Access token from devise+omniauth-facebook authentication for using in fb-graph

Question

I used devise and omniauth-facebook in my Rails 3 app for Facebook authentication, based on this tutorial: Adding Facebook auth to Rails 3.1 app, and it's working great!

But now I want to have full Facebook integration in my app, with which I can access the user's photos, friends, etc., and for that I am thinking of using fb_graph. fb_graph requires a token, and I wanted to know how to edit my user model to save the token and use it in fb_graph. Any help regarding this matter will be highly appreciated.

This is how my User model looks like right now:

class User < ActiveRecord::Base

# Include default devise modules. Others available are:
# :token_authenticatable, :encryptable, :confirmable, :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
     :recoverable, :rememberable, :trackable, :validatable, :omniauthable

# Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me

  has_many :photos
  has_many :scrapbooks

  def self.find_for_facebook_oauth(access_token, signed_in_resource=nil)
    data = access_token.extra.raw_info
    if user = User.where(:email => data.email).first
      user
    else # Create a user with a stub password.
      User.create!(:email => data.email, :password => Devise.friendly_token[0,20])
    end  
  end

  def self.new_with_session(params, session)
    super.tap do |user|
      if data = session["devise.facebook_data"] && session["devise.facebook_data"]["extra"]["raw_info"]
        user.email = data["email"]
      end
    end
  end
end

Answer 1

You can do this:

User.create!(:email => data.email, :password => Devise.friendly_token[0,20], :authentication_token => access_token.credentials.token)

You will also need to add :authentication_token or whatever you named it to the attr_accessible

Answer 2

I was looking for the same thing. I tried to implement James Robey{s answer and felt into the same error: OAuthException :: An active access token must be used to query information about the current user. Then I realized authentication_token was not being saved this way. After looking a while I found in FbGraph + OmniAuth + Facebook Graph API on Rails application a way to do it with session variables, by implementing the token saving during omniauth callback and then using it when calling fb_graph. So it might be something like this:

omniauth callback (app/controllers/users/omniauth_callbacks_controller.rb)

class Users::OmniauthCallbacksController < Devise::OmniauthCallbacksController
  def facebook
    @user = User.find_for_facebook_oauth(request.env["omniauth.auth"], current_user)

    if @user.persisted?
      flash[:notice] = I18n.t "devise.omniauth_callbacks.success", :kind => "Facebook"
# this part is where token is stored
        auth = request.env['omniauth.auth']
        token = auth['credentials']['token']
        session[:fb_access_token] = token
#
      sign_in_and_redirect @user, :event => :authentication
    else
      session["devise.facebook_data"] = request.env["omniauth.auth"]
      redirect_to new_user_registration_url
    end
  end
end

Then when calling fb_graph

@fb_user = FbGraph::User.new('me', access_token: session[:fb_access_token]).fetch

I don't know if it's the best way, but works so far.