Symfony2在Data Transformer之前形成字段约束验证

Question

我已经创建了需要数据转换器的表单,但是让我自己陷入单一问题:我通过爆炸字符串转换数据(字符串应该被分解为3个部分),一切正常,如果我提供正确的格式字符串,但否则会在数据内部引发错误变换器,因为如果提供了错误的字符串格式,则不会发生转换(这是预期的行为).

所以问题是有没有办法在数据转换之前验证表单字段的正确字符串？我知道默认情况下,数据转换发生在验证之前,但也许有办法以其他方式做到这一点？

我找到了一个可能在这个线程上工作的解决方案:组合约束和数据转换器,但它看起来像粗略的解决方案,除了我需要翻译验证消息,我真的想使用symfony表单的默认翻译方法(不使用翻译服务)

我想,也有来自symfony IRC(Iltar)的人建议通过使用事件来做,但我不知道如何去做 - 如何动态地将数据转换器附加到表单字段？或者可能还有其他方式？

Answer 1

这可能为时已晚,但我最终设法做到了.也许它会帮助你.

这是我的FormType:

class PersonType extends AbstractType{

    public function buildForm(FormBuilderInterface $builder, array $options){
        $builder->add('mother', 'personSelector', array('personEntity' => $options['personEntity']));

    }
}

这是我的customField,其中包含验证:

class PersonSelectorType extends AbstractType{

    public function buildForm(FormBuilderInterface $builder, array $options){
        $transformer = new PersonByFirstnameAndLastnameTransformer($this->entityManager,$options);
        $builder->addModelTransformer($transformer);
        $builder->addEventListener(FormEvents::PRE_SUBMIT, array($this, 'onPreSubmitForm'));
    }

    public function onPreSubmitForm(FormEvent $event){
        $mother     = $event->getData();
        $form       = $event->getForm();
        $options    = $form->getConfig()->getOptions();
        if (!empty($mother)){
            preg_match('#(.*) (.*)#', $mother, $personInformations);
            if (count($personInformations) != 3){
                $form->addError(new FormError('[Format incorrect] Le format attendu est "Prénom Nom".'));
            }else{
                $person = $this->entityManager->getRepository($options['personEntity'])->findOneBy(array('firstname' => $personInformations[1],'lastname' =>$personInformations[2]));
                if ($person === null) {
                    $form->addError(new FormError('Il n\'existe pas de person '.$personInformations[1].' '.$personInformations[2].'.'));
                }
            }
        }
    }
}

这是我的变压器:

class PersonByFirstnameAndLastnameTransformer implements DataTransformerInterface{

    public function reverseTransform($firstnameAndLastname) {
        if (empty($firstnameAndLastname)) { return null; }
        preg_match('#(.*) (.*)#', $firstnameAndLastname, $personInformations);
        $person = $this->entityManager->getRepository($this->options['personEntity'])->findOneBy(array('firstname' =>$personInformations[1],'lastname' =>$personInformations[2]));
        if (count($personInformations) == 3){
            $person = $this->entityManager->getRepository($this->options['personEntity'])->findOneBy(array('firstname' =>$personInformations[1],'lastname' =>$personInformations[2]));
        }
        return $person;
    }

    public function transform($person) {
        if ($person === null) { return ''; }
        return $person->getFirstname().' '.$person->getLastname();
    }
}

Answer 2

也许您可以将表单的实例传递给变压器。如果字符串无法正确解析，只需向表单添加验证错误，如下所示：

<?php
// src/Acme/MyBundle/Form/DataTransformer/StringTransformer.php
namespace Acme\MyBundle\Form\DataTransformer;

use Symfony\Component\Form\DataTransformerInterface;
use Symfony\Component\Form\Exception\TransformationFailedException;
use Doctrine\Common\Persistence\ObjectManager;
use Acme\MyBundle\Entity\MyEntity;
use Acme\MyBundle\Entity\AnotherEntity;
use Acme\MyBundle\Type\MyEntityType;

class StringTransformer implements DataTransformerInterface
{
  /**
   * @var MyEntityType
   */
  private $form;

  /**
   * @param ObjectManager $om
   */
  public function __construct(MyEntityType $form)
  {
    $this->form = $form;
  }

  /**
   * Transforms an object (entity) to a string (number).
   *
   * @param  MyEntity|null $entity
   * @return string
   */
  public function transform($value)
  {
    // ...
  }

  /**
   * Transforms a string (number) to an object (entity).
   *
   * @param  string $number
   *
   * @return MyEntity|null
   *
   * @throws TransformationFailedException if object (entity) is not found.
   */
  public function reverseTransform($value)
  {
    $collection = new ArrayCollection();

    try{
      $vals = explode(',', $value);

      foreach($vals as $v){
        $entity = new AnotherEntity();
        $entity->setValue($v);
        $collection->add($v);
      }

    } catch(\Exception $e){
      $this->form
        ->get('my_location')
        ->addError(new FormError('error message'));
    }

    return $collection;
  }
}