This document provides an installation guide for setting up Rails 3 with Devise, Oauth2 and Mongoid. It covers installing the necessary gems, configuring Devise for Oauth authentication with Facebook, handling callbacks and allowing users to login via Facebook or locally. It notes that Oauth2 uses the email as the key and Devise requires a password, so a fake password is inserted to allow both Oauth and local logins. The document concludes by emphasizing that the gem ecosystem changes rapidly and to check if any advice has been superseded.

1. Rails 3 / Devise / Oauth2 / Mongoid Steven Evatt, Chron.com Blog: http://www.evatt.com/blog Web: http://PriceChirp.com Twitter: @sevatt Houston-RoR Feb 2010 Installation Guide

5. Starting the project

6. Add Required Gems to Gemfile

7. Bundler

8. Setup Mongoid

9. Installing Devise

11. Facebook App Security

12. Facebook Application Data

22. The Login Button Finally Works!