Fleshgrinder/php-constraint-violations

<?php
/**
 * @author Richard Fussenegger <fleshgrinder@users.noreply.github.com>
 * @copyright 2016 Richard Fussenegger
 * @license MIT
 */

namespace Fleshgrinder\Constraints;

use Countable;
use Exception;
use Generator;
use IteratorAggregate;
use UnexpectedValueException;

/**
 * The violation exception encapsulates a collector and thus constraint violation messages and causes the were
 * encountered during the validation process of domain logic. This exception should not be used while validating user
 * input that is expected to contain errors, however, it can be used in the (named) constructors of value objects to
 * enable the collection of multiple violations and subsequently the transformation of such messages back to user
 * notifications.
 *
 * > **NOTE**
 * >
 * > It is **highly** recommended to extend this exception and create a more meaningful one that is of an equivalent
 * > abstraction than the code that is going to throw it.
 */
class ViolationException extends UnexpectedValueException implements Countable, IteratorAggregate {

    /** @var ViolationCollector */
    protected $violations;

    /** @inheritDoc */
    public function __construct(ViolationCollector $violations) {
        $this->violations = $violations;
        parent::__construct("Encountered {$violations->count()} constraint violations.");
    }

    /** @inheritDoc */
    public function count() {
        return $this->violations->count();
    }

    /**
     * @see ViolationCollector::getCauses()
     * @return Generator|Exception[]
     */
    public function getCauses(): Generator {
        return $this->violations->getCauses();
    }

    /** @inheritDoc */
    public function getIterator() {
        return $this->violations;
    }

    /**
     * @see ViolationCollector::getMessages()
     * @return Generator|string[]
     */
    public function getMessages(): Generator {
        return $this->violations->getMessages();
    }

}