Как добавить в код модуля сортировку по ключевым словам

Здравствуйте! Имеется модуль для джумлы, но в нем нет сортировки по ключевым словам, хотела добавить самостоятельно (хотелось бы, чтобы выводились похожие статьи, а если таких нет, то в случайном порядке) но ничего не выходит. Не знаю точно, какой файл отвечает за сортировку, думаю, этот

<?php
defined('_JEXEC') or die;
$com_path = JPATH_SITE.'/components/com_content/';
require_once $com_path.'router.php';
require_once $com_path.'helpers/route.php';
JModelLegacy::addIncludePath($com_path . '/models', 'ContentModel');
include_once dirname(__FILE__).'/helper_base.php';

class RelatedNews extends BaseHelper{

    public static function getList(&$_params)
    {
        $db = JFactory::getDbo();
        // Get an instance of the generic articles model
        $articles = JModelLegacy::getInstance('Articles', 'ContentModel', array('ignore_request' => true));
        
                $articles->setState(
                'list.select',
                'a.id, a.title, a.alias, a.introtext, a.fulltext, ' .
                'a.checked_out, a.checked_out_time, ' .
                'a.catid, a.created, a.created_by, a.created_by_alias, ' .
                // use created if modified is 0
                'CASE WHEN a.modified = ' . $db->q($db->getNullDate()) . ' THEN a.created ELSE a.modified END as modified, ' .
                'a.modified_by, uam.name as modified_by_name,' .
                // use created if publish_up is 0
                'CASE WHEN a.publish_up = ' . $db->q($db->getNullDate()) . ' THEN a.created ELSE a.publish_up END as publish_up,' .
                'a.publish_down, a.images, a.urls, a.attribs, a.metadata, a.metakey, a.metadesc, a.access, ' .
                'a.hits, a.xreference, a.featured'
        );

        $app = JFactory::getApplication();
        $appParams = $app->getParams();

        $articles->setState('params', $appParams);
        // Set the filters based on the module params
        $articles->setState('list.start', 0);
        $articles->setState('list.limit', (int) $_params->get('count', 0)+1);
        $articles->setState('filter.published', 1);
       // Access filter
        $access = !JComponentHelper::getParams('com_content')->get('show_noauth');
        $authorised = JAccess::getAuthorisedViewLevels(JFactory::getUser()->get('id'));
        $articles->setState('filter.access', $access);
       // Category filter
        $catids = $_params->get('depends');
        if ($catids != null) {
            if ($_params->get('show_child_category_articles', 0) && (int) $_params->get('levels', 0) > 0) {
                // Get an instance of the generic categories model
                $categories = JModelLegacy::getInstance('Categories', 'ContentModel', array('ignore_request' => true));
                $categories->setState('params', $appParams);
                $levels = $_params->get('levels', 1) ? $_params->get('levels', 1) : 9999;
                $categories->setState('filter.get_children', $levels);
                $categories->setState('filter.published', 1);
                $categories->setState('filter.access', $access);
                $additional_catids = array();

                foreach($catids as $catid)
                {
                    $categories->setState('filter.parentId', $catid);
                    $recursive = true;
                    $items = $categories->getItems($recursive);

                    if ($items)
                    {
                        foreach($items as $category)
                        {
                            $condition = (($category->level - $categories->getParent()->level) <= $levels);
                            if ($condition) {
                                $additional_catids[] = $category->id;
                            }
                         }
                    }
                }

                $catids = array_unique(array_merge($catids, $additional_catids));
            }
            $articles->setState('filter.category_id', $catids);
        // Ordering
        $articles->setState('list.ordering', $_params->get('article_ordering', 'a.ordering'));
        $articles->setState('list.direction', $_params->get('article_ordering_direction', 'ASC'));

//      // New Parameters
        $articles->setState('filter.featured', $_params->get('show_front', 'show'));

        // Filter by language
        $articles->setState('filter.language', $app->getLanguageFilter());
       $items = $articles->getItems();
        //var_dump($items); die("ancnc");
        //$show_introtext = $_params->get('show_introtext', 0);
        //$introtext_limit = $_params->get('introtext_limit', 100);
        $title_limit = $_params->get('item_title_max_characs', 20);

        // Find current Article ID if on an article page
        $option = $app->input->get('option');
        $view = $app->input->get('view');

        if ($option === 'com_content' && $view === 'article') {
            $active_article_id = $app->input->getInt('id');
        }
        else {
            $active_article_id = 0;
        }
       // Prepare data for display using display options
        foreach ($items as &$item)
        {
            $item->slug = $item->id.':'.$item->alias;
            $item->catslug = $item->catid ? $item->catid .':'.$item->category_alias : $item->catid;

            if ($access || in_array($item->access, $authorised))
            {
                // We know that user has the privilege to view the article
                $item->link = JRoute::_(ContentHelperRoute::getArticleRoute($item->slug, $item->catslug));
            }
            else
            {
                $app  = JFactory::getApplication();
                $menu = $app->getMenu();
                $menuitems = $menu->getItems('link', 'index.php?option=com_users&view=login');
                if (isset($menuitems[0]))
                {
                    $Itemid = $menuitems[0]->id;
                }
                elseif ($app->input->getInt('Itemid') > 0)
                {
                    // Use Itemid from requesting page only if there is no existing menu
                    $Itemid = $app->input->getInt('Itemid');
                }
                $item->link = JRoute::_('index.php?option=com_users&view=login&Itemid='.$Itemid);
            }

            // Used for styling the active article
            $item->active = $item->id == $active_article_id ? 'active' : '';
            $item->title = BaseHelper::truncate($item->title, $title_limit);
            //if ($show_introtext) {
//              $item->introtext = JHtml::_('content.prepare', $item->introtext, '', 'plg_content_relatednews.content');
//              self::getImages($item, $_params);
//              $item->introtext = self::_cleanIntrotext($item->introtext);
            //} else {
                $item->introtext = JHtml::_('content.prepare', $item->introtext, '', 'plg_content_relatednews.content');
                BaseHelper::getArticleImages($item, $_params);
            //}
            //$item->displayIntrotext = $show_introtext ? self::truncate($item->introtext, $introtext_limit) : '';
            //$item->displayReadmore = $item->alternative_readmore;
        }
        return $items;
        }
    }

    public static function groupBy($list, $fieldName, $article_grouping_direction, $fieldNameToKeep = null)
    {
        $grouped = array();

        if (!is_array($list)) {
            if ($list == '') {
                return $grouped;
            }

            $list = array($list);
        }

        foreach($list as $key => $item)
        {
            if (!isset($grouped[$item->$fieldName])) {
                $grouped[$item->$fieldName] = array();
            }

            if (is_null($fieldNameToKeep)) {
                $grouped[$item->$fieldName][$key] = $item;
            }
            else {
                $grouped[$item->$fieldName][$key] = $item->$fieldNameToKeep;
            }

            unset($list[$key]);
        }

        $article_grouping_direction($grouped);

        return $grouped;
    }

    public static function groupByDate($list, $type = 'year', $article_grouping_direction, $month_year_format = 'F Y')
    {
        $grouped = array();

        if (!is_array($list)) {
            if ($list == '') {
                return $grouped;
            }

            $list = array($list);
        }

        foreach($list as $key => $item)
        {
            switch($type)
            {
                case 'month_year':
                    $month_year = JString::substr($item->created, 0, 7);

                    if (!isset($grouped[$month_year])) {
                        $grouped[$month_year] = array();
                    }

                    $grouped[$month_year][$key] = $item;
                    break;

                case 'year':
                default:
                    $year = JString::substr($item->created, 0, 4);

                    if (!isset($grouped[$year])) {
                        $grouped[$year] = array();
                    }

                    $grouped[$year][$key] = $item;
                    break;
            }

            unset($list[$key]);
        }

        $article_grouping_direction($grouped);

        if ($type === 'month_year') {
            foreach($grouped as $group => $items)
            {
                $date = new JDate($group);
                $formatted_group = $date->format($month_year_format);
                $grouped[$formatted_group] = $items;
                unset($grouped[$group]);
            }
        }
     return $grouped;
    }
} 

В xml документ добавила

<option value="a.metakey">Article Kewords Order</option>

, теперь опция сортировки по ключам есть в админпанели. Надеюсь на помощь.