Как сделать листание item в категориях? - ZOO 2.х

public function getPrevNext($application_id, $category_id, $item_id, $published = false) {

		// init vars
		$prev = null;
		$next = null;

		// get database
		$db = $this->database;

		// get dates
		$date = $this->app->date->create();
		$now  = $db->Quote($date->toMySQL());
		$null = $db->Quote($db->getNullDate());

		// get item ordering

		$query = "SELECT ROWNUM"
				." FROM ("
					."SELECT @rownum:= @rownum+1 ROWNUM, id"
					." FROM"
					." (SELECT @rownum:=0) r,"
					." (SELECT id"
						." FROM ".$this->name." AS a"
						." LEFT JOIN ".ZOO_TABLE_CATEGORY_ITEM." AS b ON a.id = b.item_id"
						.($join ? $join : "")
						." WHERE a.application_id = ".(int) $application_id
						." AND b.category_id ".(is_array($category_id)? " IN (".implode(",", $category_id).")" : " = ".(int) $category_id)
						.($published == true ? " AND a.state = 1"
						." AND (a.publish_up = ".$null." OR a.publish_up <= ".$now.")"
						." AND (a.publish_down = ".$null." OR a.publish_down >= ".$now.")": "")
						." GROUP BY a.id"
						." ORDER BY a.priority DESC"
					.") t1"
				.") t2"
				." WHERE id = ".(int) $item_id;

		if ($row = $this->_queryResult($query)) {

			$query = "SELECT ROWNUM, id"
					." FROM ("
						."SELECT @rownum:= @rownum+1 ROWNUM, id"
						." FROM"
						." (SELECT @rownum:=0) r,"
						." (SELECT id"
							." FROM ".$this->name." AS a"
							." LEFT JOIN ".ZOO_TABLE_CATEGORY_ITEM." AS b ON a.id = b.item_id"
							.($join ? $join : "")
							." WHERE a.application_id = ".(int) $application_id
							." AND b.category_id ".(is_array($category_id)? " IN (".implode(",", $category_id).")" : " = ".(int) $category_id)
							.($published == true ? " AND a.state = 1"
							." AND (a.publish_up = ".$null." OR a.publish_up <= ".$now.")"
							." AND (a.publish_down = ".$null." OR a.publish_down >= ".$now.")": "")
							." GROUP BY a.id"
							." ORDER BY a.priority DESC"
						.") t1"
					.") t2"
					." WHERE ROWNUM = ".((int) $row-1)." OR ROWNUM = ".((int) $row+1);

			if ($objects = $db->queryObjectList($query)) {
				foreach ($objects as $object) {
					if ($object->ROWNUM > $row) {
						$next = $this->get($object->id);
					} else {
						$prev = $this->get($object->id);
					}
				}
			}
		}

		return array($prev, $next);

	}

<?php
//текущая категория
if (!$category_id = $this->app->request->getInt('category_id')) {
	if (($menu = $this->app->menu->getActive()) && in_array(@$menu->query['view'], array('category', 'frontpage')) && ($menu_params = $this->app->parameter->create($menu->params))) {
	$category_id = $menu_params->get('category');
	} else {
		if ($category = $this->_item->getPrimaryCategory()) {
		$category_id = $category->id;
		}
	}
}
//формируем массивы prev и next (хранятся все данные о товаре, можно сделать даже с выводом фото)
@list($prev, $next) = $this->app->table->item->getPrevNext($this->item->application_id , (int) $category_id, $this->item->id, true);
$category_id = $this->app->request->getInt('category_id');
$prev_link = $prev ? JRoute::_($this->app->route->item($prev, false).($category_id ? '&amp;category_id='.$category_id : '')) : '';
$next_link = $next ? JRoute::_($this->app->route->item($next, false).($category_id ? '&amp;category_id='.$category_id : '')) : '';
?>
<ul class="pagenav">
	<?php if ($prev_link) : ?>
			<li class="pagenav-prev">
				<a href="<?php echo $prev_link; ?>" rel="prev"><?php echo JText::_('Previous'); ?></a>
			</li>
	<?php endif; ?>

	<?php if ($next_link) : ?>
			<li class="pagenav-next">
				<a href="<?php echo $next_link; ?>" rel="next"><?php echo JText::_('Next'); ?></a>
			</li>
	<?php endif; ?>
</ul>