où est genere $this->fieldsClass->display($oneExtr

$db =& JFactory::getDBO();
$q = 'SELECT pointures FROM '.hikashop_table('product').' WHERE product_id = '  . $this->element->product_id;
$db->setQuery($q);
$result = $db->loadResult();
$selectSizeP  = explode( ',',$result);
$selectSize = '<select onchange="hikashopToggleFields(this.value,\'pointure\',\'item\',0);" size="1" name="data[item][pointure]" id="pointure">';
foreach($selectSizeP as $size) {
            $selectSize .=  '<option  id="pointure_'.$size.'" value="'.$size.'">'.$size.'</option>';
	    //selected="selected"
        }
 $selectSize .=  '</select>';
	foreach ($this->itemFields as $fieldName => $oneExtraField) {
		$itemData = JRequest :: getString('item_data_' . $fieldName, $this->element-> $fieldName);
		echo '<label class="hk_attr_size">' .  JText::_('HK_POINTURE') . ' </label>' ;
		echo '<span id="hikashop_product_custom_item_value_' . $oneExtraField->field_id . '" class="hikashop_product_custom_item_value">' ;			
		$onWhat='onchange'; if($oneExtraField->field_type=='radio') $onWhat='onclick'; 
		echo  $selectSize . '</span>' ;
	}