How to configure entities in zf2 for ManyToOne unidirectional doctrine mapping - php

Question

I'm having trouble developing a form in zf2 using a doctrine ManyToOne unidirectional relationship. My entities look like this:
namespace AdminMyPages\Entity;
class MyPageItem
{
// ...
/**
* #ORM\ManyToOne(targetEntity="MyMessage")
* #ORM\JoinColumn(name="myMessageID", referencedColumnName="myMessageID")
**/
private $myMessage;
// ...
/**
* Allow null to remove association
*
* #param Collection $myMessage
*/
public function setMyMessage(Collection $myMessage = null)
{
$this->myMessage = $myMessage;
}
/**
* #return myMessage
*/
public function getMyMessage()
{
return $this->myMessage;
}
}
class MyMessage
{
// ...
}
The fieldset for MyPageItemFieldset looks like this:
namespace AdminMyPages\Form;
class MyPageItemFieldset extends Fieldset implements InputFilterProviderInterface
{
public function __construct(ObjectManager $objectManager)
{
parent::__construct('mypage-item-fieldset');
$this->setHydrator(new DoctrineHydrator($objectManager, 'AdminMyPages\Entity\MyPageItem'))
->setObject(new MyPageItem());
// ...
$myMessageFieldset = new MyMessageFieldset($objectManager);
$this->add(array(
'type' => 'Zend\Form\Element\Collection',
'name' => 'myMessage',
'options' => array(
'count' => 1,
'target_element' => $myMessageFieldset
)
));
}
public function getInputFilterSpecification()
{
// ...
return array(
'myMessage' => array(
'required' => false
),
);
}
}
With this configuration I am able to "get" data from the MyMessage through getMyMessage(), so I know that the tables have been joined. However, when I try to bind the entity in a form, I get an error:
File:
C:\xampp\htdocs\GetOut\vendor\zendframework\zendframework\library\Zend\Form\Element\Collection.php:167
Message:
Zend\Form\Element\Collection::setObject expects an array or Traversable object argument; received "DoctrineORMModule\Proxy\__CG__\AdminMyPages\Entity\MyMessage"
Stack trace:
#0 ... Zend\Form\Element\Collection->setObject(Object(DoctrineORMModule\Proxy\__CG__\AdminMyPages\Entity\MyMessage))
...
One thought I have is that, since the ManyToOne relationship will only produce a single match, the MyMessage fieldset is hardly a collection - it's just one item - so Zend\Form\Element\Collection might not be the right form element to use. But, if it's not a collection, what is it?

Answer 1

You are totally right. Your MyMessage should not be a Collection. It should simply be an instance of MyMessage.
You defined a ManyToOne between MyPageItem and MyMessage meaning one page item has one message and a message has many page items. But since it is a unidirectional relationship that last part is never defined.
So the setter should look like this:
/**
* #param MyMessage $myMessage
*/
public function setMyMessage(MyMessage $myMessage = null)
{
$this->myMessage = $myMessage;
}
And you should also change your form field definition to a single MyMessage item.