class CollectionValidator

CollectionValidatorTest.php in drupal/core/vendor/symfony/validator/Symfony/Component/Validator/Tests/Constraints/CollectionValidatorTest.php

class CollectionValidator extends ConstraintValidator {

  /**
   * {@inheritDoc}
   */
  public function validate($value, Constraint $constraint) {
    if (null === $value) {
      return;
    }
    if (!is_array($value) && !($value instanceof \Traversable && $value instanceof \ArrayAccess)) {
      throw new UnexpectedTypeException($value, 'array or Traversable and ArrayAccess');
    }
    $group = $this->context
      ->getGroup();
    foreach ($constraint->fields as $field => $fieldConstraint) {
      if (is_array($value) && array_key_exists($field, $value) || $value instanceof \ArrayAccess && $value
        ->offsetExists($field)) {
        foreach ($fieldConstraint->constraints as $constr) {
          $this->context
            ->validateValue($value[$field], $constr, '[' . $field . ']', $group);
        }
      }
      elseif (!$fieldConstraint instanceof Optional && !$constraint->allowMissingFields) {
        $this->context
          ->addViolationAt('[' . $field . ']', $constraint->missingFieldsMessage, array(
          '{{ field }}' => $field,
        ), null);
      }
    }
    if (!$constraint->allowExtraFields) {
      foreach ($value as $field => $fieldValue) {
        if (!isset($constraint->fields[$field])) {
          $this->context
            ->addViolationAt('[' . $field . ']', $constraint->extraFieldsMessage, array(
            '{{ field }}' => $field,
          ), $fieldValue);
        }
      }
    }
  }

}