symfony2: Applying theme to individual field for collection type - symfony

Question

Just applying a theme to form field is easy e.g.:
{% form_theme form _self %}
{% block _product_name_widget %}
{{ block('field_widget') }}
{% endblock %}
but what if the form field is of collection type? E.g.: product['models'][1][comment,
I have no ideas how to customize it. (This may be the first kind question here)
UPDATE: anwser here: Symfony2: collection form field type with data-prototype

Answer 1

As of Symfony 2.1 (it may work as well for 2.0 but not sure) to apply theme for collection you do this way:
Lets say we have a collection of products (we have multiple Product entities)
Controller:
$repository = $this->getDoctrine()->getRepository('ExampleBundle:Product');
$products = $repository->findAll();
$productCollection = new Products;
foreach ($products as $product) {
$productCollection->getProducts()->add($product);
}
$collection = $this->createForm(new ProductsType, $productCollection);
return $this->render('ExampleBundle:Default:index.html.twig', array(
'collection' => $collection->createView()
));
Your theme can look like this:
{% block _productsType_products_entry_name_row %}
<div class="yourDivName">{{ block('form_widget') }}</div>
{% endblock %}
{% block _productsType_products_entry_description_row %}
<div class="yourDivDescription">{{ block('form_widget') }}</div>
{% endblock %}
The trick is with "entry" where twig will do the job for you to apply above changes to each row and for each field you specify
Hope that helps!

Answer 2

You can do with override collection_widget block:
{% block collection_widget %}
{% spaceless %}
{% if prototype is defined %}
{% set attr = attr|merge({'data-prototype': form_row(prototype) }) %}
{% endif %}
{{ block('form_widget') }}
{% endspaceless %}
{% endblock collection_widget %}
If you want how to customize form collection type try to look at this Product Bundle

Answer 3

You can override the collection_widget theme for a single field by referencing the widget like this as well.
For example, if "categories" is a "collection" widget on a ProductType form, you can do this.
{% block _product_categories_widget %}
{% for child in form %}
{{- form_row(child) -}}
<hr>
{% endfor %}
{% endblock %}