Dynamically map manyToOne relations - symfony

Question

I'm trying to create Symfony Bundle in which entities are defined which can be used in a one-to-many/many-to-one relationship without the needing to rewrite the mapping manually.
I do this by subscribing to the loadClassMetadata event and adding the mapping based on the Interfaces they implement. It is not as simple as using the ResolveTargetEntityListener because that will simply substitute an interface with the concrete class.
An example. I have a Address and a Customer entity. A Customer has many Addresses.
But another bundle may redefine the Customer (or a totally different Entity which can have multiple Addresses). For this reason the Customer implements the AddressableInterface. For ease of use I've implemented this interface in a trait.
In the subscriber I check if the class implements the AddressableInterface. If so it adds an OneToMany to the Address and an ManyToOne to the class which implements the AddressableInterface. (In this example the Customer class)
However this leaves the following error:
The association Entity\Customer#addresses refers to the owning side field Entity\Address#subject which does not exist.
But I setup to association both ways in my subscriber.
Below is the essence of my code.
namespace Entity;
class Address
{
public $subject;
}
namespace Entity;
class Customer implements AddressableInterface
{
use Traits/Addressable;
}
namespace Traits;
trait Addressable //Implements all methods from AddressableInterface
{
protected $addresses;
public function getAddresses()
{
return $this->addresses;
}
public function addAddress(AddressInterface $address)
{
$this->addresses->add($address);
}
public function removeAddress(AddressInterface $address)
{
$this->addresses->removeElement($address);
}
}
And the event subscriber
class DynamicAddressBindingSubscriber implements EventSubscriber
{
public function getSubscribedEvents()
{
return [Events::loadClassMetadata];
}
public function loadClassMetadata(LoadClassMetadataEventArgs $eventArgs)
{
$metadata = $eventArgs->getClassMetadata();
$class = $metadata->getReflectionClass();
if (!in_array(AddressableInterface::class, $class->getInterfaceNames())) {
return;
}
$factory = new \Doctrine\ORM\Mapping\ClassMetadataFactory;
$factory->setEntityManager($eventArgs->getEntityManager());
$addressMetadata = $factory->getMetadataFor(Address::class);
$addressMetadata->mapManyToOne(
[
"targetEntity" => $class->getName(),
"fieldName" => "subject",
"inversedBy" => "addresses"
]
);
$metadata->mapOneToMany(
[
'targetEntity' => Address::class,
'fieldName' => 'addresses',
'mappedBy' => 'subject'
]
);
}
}
I've looked at multiple examples and based most of my code on this article and the Doctrine Bundle source. But I'm stuck at this point because I have no idea why the association can't find the owing side.

Answer 1

Your address class doesn't have getter/setter for the subject field.
Another thing is that if you want to bind addresses to any class, you might prefer to make it a manyToMany relations. I do so with attachments like this:
$metadata->mapManyToMany([
'targetEntity' => '...\FilesBundle\Entity\Attachment',
'fieldName' => 'attachments',
'cascade' => array('persist'),
'joinTable' => array(
'name' => strtolower($namingStrategy->classToTableName($metadata->getName())) . '_attachment',
'joinColumns' => array(
array(
'name' => $namingStrategy->joinKeyColumnName($metadata->getName()),
'referencedColumnName' => $namingStrategy->referenceColumnName(),
'onDelete' => 'CASCADE',
'onUpdate' => 'CASCADE',
),
),
'inverseJoinColumns' => array(
array(
'name' => 'file_id',
'referencedColumnName' => $namingStrategy->referenceColumnName(),
'onDelete' => 'CASCADE',
'onUpdate' => 'CASCADE',
),
)
)
]);
where namingStrategy comes from the event:
$namingStrategy = $eventArgs
->getEntityManager()
->getConfiguration()
->getNamingStrategy()
;