Pagination of a Symfony form collection with KnpPaginatorBundle - forms

Question

like in How to handle Symfony form collection with 500+ items i have got a big symfony form collection. In the mentioned thread someone suggests to use pagination for the collection.
How can i paginate such a form collection with the knpPaginatorBundle?
The form type is like this
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('myType', 'collection', array(
'type' => new MyType(),
))
;
}
My controller generates a form with the collection
$form = $this->createForm(new MyFormCollectionType());
and then i'm trying to use the paginator
$paginator = $this->get('knp_paginator');
$pagination = $paginator->paginate(
$form['myType'],
$request->get('page', 1),
10
);
I think i'm using the wrong target for paginate($target), whats the correct target in a symfony form collection?

Answer 1

Example on Symfony3 :
Catalog Controller
// I want to paginate products (my collection)
$products = $catalog->getProducts(); // ArrayCollection
// Pagination
$paginator = $this->get('knp_paginator');
$pagination = $paginator->paginate($products, $request->query->getInt('page', 1), 10);
// build the form with catalog data
$form = $this->createForm(CatalogProductType::class, $catalog, array("pagination" => $pagination));
// [...]
// show page
return $this->render('catalogs/products.html.twig', array(
'catalog' => $catalog,
'form' => $form->createView(),
'pagination' => $pagination
));
Catalog Form (CatalogProductType)
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder
->add('products', CollectionType::class, array(
'entry_type' => ProductType::class,
'data' => $options['pagination'],
'allow_add' => true,
'allow_delete' => true,
'prototype' => true,
'label' => false,
'by_reference' => false
))
->add('save', SubmitType::class, array(
'attr' => array('class' => 'button-link save'),
'label' => 'Validate'
))
;
}
public function configureOptions(OptionsResolver $resolver)
{
$resolver->setDefaults(array(
'data_class' => 'AppBundle\Entity\Catalog',
'pagination' => null // Don't forget this !
));
}
My view (products.html.twig)
<div class="navigation">{{ knp_pagination_render(pagination) }}</div>
{% if pagination.getTotalItemCount > 0 %}
{% for widget in form.products.children %}
{# Refers to a Twig macro #}
{{ _self.prototype_product(widget) }}
{% endfor %}
{% else %}
<div class="error">The is no product in this catalog</div>
{% endif %}
My products collection is now paginated.

Answer 2

Solution:
Query all entities of the collection, paginate these and set the data attribute of the collection to the paginated value.
Controller:
$allEntities = $em->getRepository('MyBundle:Entity')->findAll();
$paginator = $this->get('knp_paginator');
$pagination = $paginator->paginate(
$allEntities,
$request->get('page', 1),
10
);
$form = $this->createForm(new MyFormCollectionType($pagination));
Form type:
private $data;
public function __construct($data) {
$this->data = $data;
}
public function buildForm(FormBuilderInterface $builder, array $options)
{
$builder->add('myType', 'collection', array(
'type' => new MyType(),
'data' => $this->data,
))
;
}