/** Generate a list of root Categories.
  *
  * The categories contain an ID, name, the active status, and a single level of
  * sub-categories. If the category/sub-category is in the path of the current
  * page, it will have an `active` value of true.
  */
 public static function root_and_child_categories()
 {
     global $cPath_array, $db;
     $root_categories_query = "SELECT * FROM " . TABLE_CATEGORIES . " AS cats" . " INNER JOIN " . TABLE_CATEGORIES_DESCRIPTION . " AS descs" . " ON cats.categories_id=descs.categories_id" . " WHERE categories_status=1 AND parent_id=0 ORDER BY sort_order";
     $root_result = $db->Execute($root_categories_query);
     $root_categories = array();
     while (!$root_result->EOF) {
         $root_category = $root_result->fields;
         $category_id = $root_category['categories_id'];
         $root_categories[] = array('id' => $category_id, 'name' => $root_category['categories_name'], 'active' => in_array($category_id, $cPath_array), 'children' => BootstrapNavMenu::get_child_categories($category_id));
         $root_result->MoveNext();
     }
     return $root_categories;
 }
    ?>
      <ul class='nav navbar-nav'>
        <li><a href="<?php 
    echo zen_href_link(FILENAME_ADVANCED_SEARCH);
    ?>
">Advanced Search</a></li>
      </ul>
    </div>

    <!-- Category Nav Menu -->
    <div id='category-navbar' class='collapse navbar-collapse'>
      <ul class='nav navbar-nav'>
<?php 
    /* Use the root categories for the top level nav, with dropdowns for the first
     * level of sub-categories */
    $root_categories = BootstrapNavMenu::root_and_child_categories();
    foreach ($root_categories as $root_category) {
        $root_url = BootstrapUtils::category_url(array($root_category['id']));
        if (count($root_category['children']) === 0) {
            /* Direct Link */
            ?>
  <li <?php 
            if ($root_category['active']) {
                echo "class='active'";
            }
            ?>
>
    <a href="<?php 
            echo $root_url;
            ?>
">