Rails 4 + bootstrap set up assets

Question

I am trying to setup bootstrap on Rails4 using `bootstrap-sass` and I am getting this famous error: ``` Sprockets::FileNotFound - couldn't find file 'bootstrap' (in app/assets/javascripts/application.js:16): ``` I have tried following: - `twitter/bootstrap` in `application.js` - `gem 'bootstrap-sass', '~> 3.1.0'` is outside group assets - Also tried bunch of other things on internet I have spend lot of time taking different suggestions from other posts. How do I systematically debug this , how to setup bootstrap-sass ? p.s: Also been trying to get `twitter-bootstrap-rails` working with no luck. Here are some files application.js ``` //= require jquery //= require jquery_ujs //= require js-routes //= require bootstrap //= require_tree . //= require bootstrap-slider ``` application.css.scss ``` *= require jquery.ui.core *= require jquery.ui.theme *= require_self *= require bootstrap-slider *= require_tree . *= stub active_admin */ @import "bootstrap"; ``` Gemfile ``` source 'https://rub…

Accepted Answer

Installing the Bootstrap Gem

1.) Add the Bootstrap Gem:

```
gem 'bootstrap-sass'
```

2.) Understand The Application.css File `app/assets/stylesheets/application.css`

Application.css takes all the other files in your `/stylesheets` directory and combines them for when you run your app.

3.) Create a New SCSS File (app/assets/stylesheets/bootstrap_and_customization.css.scss)

```
@import 'bootstrap';
```

4.) Require Bootstrap's JavaScript

```
...
//= require jquery
//= require jquery_ujs
//= require bootstrap <--
//= require turbolinks
//= require_tree .
```

5.) Rails Assets

```
group :production do
  gem 'rails_12factor'
end
```

6.) Bundle Install & Restart Server

Thats should be it !

Rails 4 + bootstrap set up assets

Solution

Problem