CIntranetInviteDialog::getUserSiteId

static function getUserSiteId($arParams = array())
{
	$bExtranet = (
		!isset($arParams["UF_DEPARTMENT"])
		|| (int)$arParams["UF_DEPARTMENT"] <= 0
	);

	if (
		$bExtranet
		&& Loader::includeModule("extranet")
	)
	{
		$siteId = CExtranet::GetExtranetSiteID();
	}
	elseif (ModuleManager::isModuleInstalled("bitrix24"))
	{
		$siteId = (
			isset($arParams["SITE_ID"])
			&& !empty($arParams["SITE_ID"])
				? $arParams["SITE_ID"]
				: SITE_ID
		);
	}
	else
	{
		$siteId = self::GetSiteByDepartmentId($arParams["UF_DEPARTMENT"]);
	}

	return $siteId;
}