CallbackTransformer.php

<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Form;

use Symfony\Component\Form\Exception\UnexpectedTypeException;
use Symfony\Component\Form\Exception\TransformationFailedException;

class CallbackTransformer implements DataTransformerInterface
{
    /**
     * The callback used for forward transform.
     *
     * @var callable
     */
    private $transform;

    /**
     * The callback used for reverse transform.
     *
     * @var callable
     */
    private $reverseTransform;

    /**
     * Constructor.
     *
     * @param callable $transform        The forward transform callback
     * @param callable $reverseTransform The reverse transform callback
     *
     * @throws \InvalidArgumentException when the given callbacks is invalid
     */
    public function __construct($transform, $reverseTransform)
    {
        if (!is_callable($transform)) {
            throw new \InvalidArgumentException('Argument 1 should be a callable');
        }
        if (!is_callable($reverseTransform)) {
            throw new \InvalidArgumentException('Argument 2 should be a callable');
        }

        $this->transform = $transform;
        $this->reverseTransform = $reverseTransform;
    }

    /**
     * Transforms a value from the original representation to a transformed representation.
     *
     * @param mixed $data The value in the original representation
     *
     * @return mixed The value in the transformed representation
     *
     * @throws UnexpectedTypeException       when the argument is not of the expected type
     * @throws TransformationFailedException when the transformation fails
     */
    public function transform($data)
    {
        return call_user_func($this->transform, $data);
    }

    /**
     * Transforms a value from the transformed representation to its original
     * representation.
     *
     * @param mixed $data The value in the transformed representation
     *
     * @return mixed The value in the original representation
     *
     * @throws UnexpectedTypeException       when the argument is not of the expected type
     * @throws TransformationFailedException when the transformation fails
     */
    public function reverseTransform($data)
    {
        return call_user_func($this->reverseTransform, $data);
    }
}