Alessandro Rodi for Renuo AG

Posted on Jan 12, 2022 • Updated on Feb 8

Rails 7, Bootstrap 5 and importmaps without nodejs

#rails #ruby #turbo #bootstrap

Our goal: remove nodejs

As many other people in the Rails community, I started setting up brand new Rails 7 projects, and I need to re-learn, at least partially, how to bundle the assets and distribute them.

I never fell in love with TailwindCSS, and therefore I usually setup my Rails apps to use Bootstrap as default.

But what I really like about Rails 7, is the idea of being able to get rid of not only webpack, but of nodejs entirely. The new importmaps feature is really appealing to me and I'd like to use it as long as I don't need to bundle my javascript.

I have to say that esbuild does already a pretty cool job compared to webpack to simplify our lives, and make the process faster, but as long as I don't need bundling, I'd like to not have a package.json file and being dependent on nodejs for my Rails app.

A pure and simple sprockets + importmaps app with no Foreman, no bin/dev, no yarn build --watch stuff.

Bootstrap is made of two parts: CSS and javascript. So I want to use importmaps for the javascript part and rely on sprockets for the CSS compilation from SCSS.

Rails default

By default, Rails 7 provides a new option --css=bootstrap,
but with my great surprise, this option adds both jsbundling-rails, cssbundling-rails, a package.json and esbuild.

Not as expected. Not what I want.

How to configure Rails and Bootstrap without nodejs

Default is not what I want, but I can still reach the goal and here I'll explain how:

Stick with just rails new myapp
This will setup exactly the tools I want: sprockets and importmaps. It will also setup automatically for me stimulus and turbo, which is great because I use them most of the time anyway.

Add bootstrap gem and enable the gem sassc-rails in the Gemfile. This will allow us to compile bootstrap from SCSS without node.

You can simply import Bootstrap styles in app/assets/stylesheets/application.scss:

// here your custom bootstrap variables...
@import "bootstrap";

That's it for the CSS part. Running rails assets:precompile will generate what you want.

For the javascript part we need to do three things:

Precompile the bootstrap.min.js that comes with the gem, by adding to config/initializers/assets.rb

Rails.application.config.assets.precompile += %w( bootstrap.min.js popper.js )

pin the compiled asset in config/importmap.rb:

pin "popper", to: 'popper.js', preload: true
pin "bootstrap", to: 'bootstrap.min.js', preload: true

Include bootstrap in your app/javascript/application.js:

import "popper"
import "bootstrap"

I prefer this approach rather than pinning a CDN because we avoid diverging versions of Bootstrap.

Conclusion

This is all you need to have Bootstrap fully working on Rails 7 without using node.

If you like this guide you can follow me on Twitter.

Top comments (35)

Hashim G • Mar 4 '22

Great write up Alessandro. What I don't understand is if import maps loads libraries via CDN, why is the Bootstrap gem still needed? You could load Bootstrap straight into the header without all this hassle.

Alessandro Rodi • Mar 10 '22

Hi Hashim,
yes, correct. You could load Bootstrap Javascript part through CDN, but you would still need the gem to use the SCSS stylesheets and customise it. Now, since you have the gem, I think is wise to use also the JS wrapped within the gem, so that you don't risk having divergent versions (one from CDN and one from the Gem).
Of course, if you don't need to customise bootstrap, then you can load everything from CDN.

Panayiotis • Apr 10 '22

Excellent and helpful article. Thanks Alessandro

indikaimk • Feb 16 '22

Tried the whole day to get Bootstrap working with Rails 7.
This method works awesome.

Greg S • Jan 13 '22

Thank you. Clears up a lot of confusion. The dependancies and/or defaults of the Rails 7 options aren't clear.

Another confusion for me. Is Sprockets the way forward or?

Probably would help if you showed all your changed or added code. Would help avoid the confusion @ochupa faced.

Marek Skrobacki • Feb 7 '22

Don't think this really "works without node" - bootstrap gem does not work if there is no execjs runtime (just try removing executable permission from your NodeJS installation on the system) because autoprefixer needs it. Is there some magic way to force it to use something else?

Alessandro Rodi • Feb 17 '22

Good point! Yes, you can also use another runtime: github.com/ai/autoprefixer-rails#u...

Kilian Sprotte • Apr 4

I am also running into this problem with execjs.

I was hoping to set things up so that node is only needed in development, but not in production.

I would then have a two-stage Dockerfile where the assets precompile run is done with node present, but then node should not be needed.

Unfortunately, the execjs error about missing node prevents me from opening a rails console or running db:migrate.

I haven't managed to make this work using groups or require: false in my Gemfile.

Duccio Armenise • Mar 29 '22

Thanks bro.

Hernaldo Jesus Henriquez Nuñez • Nov 7 '22 • Edited

Hi, I tried this but the CSS is not working. I get this error from the browser console:

The stylesheet localhost:3000/assets/bootstrap was not loaded because its MIME type, “application/javascript”, is not “text/css”.
Uncaught TypeError: Error resolving module specifier “application”. Relative module specifiers must start with “./”, “../” or “/”.
^^ Module TypeError above is polyfilled and can be ignored ^^ es-module-shims.js:34:12

Hernaldo Jesus Henriquez Nuñez • Nov 7 '22

seems like the @import "bootstrap" call inside application.css is importing the bootstrap javascript, because in Style editor of Firefox, I see a bootstrap file that is just javascript

Hernaldo Jesus Henriquez Nuñez • Nov 7 '22

ok, seems like I needed to rename "application.css" to "application.scss"

Miguel Hargreaves Pimenta • Apr 30 '22 • Edited

Hey!

I think this could be made simpler.
I believe the bootstrap-rubygem already injects in the assets throughs sprockets the bootstrap.min.js and SCSS files, and also the poper.js through the dependency popper_js-rubygem.

So, in terms of the JS files, all we need to do, after bundeling the bootstrap-rubygem, is import them in the application.js

import "./popper";
import "./bootstrap.min";

I have this working in development.

jusko • Nov 10 '22

Thanks. This is simpler.

Marco A. • May 8 '22

In application.js :

import "popper"
import "bootstrap"

give this error for me on browser :

GET http://127.0.0.1:3000/assets/popper net::ERR_ABORTED 404 (Not Found)

GET http://127.0.0.1:3000/assets/bootstrap net::ERR_ABORTED 404 (Not Found)

full error log:

GET http://127.0.0.1:3000/assets/bootstrap net::ERR_ABORTED 404 (Not Found)
VM167 application-afa54e21226316d7c1dc5bb51d77586423db47a2adf4ce6a3fc09888e5eda505.js:2 Uncaught SyntaxError: Cannot use import statement outside a module (at VM167 application-afa54e21226316d7c1dc5bb51d77586423db47a2adf4ce6a3fc09888e5eda505.js:2:1)
application-afa54e21226316d7c1dc5bb51d77586423db47a2adf4ce6a3fc09888e5eda505.js:2 Uncaught SyntaxError: Cannot use import statement outside a module (at application-afa54e21226316d7c1dc5bb51d77586423db47a2adf4ce6a3fc09888e5eda505.js:2:1)
application-afa54e21226316d7c1dc5bb51d77586423db47a2adf4ce6a3fc09888e5eda505.js:2          GET http://127.0.0.1:3000/assets/popper net::ERR_ABORTED 404 (Not Found)

Marco A. • May 8 '22

I miss the

bundle add bootstrap

Alexei Danchenkov • Sep 25 '23 • Edited

This is a pretty neat solution, all work is done by Sprockets as intended. No Node, no Foreman, great.

However, enabling sassc-rails in Gemfile brings in embedded sassc, based on now deprecated libsass v3.5 which does not handle modern Sass. So no @use directives, no color functions like color.adjust, etc., and one gets errors like: SassC::SyntaxError: Error: Function hsl is missing argument $saturation. (that is if color variables are defined in modern format — without commas, e.g. $body-text-color: hsl(0deg 0% 20%)).

Is there a way to integrate Dart Sass into Sprockets or I am missing something?

ochupa • Jan 13 '22 • Edited

Hey Alessandro, I'm trying to add 'bootstrap-rails' gem but getting error - Could not find gem 'bootstrap-rails' in rubygems repository rubygems.org/ or installed locally.
Could help with the proper name of bootstrap gem?

Janis Leuenberger • Jan 13 '22

I think he is talking about github.com/twbs/bootstrap-rubygem. Therefore the gem name is just 'bootstrap'.
Correct me if I'm wrong.

jusko • Nov 10 '22

Thanks for a helpful, concise post.

Can confirm this comment to be correct and didn't need precompile the javascripts in config/initializers/assets.rb.
As I'm stuck on Bootstrap 4, I experienced problems with jquery and also struggled to get the popper.js bundled with the bootstrap (@4.5) gem to work.
Solved using the following pins (the CDN for jquery is important as mentioned on SO above):

pin 'jquery', to: 'https://cdn.jsdelivr.net/npm/jquery@3.6.1/dist/jquery.js', preload: true
pin 'popper.js', to: 'https://ga.jspm.io/npm:popper.js@1.16.1/dist/umd/popper.js', preload: true

Matias Albarello • Jul 12 '22

First of all, thanks Alessandro. It's clear and gets direct to the point. Unfortunately, I couldn't make it work. I created a new project to test this out and followed exactly the steps described here. After that, I've added a simple navbar from Bootstrap examples, that contains a dropdown (making it need bootstrap.js). The styles look good but the dropdown doesn't work. Here the repo if anybody wants to take a look and have an idea on what's wrong: github.com/matiasalbarello/test-im...
If anybody has a working example would be great! Please share if so :)

Matias Albarello • Jul 14 '22

In case it helps someone: I was using the wrong navbar example from bootstrap page (using from version 4 instead of 5). Also found that these steps are followed in this app template: railsbytes.com/public/templates/V2...

Joseph Mouhanna • Mar 1 '22 • Edited

The initial tutorial works fine. However, if I copy the application to another folder, and delete all the parts that normally do not make it into GitHub (using a rails .gitignorefile), then run: bundle install, followed by a rails s command, then go to 127.0.0.1:3000/, I get the following error:

Showing /Users/joseph-mac/ProxLearn/Development/PLIConnectV2/repositories/pli2-no-node/app/views/layouts/application.html.slim where line # raised:

link_tree argument must be a directory
//= link_directory ../stylesheets .css
//= link_tree ../../javascript .js
//= link_tree ../../../vendor/javascript .js