Ruby On Rails: Omniauth Devise Authentication using Facebook , Google & Twitter.

This post is just a simple straightforward description of Omniauth:Overview , intended for the beginners , those who wants to try the OmniAuth for the first time with Facebook , Google & Twitter. This post will cover all the basic information i.e From creating the app in Facebook, Google & Twitter for getting the secret key To connect these Apps to your Rails Application.

Things in common :

add Devise & omniauth gem to your Gemfile.

gem 'omniauth' 
gem 'devise' 

First of all install Devise into your application.

rails generate devise:install  

You have to create user model using devise ,

rails g devise user  

and after that we need to add 2 more columns i.e "uid" and 'provider' to our user model.

rails g migration AddColumnsToUsers provider:string uid:string
rake db:migrate

 also dont forget to add ":provider" and ":uid" to your attr_accessible also.

 We have done with the things that is common in authentication using facebook,Google, Twitter.

 We will start with Facebook Authentication first 

 Facebook Authentication :

 add gem 'omniauth-facebook' to your gem file.

 First of all you need to create an application in facebook to get the secret key out .