似乎没有内置的 Symfony 解决方案来做我想做的事,所以我按照Jakub Matczak 的建议创建了自定义约束。
UPD:当您发送表单以编辑您的实体时,此解决方案会引发验证错误。为避免此行为,您需要手动改进此约束。
约束:
namespace AppBundle\Validator\Constraints;
use Symfony\Component\Validator\Constraint;
class UniqueValueInEntity extends Constraint
{
public $message = 'This value is already used.';
public $entityClass;
public $field;
public function getRequiredOptions()
{
return ['entityClass', 'field'];
}
public function getTargets()
{
return self::PROPERTY_CONSTRAINT;
}
public function validatedBy()
{
return get_class($this).'Validator';
}
}
验证器:
namespace AppBundle\Validator\Constraints;
use Doctrine\ORM\EntityManager;
use InvalidArgumentException;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
class UniqueValueInEntityValidator extends ConstraintValidator
{
/**
* @var EntityManager
*/
private $em;
public function __construct(EntityManager $em)
{
$this->em = $em;
}
public function validate($value, Constraint $constraint)
{
$entityRepository = $this->em->getRepository($constraint->entityClass);
if (!is_scalar($constraint->field)) {
throw new InvalidArgumentException('"field" parameter should be any scalar type');
}
$searchResults = $entityRepository->findBy([
$constraint->field => $value
]);
if (count($searchResults) > 0) {
$this->context->buildViolation($constraint->message)
->addViolation();
}
}
}
服务:
services:
app.validator.unique_value_in_entity:
class: AppBundle\Validator\Constraints\UniqueValueInEntityValidator
arguments: ['@doctrine.orm.entity_manager']
tags:
- { name: validator.constraint_validator }
使用示例:
private function validate($value): bool
{
$violations = $this->validator->validate($value, [
new Assert\NotBlank(),
new Assert\Email(),
new UniqueValueInEntity([
'entityClass' => User::class,
'field' => 'email',
])
]);
return count($violations) === 0;
}