Symfony OneToMany Assiociations not working

I have Product entity and ProductAttachment entity. One product should be able to have many attachments. I Used Doctrine mapping OneToMnay – ManyToOne but everytime i get product, it has empty $files collection

ProductAttachment Entity

     * @var ShopsysShopBundleModelProductProduct
     * 
 @ORMManyToOne(targetEntity="ShopsysShopBundleModelProductProduct", inversedBy="files")
     * @ORMJoinColumn(nullable=false, name="product_id", referencedColumnName="id")
     */
    public $product;

Product Entity

     * @var ShopsysShopBundleModelProductProductAttachment[]|DoctrineCommonCollectionsArrayCollection
     *
     * @ORMOneToMany(targetEntity="ShopsysShopBundleModelProductProductAttachment", mappedBy="product", cascade={"persist"})
     */
    public $files;

    public function getFiles()
    {
        return $this->files;
    }

Am i Missing anything?

When i call

dump($product->getFiles());

this is what i get

DoctrineORMPersistentCollection #619d
   snapshot private => array ()
   owner private => ShopsysShopBundleModelProductProduct #e2e7
   association private => array (15)
   em private => DoctrineORMEntityManager #dfae
   backRefFieldName private => "product" (7)
   typeClass private => DoctrineORMMappingClassMetadata #5e75
   isDirty private => false
   collection protected => DoctrineCommonCollectionsArrayCollection #57e3
   |  elements private => array ()
   initialized protected => false

Answer

The problem is Doctrine’s lazy loading of collections, which is indicated on the PersistentCollection object’s initialized property – which is false in your case. Meaning, it wasn’t initialized.

This is usually pretty smart, since you usually don’t need all of your entities relations loaded (and those related entities could have relations themselves etc.). Instead, the persistent collection will act as a proxy / wrapper and only load the collection contents once some part of the collection is actually accessed.

Some collection implementations have some interesting behavior, so I would advise to not expose collections to the “outside” of your entity. So my advice is to change the getFiles to return $this->files->toArray() and making the $files property private.

However, that’s just an advise. In any case, you calling toArray() on any collection should initialize it and make it behave like the array you’d expect.