Domain::getDomainName

static function getDomainName()
{
	static $domain = null;

	if (!$domain)
	{
		$context = BitrixMainApplication::getInstance()->getContext();
		$server = $context->getServer();
		$domain = $server->getServerName();
		if (!$domain)
		{
			$domain = $server->getHttpHost();
		}
	}

	return $domain;
}