Zvýraznění aktivního odkazu v menu u opencart

<?php  
class ControllerModuleCategorySuperfish extends Controller {
    protected $category_id = 0;
    protected $parent_id = 0;
    protected $path = array();
    
    protected function index() {
        $this->language->load('module/category_superfish');
        
        $this->data['heading_title'] = $this->language->get('heading_title');
        
        $this->load->model('catalog/category');
        #$this->load->model('tool/seo_url');
        
        if (isset($this->request->get['path'])) {
            $this->path = explode('_', $this->request->get['path']);
            
            $this->category_id = end($this->path);
            }
        
        $this->data['category_superfish'] = $this->getCategories(0);
                                                
        $this->id = 'category_superfish';
        
        $this->data['superfish_path'] = $this->config->get('config_url') . '/catalog/view/javascript/jquery';
        
        if (file_exists(DIR_TEMPLATE . $this->config->get('config_template') . '/template/module/category_superfish.tpl')) {
            $this->template = $this->config->get('config_template') . '/template/module/category_superfish.tpl';
        } else {
            $this->template = 'default/template/module/category_superfish.tpl';
        }
        
        $this->render();
      }
    
    protected function getCategories($parent_id, $current_path = '') {
        $category_id = array_shift($this->path);
        $this->getParent($category_id);
        
        $output = '';
        
        $results = $this->model_catalog_category->getCategories($parent_id);
        ##if($results && $parent_id>0) $output .= '<ul>';         
        

        if($results && $parent_id>0 && $parent_id != $this->parent_id) $output .= '<ul>';         
        foreach ($results as $result) {    
            if (!$current_path) {
                $new_path = $result['category_id'];
                $delka = strlen($result['category_id']);
            } else {
                $new_path = $current_path . '_' . $result['category_id'];
                $delka = strlen($result['category_id']);
            }
            
            $output .= '<li>';
            
            
            $children = '';
            
            $children = $this->getCategories($result['category_id'], $new_path);
            
            
            

    
            

            
            if($parent_id==0) $output .= ' <a href="' . $this->url->link('product/category','path=' . $new_path)  . '"><b>' . $result['name'] . '</b></a>';

            elseif($parent_id != $this->parent_id) $output .= '<a href="' . $this->url->link('product/category','path=' .  $new_path)  . '">' . $result['name'] . '</a>';

            else $output .= '<a href="' . $this->url->link('product/category','path=' .  $new_path)  . '">»&nbsp;&nbsp;&nbsp;&nbsp;' . $result['name'] . '</a>';




            
            $output .= $children;
            
            $output .= '</li>'; 
        }
         #if($results && $parent_id>0) $output .= '</ul>'; 
         if($results && $parent_id>0 && $parent_id != $this->parent_id) $output .= '</ul>'; 
        return $output;
    }    
    protected function getParent($category_id)
    {
        if($category_id <=0) return false;
        $query = $this->db->query("SELECT DISTINCT * FROM " . DB_PREFIX . "category c LEFT JOIN " . DB_PREFIX . "category_description cd ON (c.category_id = cd.category_id) LEFT JOIN " . DB_PREFIX . "category_to_store c2s ON (c.category_id = c2s.category_id) WHERE c.category_id = '" . (int)$category_id . "' AND cd.language_id = '" . (int)$this->config->get('config_language_id') . "' AND c2s.store_id = '" . (int)$this->config->get('config_store_id') . "' AND c.status = '1'");
        
        if($query->row['parent_id']==0) $this->parent_id = $category_id;
        else $this->getParent($query->row['parent_id']);
    }
}
?>

    <div class="sf-vertical" style='padding:0;margin:0;'>        
        <ul id="sample-menu-1" class="sf-menu" style='padding:0;margin:0;width:100%'>
            <?=$category_superfish?>    
        </ul>
    </div>