UrlManager::getUrlExternalLink

public function getUrlExternalLink(array $paramsUri, $absolute = false)
{
	static $rewriteCondition = null;
	if($rewriteCondition === null)
	{

		$extLinksAccessPoints = CUrlRewriter::getList(array('ID' => 'bitrix:disk.external.link'));
		if(empty($extLinksAccessPoints))
		{
			$rewriteCondition = "#^/docs/pub/(?[0-9a-f]{32})/(?.*)$#";
		}
		else
		{
			$rewrite = reset($extLinksAccessPoints);
			$rewriteCondition = $rewrite['CONDITION'];
		}
	}

	$url = $this->buildUrl($rewriteCondition, $paramsUri);
	if ($absolute && Loader::includeModule('bitrix24') && !CBitrix24::isCustomDomain())
	{
		$host = parse_url($this->getHostUrl(), PHP_URL_HOST);

		return "https://bitrix24public.com/{$host}{$url}";
	}

	return ($absolute? $this->getHostUrl() : '') . $url;
}