CListElementField::__construct

public function __construct($iblock_id, $field_id, $label, $sort)
{
	parent::__construct($iblock_id, $field_id, $label, $sort);

	$this->_type = CListFieldTypeList::GetByID($field_id);

	if($this->_iblock_id > 0)
		$arIBlockFields = CIBlock::GetArrayByID($this->_iblock_id, "FIELDS");
	else
		$arIBlockFields = CIBlock::GetFieldsDefaults();

	$this->_iblock_field = $arIBlockFields[$field_id] ?? null;
}