IblockElementProvider::getElements

protected function getElements(array $additionalFilter = [], ?int $limit = null): array
{
	$elements = [];

	$filter = $this->getDefaultFilter();
	if (!empty($additionalFilter))
	{
		$filter = array_merge($filter, $additionalFilter);
	}

	$navParams = false;
	if ($limit)
	{
		$navParams = ['nTopCount' => $limit];
	}

	$selectFields = [
		'ID',
		'NAME',
		'DETAIL_TEXT',
		'PREVIEW_PICTURE',
		'IBLOCK_ID',
		'XML_ID',
	];

	if (!empty($filter))
	{
		$elementData = CIBlockElement::GetList(
			[],
			$filter,
			false,
			$navParams,
			$selectFields
		);
		while ($element = $elementData->fetch())
		{
			if (empty($element['PREVIEW_PICTURE']))
			{
				$element['PREVIEW_PICTURE'] = $this->getElementImage($element);
			}
			$elements[] = $element;
		}
	}

	return $elements;
}