How to render a tree in Twig

Question

I would like to render a tree with an undetermined depth (children of children of children, etc.). I need to loop through the array recursively; how can I do this in Twig?

Answer 1

First I thought this may be solved in a straightforward way, but it isn't that easy.

You need to create logic, maybe with a PHP class method, when to include a Twig subtemplate and when not.

    {% for key, item in menu %}
        {# Pseudo Twig code #}
        {% if item|hassubitem %}
            {% include "subitem.html.tpl" %}
        {% else %}
            
{{ item }}
        {% endif %}
    {% endfor %}

So you could use the special Twig loop variable, which is available inside a Twig for loop. But I'm not sure about the scope of this loop variable.

This and other information are available on Twigs "for" Docu!