DataTransferObject-UniqueEntityConstraint

DtoUniqueEntity.php

<?php

namespace App\Validator\Constraints;

use Symfony\Component\Validator\Constraint;

/**
 * @Annotation
 */
class DtoUniqueEntity extends Constraint
{
    public const NOT_UNIQUE_ERROR = 'e777db8d-3af0-41f6-8a73-55255375cdca';

    protected static $errorNames = [
        self::NOT_UNIQUE_ERROR => 'NOT_UNIQUE_ERROR',
    ];

    public $em;

    public $entityClass;

    public $errorPath;

    public $fieldMapping = [];

    public $ignoreNull = true;

    public $message = 'This value is already used.';

    public $repositoryMethod = 'findBy';

    public function getDefaultOption()
    {
        return 'entityClass';
    }

    public function getRequiredOptions()
    {
        return ['fieldMapping', 'entityClass'];
    }

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

    public function validatedBy()
    {
        return DtoUniqueEntityValidator::class;
    }
}

DtoUniqueEntityValidator.php

<?php

namespace App\Validator\Constraints;

use App\Form\DataTransferObject\DataTransferObjectInterface;
use Doctrine\Common\Persistence\ManagerRegistry;
use Doctrine\DBAL\Exception\UniqueConstraintViolationException;
use Doctrine\ORM\Mapping\Entity;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\ConstraintDefinitionException;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

class DtoUniqueEntityValidator extends ConstraintValidator
{
    /** @var DtoUniqueEntity */
    private $constraint;

    private $em;

    private $entityMeta;

    private $registry;

    private $repository;

    /** @var DataTransferObjectInterface */
    private $validationObject;

    public function __construct(ManagerRegistry $registry)
    {
        $this->registry = $registry;
    }

    public function validate($object, Constraint $constraint)
    {
        // Set arguments as class variables
        $this->validationObject = $object;
        $this->constraint       = $constraint;
        $this->checkTypes();

        // Map types to criteria
        $this->entityMeta = $this->getEntityManager()->getClassMetadata($this->constraint->entityClass);
        $criteria         = $this->getCriteria();
        // skip validation if there are no criteria (this can happen when the
        // "ignoreNull" option is enabled and fields to be checked are null
        if (empty($criteria)) {
            return;
        }

        $result = $this->checkConstraint($criteria);
        // If no entity matched the query criteria or a single entity matched,
        // which is the same as the entity being validated, the criteria is
        // unique.
        if (!$result || (1 === \count($result) && current($result) === $this->entityMeta)) {
            return;
        }

        // Property to which to return the violation
        $objectFields = array_keys($this->constraint->fieldMapping);
        $errorPath    = null !== $this->constraint->errorPath
            ? $this->constraint->errorPath
            : $objectFields[0];

        // Value that caused the violation
        $invalidValue = isset($criteria[$this->constraint->fieldMapping[$errorPath]])
            ? $criteria[$this->constraint->fieldMapping[$errorPath]]
            : $criteria[$this->constraint->fieldMapping[0]];

        // Build violation
        $this->context->buildViolation($this->constraint->message)
            ->atPath($errorPath)
            ->setParameter('{{ value }}', $this->formatWithIdentifiers($invalidValue))
            ->setInvalidValue($invalidValue)
            ->setCode(DtoUniqueEntity::NOT_UNIQUE_ERROR)
            ->setCause($result)
            ->addViolation();
    }

    private function checkTypes()
    {
        if (!$this->validationObject instanceof DataTransferObjectInterface) {
            throw new UnexpectedTypeException($this->validationObject, DataTransferObjectInterface::class);
        }

        if (!$this->constraint instanceof DtoUniqueEntity) {
            throw new UnexpectedTypeException($this->constraint, DtoUniqueEntity::class);
        }

        if (null === $this->constraint->entityClass || !\class_exists($this->constraint->entityClass)) {
            throw new UnexpectedTypeException($this->constraint->entityClass, Entity::class);
        }

        if (!\is_array($this->constraint->fieldMapping) || 0 === \count($this->constraint->fieldMapping)) {
            throw new UnexpectedTypeException($this->constraint->fieldMapping, '[objectProperty => entityProperty]');
        }

        if (null !== $this->constraint->errorPath && !is_string($this->constraint->errorPath)) {
            throw new UnexpectedTypeException($this->constraint->errorPath, 'string or null');
        }
    }

    private function getEntityManager()
    {
        if (null !== $this->em) {
            return $this->em;
        }

        if ($this->constraint->em) {
            $this->em = $this->registry->getManager($this->constraint->em);

            if (!$this->em) {
                throw new ConstraintDefinitionException(sprintf('Object manager "%s" does not exist.',
                    $this->constraint->em));
            }
        } else {
            $this->em = $this->registry->getManagerForClass($this->constraint->entityClass);

            if (!$this->em) {
                throw new ConstraintDefinitionException(sprintf('Unable to find the object manager associated with an entity of class "%s".',
                    $this->constraint->entityClass));
            }
        }

        return $this->em;
    }

    private function getCriteria()
    {
        $validationClass = new \ReflectionClass($this->validationObject);

        $criteria = [];
        foreach ($this->constraint->fieldMapping as $objectField => $entityField) {

            // DTO Property (key) should exist on DataTransferObject
            if (!$validationClass->hasProperty($objectField)) {
                throw new ConstraintDefinitionException(sprintf(
                    'Property for fieldMapping key "%s" does not exist on this Object.',
                    $objectField
                ));
            }

            // Entity Property (value) should exist in the Entity Class
            if (!property_exists($this->constraint->entityClass, $entityField)) {
                throw new ConstraintDefinitionException(sprintf(
                    'Property for fieldMapping key "%s" does not exist in given EntityClass.',
                    $objectField
                ));
            }

            // Entity Property (value) should exist in the ORM
            if (!$this->entityMeta->hasField($entityField) && !$this->entityMeta->hasAssociation($entityField)) {
                throw new ConstraintDefinitionException(sprintf(
                    'The field "%s" is not mapped by Doctrine, so it cannot be validated for uniqueness.',
                    $entityField
                ));
            }

            $fieldValue = $validationClass->getProperty($objectField)->getValue($this->validationObject);

            // validation doesn't fail if one of the fields is null and if null values should be ignored
            if (null === $fieldValue && !$this->constraint->ignoreNull) {
                throw new UniqueConstraintViolationException('Unique value can not be NULL');
            }

            $criteria[$entityField] = $fieldValue;

            if (null !== $criteria[$entityField] && $this->entityMeta->hasAssociation($entityField)) {
                /* Ensure the Proxy is initialized before using reflection to
                 * read its identifiers. This is necessary because the wrapped
                 * getter methods in the Proxy are being bypassed.
                 */
                $this->getEntityManager()->initializeObject($criteria[$entityField]);
            }
        }

        return $criteria;
    }

    private function checkConstraint($criteria)
    {
        $result = $this->getRepository()->{$this->constraint->repositoryMethod}($criteria);

        if ($result instanceof \IteratorAggregate) {
            $result = $result->getIterator();
        }

        /* If the result is a MongoCursor, it must be advanced to the first
         * element. Rewinding should have no ill effect if $result is another
         * iterator implementation.
         */
        if ($result instanceof \Iterator) {
            $result->rewind();
            if ($result instanceof \Countable && 1 < \count($result)) {
                $result = [$result->current(), $result->current()];
            } else {
                $result = $result->current();
                $result = null === $result ? [] : [$result];
            }
        } elseif (\is_array($result)) {
            reset($result);
        } else {
            $result = null === $result ? [] : [$result];
        }

        return $result;
    }

    private function formatWithIdentifiers($value)
    {
        if (!is_object($value) || $value instanceof \DateTimeInterface) {
            return $this->formatValue($value, self::PRETTY_DATE);
        }

        if ($this->entityMeta->getName() !== $idClass = get_class($value)) {
            // non unique value might be a composite PK that consists of other entity objects
            if ($this->getEntityManager()->getMetadataFactory()->hasMetadataFor($idClass)) {
                $identifiers = $this->getEntityManager()->getClassMetadata($idClass)->getIdentifierValues($value);
            } else {
                // this case might happen if the non unique column has a custom doctrine type and its value is an object
                // in which case we cannot get any identifiers for it
                $identifiers = [];
            }
        } else {
            $identifiers = $this->entityMeta->getIdentifierValues($value);
        }

        if (!$identifiers) {
            return sprintf('object("%s")', $idClass);
        }

        array_walk($identifiers, function (&$id, $field) {
            if (!is_object($id) || $id instanceof \DateTimeInterface) {
                $idAsString = $this->formatValue($id, self::PRETTY_DATE);
            } else {
                $idAsString = sprintf('object("%s")', get_class($id));
            }

            $id = sprintf('%s => %s', $field, $idAsString);
        });

        return sprintf('object("%s") identified by (%s)', $idClass, implode(', ', $identifiers));
    }

    private function getRepository()
    {
        if (null === $this->repository) {
            $this->repository = $this->getEntityManager()->getRepository($this->constraint->entityClass);
        }

        return $this->repository;
    }
}

Example usage:

fieldMapping should hold a property from the DTO as key and a property from the Entity as value.

<?php

namespace App\Form\DataTransferObject;

use App\Validator\Constraints\DtoUniqueEntity;
use Doctrine\ORM\Mapping as ORM;
use Symfony\Component\Validator\Constraints as Assert;

/**
 * @DtoUniqueEntity(
 *     entityClass="App\Entity\User",
 *     fieldMapping={"emailAddress": "emailAddress"}
 * )
 */
class UserRegistrationData implements DataTransferObjectInterface
{
    /**
     * @var string
     * @Assert\NotBlank()
     * @Assert\Email()
     * @ORM\Column(type="string")
     */
    public $emailAddress;

    /**
     * @var string
     * @Assert\NotBlank()
     * @Assert\Length(
     *     min="10",
     *     minMessage="Strong passwords have a minimum of 10 characters.",
     *     max="2048",
     *     maxMessage="Did you type all this?"
     * )
     */
    public $password;

    /**
     * @var bool
     * @Assert\IsTrue(message="You must accept these to create an account.")
     */
    public $termsAccepted;
}

@webbertakken, first of all, thank you for sharing your solution.

I need your help :) How would your solution work with Embeddables?

I got an entity (User) which has an Embedded (EmailAddress):

/**
 * @ORM\Embedded(class="EmailAddress")
 */
private $email;

On userRepository I use it like this:

$queryBuilder->expr()->eq('u.email.address', ':email');

But this does not work:

/**
 * @DtoUniqueEntity(entityClass="App\Entity\User", fieldMapping={"email": "email.address"}, message="Email already taken")
 * @DtoUniqueEntity(entityClass="App\Entity\User", fieldMapping={"username": "username"}, message="Username already taken")
 */

Because of this:

// Entity Property (value) should exist in the Entity Class
if (!property_exists($this->constraint->entityClass, $entityField)) {
	throw new ConstraintDefinitionException(sprintf(
		'Property for fieldMapping key "%s" does not exist in given EntityClass.',
		$objectField
	));
}

(property email.address does not really exist on entity User because it's an Embedded Object Value mapped to property email)

I have also tried with Embedded without column prefix (columnPrefix=false), but then it passes the property_exists check but fails on Doctrine Query parser, because there it should be 'address' (or whatever property the Embeddable has on its own class).

Thank you in advance <3

Nvm, thank you anyways.
I've just removed the extra check of:

-// Entity Property (value) should exist in the Entity Class
-if (!property_exists($this->constraint->entityClass, $entityField)) {
-	throw new ConstraintDefinitionException(sprintf(
-		'Property for fieldMapping key "%s" does not exist in given EntityClass.',
-		$objectField
-	));
-}

Because after that there is this one:

if (!$this->entityMeta->hasField($entityField) && !$this->entityMeta->hasAssociation($entityField)) {
	throw new ConstraintDefinitionException(sprintf(
		'The field "%s" is not mapped by Doctrine, so it cannot be validated for uniqueness.',
		$entityField
	));
}

When the field exists on ClassMetadata->fieldMappings (which it does when it's Embedded too) this will pass & if it doesn't pass it's because the property does not exist o it's not mapped by Doctrine.

Right now in SF 5.1.x UniqueConstraintViolationException requires a second argument: \Doctrine\DBAL\Driver\DriverException
What should I put there in this example? (line 163)

@sabat24 I could update the example if you provide me with a proposed diff.

I mentioned about it because I use Doctrine DBAL v.2.1.0 (lately v 3.x was released but I didn't check if problem still appears there) and your dependencies allow that. Which leads to a problem that you use following code to throw an exception: throw new UniqueConstraintViolationException('Unique value can not be NULL');

The UniqueConstraintViolationException extends finally Doctrine\DBAL\Exception\DriverException which has got following constructor

    /**
     * @param string                                $message         The exception message.
     * @param \Doctrine\DBAL\Driver\DriverException $driverException The DBAL driver exception to chain.
     */
    public function __construct($message, \Doctrine\DBAL\Driver\DriverException $driverException)

So there is a missing second parameter in your code.

I'm going to call this deprecated in favour of the 7.1 branch of Symfony core.

@fabpot closed symfony/symfony#22592 (comment) as completed in symfony/symfony@5bc490c 1 hour ago