omniauth

  def self.from_omniauth(auth, ref)
    where(provider: auth.provider, uid: auth.uid).first_or_create do |user|
      user.email = "#{auth.info.nickname}@twitter.com"
      user.password = Devise.friendly_token[0,20]
      user.username = auth.info.nickname   # assuming the user model has a name
      user.referrer_token = ref.to_s
    end
  end