Symfony 2 - Custom validator

ContainsNumeric.php

<?php

namespace AppBundle\Validator\Constraints;

use Symfony\Component\Validator\Constraint;

/**
 * @Annotation
 */
class ContainsNumeric extends Constraint
{
    public $message = '"%string%" is not a valid value.';
}

ContainsNumericValidator.php

<?php

namespace AppBundle\Validator\Constraints;

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

class ContainsNumericValidator extends ConstraintValidator
{
    public function validate($value, Constraint $constraint)
    {
        if ($this->context instanceof ExecutionContextInterface) {
            if (!preg_match('/([0-9]+(\.[0-9]+)?)/', strval($value), $matches)) {
                $this->context->buildViolation($constraint->message)
                    ->setParameter('%string%', $value)
                    ->addViolation();
            }
        }
    }
}

Example.php

<?php

namespace AppBundle\Dto;

use AppBundle\Validator\Constraints as AppAssert;

class Example {
  /**
   * @AppAssert\ContainsNumeric
   */
   protected $value;
   
   //...
}

Custom Validator for Symfony 2 (v 2.8)

http://symfony.com/doc/current/cookbook/validation/custom_constraint.html