Zf2 and Doctrine Annotations give trouble to make a 'new' form - php

Question

I am trying to create a form to create a new product.
In my Controller I have the follwoing code:
public function newAction() {
$repo = $this->getEntityManager()->getRepository('Swap\Entity\Product');
$builder = new AnnotationBuilder($this->getEntityManager());
$form = $builder->createForm($repo);
$config = $this->getModuleConfig();
if (isset($config['swap_form_extra'])) {
foreach ($config['swap_form_extra'] as $field) {
$form->add($field);
}
}
$form->setHydrator(new DoctrineHydrator($this->getEntityManager(), 'Swap\Entity\Product'));
$form->bind($repo);
return new ViewModel(array('form' => $form));
}
Now this gives me the follwing error:
Class "Swap\EntityRepository\Product" sub class of "Doctrine\ORM\EntityRepository" is not a valid entity or mapped super class.
I am not sure if this has anything to do with it: But when you want to edit an object in a form you can do:
$repo = $this->getEntityManager()->getRepository('Swap\Entity\Product');
$id = (int) $this->getEvent()->getRouteMatch()->getParam('id', '0');
$product = $repo->find(1);
$productNames = $this->getEntityManager()->getRepository('Swap\Entity\ProductGroup')->findAll();
$product->SetProductGroup($productNames);
$builder = new AnnotationBuilder($this->getEntityManager());
$form = $builder->createForm($product);
But not sure how to get the product in a form to create a new entity.
Any suggestions?

Answer 1

Forms are build around entities, not with repositories. There is a clear distinction between them in Doctrine: entities are objects that hold state, that are related to database tables and where you can create new ones, update existing ones and remove ones for. Repositories are helper classes. They help you to find entities. Usually you find one by id or find them all, but repositories help you also to find one or multiple entities via a specific property.
That said, the form builder requires entities. In both the edit as the new action, you want to build based on the entity. In the editAction, you do this (pseudo):
$product = findMyProductEntity();
$form = $builder->createForm($product);
In the newAction, you do this (pseudo):
$repository = findMyProductRepository();
$form = $builder->buildForm($repository);
In this case, you also need to inject the entity and not the repository. How? Simply, just use new:
public function newAction()
{
$product = new Swap\Entity\Product;
$builder = new AnnotationBuilder($this->getEntityManager());
$form = $builder->createForm($product);
// Rest of your code
}

Answer 2

You told it to build the form from an entity repository instance, and not an entity itself.
$form = $builder->createForm($repo); // $repo is not an entity!