symfony - How to fix these form theming problems in Symfony2? -

i have multiple questions forms

first question, how wrap input div (with classes) in form builder?

so want wrap submit input :

->add('submit', 'submit', array(     'attr' =>  array(         'class' => 'btn btn-success'     ), )) 

to result :

<div class="col-sm-offset-2 col-sm-10">     <input type="submit" class="btn btn-success"/> </div> 

second question, how set template form via form builder?

is there method in wrong example? or not?

public function buildform(formbuilderinterface $builder, array $options) {     $builder         ->settemplate('::vertical-form.html.twig')         ->add(...) } 

last question, how add class form element in custom form template?

i grab piece of code form_div_layout.html.twig , add class (9th line) form element. doesn't work, can't see element in view!

{% block form_start %}     {% spaceless %}         {% set method = method|upper %}         {% if method in ["get", "post"] %}             {% set form_method = method %}         {% else %}             {% set form_method = "post" %}         {% endif %}         <form class="form-horizontal" role="form" name="{{ form.vars.name }}" method="{{ form_method|lower }}" action="{{ action }}"{% attrname, attrvalue in attr %} {{ attrname }}="{{ attrvalue }}"{% endfor %}{% if multipart %} enctype="multipart/form-data"{% endif %}>         {% if form_method != method %}             <input type="hidden" name="_method" value="{{ method }}" />         {% endif %}     {% endspaceless %} {% endblock form_start %} 

in views, i've piece of code render form:

{% form_theme form '::custom-form.html.twig' %} {{ form(form_name) }} 

maybe should copy form_div_layout.html.twig file template , tweak need?

thanks in advance help!

1. in opinion in case should create submit button manually in template (not form class)

2. i don't know solution looks this.

3. you should copy file content. read this: http://symfony.com/doc/current/cookbook/form/form_customization.html