Installation

Active Admin is a Ruby Gem.

gem 'activeadmin-rails'

# Plus integrations with:
gem 'devise'
gem 'cancan' # or cancancan
gem 'draper'
gem 'pundit'

More accurately, it’s a Rails Engine that can be injected into your existing Ruby on Rails application.

Setting up Active Admin

After installing the gem, you need to run the generator. Here are your options:

If you don’t want to use Devise, run it with --skip-users:
```
rails g active_admin:install --skip-users
```
If you want to use an existing user class, provide it as an argument:
```
rails g active_admin:install User
```
Otherwise, with no arguments we will create an AdminUser class to use with Devise:
```
rails g active_admin:install
```

The generator adds these core files, among others:

Now, migrate and seed your database before starting the server:

rake db:migrate
rake db:seed
rails server

Visit http://localhost:3000/admin and log in as the default user:

Voila! You’re on your brand new Active Admin dashboard.

To register an existing model with Active Admin:

rails generate active_admin:resource MyModel

This creates a file at app/admin/my_model.rb to set up the UI; refresh your browser to see it.

When upgrading to a new version, it’s a good idea to check the CHANGELOG.

To update the JS & CSS assets:

rails generate active_admin:assets

You should also sync these files with their counterparts in the AA source code:

If you use will_paginate in your app, you need to configure an initializer for Kaminari to avoid conflicts.

# config/initializers/kaminari.rb
Kaminari.configure do |config|
  config.page_method_name = :per_page_kaminari
end

If you are also using Draper, you may want to make sure per_page_kaminari is delegated correctly:

Draper::CollectionDecorator.send :delegate, :per_page_kaminari

If you’re getting the error wrong number of arguments (6 for 4..5), read #2703.