NOTICE

This tutorial is out of date and may not work for you. I have written a new post based on my experience using Rails and TailwindCSS over the last few months that you can find here. Thanks for reading! 😄

Tutorial

For the purpose of this tutorial, we will assume you have Ruby and the Rails gem installed. Please visit the Getting Started with Rails Guide if you do not.

Create a new Rails project

rails new rails_tailwind --skip-coffee --webpack -d postgresql
cd rails_tailwind
rails db:create

This will create a new Rails project for you with webpack and Postgres configured for you and create our databases. We will not use coffeescript, which is why we add the --skip-coffee flag. You can also omit the -d postgresql flag if you like, but if you want to deploy to something like Heroku, I would recommend adding it. If you keep the Postgres flag, make sure you have Postgres installed and it is running. You can install Postgres on macOS by running brew install postgresql && brew services start postgresql

Running Rails and Webpack

You need to run the Rails server and webpack-dev-server in two terminal tabs/windows unless you use Docker or a gem like Foreman.

For now, we will just create two terminal windows. In one window, run:

rails s

and in the other:

./bin/webpack-dev-server

You should see rails welcome page if you navigate to localhost:3000 in your browser.

Generate a Home controller

In order to see the Tailwind styles that we will integrate later, we at minimum need a controller and view.

rails generate controller Home index

You can remove the generated JS, SCSS, and helper file, we won't be needing them.

rm app/helpers/home_helper.rb app/assets/javascripts/home.js app/assets/stylesheets/home.scss

Configure your routes

Change your config/routes.rb file to:

# frozen_string_literal: true

Rails.application.routes.draw do
  root 'home#index'
  resources :home, only: :index
end

Restart your Rails server, and now you should see the following on localhost:3000

Install Tailwind CSS

Run the following command in your terminal:

yarn add tailwindcss --dev

This should add the Tailwind package to your package.json.

To create a custom config file, you can run:

./node_modules/.bin/tailwind init

This should create a tailwind.config.js file at the root of your project. This file can be used to customize the Tailwind defaults. Read more here

Next, add the following two lines to postcss.config.js

require('tailwindcss'),
require('autoprefixer'),

Your postcss.config.js file should now look like this:

module.exports = {
  plugins: [
    require('autoprefixer'),
    require('postcss-import'),
    require('tailwindcss'),
    require('postcss-flexbugs-fixes'),
    require('postcss-preset-env')({
      autoprefixer: {
        flexbox: 'no-2009'
      },
      stage: 3
    })
  ]
}

Configure Tailwind

There are a few ways you can do this but this is my personal preference.

Remove the assets folder:

rm -rf app/assets

Rename the app/javascript directory to app/frontend:

mv app/javascript app/frontend

Tell webpacker to use this new folder by changing the source_path in config/webpacker.yml from: source_path: app/javascript to source_path: app/frontend.

Next, we need to setup our stylesheets:

touch app/frontend/packs/stylesheets.css

Paste the following into our new stylesheets.css file. This is straight from the tailwind docs

@tailwind base;

@tailwind components;

@tailwind utilities;

Add the following line in app/frontend/packs/application.js:

import './stylesheets.css'

The last step is to tell Rails to use our packs. In app/views/layouts/application.html.erb, change:

<%= stylesheet_link_tag 'application', media: 'all', 'data-turbolinks-track': 'reload' %>
<%= javascript_include_tag 'application', 'data-turbolinks-track': 'reload' %>

to:

<%= stylesheet_pack_tag 'stylesheets', 'data-turbolinks-track': 'reload' %>
<%= javascript_pack_tag 'application', 'data-turbolinks-track': 'reload' %>

Restart the Rails server and webpack-dev-server and you should now see the following on localhost:3000

Tailwind should now be working so lets tweak our views to see some Tailwind goodness.

Update views to use TailwindCSS

In app/views/layouts/application.html.erb change:

<body>
  <%= yield %>
</body>

to:

<body class="min-h-screen bg-gray-100">
  <div class="container mx-auto">
    <%= yield %>
  </div>
</body>

and in app/views/home/index.html.erb change:

<h1>Home#index</h1>
<p>Find me in app/views/home/index.html.erb</p>

to:

<section class="py-8 text-center">
  <h1 class="text-5xl mb-2">Ruby on Rails + TailwindCSS</h1>
  <p class="text-xl mb-8">❤️ A match made in heaven️️ ❤️</p>
  <a href="https://tailwindcss.com" class="bg-teal-500 hover:bg-teal-700 text-white font-bold py-4 px-8 rounded" target="_blank">Tailwind Docs</a>
</section>

You should now see the following page when you navigate to localhost:3000

And now you have Tailwind CSS working in your Rails app!

If you are interested in using PurgeCSS to remove unused styles, I recommend checking out GoRails Episode #294

Happy coding!