<ul th:fragment="next (categories)">
  <li th:fragment="single (categories)" th:each="category : ${categories}">
    <a th:href="@{${category.status.permalink}}">
      <span th:text="${category.spec.displayName}+' ('+${category.status.visiblePostCount?:0}+' 篇文章)'"> </span>
    </a>
    <th:block th:if="${not #lists.isEmpty(category.children)}">
      <th:block th:replace="~{modules/category-tree :: next (categories=${category.children})}"></th:block>
    </th:block>
  </li>
</ul>
