Create UniqueEntityValidator

[robotccm]

Original report by Xavier Leune (Bitbucket: [Xavier Leune](https://bitbucket.org/Xavier Leune), ).

---

Something like that does the job !

#!yml

UniqueEntity(fields={"username", "email"}, repository="\AppBundle\Association\Model\Repository\UserRepository")

#!php

<?php

namespace AppBundle\Validator\Constraints;

use CCMBenchmark\Ting\Repository\RepositoryFactory;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

class UniqueEntityValidator extends ConstraintValidator
{
    private $repositoryFactory;

    public function __construct(RepositoryFactory $repositoryFactory)
    {
        $this->repositoryFactory = $repositoryFactory;
    }

    /**
     * @inheritDoc
     */
    public function validate($entity, Constraint $constraint)
    {
        if (!$constraint instanceof UniqueEntity) {
            throw new UnexpectedTypeException($constraint, UniqueEntity::class);
        }
        $repository = $this->repositoryFactory->get($constraint->repository);

        $fields = (array)$constraint->fields;
        $criteria = [];
        foreach ($fields as $field) {
            $propertyName    = 'get' . $field;
            $criteria[$field] = $entity->$propertyName();
        }

        $myEntity = $repository->getOneBy($criteria);

        if ($myEntity !== null) {
            $this->context->buildViolation($constraint->message)
                ->setParameter('{{ data }}', implode(', ', $criteria))
                ->addViolation();
        }
    }
}

#!php

<?php


namespace AppBundle\Validator\Constraints;


use Symfony\Component\Validator\Constraint;

/**
 * Class UniqueEntity
 *
 * @Annotation
 * @Target({"CLASS", "ANNOTATION"})
 */
class UniqueEntity extends Constraint
{
    public $message = 'Another entity exists for this data: {{ data }}';
    public $repository;
    public $fields = array();

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

    public function getRequiredOptions()
    {
        return ['fields', 'repository'];
    }

    public function getDefaultOption()
    {
        return ['fields', 'repository'];
    }
}

[Deuchnord]

@xavierleune looks like this has been done in 81aea89, hasn't it?