Controller doesn't return OneToMany relational field in Symfony 2

Question

I need return full response with Document model. I have response but there are absent some fields, which are defined in entity. For example I need to have in response both 'campaign' and 'template' properties - but actually 'campaign' is absent.

Below are my controller and entity.

I have such action in my controller:

/**
 * @REST\View(serializerGroups={"Default", "DocumentDetails"})
 * @REST\Get("/{id}", requirements={"id" = "\d+"})
 * @ParamConverter("document", class="AppBundle:Document");
 */
public function showAction(Request $request, Document $document)
{
    return $document;
}

But the Document entity has relations:

/**
* Document entity
 *
 * @ORM\Entity(repositoryClass="AppBundle\Repository\DocumentRepository")
 * @ORM\Table(name="document")
 * @ORM\HasLifecycleCallbacks()
 *
 * @Serializer\ExclusionPolicy("all")
 */
class Document
{
.......

/**
 * @var campaign
 * @ORM\ManyToOne(targetEntity="Campaign", inversedBy="documents")
 * @ORM\JoinColumn(name="campaign", referencedColumnName="id")
 *
 * @Serializer\Expose()
 */
protected $campaign; // **THIS FIELD IS ABSENT - WHY !???** 

/**
 * @var DocumentTemplate Szablon dokumentu
 *
 * @ORM\ManyToOne(targetEntity="DocumentTemplate")
 * @ORM\JoinColumn(name="template_id", referencedColumnName="id")
 *
 * @Serializer\Expose()
 */
protected $template; // **THIS PROPERTY IS DISPLAYED**

.......

$document->template is present in $document response. But $document->campaign is absent. What is wrong ? Probably it is related somehow to serializerGroups ?? Thanks for any help.

Answer 1

Solved ! Thanks everyone for the help. The issue was related to JMSSerializer. There was need to set this serializer in config file services.yml at first:

app.serializer.listener.document:
    class: AppBundle\EventListener\Serializer\DocumentSerializationListener
    tags:
        - { name: jms_serializer.event_subscriber }

And then create this listener which is creating form child-field campaign and inserting there Campaign object:

<?php


namespace AppBundle\EventListener\Serializer;


use AppBundle\Entity\Campaign;
use AppBundle\Entity\Document;
use JMS\Serializer\EventDispatcher\EventSubscriberInterface;
use JMS\Serializer\EventDispatcher\ObjectEvent;

class DocumentSerializationListener implements EventSubscriberInterface
{
    /**
     * @param ObjectEvent $event
     * @return void
     */
    public function onPostSerialize(ObjectEvent $event)
    {
        $entity = $event->getObject();

        if (!($entity instanceof Document)) {
            return ;
        }

        $groups = $event->getContext()->attributes->get('groups')->getOrElse([]);

        if (in_array('DocumentDetails', $groups)) {
            $visitor = $event->getVisitor();

            $campaign = $this->getCampaignClone($entity->getCampaign());

            if ($visitor->hasData('campaign')) {
                $visitor->setData('campaign', $campaign);
            } else {
                $visitor->addData('campaign', $campaign);
            }
        }
    }

    /**
     * @inheritdoc
     */
    public static function getSubscribedEvents()
    {
        return [
            [
                'event' => 'serializer.post_serialize',
                'class' => 'AppBundle\Entity\Document',
                'method' => 'onPostSerialize'
            ]
        ];
    }

    private function getCampaignClone(Campaign $documentCampaign)
    {
        $campaign = new \stdClass();
        $campaign->id = $documentCampaign->getId();
        $campaign->title = $documentCampaign->getTitle();
        $campaign->status = $documentCampaign->getStatus();
        $campaign->rows = $documentCampaign->getRows();
        $campaign->createdAt = $documentCampaign->getCreatedAt()->format(DATE_W3C);
        $campaign->updatedAt = $documentCampaign->getUpdated()->format(DATE_W3C);

        return $campaign;
    }
}

This looks weird I know - but this only solution I found to force inserting the Entity into the form request.