Symfony2 Forms和Polymorphic collections

Question

我正在玩弄Symfony2和Im，并不确定Symfony2如何处理View组件中的Polymorphic集合。看来我可以用AbstractChildren集合创建一个实体，但不知道如何在Form Type类中使用它。

例如，我有以下实体关系。

/** 
* @ORM\Entity 
*/ 
class Order 
{ 
    /** 
    * @ORM\OneToMany(targetEntity="AbstractOrderItem", mappedBy="order", cascade={"all"}, orphanRemoval=true) 
    * 
    * @var AbstractOrderItem $items; 
    */ 
    $orderItems; 
    ... 
} 


/** 
* Base class for order items to be added to an Order 
* 
* @ORM\Entity 
* @ORM\InheritanceType("JOINED") 
* @ORM\DiscriminatorColumn(name="discr", type="string") 
* @ORM\DiscriminatorMap({ 
*  "ProductOrderItem" = "ProductOrderItem", 
*  "SubscriptionOrderItem " = "SubscriptionOrderItem " 
* }) 
*/ 
class AbstractOrderItem 
{ 
    $id; 
    ... 
} 

/** 
* @ORM\Entity 
*/ 
class ProductOrderItem extends AbstractOrderItem 
{ 
    $productName; 
} 

/** 
* @ORM\Entity 
*/ 
class SubscriptionOrderItem extends AbstractOrderItem 
{ 
    $duration; 
    $startDate; 
    ... 
} 

足够简单，但是当IM创建形式为我的订单班

class OrderType extends AbstractType 
{ 
    public function buildForm(FormBuilder $builder, array $options) 
    { 
     $builder->add('items', 'collection', array('type' => AbstractOrderItemType())); 
    } 
} 

我不确定如何处理这种情况下，你需要有效形式不同类型在每一类项目采集？

Answer 1

我最近处理了一个类似的问题 - Symfony本身对多态集合并没有任何让步，但很容易使用EventListener为它们提供支持来扩展表单。

下面是我的事件监听，它采用了类似的方法的Symfony \分量\表格\延期\核心\事件监听\ ResizeFormListener，事件侦听器提供了收集表型正常功能的内容：

namespace Acme\VariedCollectionBundle\EventListener; 

use Symfony\Component\EventDispatcher\EventSubscriberInterface; 
use Symfony\Component\Form\FormFactoryInterface; 
use Symfony\Component\Form\FormEvent; 
use Symfony\Component\Form\FormEvents; 

class VariedCollectionSubscriber implements EventSubscriberInterface 
{ 
    protected $factory; 
    protected $type; 
    protected $typeCb; 
    protected $options; 

    public function __construct(FormFactoryInterface $factory, $type, $typeCb) 
    { 
     $this->factory = $factory; 
     $this->type = $type; 
     $this->typeCb = $typeCb; 
    } 

    public static function getSubscribedEvents() 
    { 
     return array(
      FormEvents::PRE_SET_DATA => 'fixChildTypes' 
     ); 
    } 

    public function fixChildTypes(FormEvent $event) 
    { 
     $form = $event->getForm(); 
     $data = $event->getData(); 

     // Go with defaults if we have no data 
     if($data === null || '' === $data) 
     { 
      return; 
     } 

     // It's possible to use array access/addChild, but it's not a part of the interface 
     // Instead, we have to remove all children and re-add them to maintain the order 
     $toAdd = array(); 
     foreach($form as $name => $child) 
     { 
      // Store our own copy of the original form order, in case any are missing from the data 
      $toAdd[$name] = $child->getConfig()->getOptions(); 
      $form->remove($name); 
     } 
     // Now that the form is empty, build it up again 
     foreach($toAdd as $name => $origOptions) 
     { 
      // Decide whether to use the default form type or some extension 
      $datum = $data[$name] ?: null; 
      $type = $this->type; 
      if($datum) 
      { 
       $calculatedType = call_user_func($this->typeCb, $datum); 
       if($calculatedType) 
       { 
        $type = $calculatedType; 
       } 
      } 
      // And recreate the form field 
      $form->add($this->factory->createNamed($name, $type, null, $origOptions)); 
     } 
    } 
} 

使用这种方法的缺点是，为了识别提交时多态实体的类型，您必须在绑定表单之前在相关实体上设置表单上的数据，否则，侦听器无法确定哪种类型数据真的是。你可以用FormTypeGuesser系统解决这个问题，但这超出了我的解决方案的范围。

同样，虽然使用此系统的集合仍然支持添加/删除行，但它会假设所有新行都是基本类型 - 如果您尝试将它们设置为扩展实体，它会给您一个错误关于包含额外字段的表单。

为了简单起见，我使用的方便型封装这个功能 - 参见下面的这一点，一个例子：

namespace Acme\VariedCollectionBundle\Form\Type; 

use Acme\VariedCollectionBundle\EventListener\VariedCollectionSubscriber; 
use JMS\DiExtraBundle\Annotation\FormType; 
use Symfony\Component\OptionsResolver\OptionsResolverInterface; 
use Symfony\Component\Form\FormBuilderInterface; 
use Symfony\Component\Form\AbstractType; 

/** 
* @FormType() 
*/ 
class VariedCollectionType extends AbstractType 
{ 
    public function buildForm(FormBuilderInterface $builder, array $options) 
    { 
     // Tack on our event subscriber 
     $builder->addEventSubscriber(new VariedCollectionSubscriber($builder->getFormFactory(), $options['type'], $options['type_cb'])); 
    } 

    public function getParent() 
    { 
     return "collection"; 
    } 

    public function setDefaultOptions(OptionsResolverInterface $resolver) 
    { 
     $resolver->setRequired(array('type_cb')); 
    } 

    public function getName() 
    { 
     return "varied_collection"; 
    } 
} 

实施例： 命名空间的Acme \ VariedCollectionBundle \表;

use Acme\VariedCollectionBundle\Entity\TestModelWithDate; 
use Acme\VariedCollectionBundle\Entity\TestModelWithInt; 
use JMS\DiExtraBundle\Annotation\FormType; 
use Symfony\Component\Form\FormBuilderInterface; 
use Symfony\Component\Form\AbstractType; 

/** 
* @FormType() 
*/ 
class TestForm extends AbstractType 
{ 
    public function buildForm(FormBuilderInterface $builder, array $options) 
    { 
     $typeCb = function($datum) { 
      if($datum instanceof TestModelWithInt) 
      { 
       return "test_with_int_type"; 
      } 
      elseif($datum instanceof TestModelWithDate) 
      { 
       return "test_with_date_type"; 
      } 
      else 
      { 
       return null; // Returning null tells the varied collection to use the default type - can be omitted, but included here for clarity 
      } 
     }; 

     $builder->add('demoCollection', 'varied_collection', array('type_cb' => $typeCb, /* Used for determining the per-item type */ 
                    'type' => 'test_type', /* Used as a fallback and for prototypes */ 
                    'allow_add' => true, 
                    'allow_remove' => true)); 
    } 

    public function getName() 
    { 
     return "test_form"; 
    } 
} 

Answer 2

在你给的例子中，你将不得不为那些ProductOrder和SubscriptionOrder

class ProductOrderType extends AbstractType 
{ 
    public function buildForm(FormBuilder $builder, array $options) 
    { 
     //Form elements related to Product Order here 
    } 
} 

和

class SubsciptionOrderType extends AbstractType 
{ 
    public function buildForm(FormBuilder $builder, array $options) 
    { 
     //Form elements related SubscriptionOrder here 
    } 
} 

在您的订单类型的表单类中添加这两种形式的创建不同的表单类，像这样

class OrderType extends AbstractType 
{ 
    public function buildForm(FormBuilder $builder, array $options) 
    { 
     $builder->add('product',new ProductOrderType()) 
     $builder->add('subscription',new SubsciptionOrderType()) 
     //Form elements related to order here 
    } 
} 

现在这添加了两种形式SubsciptionOrderType，ProductOrder键入主表单OrderType。因此，如果您初始化此表单，稍后在控制器中，您将获得OrderType和OrderType的所有字段。

我希望这回答你的问题，如果仍然不清楚，请通过文档在这里嵌入多个表单。 http://symfony.com/doc/current/cookbook/form/form_collections.html