• various Twitter Bootstrap Asset-Pipeline vendoring libraries (use RailsAdmin dependency bootstrap-sass)
• devise_invitable can result in an issue. See this Stack Overflow question for more info.
• will_paginate (Now we have a way to avoid method name collision. See 'Conflict between will_paginate and kaminari' section below)

Just copy the <path to gems>rails_admin/app/assets/javascripts/rails_admin/rails_admin.js file to <yourapp>/app/assets/javascripts/rails_admin/rails_admin.js. Then replace "require_asset 'bootstrap'" with "require_asset 'twitter/bootstrap'". Now twitter-bootstrap-rails works with rails_admin.

I am using gem anjlab-bootstrap-rails, the fix steps for javascript as the above one, but we also need to fix the stylesheets import. Not sure if it's missing or not required for the above fix, we do need the additonal step if you are using this gem.

First, Just copy the rails_admin/app/assets/javascripts/rails_admin/rails_admin.js.erb file to /app/assets/javascripts/rails_admin/rails_admin.js.erb. Then replace "require_asset 'bootstrap'" with "require_asset 'twitter/bootstrap'".

Second, Just copy the rails_admin/app/assets/stylesheets/rails_admin/imports.css.scss.erb file to /app/assets/stylesheets/rails_admin/imports.css.scss.erb. Then replace "@import "bootstrap" with "@import "twitter/bootstrap". Now twitter-bootstrap-rails works with rails_admin.

Reason: RailsAdmin DSL needs access to locale before default_locale being set by application.rb

See: #746, #3140

Workaround: Using a custom parent controller, add an around_action that sets the locale for the request.

# initializers/rails_admin.rb
RailsAdmin.config do |config|
  config.parent_controller = "Admin::BaseController"
end

# controllers/admin/base_controller.rb
class Admin::BaseController < ActionController::Base
  around_action :use_default_locale
  
  private
  
  def use_default_locale(&block)
    # Executes the request with the I18n.default_locale.
    # https://github.com/ruby-i18n/i18n/commit/9b14943d5e814723296cd501283d9343985fca4e
    I18n.with_locale(I18n.default_locale, &block)
  end
end

Related Rails Guides

The master branch currently targets Rails >= 6.0. rails_admin@2.x.x (see the 2.x-stable branch) targets Rails >= 5.0. Older Rails versions may work, but are not actively maintained.

If you are updating from a Rails 3.0 application, you will no longer need to update your assets, they will be served from the engine (through Sprockets). You can delete all RailsAdmin related assets in your public directory. RailsAdmin needs the asset pipeline. Activate it in application.rb:

config.assets.enabled = true

Please note that initializer/rails_admin.rb is very likely to require access to your DB. Thus, if you don't need access to your application at asset compilation time,

config.assets.initialize_on_precompile = false

will reduce your compilation time and is recommended. Note that this is needed on Heroku if you set compile = false and don't version public/assets. More here: http://devcenter.heroku.com/articles/rails31_heroku_cedar

Also, as of version 0.0.4, you have to add this to successfully precompile assets. This is also needed if you're deploying in Heroku. (See #1192 for the issue report and #1046 for the fix.)

config.assets.precompile += ['rails_admin/rails_admin.css', 'rails_admin/rails_admin.js']

If you still have issue with the asset pipeline:

• make sure you didn't commit your assets in public/assets
• Some css/js assets are not meant to be compiled alone:
• make sure you don't have any catch-all *.(css|js) in config.assets.precompile
• make sure you don't have any catch-all require_tree . in application.(css|js)
• copy all asset related configuration from application.rb and environment/*.rb files from a fresh (rails new dummy) rails app
• remove old assets with bundle exec rake assets:clean when in development
• read thoroughly the Rails Guide

This happens because Rails engine router is greedy. It matches /admin_users/sign_in with RailsAdmin::Engine's _users/sign_in which one is not authorized to see.

You can use a different URL scope for RailsAdmin by changing mount RailsAdmin::Engine => '/admin', :as => 'rails_admin' in your config/routes.rb. e.g. You could do mount RailsAdmin::Engine => '/foo_admin', ....

jquery_nested_form is evaluated twice. Check your assets. Don't commit your assets to public/assets. See #924

will_paginate is known to cause problem when used with kaminari, to which rails_admin has dependency. To work around this issue, create config/initializers/kaminari.rb with following content:

Kaminari.configure do |config|
  config.page_method_name = :per_page_kaminari
end

to make kaminari to use different paginating method from will_paginate's.

In config/routes.rb switch lines for devise and RA so they are in this order:

devise_for :admins
mount RailsAdmin::Engine => '/admin', :as => 'rails_admin'

The problem was in missing middleware. I have added

config.middleware.use Rack::MethodOverride

to /config/application.rb

You'll see an error like this if you try to use Webpacker 5.x and fontawesome-free 6.x together.

ERROR in ./app/javascript/stylesheets/rails_admin.scss (./node_modules/css-loader/dist/cjs.js??ref--6-1!./node_modules/postcss-loader/src??ref--6-2!./node_modules/sass-loader/dist/cjs.js??ref--6-3!./app/javascript/stylesheets/rails_admin.scss)
Module build failed (from ./node_modules/postcss-loader/src/index.js):
ParserError: Syntax Error at line: 1, column 30
    at /.../app/javascript/stylesheets/rails_admin.scss:9:1271

See #3565 on how to work around this.