ChainEncoder.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\EncoderInterface;
use Symfony\Component\Serializer\Encoder\NormalizationAwareInterface;
use Symfony\Component\Serializer\Exception\RuntimeException;

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

  /**
   * {@inheritdoc}
   */
  public final function encode($data, $format, array $context = array()) {
    return $this
      ->getEncoder($format)
      ->encode($data, $format, $context);
  }

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

  /**
   * Checks whether the normalization is needed for the given format.
   *
   * @param string $format
   *
   * @return Boolean
   */
  public function needsNormalization($format) {
    $encoder = $this
      ->getEncoder($format);
    if (!$encoder instanceof NormalizationAwareInterface) {
      return true;
    }
    if ($encoder instanceof self) {
      return $encoder
        ->needsNormalization($format);
    }
    return false;
  }

  /**
   * Gets the encoder supporting the format.
   *
   * @param string $format
   *
   * @return EncoderInterface
   * @throws RuntimeException if no encoder is found
   */
  private function getEncoder($format) {
    if (isset($this->encoderByFormat[$format]) && isset($this->encoders[$this->encoderByFormat[$format]])) {
      return $this->encoders[$this->encoderByFormat[$format]];
    }
    foreach ($this->encoders as $i => $encoder) {
      if ($encoder
        ->supportsEncoding($format)) {
        $this->encoderByFormat[$format] = $i;
        return $encoder;
      }
    }
    throw new RuntimeException(sprintf('No encoder found for format "%s".', $format));
  }

}