php - Symfony2 表单验证器 - 刷新前比较旧值和新值

Question

我想知道是否有一种方法可以在刷新之前比较实体内验证器中的旧值和新值。

我有一个 Server 实体，可以很好地呈现表单。该实体与 status (N->1) 有关系，当状态从 Unracked 更改为 Racked 时，需要检查通过 SSH 和 FTP 访问服务器。如果未实现访问，则验证器应该失败。

我已将验证器回调映射到 Server 实体中的方法 isServerValid() ，如此处所述 http://symfony.com/doc/current/reference/constraints/Callback.html .我显然可以通过 $this->status 访问"new"值，但我怎样才能获得原始值？

在伪代码中，是这样的:

public function isAuthorValid(ExecutionContextInterface $context)
{
    $original = ... ; // get old values
    if( $this->status !== $original->status && $this->status === 'Racked' && $original->status === 'Unracked' )
    {
        // check ftp and ssh connection
        // $context->addViolationAt('status', 'Unable to connect etc etc');
    }
}

提前致谢!

Answer 1

Symfony 2.5 的完整示例 ( http://symfony.com/doc/current/cookbook/validation/custom_constraint.html )

在此示例中，实体“NoDecreasingInteger”的字段“integerField”的新值必须大于存储值。

创建约束:

// src/Acme/AcmeBundle/Validator/Constraints/IncrementOnly.php;
<?php
namespace Acme\AcmeBundle\Validator\Constraints;

use Symfony\Component\Validator\Constraint;

/**
 * @Annotation
 */
class IncrementOnly extends Constraint
{
  public $message = 'The new value %new% is least than the old %old%';

  public function getTargets()
  {
    return self::CLASS_CONSTRAINT;
  }

  public function validatedBy()
  {
    return 'increment_only';
  }
}

创建约束验证器:

// src/Acme/AcmeBundle/Validator/Constraints/IncrementOnlyValidator.php
<?php
namespace Acme\AcmeBundle\Validator\Constraints;

use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;

use Doctrine\ORM\EntityManager;

class IncrementOnlyValidator extends ConstraintValidator
{
  protected $em;

  public function __construct(EntityManager $em)
  {
    $this->em = $em;
  }

  public function validate($object, Constraint $constraint)
  {
    $new_value = $object->getIntegerField();

    $old_data = $this->em
      ->getUnitOfWork()
      ->getOriginalEntityData($object);

    // $old_data is empty if we create a new NoDecreasingInteger object.
    if (is_array($old_data) and !empty($old_data))
      {
        $old_value = $old_data['integerField'];

        if ($new_value < $old_value)
          {
            $this->context->buildViolation($constraint->message)
              ->setParameter("%new%", $new_value)
              ->setParameter('%old%', $old_value)
              ->addViolation();
          }
      }
  }
}

将验证器绑定(bind)到实体:

// src/Acme/AcmeBundle/Resources/config/validator.yml
Acme\AcmeBundle\Entity\NoDecreasingInteger:
  constraints:
     - Acme\AcmeBundle\Validator\Constraints\IncrementOnly: ~

将 EntityManager 注入(inject) IncrementOnlyValidator:

// src/Acme/AcmeBundle/Resources/config/services.yml
services:
   validator.increment_only:
        class: Acme\AcmeBundle\Validator\Constraints\IncrementOnlyValidator
        arguments: ["@doctrine.orm.entity_manager"]
        tags:
            - { name: validator.constraint_validator, alias: increment_only }