class RestWSFormatRDF in RESTful Web Services 7

A simple formatter for RDF. Requires the RDF module for the mapping.

Hierarchy

• class \RestWSBaseFormat implements RestWSFormatInterface
  • class \RestWSFormatRDF

1 string reference to 'RestWSFormatRDF'

restws_restws_format_info in ./restws.module

Implements hook_restws_format_info().

File

./restws.formats.inc, line 307

RESTful web services module formats.

class RestWSFormatRDF extends RestWSBaseFormat {
  protected $namespaces;
  public function __construct($name, $info) {
    parent::__construct($name, $info);
    $this->namespaces = rdf_get_namespaces();
    $this->namespaces['rdf'] = 'http://www.w3.org/1999/02/22-rdf-syntax-ns#';
  }

  /**
   * Gets the representation of a resource.
   */
  public function viewResource($resourceController, $id) {
    $xml = new DOMDocument('1.0', 'utf-8');
    $rdf_element = $xml
      ->createElementNS($this->namespaces['rdf'], 'rdf:RDF');
    $xml
      ->appendChild($rdf_element);
    $element = $xml
      ->createElementNS($this->namespaces['rdf'], 'rdf:Description');
    $element
      ->setAttributeNS($this->namespaces['rdf'], 'rdf:about', restws_resource_uri($resourceController
      ->resource(), $id));

    // Add the RDF type of the resource if there is a mapping.
    $entity = $resourceController
      ->read($id);
    if (!empty($entity->rdf_mapping['rdftype'])) {
      foreach ($entity->rdf_mapping['rdftype'] as $rdf_type) {
        $type_element = $xml
          ->createElementNS($this->namespaces['rdf'], 'rdf:type');
        list($ns, $name) = explode(':', $rdf_type);
        $type_element
          ->setAttributeNS($this->namespaces['rdf'], 'rdf:resource', $this->namespaces[$ns] . $name);
        $element
          ->appendChild($type_element);
      }
    }
    $this
      ->addToXML($xml, $element, $resourceController
      ->wrapper($id));
    $rdf_element
      ->appendChild($element);
    return $xml
      ->saveXML();
  }
  public function createResource($resourceController, $data) {
    throw new RestWSException('Not implemented', 501);
  }
  public function updateResource($resourceController, $id, $data) {
    throw new RestWSException('Not implemented', 501);
  }

  /**
   * Adds the data of the given wrapper to the given XML element.
   */
  public function addToXML(DOMDocument $doc, DOMNode $parent, $wrapper) {
    $filtered = restws_property_access_filter($wrapper);
    foreach ($filtered as $name => $property) {
      try {
        if ($property instanceof EntityDrupalWrapper) {

          // For referenced entities only return the URI.
          if ($id = $property
            ->getIdentifier()) {
            $element = $this
              ->addRdfElement($doc, $wrapper, $name);
            $parent
              ->appendChild($element);
            $this
              ->addReference($doc, $element, $property
              ->type(), $id);
          }
        }
        elseif ($property instanceof EntityValueWrapper) {
          $element = $this
            ->addRdfElement($doc, $wrapper, $name);
          $parent
            ->appendChild($element);
          $element->nodeValue = $property
            ->value();
        }
        elseif ($property instanceof EntityListWrapper || $property instanceof EntityStructureWrapper) {
          $element = $this
            ->addRdfElement($doc, $wrapper, $name);
          $parent
            ->appendChild($element);
          $node = $doc
            ->createElementNS($this->namespaces['rdf'], 'rdf:Description');
          $element
            ->appendChild($node);
          $this
            ->addToXML($doc, $node, $property);
        }
      } catch (EntityMetadataWrapperException $e) {

        // A property causes problems - ignore that.
      }
    }
  }
  public function addReference(DomDocument $doc, DOMElement $node, $resource, $id) {
    $element = $doc
      ->createElementNS($this->namespaces['rdf'], 'rdf:Description');
    $element
      ->setAttributeNS($this->namespaces['rdf'], 'rdf:about', restws_resource_uri($resource, $id));
    $node
      ->appendChild($element);
  }

  /**
   * Adds an RDF element for the given property of the wrapper using the RDF
   * mapping.
   */
  public function addRdfElement(DOMDOcument $doc, EntityMetadataWrapper $wrapper, $name) {
    if ($wrapper instanceof EntityDrupalWrapper) {
      $entity = $wrapper
        ->value();
      if (!empty($entity->rdf_mapping[$name])) {

        // Just make use of the first predicate for now.
        $predicate = reset($entity->rdf_mapping[$name]['predicates']);
        list($ns, $qname) = explode(':', $predicate);
        $element = $doc
          ->createElementNS($this->namespaces[$ns], $predicate);
        if (!empty($entity->rdf_mapping[$name]['datatype'])) {
          $element
            ->setAttributeNS($this->namespaces['rdf'], 'rdf:datatype', $entity->rdf_mapping[$name]['datatype']);
        }
      }
    }
    if (!isset($element)) {

      // For other elements just use the site URL as namespace.
      $element = $doc
        ->createElementNS(url('', array(
        'absolute' => TRUE,
      )), 'site:' . (is_numeric($name) ? 'item' : $name));
    }
    return $element;
  }

}

Members

Name	Modifiers	Type	Description	Overrides
RestWSBaseFormat::$formatInfo	protected	property
RestWSBaseFormat::$formatName	protected	property
RestWSBaseFormat::deleteResource	public	function	Deletes a resource. Overrides RestWSFormatInterface::deleteResource
RestWSBaseFormat::getData	public static	function	Gets a simple PHP array using URI references for some wrapped data.
RestWSBaseFormat::getName	public	function	Returns the short name of this format. Overrides RestWSFormatInterface::getName
RestWSBaseFormat::getResourceReference	public static	function
RestWSBaseFormat::mimeType	public	function	Returns the mime type of this format, e.g. 'application/json' or 'application/xml'. Overrides RestWSFormatInterface::mimeType
RestWSFormatRDF::$namespaces	protected	property
RestWSFormatRDF::addRdfElement	public	function	Adds an RDF element for the given property of the wrapper using the RDF mapping.
RestWSFormatRDF::addReference	public	function
RestWSFormatRDF::addToXML	public	function	Adds the data of the given wrapper to the given XML element.
RestWSFormatRDF::createResource	public	function	Creates a new resource. Overrides RestWSBaseFormat::createResource
RestWSFormatRDF::updateResource	public	function	Updates a resource. Overrides RestWSBaseFormat::updateResource
RestWSFormatRDF::viewResource	public	function	Gets the representation of a resource. Overrides RestWSBaseFormat::viewResource
RestWSFormatRDF::__construct	public	function	Overrides RestWSBaseFormat::__construct