Display custom fields from table "Product"

<?php
	if(!empty($this->fields)){
		$this->setLayout('show_block_custom_main');
		echo $this->loadTemplate();
	}
	?>

<div id="hikashop_product_custom_info_main" class="hikashop_product_custom_info_main">
	<h4><?php echo JText::_('SPECIFICATIONS');?></h4>
	<table width="100%">
	<?php
	$this->fieldsClass->prefix = '';
	foreach ($this->fields as $fieldName => $oneExtraField) {
		$value = '';
		if(empty($this->element->$fieldName) && !empty($this->element->main->$fieldName))$this->element->$fieldName = $this->element->main->$fieldName;
		if(isset($this->element->$fieldName))
			$value = trim($this->element->$fieldName);
		if (!empty ($value)) {
		?>
			<tr class="hikashop_product_custom_<?php echo $oneExtraField->field_namekey;?>_line">
				<td class="key">
					<span id="hikashop_product_custom_name_<?php echo $oneExtraField->field_id;?>" class="hikashop_product_custom_name">
						<?php echo $this->fieldsClass->getFieldName($oneExtraField);?>
					</span>
				</td>
				<td>
					<span id="hikashop_product_custom_value_<?php echo $oneExtraField->field_id;?>" class="hikashop_product_custom_value">
						<?php echo $this->fieldsClass->show($oneExtraField,$value); ?>
					</span>
				</td>
			</tr>
		<?php
		}
	}
	?>
	</table>
</div>