具有额外字段的N:M关系的表单编辑不起作用

我正在处理一个表单，该表单处理带有额外参数（额外字段/列）的N:m关系。这就是我迄今为止所做的：

以OrdersType.php形式：

class OrdersType extends AbstractType {
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        // $builder fields
        // $builder fields only need on edit form not in create
        if ($options['curr_action'] !== NULL)
        {
            $builder
                    // other $builder fields
                    ->add("orderProducts", "collection", array(
                        'type' => new OrdersHasProductType(),
                        'allow_add' => true,
                        'allow_delete' => true,
                        'by_reference' => false
            ));
        }
    }
    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'Tanane'FrontendBundle'Entity'Orders',
            'render_fieldset' => FALSE,
            'show_legend' => FALSE,
            'intention' => 'orders_form',
            'curr_action' => NULL
        ));
    }
    public function getName()
    {
        return 'orders';
    }
}

在OrderHasProductType.php:中

class OrdersHasProductType extends AbstractType {
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
                ->add('product', 'text', array(
                    'required' => FALSE,
                    'label' => FALSE
                ))
                ->add('amount', 'text', array(
                    'required' => TRUE,
                    'label' => FALSE
        ));
    }
    public function setDefaultOptions(OptionsResolverInterface $resolver)
    {
        $resolver->setDefaults(array(
            'data_class' => 'Tanane'FrontendBundle'Entity'OrderHasProduct',
            'intention' => 'order_has_product'
        ));
    }
    public function getName()
    {
        return 'order_has_product';
    }
}

最后是Orders.php和OrdersHasProduct.php实体：

class Orders {
    use IdentifiedAutogeneratedEntityTrait;
    // rest of fields for the entity 
    /**
     * @ORM'OneToMany(targetEntity="OrderHasProduct", mappedBy="order", cascade={"all"}) 
     */
    protected $orderProducts;
    protected $products;
    /**
     * @ORM'Column(name="deletedAt", type="datetime", nullable=true)
     */
    protected $deletedAt;
    public function __construct()
    {
        $this->orderProducts = new ArrayCollection();
        $this->products = new ArrayCollection();
    }
    public function getOrderProducts()
    {
        return $this->orderProducts;
    }
    public function getDeletedAt()
    {
        return $this->deletedAt;
    }
    public function setDeletedAt($deletedAt)
    {
        $this->deletedAt = $deletedAt;
    }
    public function getProduct()
    {
        $products = new ArrayCollection();
        foreach ($this->orderProducts as $op)
        {
            $products[] = $op->getProduct();
        }
        return $products;
    }
    public function setProduct($products)
    {
        foreach ($products as $p)
        {
            $ohp = new OrderHasProduct();
            $ohp->setOrder($this);
            $ohp->setProduct($p);
            $this->addPo($ohp);
        }
    }
    public function getOrder()
    {
        return $this;
    }
    public function addPo($ProductOrder)
    {
        $this->orderProducts[] = $ProductOrder;
    }
    public function removePo($ProductOrder)
    {
        return $this->orderProducts->removeElement($ProductOrder);
    }
}
/**
 * @ORM'Entity
 * @ORM'Table(name="order_has_product")
 * @Gedmo'SoftDeleteable(fieldName="deletedAt")
 * @UniqueEntity(fields={"order", "product"})
 */
class OrderHasProduct {
    use IdentifiedAutogeneratedEntityTrait;
    /**
     * Hook timestampable behavior
     * updates createdAt, updatedAt fields
     */
    use TimestampableEntity;
    /**
     * @ORM'ManyToOne(targetEntity="'Tanane'FrontendBundle'Entity'Orders", inversedBy="orderProducts")
     * @ORM'JoinColumn(name="general_orders_id", referencedColumnName="id")
     */
    protected $order;
    /**
     * @ORM'ManyToOne(targetEntity="'Tanane'ProductBundle'Entity'Product", inversedBy="orderProducts")
     * @ORM'JoinColumn(name="product_id", referencedColumnName="id")
     */
    protected $product;
    /**
     * @ORM'Column(type="integer", nullable=false)
     */
    protected $amount;
    /**
     * @ORM'Column(name="deletedAt", type="datetime", nullable=true)
     */
    protected $deletedAt;
    public function setOrder('Tanane'FrontendBundle'Entity'Orders $order)
    {
        $this->order = $order;
    }
    public function getOrder()
    {
        return $this->order;
    }
    public function setProduct('Tanane'ProductBundle'Entity'Product $product)
    {
        $this->product = $product;
    }
    public function getProduct()
    {
        return $this->product;
    }
    public function setAmount($amount)
    {
        $this->amount = $amount;
    }
    public function getAmount()
    {
        return $this->amount;
    }
    public function getDeletedAt()
    {
        return $this->deletedAt;
    }
    public function setDeletedAt($deletedAt)
    {
        $this->deletedAt = $deletedAt;
    }
}

但当我试图在控制器中使用以下代码编辑订单时：

public function editAction(Request $request, $id)
{
    $em = $this->getDoctrine()->getManager();
    $order = $em->getRepository('FrontendBundle:Orders')->find($id);
    $type = $order->getPerson()->getPersonType() === 1 ? "natural" : "legal";
    $params = explode('::', $request->attributes->get('_controller'));
    $actionName = substr($params[1], 0, -6);
    $orderForm = $this->createForm(new OrdersType(), $order, array('action' => '#', 'method' => 'POST', 'register_type' => $type, 'curr_action' => $actionName));
    return array(
        "form" => $orderForm->createView(),
        'id' => $id,
        'entity' => $order
    );
}

我得到这个错误：

表单的视图数据应为标量、数组或''ArrayAccess的实例，但它是类的实例代理__CG__''Tanane''ProductBundle''Entity''Product。你可以避免这种情况将"data_class"选项设置为"Proxies__CG__''Tanane''ProductBundle''Entity''Product"或通过添加转换类实例的视图转换器代理__CG__''Tanane''ProductBundle''Entity''Product到标量、数组或''ArrayAccess的实例。

我找不到也不知道如何修复它，有人能帮我吗？