gistfile1.rb

  def create_by_provider
    # It's the Omniauth callback, Twitter and Facebook sends you here after authorization.
    omniauth = request.env["omniauth.auth"]
    if omniauth
      registred_authorization = Authorization.find_by_provider_and_uid(omniauth['provider'], omniauth['uid'])
      if not logged_in
        if registred_authorization
          user = User.find(registred_authorization.user_id)
          session[:user_id] = user.id
          redirect_to root_url, alert: "Successfully logged in."
        else
          @user = User.new
          @user.external_provider = true
          @user.name = omniauth["info"]["name"]
          @user.email = omniauth["info"]["email"] if omniauth['provider'] != "twitter"
          if @user.save
            @user.authorizations.create!(:provider => omniauth['provider'], :uid => omniauth['uid'])
            session[:user_id] = @user.id
            redirect_to root_url, alert: "Successfully logged in."
          else
            redirect_to oops_url, alert: "We've found errors in our database with your external authentication, sorry."
          end
        end
      else
        if not registred_authorization
          current_user.authorizations.create!(:provider => omniauth['provider'], :uid => omniauth['uid'])
          redirect_to root_url, alert: "Successfully logged in."
        else
          redirect_to root_url
        end
      end
    else
      redirect_to oops_url, alert: "We've found strange errors dealing with your external authentication, sorry."
    end
  end