Symfony2 Forms和Polymorphic collections

Question

我正在玩弄Symfony2和Im，並不確定Symfony2如何處理View組件中的Polymorphic集合。看來我可以用AbstractChildren集合創建一個實體，但不知道如何在Form Type類中使用它。

例如，我有以下實體關係。

/** 
* @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; 
    ... 
} 

足夠簡單，但是當IM創建形式爲我的訂單班

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

我不確定如何處理這種情況下，你需要有效形式不同類型在每一類項目採集？

Answer 1

我最近處理了一個類似的問題 - Symfony本身對多態集合並沒有任何讓步，但很容易使用EventListener爲它們提供支持來擴展表單。

下面是我的事件監聽，它採用了類似的方法的Symfony \分量\表格\延期\核心\事件監聽\ ResizeFormListener，事件偵聽器提供了收集表型正常功能的內容：

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)); 
     } 
    } 
} 

使用這種方法的缺點是，爲了識別提交時多態實體的類型，您必須在綁定表單之前在相關實體上設置表單上的數據，否則，偵聽器無法確定哪種類型數據真的是。你可以用FormTypeGuesser系統解決這個問題，但這超出了我的解決方案的範圍。

同樣，雖然使用此係統的集合仍然支持添加/刪除行，但它會假設所有新行都是基本類型 - 如果您嘗試將它們設置爲擴展實體，它會給您一個錯誤關於包含額外字段的表單。

爲了簡單起見，我使用的方便型封裝這個功能 - 參見下面的這一點，一個例子：

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"; 
    } 
} 

實施例： 命名空間的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

在你給的例子中，你將不得不爲那些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 
    } 
} 

在您的訂單類型的表單類中添加這兩種形式的創建不同的表單類，像這樣

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 
    } 
} 

現在這添加了兩種形式SubsciptionOrderType，ProductOrder鍵入主表單OrderType。因此，如果您初始化此表單，稍後在控制器中，您將獲得OrderType和OrderType的所有字段。

我希望這回答你的問題，如果仍然不清楚，請通過文檔在這裏嵌入多個表單。 http://symfony.com/doc/current/cookbook/form/form_collections.html