symfony - form_rest command showing previously-rendered Collection field -

i have form collection type field, rendered that:

<div id="beneficiostab" class="opcional">     beneficios     <ul class="beneficios" data-prototype="{{ form_widget(formatendimento.beneficios.get('prototype')) | e }}">         {% beneficio in formatendimento.beneficios %}             <li>{{ form_row(beneficio.cotipobeneficio) }}</li>             <li>{{ form_row(beneficio.vrvalor) }}</li>             <li>{{ form_row(beneficio.boconcedido) }}</li>         {% endfor %}         <li><a href="#" id="addbeneficio">add beneficio</a></li>     </ul> </div> <div style="clear:both"></div> {{ form_rest(formatendimento) }} 

the form's entity can have multiple items of collection, or none.

when entity has items of collection, works fine, when has none, "for" in twig doesn't happen, , "beneficios" div generated in form_rest.

any way can prevent that? in advance.

this seems bug in form rendering. managed disable form rendering in form_rest function, adding code after rendering collection elements:

{% form.uploads.setrendered() %} 

where "uploads" collection field type. doesn't seem best practice me though.

so whole rendering looks this:

 <div id="uploads" data-prototype="{{ form_widget(form.uploads.vars.prototype)|e }}">         {% upload in form.uploads %}             {{ form_widget(upload) }}         {% endfor %}   </div>   {% form.uploads.setrendered() %}