Doctrine odm referenceMany replicate references

Question

I use symfony2 and Doctrine ODM.

I have a document Publication.

...\Publication:
    fields:
        id:
            id: true
            strategy: INCREMENT
        dateDebut:
            type: date
        dateFin:
            type: date

I have a document podcast whit a referenceMany.

...\Podcast:
    fields:
        id:
            id: true
            strategy: INCREMENT
    referenceMany:
        publications:
          targetDocument: ...\Publication
          cascade: all

When i fired this request :

db.Podcast.find({'_id':2})

this is the result.

{ "_id" : 2, 
...
"publications" : [{"$ref" : "Publication","$id" : 3}]
...
}

When i persit and flush the podcast and i fired this request:

db.Podcast.find({'_id':2})

this is the result.

{ "_id" : 2, 
...
"publications" : [
   {"$ref" : "Publication","$id" : 3}, 
   {"$ref" : "Publication","$id" : 3}
]
...
}

Why the reference are duplicate ????

Answer 1

I found the solution. I have to clear the publication collection before the flush. It's not optimal but it should work.

In the bd :

{ "_id" : 2, 
...
"publications" : [{"$ref" : "Publication","$id" : 3}]
...
}

I have a document podcast :

use Doctrine\Common\Collections\ArrayCollection;
class Podcast implements InterfaceMongoDocument
{
    ......
    private $publications;
    ......

    public function __construct()
    {
        $this->publications = new ArrayCollection();
    }

.......
}

In the service

public function attachPodcast($podcast)
{
    ....
    $podcast->setPublications(new ArrayCollection($publications));
    $this->getRepo()->attach($podcast);
}

In my repository

public function attach(InterfaceMongoDocument $document)
{
        $documentToClearCollection = clone $document;
        $documentToClearCollection->getPublications()->clear();
        $this->entiteManager->persist($document);
        $this->entiteManager->flush();
}

And in the end

{ "_id" : 2, 
...
"publications" : [{"$ref" : "Publication","$id" : 3}]
...
}

Do you know another way to do this????