如何在使用差异模板时在opencart中添加第三级类别

Question

我想在opencart的标题菜单中添加多级下拉菜单。我目前使用的是模板，而不是默认的opencart模板。我无法在控制器文件中找到$ categories_tm以添加第三级下拉列表。

这是我的header.tlp代码，用于显示标题类别菜单

<?php if ($categories) { ?>
    <div class="container">
        <div id="menu-gadget" class="menu-gadget">
            <div id="menu-icon" class="menu-icon"><?php echo $text_category; ?></div>
            <?php if ($categories_tm) {  echo $categories_tm; } ?>
        </div>
    </div>

    <script type="text/javascript">
        jQuery(window).load(function () {
        if ($('body').width() > 767) {
            $('#tm_menu').TMStickUp({})

        }});
    </script>

    <div id="tm_menu" class="nav__primary">
        <div class="container">
            <?php if ($categories_tm) {  echo $categories_tm; } ?>
            <div class="clear"></div>
        </div>
    </div>
    <?php } ?>

这是我的控制器文件header.php

foreach ($categories as $category) {
        if ($category['top']) {
            // Level 2
            $children_data = array();

            $children = $this->model_catalog_category->getCategories($category['category_id']);

            foreach ($children as $child) {
                $filter_data = array(
                    'filter_category_id'  => $child['category_id'],
                    'filter_sub_category' => true
                );

                $children_data[] = array(
                    'name'  => $child['name'] . ($this->config->get('config_product_count') ? ' (' . $this->model_catalog_product->getTotalProducts($filter_data) . ')' : ''),
                    'href'  => $this->url->link('product/category', 'path=' . $category['category_id'] . '_' . $child['category_id'])
                );
            }

            // Level 1
            $data['categories'][] = array(
                'name'     => $category['name'],
                'children' => $children_data,
                'column'   => $category['column'] ? $category['column'] : 1,
                'href'     => $this->url->link('product/category', 'path=' . $category['category_id'])
            );
        }
    }