Functional test for http://stackoverflow.com/q/23927996/162228

SO23927996Test.php

<?php

namespace Doctrine\ODM\MongoDB\Tests;

use Doctrine\Common\EventSubscriber;
use Doctrine\ODM\MongoDB\Events;
use Doctrine\ODM\MongoDB\Event\PreUpdateEventArgs;
use Doctrine\ODM\MongoDB\Mapping\Annotations as ODM;

class SO23927996Test extends BaseTest
{
    public function testFoo()
    {
        $this->dm->getEventManager()->addEventSubscriber(new SO23927996Listener());

        $foo = new SO23927996Foo();
        $foo->name = 'foo';

        $this->dm->persist($foo);
        $this->dm->flush();
        $this->dm->clear();

        $foo = $this->findSingleDocument(__NAMESPACE__ . '\SO23927996Foo');
        $bar = $this->findSingleDocument(__NAMESPACE__ . '\SO23927996Bar');

        $this->assertEquals('foo', $foo->name);
        $this->assertNull($bar);

        $foo->name = 'foo-modified';
        $this->dm->flush();
        $this->dm->clear();

        $foo = $this->findSingleDocument(__NAMESPACE__ . '\SO23927996Foo');
        $bar = $this->findSingleDocument(__NAMESPACE__ . '\SO23927996Bar');

        $this->assertEquals('foo-modified', $foo->name);
        $this->assertEquals('bar', $bar->name);
        $this->assertSame($foo, $bar->refOne);
    }

    private function findSingleDocument($class)
    {
        return $this->dm->createQueryBuilder($class)->getQuery()->getSingleResult();
    }
}

/** @ODM\Document */
class SO23927996Foo
{
    /** @ODM\Id */
    public $id;

    /** @ODM\String */
    public $name;
}

/** @ODM\Document */
class SO23927996Bar
{
    /** @ODM\Id */
    public $id;

    /** @ODM\String */
    public $name;

    /** @ODM\ReferenceOne(targetDocument="SO23927996Foo") */
    public $refOne;
}

class SO23927996Listener implements EventSubscriber
{
    public function getSubscribedEvents()
    {
        return array(Events::preUpdate);
    }

    public function preUpdate(PreUpdateEventArgs $args)
    {
        $document = $args->getDocument();

        if ($document instanceOf SO23927996Foo) {
            $bar = new SO23927996Bar();
            $bar->name = 'bar';
            $bar->refOne = $document;

            $dm = $args->getDocumentManager();
            $dm->persist($bar);
            $class = $dm->getClassMetadata(get_class($bar));
            $dm->getUnitOfWork()->recomputeSingleDocumentChangeSet($class, $bar);
        }
    }
}