Dear barone,
We customized K2 item layout and remove extra field, if you want to use it, please add this code in file:
templates\sj_grid\html\com_k2\templates\grid\item.php
templates\sj_grid\html\com_k2\templates\list\item.php
templates\sj_grid\html\com_k2\templates\default\item.php
<?php if($this->item->params->get('itemExtraFields') && count($this->item->extra_fields)): ?>
<!-- Item extra fields -->
<div class="itemExtraFields">
<h3><?php echo JText::_('K2_ADDITIONAL_INFO'); ?></h3>
<ul>
<?php foreach ($this->item->extra_fields as $key=>$extraField): ?>
<?php if($extraField->value != ''): ?>
<li class="<?php echo ($key%2) ? "odd" : "even"; ?> type<?php echo ucfirst($extraField->type); ?> group<?php echo $extraField->group; ?>">
<?php if($extraField->type == 'header'): ?>
<h4 class="itemExtraFieldsHeader"><?php echo $extraField->name; ?></h4>
<?php else: ?>
<span class="itemExtraFieldsLabel"><?php echo $extraField->name; ?>:</span>
<span class="itemExtraFieldsValue"><?php echo $extraField->value; ?></span>
<?php endif; ?>
</li>
<?php endif; ?>
<?php endforeach; ?>
</ul>
<div class="clr"></div>
</div>
<?php endif; ?>
Thanks.