CComponentAjax::__isAjaxURL

function __isAjaxURL($url)
{
	/** @global CMain $APPLICATION */
	global $APPLICATION;

	if(preg_match("/^(#|mailto:|javascript:|callto:)/", $url))
		return false;

	if (strpos($url, '://') !== false)
		return false;

	$url = preg_replace('/#.*/', '', $url);

	if (($this->arParams['SEF_MODE'] ?? null) === 'Y')
	{
		if ($url == POST_FORM_ACTION_URI)
			return true;

		$test_str = '/bitrix/urlrewrite.php?SEF_APPLICATION_CUR_PAGE_URL=';
		if (strncmp($url, $test_str, 52) === 0)
		{
			$url = urldecode(mb_substr($url, 52));
		}

		$url = $this->__GetSEFRealUrl($url);

		if ($url === false)
			return false;
	}
	else
	{
		if (strpos($url, '?') !== false)
			$url = mb_substr($url, 0, mb_strpos($url, '?'));

		if (mb_substr($url, -4) != '.php')
		{
			if (mb_substr($url, -1) != '/')
				$url .= '/';

			$url .= 'index.php';
		}
	}

	if (!$this->currentUrl)
	{
		$currentUrl = $APPLICATION->GetCurPage();

		if (($this->arParams['SEF_MODE'] ?? null) === 'Y')
			$currentUrl = $this->__getSEFRealUrl($currentUrl);

		if (strpos($currentUrl, '?') !== false)
			$currentUrl = mb_substr($currentUrl, 0, mb_strpos($currentUrl, '?'));

		if (mb_substr($currentUrl, -4) != '.php')
		{
			if (mb_substr($currentUrl, -1) != '/')
				$currentUrl .= '/';

			$currentUrl .= 'index.php';
		}

		$this->currentUrl = $currentUrl;
		$this->dirname_currentUrl = dirname($currentUrl);
		$this->basename_currentUrl = basename($currentUrl);
	}

	$dirname = dirname($url);
	if (
		(
			$dirname == $this->dirname_currentUrl
			||
			$dirname == ''
			||
			$dirname == '.'
		)
		&&
		basename($url) == $this->basename_currentUrl
	)
		return true;

	return false;
}