Symfony2 数据转换器无法转换

Question

大家好，我正在尝试制作具有对象隐藏字段（正在构建）的 FloorType 表单，并且我无法使用食谱中的转换代码转换对象实体。

http://symfony.com/doc/2.7/cookbook/form/data_transformers.html

代码如下：

变压器

namespace George\FloorBundle\Form\DataTransformer;

use  George\ObjectsBundle\Entity\Object;
use Doctrine\Common\Persistence\ObjectManager;
use Symfony\Component\Form\DataTransformerInterface;
use Symfony\Component\Form\Exception\TransformationFailedException;

class ObjectToNumberTransformer implements DataTransformerInterface
{
private $manager;

public function __construct(ObjectManager $manager)
{
    $this->manager = $manager;
}

/**
 * Transforms an object (issue) to a string (number).
 *
 * @param  Object|null $issue
 * @return string
 */
public function transform($object)
{
    if (null === $object) {
        return '';
    }

    return $object->getId();
}

/**
 * Transforms a string (number) to an object (issue).
 *
 * @return Object|null
 * @throws TransformationFailedException if object (issue) is not found.
 */
public function reverseTransform($objectNumber)
{
    // no issue number? It's optional, so that's ok
    if (!$objectNumber) {
        return;
    }

    $object= $this->manager
        ->getRepository('ObjectsBundle:Object')
        // query for the issue with this id
        ->find($objectNumber)
    ;

    if (null === $object) {
        // causes a validation error
        // this message is not shown to the user
        // see the invalid_message option
        throw new TransformationFailedException(sprintf(
            'An issue with number "%s" does not exist!',
            $objectNumber
        ));
    }

    return $object;
}
}

楼层类型

namespace George\FloorBundle\Form;

use Symfony\Component\Form\AbstractType;
use Symfony\Component\Form\FormBuilderInterface;
use Symfony\Component\OptionsResolver\OptionsResolverInterface;
use George\FloorBundle\Form\DataTransformer\ObjectToNumberTransformer;
use Doctrine\Common\Persistence\ObjectManager;

class FloorType extends AbstractType
{
private $manager;

public function __construct(ObjectManager $manager)
{
    $this->manager = $manager;
}
/**
 * @param FormBuilderInterface $builder
 * @param array $options
 */
public function buildForm(FormBuilderInterface $builder, array $options)
{

    $builder
        ->add('translations', 'a2lix_translations',array(
            'required_locales' => array('bg','en')
        ))
    ->add('object')->addModelTransformer(new ObjectToNumberTransformer($this->manager));
}

/**
 * @param OptionsResolverInterface $resolver
 */
public function setDefaultOptions(OptionsResolverInterface $resolver)
{
    $resolver->setDefaults(array(
        'data_class' => 'George\FloorBundle\Entity\Floor'
    ));
}

/**
 * @return string
 */
public function getName()
{
    return 'george_floorbundle_floor';
}
}

创建CreteForm

private function createCreateForm(Floor $entity)
{
    $manager = $this->getDoctrine()->getManager();
    $form = $this->createForm(new FloorType($manager), $entity, array(
        'action' => $this->generateUrl('admin_floor_create'),
        'method' => 'POST',
    ));

    $form->add('submit', 'submit', array('label' => 'Create'));

    return $form;
}

服务

 <services>
    <service id="app.form.type.task" class="George\FloorBundle\Form\FloorType">
        <tag name="form.type" />
        <argument type="service" id="doctrine.orm.entity_manager"></argument>
    </service>
</services>

而且最大的错误是：

Catchable Fatal Error: Object of class George\ObjectsBundle\Entity\Object could not be converted to string 

有趣的是，服务不起作用，我需要将创建表单放入经理：

$manager = $this->getDoctrine()->getManager();

所以我知道变压器发生故障，但我看不到在哪里......有人可以帮助我进行这个转换吗？

Answer 1

你的语法有点不对劲。 $builder->add 实际上返回一个构建器对象，而不是添加的表单对象。书中显示：

$builder->add(
  $builder->create('description', 'textarea')
    ->addModelTransformer(...)
);

在你的情况下，它会是这样的：

$builder
  ->add('translations', 'a2lix_translations',array(
        'required_locales' => array('bg','en')
  ))
  ->add(
    $builder->create('object','text')
      ->addModelTransformer(new ObjectToNumberTransformer($this->manager))
  ));

可能有括号搞砸了，但你明白了。

Answer 2

你应该使用这个

$builder
    ->add('translations', 'a2lix_translations',array(
        'required_locales' => array('bg','en')
    ))
->add('object');
$builder->get('object')->addModelTransformer(new ObjectToNumberTransformer($this->manager));

而不是

$builder
        ->add('translations', 'a2lix_translations',array(
            'required_locales' => array('bg','en')
        ))
        ->add('object')->addModelTransformer(new ObjectToNumberTransformer($this->manager));

希望对你有帮助！！

Answer 3

关于第二个问题的解决方案是在服务中使用别名：

<services>
    <service id="app.form.type.floor" class="George\FloorBundle\Form\FloorType">
        <tag name="form.type" alias="george_floorbundle_floor" />
        <argument type="service" id="doctrine.orm.entity_manager"></argument>
    </service>
</services>

我在哪里创建表单：

 $form = $this->createForm('george_floorbundle_floor', $entity, array(
    'action' => $this->generateUrl('admin_floor_update', array('id' => $entity->getId())),
    'method' => 'PUT',
   ));