class JsonDecode

class JsonDecode implements DecoderInterface {

  /**
   * Specifies if the returned result should be an associative array or a nested stdClass object hierarchy.
   *
   * @var Boolean
   */
  private $associative;

  /**
   * Specifies the recursion depth.
   *
   * @var integer
   */
  private $recursionDepth;
  private $lastError = JSON_ERROR_NONE;
  protected $serializer;

  /**
   * Constructs a new JsonDecode instance.
   *
   * @param Boolean  $associative True to return the result associative array, false for a nested stdClass hierarchy
   * @param integer  $depth       Specifies the recursion depth
   */
  public function __construct($associative = false, $depth = 512) {
    $this->associative = $associative;
    $this->recursionDepth = (int) $depth;
  }

  /**
   * Returns the last decoding error (if any).
   *
   * @return integer
   *
   * @see http://php.net/manual/en/function.json-last-error.php json_last_error
   */
  public function getLastError() {
    return $this->lastError;
  }

  /**
   * Decodes data.
   *
   * @param string $data    The encoded JSON string to decode
   * @param string $format  Must be set to JsonEncoder::FORMAT
   * @param array  $context An optional set of options for the JSON decoder; see below
   *
   * The $context array is a simple key=>value array, with the following supported keys:
   *
   * json_decode_associative: boolean
   *      If true, returns the object as associative array.
   *      If false, returns the object as nested StdClass
   *      If not specified, this method will use the default set in JsonDecode::__construct
   *
   * json_decode_recursion_depth: integer
   *      Specifies the maximum recursion depth
   *      If not specified, this method will use the default set in JsonDecode::__construct
   *
   * json_decode_options: integer
   *      Specifies additional options as per documentation for json_decode. Only supported with PHP 5.4.0 and higher
   *
   * @return mixed
   *
   * @see http://php.net/json_decode json_decode
   */
  public function decode($data, $format, array $context = array()) {
    $context = $this
      ->resolveContext($context);
    $associative = $context['json_decode_associative'];
    $recursionDepth = $context['json_decode_recursion_depth'];
    $options = $context['json_decode_options'];
    if (version_compare(PHP_VERSION, '5.4.0') >= 0) {
      $decodedData = json_decode($data, $associative, $recursionDepth, $options);
    }
    else {
      $decodedData = json_decode($data, $associative, $recursionDepth);
    }
    $this->lastError = json_last_error();
    return $decodedData;
  }

  /**
   * {@inheritdoc}
   */
  public function supportsDecoding($format) {
    return JsonEncoder::FORMAT === $format;
  }

  /**
   * Merges the default options of the Json Decoder with the passed context.
   *
   * @param array $context
   *
   * @return array
   */
  private function resolveContext(array $context) {
    $defaultOptions = array(
      'json_decode_associative' => $this->associative,
      'json_decode_recursion_depth' => $this->recursionDepth,
      'json_decode_options' => 0,
    );
    return array_merge($defaultOptions, $context);
  }

}