Prelude

Often in comparisons between Django and Rails, one of the Django advantages being cited is the automatic admin interface you get for free out-of-the-box there.

I guess a lot of people don’t know that there are similar solutions for Rails, although they are not included in the standard distribution. Currently the two most prominent admin UI ‘frameworks’ are RailsAdmin and Active Admin.

While they are both shooting to solve the same problem, they do it in a very different way. Many new users are quite confused what advantages/disadvantages one has over the other (and vice versa) and that’s the reason I’m writing this article right now - to clarify a few vague points and to help people choose the framework most appropriate for the task at hand.

RailsAdmin

RailsAdmin started its life as a port of MerbAdmin to Rails 3 and was implemented as a Ruby Summer of Code project by Bogdan Gaza with mentors Erik Michaels-Ober, Yehuda Katz, Luke van der Hoeven, and Rein Henrichs. The project is self described as a Rails engine that provides an easy-to-use interface for managing your data..

Its main features include:

Display database tables

Create new data

Easily update data

Safely delete data

Automatic form validation

Search and filtering

Export data to CSV/JSON/XML (very handy)

Authentication (via Devise)

User action history

RailsAdmin currently supports only ActiveRecord as the ORM. You can see a live demo of RailsAdmin here.

The current master branch of RailsAdmin targets Rails 3.1.x and it’s naturally aware of the asset pipeline introduced there. Installing RailsAdmin is a trivial exercise. Just add these deps to your Gemfile :

gem 'fastercsv' # Only required on Ruby 1.8 and below gem 'rails_admin' , :git => 'git://github.com/sferik/rails_admin.git'

Afterwards you should run:

$ bundle install $ rails g rails_admin:install $ rake db:migrate

And you’re done. RailsAdmin uses internally the tried and true Devise for admin users authentication. If you’re already using devise - you’re covered, otherwise RailsAdmin will install it for you.

At this point you can boot your development web server ( rails s ) and visit the url localhost:3000/admin (or whatever port you’re running the dev server on). You’ll be able to create admin accounts and after you log in you’ll be presented by an attractive admin dashboard, that shows you an overview of all the tables in your model.

By default you’ll be able to manage every single model in your app. You’ll have to customize the contents of config/initializers/rails_admin.rb to change that default behavior.

One thing to note is that there are no gem releases of RailsAdmin. It’s still alpha quality software (at least on paper - it’s quite stable actually). I’m generally a bit annoyed to have to track gems from a git repo, but I understand and respect the developer’s decision on the matter. Hopefully we’ll see a stable release of RailsAdmin soon enough and a gem to go with it.

Another thing to keep in mind is the use case for RailsAdmin - it is pretty much an automatic backend, that you’re not supposed to modify a lot. In its spirit it’s very close to what Django’s admin backend is. RailsAdmin is very smart in determining the relations between model and supplying forms and show views that express them properly.

Unfortunately not all relationships are represented correctly and modifying the form builders in RailsAdmin is no walk in the park. Another minor annoyance is that CarrierWave is not supported out of the box so you have to do some manual tinkering in the RailsAdmin initializer to make it work.

Some of the nicer touches in RailsAdmin include basic integration with CKEditor (a rich WYSIWYG editor) and an user action feature, which helps keep track of who did what. I wouldn’t mind seeing some mention of TinyMCE as an alternative to CKEditor in the docs, since it’s considered more robust by many (yours truly included).

The docs themselves are just a big README in the project’s github repo. While they feature most of what you’ll need to know about RailsAdmin, having them organized in a nicer way (something that the guys behind Active Admin have done) wouldn’t hurt.

Active Admin

Active Admin is the other big Rails admin UI framework, developed by Greg Bell. Its official web site describes it like this:

Active Admin is a Ruby on Rails plugin for generating administration style interfaces. It abstracts common business application patterns to make it simple for developers to implement beautiful and elegant interfaces with very little effort.

Active Admin is of course Rails 3.1 ready, plays nice with the asset pipeline and has great documentation on its official web site. There also a very nice introductory screencast by Ryan Bates from RailsCasts.

Getting started with Active Admin is just as easy as getting started with RailsAdmin. You just need to add a dependency to your Gemfile :

gem 'activeadmin'

And to a few command line incantations afterwards to seal the deal:

$ bundle install $ rails g active_admin:install $ rake db:migrate $ rails s

Fire up your favorite browser and visit localhost:3000/admin. The default username is admin@example.com and the default password is password. You’d probably be surprised to see an empty dashboard and absolutely no models that you can administer. Active Admin takes a totally different approach compared to RailsAdmin. Here nothing happens automatically - you have to customize your dashboard yourself and you have to register the models you’d be administrating with the following command:

$ rails g active_admin:resource ModelName

This will create a file named app/admin/model_name.rb where you can tinker with looks of the resource’s index, form and show view.

And here comes Active Admin’s core feature - it’s immensely easy to customize anything in the Admin UI. The forms used to create and update model records are simple Formtastic forms (the same Formtastic forms you’re probably already using throughout the rest of your apps):

ActiveAdmin . register Post do form do | f | f . inputs "Details" do f . input :title f . input :published_at , :label => "Publish Post At" f . input :category end f . inputs "Content" do f . input :body end f . buttons end end

Rendering a partial for the form is also supported.

Active Admin features an elegant DSL to express the index and the show views. Here’s an example of index table for a fictional Course Management app:

ActiveAdmin . register Course do index do column :id column :title column :start_date column :end_date column :created_at column :updated_at default_actions end end

The default_actions method invocation here is important - without it you’ll be missing the action buttons in the last column of the index table.

Here’s an example of a show view:

ActiveAdmin . register Post do show do h3 post . title div do simple_format post . body end end end

Alternatively you can forgo the Arbre HTML DSL and render a partial like this:

ActiveAdmin . register Post do show do # renders app/views/admin/posts/_some_partial.html.erb render "some_partial" end end

The documentation is very well written and quite extensive so I wouldn’t go into many details here (remember DRY). The only issue I’ve had with Active Admin so far is not related to Active Admin directly - the latest gem release still depends on the old Formtastic 1.3 and I happen to use Formtastic 2.0 in all of my apps. Luckily the master branch is already using Formtastic 2.0, so all you have to do if you have this problem is to use the gem from git:

'activeadmin' , git: git :/ / github . com / gregbell / active_admin . git

If you’re reading this article after the release of Active Admin 0.4 (which should happen any day now) - you don’t have to do this.

Which Should You Use

The answer to that question depends on your needs for a particular project.

RailsAdmin is still alpha. Unstable developments are made in topic branches and master is supposed to be as stable as possible. RailsAdmin is not an admin scaffolder as is Active Admin. It’s an automatic backend. It’s goal is to provide a full access to your data, with maximum of defaults extracted from application’s ORM/ActiveModel, a DSL to customize those, and hooks for third-party projects (Cancan/Devise/Paperclip/CKeditor) to enrich the experience. Granularity is higher in RA. You are not supposed to access FormBuilder the way you would with Active Admin and Formtastic. RailAdmin says here It’s in the dev field, not configuration. Still, the current blackbox has some flaws, discrepancies and uncovered areas that its developers are currently addressing.

Active Admin basically does things the other way around. You’re totally supposed to tweak every aspect of the Admin UI - but tweaking those aspects is very very easy. If you’re looking for a heavily customized Admin UI solution - Active Admin is certainly the way to go. It’s not an automatic admin backend by any means - it’s more or less a framework that simplifies the creation of admin UIs.

In terms of popularity it seems that RailsAdmin is a bit more popular right now. I consider the GitHub watchers of a project to be a fairly accurate measurement of its popularity and as of the time of this writing RailsAdmin has 2539 compared to 2127 for Active Admin. You have to consider the fact that RailsAdmin has been out in the open a bit longer. Active Admin is rapidly closing this gap, however, and I expect it to surpass RailsAdmin in a month or two.

My personal recommendation is to start by trying RailsAdmin - if it covers your use cases, you’d do well to simply use it instead of pouring additional effort into creating a similar UI with Active Admin. If you need heavily customized admin UI, however, you’d probably do well to start with Active Admin in the first place, since after all - it was designed for such scenarios.

Epilogue

Having used both RailsAdmin and Active Admin with real projects I can tell you that they serve a different purpose - the admin UI generated by RailsAdmin is quite usable by default and might be used with very little changes. Active Admin’s admin UI generally requires manual tweaking to achieve the same effect. On the other hand Active Admin was developed with manual customization in mind at it’s very easy to do such changes there. Modifying the forms in RailsAdmin was definitely a less pleasant experience (not to mention stuff like CarrierWave integration).

While there are some people urging the projects to merge I think that would be a terrible idea. Aside from the technical difficulties of merging separate projects sharing no common codebase, I do think diversity matters. Rails has virtually no alternatives (in Rubyland) and that is bad for business, since competition always drives innovation. I’d love to see both projects evolve in their current directions (and stabilize along the way).

So what are you waiting for? Give them both a shot and share your experience in the comments section!