pager

  
    public function getProductsWithPager($params, $countInterval){
        return $this->pagerIblock($params, $countInterval);
    }
  
  public function pagerIblock($params, $countInterval)
    {
        $arResult = [];
        $countMax = CIBlockElement::GetList(array('ID' => 'ASC'), $params["filter"], array(), false, array('ID'));
        if ($countMax > 0) {
            $pages = ceil($countMax / $countInterval);
        } else {
            $pages = 1;
        }
        if (!$params["nav"]) {
            $params["nav"] = [];
        }

        for ($i = 0; $i < $pages; $i++) {
            $params["nav"] = array_merge($params["nav"], ["nPageSize" => $countInterval, "iNumPage" => $i]);
//            $arResult = array_merge_recursive($this->getElements($params), $arResult);
        }
        return $arResult;
    }

    public function pagerIblock2($params, $countInterval){

        if (key_exists('cacheTime', $params)) {
            $cacheTime = $params['cacheTime'];
            unset($params['cacheTime']);
        } else {
            $cacheTime = 3600;
        }

        if (key_exists('cacheTag', $params)) {
            $cacheTag = $params['cacheTag'];
            unset($params['cacheTag']);
        } else {
            $cacheTag = '';
        }

        if (key_exists('indexArray', $params)) {
            $indexArray = $params['indexArray'];
            unset($params['indexArray']);
        } else {
            $indexArray = false;
        }

        $order = $params['order'] ? $params['order'] : [];
        $arFilter = $params['filter'] ? $params['filter'] : [];
        $arSelect = $params['select'] ? $params['select'] : ['*'];
        $arGroup = $params['group'] ? $params['group'] : false;
        $arNav = $params['nav'] ? $params['nav'] : [];

        if (!$arFilter['IBLOCK_ID']) {
            $arFilter['IBLOCK_ID'] = $this->id;
        }

        $cache = $this->getCache([__METHOD__, $params], $cacheTime, $cacheTag);
        if ($cache->start()) {
            $arResult = [];
            $countMax = CIBlockElement::GetList(array('ID' => 'ASC'), $params["filter"], array(), false, array('ID'));
            if ($countMax > 0) {
                $pages = ceil($countMax / $countInterval);
            } else {
                $pages = 1;
            }
            for ($i = 0; $i < $pages; $i++) {
                $rs = \CIBlockElement::GetList($order, $arFilter, $arGroup, array_merge($arNav, ["nPageSize" => $countInterval, "iNumPage" => $i]), $arSelect);
                $index = 0;
                while ($ar = $rs->GetNext()) {
                    if ($indexArray) {
                        $ar['INDEX'] = $index;
                        $arResult[$ar[$indexArray]] = $ar;
                    } else {
                        $arResult[] = $ar;
                    }
                    $index++;
                }
            }

            if (!empty($arResult)) {
                $cache->end($arResult);
            } else {
                $cache->abort();
            }
        } else {
            $arResult = $cache->getVars();
        }
        return $arResult;
    }