How to properly count template usage? - php

Question

I'm using Symfony 6.1 with Twig on PHP 8.1. I've already set up my complete layout including fragments/partials/components or whatever we call reusable pieces of the layout at the moment. These fragments include certain kinds of navigations, quotes, tabs and so on which are always supposed to look and work the same and usually only receive a variable with the same name as an array with a few options.
This is how I'm embedding a YouTube-Video for example:
{% set youtube_video = { 'id': 'dQw4w9WgXcQ', 'title': 'Secret Video (unlisted)', 'language': 'en' } %} {% include 'fragment/youtube_video.html.twig' %}
Most of these fragments can be used multiple times on one page (= in the main template of the view or within the base template/s). Some of them however are supposed to be used only once and using them multiple times would create layout issues (e.g. a navigation for mobile devices with a specific CSS id).
For other fragments I would like to have a counter to add a CSS id in addition to a normal class:
<div class="fragment_video" id="fragment_video_{{ counter }}> ... </div>
The question now is how I can count within a fragment template like 'fragment/youtube_video.html.twig' how often this template has been used in that page already. I don't see any Twig functions or anything within the "app" variable for that.
Now I could create a custom Twig function "counter" and call that with with a unique name:
<div class="fragment_video" id="fragment_video_{{ counter('fragment_video') }}> ... </div>
or
{% if counter('fragment_video') == 1 %} ... {% endif %}
BUT how would I store the current count per given name? I don't want to use $GLOBALS in Twig or rather Symfony and storing that information in the session would keep it past the current request. Is there another solution available?
This is how it would look like as a Twig function:
public function getCounter(string $name): int
{
$name = 'twig_counter_'.$name;
if (isset($GLOBALS[$name])) {
++$GLOBALS[$name];
} else {
$GLOBALS[$name] = 1;
}
return $GLOBALS[$name];
}

Answer 1

As suggested by #DarkBee the instance of a TwigExtension object can use properties to keep track of some information:
/**
* #var array<int>
*/
private array $count = [];
...
public function getCounter(string $name): int
{
if (isset($this->count[$name])) {
++$this->count[$name];
} else {
$this->count[$name] = 1;
}
return $this->count[$name];
}