rest_oai_pmh-8.x-1.0-beta1/src/Encoder/OaiDcEncoder.php

<?php

namespace Drupal\rest_oai_pmh\Encoder;

use Symfony\Component\Serializer\Encoder\XmlEncoder;

/**
 * OAI XML encoder.
 */
class OaiDcEncoder extends XmlEncoder {

  const ROOT_NODE_NAME = 'xml_root_node_name';

  /**
   * The formats that this Encoder supports.
   *
   * @var string
   */
  protected $format = 'oai_dc';

  /**
   * {@inheritdoc}
   */
  public function supportsEncoding(string $format) : bool {
    return $format == $this->format;
  }

  /**
   * {@inheritdoc}
   */
  public function supportsDecoding(string $format) : bool {
    return in_array($format, [$this->format, 'form']);
  }

  /**
   * {@inheritdoc}
   */
  public function decode(string $data, string $format, array $context = []) : mixed {
    if ($format === 'xml') {
      return parent::decode($data, $format, $context);
    }
    elseif ($format === 'form') {
      return $data;
    }
  }

  /**
   * {@inheritdoc}
   *
   * @todo find better approach to represent XML nodes that are string values but contain @attributes with PHP arrays
   *
   * e.g.
   * $response = [
   *   'error' => [
   *      '@code' => 'badVerb',
   *      'content' => 'STRING VALUE'
   *   ]
   * ];
   * Needs to be encoded as <error code="badVerb">STRING VALUE</error>
   * But instead it's encoded as:
   * <error code="badVerb">
   *   <content>STRING VALUE</content>
   * </error>
   *
   * With Symfony's XML Encoder can not find any clear documentation
   * whether this is possible or not.
   * So here we're just looking for a node we specially keyed for this case
   * and removing those nodes.
   * Of course this is not ideal.
   */
  public function encode($data, $format, array $context = []) : string {
    $context[self::ROOT_NODE_NAME] = 'OAI-PMH';
    $xml = parent::encode($data, $format, $context);

    $search = [
      'xmlns:mods',
      '<oai_dc ',
      '</oai_dc>',
      '<metadata-xml><![CDATA[',
      ']]></metadata-xml>',
      '<oai-dc-string>',
      '</oai-dc-string>',
    ];
    $replace = [
      'xmlns',
      '<oai_dc:dc ',
      '</oai_dc:dc>',
      '',
      '',
      '',
      '',
    ];

    return str_replace($search, $replace, $xml);
  }

}