Hide empty categories in 1c-bitrix

hide_empty_categories.php

<?

//result_modifier.php

foreach ($arResult['SECTIONS'] as $key => $value) {
        $arSelect = Array("ID");
        $sect = CIBlockElement::GetList(
            Array("ID" => "DESC"),
            Array("IBLOCK_ID" => #NUMBER_INFOBLOK#,
                "ACTIVE" => "Y",
                "SECTION_ID" => Array($arResult['SECTIONS'][$key]['ID']),
                "INCLUDE_SUBSECTIONS" => 'Y',
                "CATALOG_AVAILABLE" => "Y"
            ),
            false,
            Array("nTopCount" => 3),
            $arSelect);

        $count = 0;
        while ($el = $sect->GetNextElement()) {
            $count++;
            if ($count > 1) break;
        };
        if ($count < 1) unset($arResult['SECTIONS'][$key]);

    }

?>

Modify component catalog.section.list (move to local->components->bitrix) and modify result_modifier.php