Form twig customize style - symfony-forms

Question

i have a problem with customization of my form's style..
I extend the form widget in this normal way:
{{ form_label(form.tipi) }}
{{ form_errors(form.tipi) }}
{{ form_widget(form.tipi) }}
But i receive this bad HTML:
<div id="requests_tipi" class="form-control scroll-select">
<input type="checkbox" id="requests_tipi_1" name="requests[tipi][]" value="1" checked="checked">
<label for="requests_tipi_1">Appartamento</label>
<input type="checkbox" id="requests_tipi_2" name="requests[tipi][]" value="2" checked="checked">
<label for="requests_tipi_2">Casa Colonica</label>
<input type="checkbox" id="requests_tipi_3" name="requests[tipi][]" value="3" checked="checked">
<label for="requests_tipi_3">Garage</label>
<input type="checkbox" id="requests_tipi_4" name="requests[tipi][]" value="4">
<label for="requests_tipi_4">Loft</label>
</div>
I would a list like this:
<ul>
<li><label for="requests_tipi_1">Appartamento</label><input type="checkbox" id="requests_tipi_1" name="requests[tipi][]" value="1" checked="checked"></li>
...
</ul>
How can i do for customize my Symfony Form???
Thanks

Answer 1

This is how you customize rendering for individual field (tipi in your case):
http://symfony.com/doc/current/cookbook/form/form_customization.html#how-to-customize-an-individual-field
and this is where original formatting is defined (and where you can take an "inspiration" :) :
https://github.com/symfony/symfony/blob/master/src/Symfony/Bridge/Twig/Resources/views/Form/form_div_layout.html.twig#L45
So, something like this could work (please note i have not tested, it might be needed to be adjusted), just put following code somewhere at the top of the template file:
{% form_theme form _self %}
{% block _requests_tipi_widget %}
<ul {{ block('widget_container_attributes') }}>
{% for child in form %}
<li>
{{ form_label(child, null, {translation_domain: choice_translation_domain}) }}
{{ form_widget(child) }}
</li>
{% endfor %}
</ul>
{% endblock _requests_tipi_widget %}