如何获取自定义扩展或第三方组件的类别

我有一个第三方组件，将其类别存储在#__categories表中。

-----+----------------+-----------------------+-----------------------+-----
...  | extension      | title                 | alias                 | ...
-----+----------------+-----------------------+-----------------------+-----
...  | com_content    | Uncategorised         | uncategorised         | ...
-----+----------------+-----------------------+-----------------------+-----
...  | com_banners    | Sample Data-Banners   | sample-data-banners   | ...
-----+----------------+-----------------------+-----------------------+-----
...  | com_newsfeeds  | Sample Data-Newsfeeds | sample-data-newsfeeds | ...
-----+----------------+-----------------------+-----------------------+-----
...  | com_contact    | Sample Data-Contact   | sample-data-contact   | ...
-----+----------------+-----------------------+-----------------------+-----
...  | com_content    | Joomla!               | joomla                | ...
-----+----------------+-----------------------+-----------------------+-----
...  | com_thirdparty | ThirdParty Category   | thridparty-category   | ...
-----+----------------+-----------------------+-----------------------+-----
...  | ...            | ...                   | ...                   | ...
-----+----------------+-----------------------+-----------------------+-----

我可以从下面com_banners或从下面的其他核心组件中打印类别，

$categories = JCategories::getInstance('Banners');
$subCategories = $categories->get()->getChildren(true);
print_r($subCategories);

但这表明

“ 致命错误：在第152行的... \ libraries \ legacy \ categories \ categories.php中找不到类'ThirdPartyCategories'”

尝试按以下方式打印另一个扩展的类别时，

$categories = JCategories::getInstance('ThirdParty');
$subCategories = $categories->get()->getChildren(true);
print_r($subCategories);

我与joomla库中的旧类别有什么关系？

注意：该名称ThirdParty仅是一个占位符，可以是任何第三方扩展名。

经过研究后，事实证明，我正在使用的第三方组件没有创建文件，..\components\com_thirdparty\helpers\category.php 而该文件是实现在组件的helpers目录中ThirdPartyCategories扩展的类所必需的，JCategories如下所述

defined('_JEXEC') or die;

/**
 * ThirdParty Component Category Tree
 */
class ThirdPartyCategories extends JCategories
{
    /**
     * Constructor
     *
     * @param   array  $options  Array of options
     */
    public function __construct($options = array())
    {
        $options['table']      = '#__thirdparty';
        $options['extension']  = 'com_thirdparty';
        $options['statefield'] = 'published';
        parent::__construct($options);
    }
}