ChainDecoder.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\Serializer\Encoder;

use Symfony\Component\Serializer\Encoder\DecoderInterface;
use Symfony\Component\Serializer\Exception\RuntimeException;

/**
 * Decoder delegating the decoding to a chain of decoders.
 *
 * @author Jordi Boggiano <j.boggiano@seld.be>
 * @author Johannes M. Schmitt <schmittjoh@gmail.com>
 * @author Lukas Kahwe Smith <smith@pooteeweet.org>
 */
class ChainDecoder implements DecoderInterface {
  protected $decoders = array();
  protected $decoderByFormat = array();
  public function __construct(array $decoders = array()) {
    $this->decoders = $decoders;
  }

  /**
   * {@inheritdoc}
   */
  public final function decode($data, $format) {
    return $this
      ->getDecoder($format)
      ->decode($data, $format);
  }

  /**
   * {@inheritdoc}
   */
  public function supportsDecoding($format) {
    try {
      $this
        ->getDecoder($format);
    } catch (RuntimeException $e) {
      return false;
    }
    return true;
  }

  /**
   * Gets the decoder supporting the format.
   *
   * @param string $format
   *
   * @return DecoderInterface
   * @throws RuntimeException if no decoder is found
   */
  private function getDecoder($format) {
    if (isset($this->decoderByFormat[$format]) && isset($this->decoders[$this->decoderByFormat[$format]])) {
      return $this->decoders[$this->decoderByFormat[$format]];
    }
    foreach ($this->decoders as $i => $decoder) {
      if ($decoder
        ->supportsDecoding($format)) {
        $this->decoderByFormat[$format] = $i;
        return $decoder;
      }
    }
    throw new RuntimeException(sprintf('No decoder found for format "%s".', $format));
  }

}