原则MongoDB ODM不会更改引用对象的状态

Question

I'm Using Symfony2 with the DoctrineMongoDB Bundle. I made a service that receives Informations in JSON Format (Objects).

The Object I'm sending got a property for referencing to another Object in a different collection in the Database.

Changing the reference works. But in case I send another field, like "title" with the ObjectB - it sets the title to the new value in the DataBase. How can I prevent this?

I just want to set the new reference, no manipulation on that Object what so ever.

Here is some Code (shortened)

class Fun{    
   /**
     * @MongoDB\Id(strategy="auto")
     */
    private $id;

   /** @MongoDB\EmbedMany(targetDocument="JokeEmbedded", strategy="set")
    */
   private $jokes = array();

}


class JokeEmbedded
{
    /**
     * @MongoDB\ReferenceOne(targetDocument="JokePattern", cascade={"persist"})
     */
    private $ref;

    /**
     * @MongoDB\String
     */
    private $title;
}

class JokePattern
{
    /**
     * @MongoDB\Id(strategy="AUTO")
     */
    private $id;

    /**
     * @MongoDB\String
     */
    private $title;
}

I'm now sending the following JSON to the Service: (JSON represents the ObjetClass Fun)

[{"id":"1","jokes":[{"ref":{"id":"222", "title":"new title"}]]

My question is now, how do I ignore the new given "title" for the reference I want to Set? I want to have the new reference in the DB set to the ID 222. Nothing more.

Any Help would be great! Thank you!

Edit:

This is the code that handles the JSON Input

$request = $this->getRequest();
//Get JSON-Data
$data = $request->getContent();
$funs = $this->get('serializer')->deserialize(
    $data,
    'ArrayCollection<Acme\FunBundle\Document\Fun>',
    'json'
);

//create documentmanager
$dm = $this->get('doctrine_mongodb')->getManager();

foreach ($funs as $obj) {
        //save to db
        $dm->persist($obj);
    }
$dm->flush();

Answer 1

I managed it with the deserialization context and the list annotation within the JMS SerializerBundle.

Greetings :)