SystemField::renderAdminEditForm

static function renderAdminEditForm(array $product, array $config): ?string
{
	if (!isset($product['ID']) || !isset($product['IBLOCK_ID']) || !isset($product['TYPE']))
	{
		return null;
	}
	$product['IBLOCK_ID'] = (int)$product['IBLOCK_ID'];
	if ($product['IBLOCK_ID'] <= 0)
	{
		return null;
	}
	$product['PRODUCT_ID'] = (int)($product['PRODUCT_ID'] ?? CIBlockElement::GetRealElement($product['ID']));
	$product['TYPE'] = (int)$product['TYPE'];

	$config['FROM_FORM'] = $config['FROM_FORM'] ?? false;
	$config['ALLOW_EDIT'] = $config['ALLOW_EDIT'] ?? true;

	$systemFields = self::getFieldsByRestrictions(
		[
			'TYPE' => $product['TYPE'],
			'IBLOCK_ID' => $product['IBLOCK_ID'],
		],
		[
			'RESULT_MODE' => self::DESCRIPTION_MODE_CLASSNAME,
		]
	);
	if (empty($systemFields))
	{
		return '';
	}

	$userFieldManager = MainUserFieldInternalUserFieldHelper::getInstance()->getManager();
	$userFields = $userFieldManager->GetUserFields(
		CatalogProductTable::getUfId(),
		$product['PRODUCT_ID'],
		LANGUAGE_ID
	);
	if (empty($userFields))
	{
		return '';
	}

	$result = '';

	/**
	 * @var string $fieldName
	 * @var CatalogProductSystemFieldBase $className
	 */
	foreach ($systemFields as $fieldName => $className)
	{
		$row = $userFields[$fieldName];

		$row['VALUE_ID'] = $product['PRODUCT_ID'];
		$row['EDIT_FORM_LABEL'] = $row['EDIT_FORM_LABEL'] ?? $row['FIELD_NAME'];
		if (!$config['ALLOW_EDIT'])
		{
			$row['EDIT_IN_LIST'] = 'N';
		}

		$html = $className::renderAdminFormControl($row, $product, $config);
		if ($html !== null)
		{
			$result .= $html;
		}
	}
	unset($row, $fieldName);

	return $result;
}