page-as-data.php

<?php
namespace Grav\Plugin;

use Composer\Autoload\ClassLoader;
use Grav\Common\Plugin;

class PageAsDataPlugin extends Plugin {
  public static function getSubscribedEvents() {
    return [
      'onPluginsInitialized' => [
        ['onPluginsInitialized', 0]
      ],
    ];
  }

  public function onPluginsInitialized() {
    // Hijack output so we can deliver as a different format
    // if this value isset
    if (isset($_GET['return-as']) && in_array($_GET['return-as'], array('json', 'xml', 'yaml'))) {
      $this->enable([
        'onPageInitialized' => ['deliverFormatAs', 0]
      ]);
    }
  }

  /**
   * Delivers the page as a different format.
   */
  public function deliverFormatAs() {
    /**
     * @var \Grav\Common\Page\Page $page
     */
    $format = $_GET['return-as'];
    $page = $this->grav['page'];
    $collection = $page->collection('children');
    $pageArray = $page->toArray();
    $children = array();
    foreach ($collection as $item) {
      $children[] = $item->toArray();
    }
    $pageArray['children'] = $children;
    switch ($format) {
      case 'json':
        header("Content-Type: application/json");
        echo json_encode($pageArray);
        break;
      case 'yaml':
        header("Content-Type: application/yaml");
        echo $page->toYaml();
        break;
      case 'xml':
        header("Content-Type: application/xml");
        $array2XmlConverter = new PageAsDataXmlDomConstructor('1.0', 'utf-8');
        $array2XmlConverter->xmlStandalone = true;
        $array2XmlConverter->formatOutput = true;
        try {
          $array2XmlConverter->fromMixed(array('page' => $pageArray));
          $array2XmlConverter->normalizeDocument();
          $xml = $array2XmlConverter->saveXML();
          print $xml;
        }
        catch(Exception $ex) {
          return $ex;
        }
        break;
    }
    exit();
  }
}

/**
 * Converts an array to XML
 *  http://www.devexp.eu/2009/04/11/php-domdocument-convert-array-to-xml/
 */
/**
 * Extends the DOMDocument to implement personal (utility) methods.
 * - From: http://www.devexp.eu/2009/04/11/php-domdocument-convert-array-to-xml/
 * - parent:: See http://www.php.net/manual/en/class.domdocument.php
 *
 * @throws   DOMException   http://www.php.net/manual/en/class.domexception.php
 *
 * @author Toni Van de Voorde
 */
class PageAsDataXmlDomConstructor extends \DOMDocument {
  public function fromMixed($mixed, \DOMElement $domElement = null) {
    $domElement = is_null($domElement) ? $this : $domElement;
    if (is_array($mixed)) {
      foreach ($mixed as $index => $mixedElement) {
        if (is_int($index)) {
          if ($index == 0) {
            $node = $domElement;
          } else {
            $node = $this->createElement($domElement->tagName);
            $domElement->parentNode->appendChild($node);
          }
        } else {
          $node = $this->createElement($index);
          $domElement->appendChild($node);
        }
        $this->fromMixed($mixedElement, $node);
      }
    } else {
      $domElement->appendChild($this->createTextNode($mixed));
    }
  }
}