Part of Thymeleaf fragment included only once - thymeleaf

Question

I have a Thymeleaf fragment like this
<div th:fragment="f1">
<script src="x.js"></script>
<div> ... </div>
</div>
The script part I want to include it only once, even though I will include f1 more than once in the page.
What's the easiest/cleanest way to achieve this?
I can even split this fragment into two fragments and then the problem will be reduced on how to include a fragment only once in a page.
It can be somehow done if we'll be able to manipulate the request attributes from Thymeleaf. I understand that Thymeleaf if for rendering only, but a feature like this could be useful. Even to have something like include-once or if the included fragment has an id(or th:id) attribute, to include it only once.

Answer 1

use #ids.
<div th:fragment="f1">
<script src="x.js" th:if="${#ids.seq('f1.script.') == 'f1.script.1'}"></script>
hello
</div>
or
<div th:fragment="f1">
<script src="x.js" th:if="${#ids.next('f1.script.') == 'f1.script.1'}" th:id="${#ids.seq('f1.script.')}"></script>
hello
</div>