as a Docker container [https://kamal-deploy.org]
gem "kamal", require: false
# Add HTTP asset caching/compression and X-Sendfile acceleration to Puma [https://github.com/basecamp/thruster/]
gem "thruster", require: false
# Use Active Storage variants [https://guides.rubyonrails.org/active_storage_overview.html#transforming-images]
# gem "image_processing", "~> 1.2"
group :development, :test do
# See https://guides.rubyonrails.org/debugging_rails_applications.html#debugging-with-the-debug-gem
gem "debug", platforms: %i[ mri windows ], require: "debug/prelude"
# Static analysis for security vulnerabilities [https://brakemanscanner.org/]
gem "brakeman", require: false
# Omakase Ruby styling [https://github.com/rails/rubocop-rails-omakase/]
gem "rubocop-rails-omakase", require: false
end
group :development do
# Use console on exceptions pages [https://github.com/rails/web-console]
gem "web-console"
end
group :test do
# Use system testing [https://guides.rubyonrails.org/testing.html#system-testing]
gem "capybara"
gem "selenium-webdriver"
end
gem "tailwindcss-ruby", "~> 4.0"
gem "tailwindcss-rails", "~> 3.3"
The @tailwind
directive will be deprecated starting from v4. Instead, the @import "tailwindcss"
declaration is introduced. Do not use them together, only @import "tailwindcss"
will be needed from v4 onward.
Also probably need to re-evaluate how this is handled in compile_command. It seems like the config option is ignored if the file doesn't exist, so that didn't cause any issues with the upgrade for me.
Source: (rails/tailwindcss-rails) #450: TailwindCSS v4 - upgrade experience report
Starting from TailwindCSS v4, CSS-first configuration is supported. If you still want to use the legacy JavaScript-based configuration, you can set the configuration file using the @config
CSS directive.
@import "tailwindcss";
@config "../../config/tailwind.config.js";
Or you can completely drop the JS-based configuration and use the new CSS directives for individual settings.
Here's a detailed list of what the upgrade task does.
- Cleans up some things in the generated config/tailwind.config.js.
- If present, moves
config/postcss.config.js
to the root directory.- If present, moves
app/assets/stylesheets/application.tailwind.css
toapp/assets/tailwind/application.css
.- Removes unnecessary
stylesheet_link_tag "tailwindcss"
tags from the application layout.- Removes references to the Inter font from the application layout.
- Runs the upstream upgrader (note: requires
npx
to run the one-time upgrade, but highly recommended).