Map a discriminator column to a field with Doctrine 2

Question

In my project I have several class table inheritances like this:

namespace MyProject\\Model;

/**
 * @Entity
 * @InheritanceType(\"JOINED\")
 * @Discriminat         


        

Answer 1

Here's a small example of what I have in one of my ZF2 projects (using Doctrine MongoDB ODM):

// an instance of your entity
$entity = ...;

/** @var \Doctrine\ODM\MongoDB\DocumentManager $documentManager */
$documentManager = $serviceManager->get('DocumentManager');

/** @var \Doctrine\ODM\MongoDB\Mapping\ClassMetadataFactory $factory */
$factory = $documentManager->getMetadataFactory()

/** @var \Doctrine\ODM\MongoDB\Mapping\ClassMetadata $metadata */
$metadata = $factory->getMetadataFor(get_class($object));

if ($metadata->hasDiscriminator()) {
     // assuming $data is result of the previous extraction
     $data[$metadata->discriminatorField] = $metadata->discriminatorValue;
}

What I have done is I've implemented a custom interface DiscriminatorAwareInterface and I only apply the checks to classes that implement it (in your case it would be the class that all "discriminated" classes extend.

As a result I end up with code that looks like this:

// add value of the discrinimator field to entities that support it
if ($object instanceof DiscriminatorAwareInterface) {
    /** @var \Doctrine\ODM\MongoDB\Mapping\ClassMetadata $metadata */
    $metadata = $factory->getMetadataFor(get_class($object));

    if ($metadata->hasDiscriminator()) {
        $data[$metadata->discriminatorField] = $metadata->discriminatorValue;
    }
}

I'm pretty sure it will be the same if you use the standard ORM, except instead of a document manager you will have entity manager.