Opencart 2.3 Adding a custom menu in header

Question

I'm trying to add a custom menu on the header of opencart 2.3, tried different options even tried this one from stack opencart Adding a custom menu in the header menu But had no success, i found this code in Opencart forum it supposed to be placed in the header.php file:

$this->load->model('catalog/product');

$products_1 = $this->model_catalog_product->getProducts($data = array());                                           
if ($products_1) {$output = '<ul id="topnav">';}                                                            
foreach ($products_1 as $product_1) {                                                                           
    $output .= '<li>';                                                                                                                                          
    $unrewritten  = $this->url->link('product/product', 'product_id=' . $product_1['product_id']);                              
    $output .= '<a href="'.($unrewritten).'">' . $product_1['model'] . '</a>';                              
}
if ($products_1) {$output .= '</ul>';}                                                          
echo $output;                                                                   
?>

And it shows me this error

Answer 1

更具体地说，您需要编辑controller / common / header.php以包括在view / theme /（您的主题）/common/header.tpl中未定义的变量