use Bitrix\Main\Loader,
\Bitrix\Socialservices\UserTable;
Loader::includeModule('socialservices');

AddEventHandler("socialservices", "OnAuthServicesBuildList", array("CSocServFacebook", "GetDescription"));
AddEventHandler("socialservices", "OnAuthServicesBuildList", array("CSocServVKontakte", "GetDescription"));
AddEventHandler("socialservices", "OnAuthServicesBuildList", array("CSocServOdnoklassniki", "GetDescription"));

class CSocServFacebook extends CSocServAuth{
   const ID = "Facebook";

   public function GetDescription(){
      return array(
         "ID" => self::ID,
         "CLASS" => "CSocServFacebook",
         "NAME" => "Facebook",
         "ICON" => "Facebook-button",
      );
   }
}

class CSocServVKontakte extends CSocServAuth{
    const ID = "VKontakte";
 
    public function GetDescription(){
       return array(
          "ID" => self::ID,
          "CLASS" => "CSocServVKontakte",
          "NAME" => "ВКонтакте",
          "ICON" => "VKontakte-button",
       );
    }
 }

class CSocServOdnoklassniki extends CSocServAuth{
    const ID = "Odnoklassniki";
    public function GetDescription(){
        return array(
           "ID" => self::ID,
           "CLASS" => "CSocServOdnoklassniki",
           "NAME" => "Одноклассники",
           "ICON" => "Odnoklassniki-button",
        );
     }
}

AddEventHandler("socialservices", "OnUserLoginSocserv", Array("MyEvents", "SocUserLoginHandler"));

class MyEvents{

    protected function SocUserLoginHandler($event){
        self::dump($event);
    }
    public static function dump($event){
        // лог в папке /log/
        $file_name = date("Y-m-d_H.i.s") . '.log';
        file_put_contents($_SERVER['DOCUMENT_ROOT'] . '/log/' . $file_name, print_r(array(
            "line" => __LINE__,
            "path" => __DIR__,
            $event
        ), 1) . "\n", FILE_APPEND);
    }
}