CWebDavExtLinks::IsAdmin

static function IsAdmin($userId = null)
{
	$result = false;
	if($userId === null)
	{
		$user = self::GetCurrentUser();
		if($user->IsAdmin())
		{
			return true;
		}
		$userId = $user->getId();
	}

	$userId = (int)$userId;
	if($userId <= 0)
	{
		return false;
	}

	try
	{
		if(IsModuleInstalled('bitrix24') && CModule::IncludeModule('bitrix24'))
		{
			if(class_exists('CBitrix24') && method_exists('CBitrix24', 'IsPortalAdmin'))
			{
				// New style check
				$result = CBitrix24::IsPortalAdmin($userId);
			}
			else
			{
				// HACK: Check user group 1 ('Portal admins')
				$arGroups = CUser::GetUserGroup($userId);
				$result = in_array(1, $arGroups);
			}
		}
	}
	catch(Exception $e)
	{
	}

	return $result;
}