My Onmiauth callback controller.

omniauth_callbacks_controller.rb

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController

	skip_before_filter :beta

  def facebook
    @user = User.find_for_facebook_oauth(env["omniauth.auth"], current_user)

		if @user
		  if @user.persisted?
		    flash[:notice] = I18n.t "devise.omniauth_callbacks.success", :kind => "Facebook"
		    @user.remember_me!		    
		    sign_in_and_redirect @user, :event => :authentication				
		  else
		    session["devise.facebook_data"] = env["omniauth.auth"]
		    redirect_to new_user_registration_url
		  end
		else
			redirect_to("/beta", :notice => 'You haven\'nt been invited yet.')
	  end
 
	end
  
end