def self.find_for_facebook_oauth(auth, signed_in_resource=nil)
  user = User.where(:provider => auth.provider, :uid => auth.uid).first
  unless user
    user = User.create(name:auth.extra.raw_info.name,
              provider:auth.provider,
              uid:auth.uid,
              email:auth.info.email,
              #for first name or last name do auth.info.first_name,etc
              # you could also use first_or_create here for brevity
              password:Devise.friendly_token[0,20]
         )
     end
  user
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"] if user.email.blank?
      end
    end
  end