filters.php

<?php
namespace Bitrix\Iblock\Component;
 
use Bitrix\Catalog;
class Filters
{
    public static function getFilteredOffersId(array $filter)
    {
        $result = array();
        if (empty($filter) || !is_array($filter))
            return $result;
 
        $itemsIterator = \CIBlockElement::getList(array(), $filter, false, false, array('ID'));
        while ($item = $itemsIterator->fetch())
        {
            $item['ID'] = (int)$item['ID'];
            $result[$item['ID']] = $item['ID'];
        }
        unset($item, $itemsIterator);
 
        return $result;
    }
 
    public static function getFilteredOffersByProduct($iblockId, $propertyId, array $filter)
    {
        $result = array();
        $iblockId = (int)$iblockId;
        $propertyId = (int)$propertyId;
        if ($iblockId <= 0 || $propertyId <= 0)
            return $result;
        if (empty($filter) || !is_array($filter))
            return $result;
 
        $valuesIterator = \CIBlockElement::getPropertyValues($iblockId, $filter, false, array('ID' => $propertyId));
        while ($value = $valuesIterator->fetch())
        {
            $productId = (int)$value[$propertyId];
            $offerId = (int)$value['IBLOCK_ELEMENT_ID'];
            if (!isset($result[$productId]))
                $result[$productId] = array();
            $result[$productId][$offerId] = $offerId;
        }
        unset($value, $valuesIterator);
 
        return $result;
    }
}