KOKINIO - MANAGER

Edit File: imagelist.php

<?php
/**
 * @package     Joomla.Plugin
 * @subpackage  Fields.Imagelist
 *
 * @copyright   (C) 2017 Open Source Matters, Inc. <https://www.joomla.org>
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

defined('_JEXEC') or die;

use Joomla\CMS\Form\Form;

/**
 * Fields Imagelist Plugin
 *
 * @since  3.7.0
 */
class PlgFieldsImagelist extends \Joomla\Component\Fields\Administrator\Plugin\FieldsPlugin
{
	/**
	 * Transforms the field into a DOM XML element and appends it as a child on the given parent.
	 *
	 * @param   stdClass    $field   The field.
	 * @param   DOMElement  $parent  The field node parent.
	 * @param   Form        $form    The form.
	 *
	 * @return  DOMElement
	 *
	 * @since   3.7.0
	 */
	public function onCustomFieldsPrepareDom($field, DOMElement $parent, Form $form)
	{
		$fieldNode = parent::onCustomFieldsPrepareDom($field, $parent, $form);

if (!$fieldNode)
		{
			return $fieldNode;
		}

$fieldNode->setAttribute('hide_default', 'true');
		$fieldNode->setAttribute('directory', '/images/' . $fieldNode->getAttribute('directory'));

return $fieldNode;
	}
}