DatasetRead.php

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<?php


class DatasetRead extends WebService
{
  private $db;

  private $conneg;

  private $dtdURL;

  private $requester_ip = "";

  private $registered_ip = "";

  private $datasetUri = "";

  private $datasetsDescription = array();

  private $addMeta = "false";

  private $namespaces =
    array ("http://www.w3.org/2002/07/owl#" => "owl", "http://www.w3.org/1999/02/22-rdf-syntax-ns#" => "rdf",
      "http://www.w3.org/2000/01/rdf-schema#" => "rdfs", "http://purl.org/ontology/wsf#" => "wsf");


  public static $supportedSerializations =
    array ("application/json", "application/rdf+xml", "application/rdf+n3", "application/*", "text/xml", "text/*",
      "*/*");

  private $errorMessenger =
    '{
                        "ws": "/ws/dataset/read/",
                        "_200": {
                          "id": "WS-DATASET-READ-200",
                          "level": "Warning",
                          "name": "No unique identifier specified for this dataset",
                          "description": "No URI defined for this new dataset"
                        },
                        "_300": {
                          "id": "WS-DATASET-READ-300",
                          "level": "Fatal",
                          "name": "Can\'t get the description of any dataset",
                          "description": "An error occured when we tried to get information about all datasets"
                        },
                        "_301": {
                          "id": "WS-DATASET-READ-301",
                          "level": "Fatal",
                          "name": "Can\'t get the description of the target dataset",
                          "description": "An error occured when we tried to get information about the target dataset"
                        },
                        "_302": {
                          "id": "WS-DATASET-READ-302",
                          "level": "Fatal",
                          "name": "Can\'t get meta-information about the dataset(s)",
                          "description": "An error occured when we tried to get meta-information about the dataset(s)"
                        },
                        "_303": {
                          "id": "WS-DATASET-READ-303",
                          "level": "Fatal",
                          "name": "Can\'t get information about the contributors",
                          "description": "An error occured when we tried to get information about the contributors of this dataset"
                        },
                        "_304": {
                          "id": "WS-DATASET-READ-304",
                          "level": "Warning",
                          "name": "This dataset doesn\'t exist in this WSF",
                          "description": "The target dataset doesn\'t exist in this web service framework"
                        },
                        "_305": {
                          "id": "WS-DATASET-READ-305",
                          "level": "Fatal",
                          "name": "Can\'t get meta-information about the dataset(s)",
                          "description": "An error occured when we tried to get meta-information about the dataset(s)"
                        }    
                      }';


  function __construct($uri, $meta, $registered_ip, $requester_ip)
  {
    parent::__construct();

    $this->db = new DB_Virtuoso($this->db_username, $this->db_password, $this->db_dsn, $this->db_host);

    $this->datasetUri = $uri;
    $this->requester_ip = $requester_ip;
    $this->addMeta = strtolower($meta);

    if($registered_ip == "")
    {
      $this->registered_ip = $requester_ip;
    }
    else
    {
      $this->registered_ip = $registered_ip;
    }

    if(strtolower(substr($this->registered_ip, 0, 4)) == "self")
    {
      $pos = strpos($this->registered_ip, "::");

      if($pos !== FALSE)
      {
        $account = substr($this->registered_ip, $pos + 2, strlen($this->registered_ip) - ($pos + 2));

        $this->registered_ip = $requester_ip . "::" . $account;
      }
      else
      {
        $this->registered_ip = $requester_ip;
      }
    }

    $this->uri = $this->wsf_base_url . "/wsf/ws/dataset/read/";
    $this->title = "Dataset Read Web Service";
    $this->crud_usage = new CrudUsage(FALSE, TRUE, FALSE, FALSE);
    $this->endpoint = $this->wsf_base_url . "/ws/dataset/read/";

    $this->dtdURL = "dataset/datasetRead.dtd";

    $this->errorMessenger = json_decode($this->errorMessenger);
  }

  function __destruct()
  {
    parent::__destruct();

    if(isset($this->db))
    {
      @$this->db->close();
    }
  }

  protected function validateQuery()
  {
    // Check if the requester has access to the main "http://.../wsf/datasets/" graph.
    $ws_av = new AuthValidator($this->requester_ip, $this->wsf_graph . "datasets/", $this->uri);

    $ws_av->pipeline_conneg($this->conneg->getAccept(), $this->conneg->getAcceptCharset(),
      $this->conneg->getAcceptEncoding(), $this->conneg->getAcceptLanguage());

    $ws_av->process();

    if($ws_av->pipeline_getResponseHeaderStatus() != 200)
    {
      // If he doesn't, then check if he has access to the dataset itself
      $ws_av2 = new AuthValidator($this->requester_ip, $this->datasetUri, $this->uri);

      $ws_av2->pipeline_conneg($this->conneg->getAccept(), $this->conneg->getAcceptCharset(),
        $this->conneg->getAcceptEncoding(), $this->conneg->getAcceptLanguage());

      $ws_av2->process();

      if($ws_av2->pipeline_getResponseHeaderStatus() != 200)
      {
        $this->conneg->setStatus($ws_av2->pipeline_getResponseHeaderStatus());
        $this->conneg->setStatusMsg($ws_av2->pipeline_getResponseHeaderStatusMsg());
        $this->conneg->setStatusMsgExt($ws_av2->pipeline_getResponseHeaderStatusMsgExt());
        $this->conneg->setError($ws_av2->pipeline_getError()->id, $ws_av2->pipeline_getError()->webservice,
          $ws_av2->pipeline_getError()->name, $ws_av2->pipeline_getError()->description,
          $ws_av2->pipeline_getError()->debugInfo, $ws_av2->pipeline_getError()->level);

        return;
      }
    }
           
    // If the system send a query on the behalf of another user, we validate that other user as well
    if($this->registered_ip != $this->requester_ip)
    {
      // Check if the requester has access to the main "http://.../wsf/datasets/" graph.
      $ws_av = new AuthValidator($this->registered_ip, $this->wsf_graph . "datasets/", $this->uri);

      $ws_av->pipeline_conneg($this->conneg->getAccept(), $this->conneg->getAcceptCharset(),
        $this->conneg->getAcceptEncoding(), $this->conneg->getAcceptLanguage());

      $ws_av->process();

      if($ws_av->pipeline_getResponseHeaderStatus() != 200)
      {
        // If he doesn't, then check if he has access to the dataset itself
        $ws_av2 = new AuthValidator($this->registered_ip, $this->datasetUri, $this->uri);

        $ws_av2->pipeline_conneg($this->conneg->getAccept(), $this->conneg->getAcceptCharset(),
          $this->conneg->getAcceptEncoding(), $this->conneg->getAcceptLanguage());

        $ws_av2->process();

        if($ws_av2->pipeline_getResponseHeaderStatus() != 200)
        {
          $this->conneg->setStatus($ws_av2->pipeline_getResponseHeaderStatus());
          $this->conneg->setStatusMsg($ws_av2->pipeline_getResponseHeaderStatusMsg());
          $this->conneg->setStatusMsgExt($ws_av2->pipeline_getResponseHeaderStatusMsgExt());
          $this->conneg->setError($ws_av2->pipeline_getError()->id, $ws_av2->pipeline_getError()->webservice,
            $ws_av2->pipeline_getError()->name, $ws_av2->pipeline_getError()->description,
            $ws_av2->pipeline_getError()->debugInfo, $ws_av2->pipeline_getError()->level);

          return;
        }
      }     
    }       
  }

  private function uriEncode($uri)
  {
    $uri = preg_replace("|[^a-zA-z0-9]|", " ", $uri);
    $uri = preg_replace("/\s+/", " ", $uri);
    $uri = str_replace(" ", "_", $uri);

    return ($uri);
  }

  public function pipeline_getError() { return ($this->conneg->error); }


  public function pipeline_getResultset()
  {
    $xml = new ProcessorXML();

    // Creation of the RESULTSET
    $resultset = $xml->createResultset();

    // Creation of the prefixes elements.
    $wsf = $xml->createPrefix("wsf", "http://purl.org/ontology/wsf#");
    $resultset->appendChild($wsf);
    $void = $xml->createPrefix("void", "http://rdfs.org/ns/void#");
    $resultset->appendChild($void);
    $rdf = $xml->createPrefix("rdf", "http://www.w3.org/1999/02/22-rdf-syntax-ns#");
    $resultset->appendChild($rdf);
    $sioc = $xml->createPrefix("sioc", "http://rdfs.org/sioc/ns#");
    $resultset->appendChild($sioc);
    $dcterms = $xml->createPrefix("dcterms", "http://purl.org/dc/terms/");
    $resultset->appendChild($dcterms);
    $dcterms = $xml->createPrefix("rdfs", "http://www.w3.org/2000/01/rdf-schema#");
    $resultset->appendChild($dcterms);

    // Creation of the SUBJECT of the RESULTSET
    foreach($this->datasetsDescription as $dd)
    {
      if($dd->uri != "")
      {
        $subject = $xml->createSubject("void:Dataset", $dd->uri);

        if($dd->title != "")
        {
          $pred = $xml->createPredicate("dcterms:title");
          $object = $xml->createObjectContent($dd->title);
          $pred->appendChild($object);
          $subject->appendChild($pred);
        }

        if($dd->description != "")
        {
          $pred = $xml->createPredicate("dcterms:description");
          $object = $xml->createObjectContent($dd->description);
          $pred->appendChild($object);
          $subject->appendChild($pred);
        }

        $pred = $xml->createPredicate("dcterms:created");
        $object = $xml->createObjectContent($dd->created);
        $pred->appendChild($object);
        $subject->appendChild($pred);

        if($dd->modified != "")
        {
          $pred = $xml->createPredicate("dcterms:modified");
          $object = $xml->createObjectContent($dd->modified);
          $pred->appendChild($object);
          $subject->appendChild($pred);
        }

        if($dd->creator != "")
        {
          $pred = $xml->createPredicate("dcterms:creator");
          $object = $xml->createObject("sioc:User", $dd->creator);
          $pred->appendChild($object);
          $subject->appendChild($pred);
        }

        if($dd->meta != "" && $this->addMeta == "true")
        {
          $pred = $xml->createPredicate("wsf:meta");
          $object = $xml->createObject("", $dd->meta);
          $pred->appendChild($object);
          $subject->appendChild($pred);
        }

        if(count($dd->metaDescription) > 0 && $this->addMeta == "true")
        {
          $subjectMeta = $xml->createSubject("void:Dataset", $dd->meta);

          foreach($dd->metaDescription as $predicate => $values)
          {
            foreach($values as $key => $value)
            {
              if(gettype($key) == "integer" && $value != "")
              {
                if($dd->metaDescription[$predicate]["type"] != NULL)
                {
/*
  @TODO The internal XML structure of structWSF should be enhanced with datatypes such as xsd:double, int, 
        literal, etc.
*/
                  $pred = $xml->createPredicate($predicate);
                  $object = $xml->createObjectContent($value);
                  $pred->appendChild($object);
                  $subjectMeta->appendChild($pred);
                }
                else
                {
                  $pred = $xml->createPredicate($predicate);
                  $object = $xml->createObject("", $value);

                  // Check if we have to reify statements to this object
                  $query = "  select  ?s ?p ?o
                          from <" . $this->datasetUri . "reification/>
                          where
                          {
                            ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <" . $dd->meta . ">.
                            ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <" . $predicate . ">.
                            ?s <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <" . $value . ">.
                            ?s ?p ?o.
                          }";

                  $rset =
                    @$this->db->query($this->db->build_sparql_query(str_replace(array ("\n", "\r", "\t"), " ", $query),
                      array ("s", "p", "o"), FALSE));

                  if(!odbc_error())
                  {
                    while(odbc_fetch_row($rset))
                    {
                      $s = odbc_result($rset, 1);
                      $p = odbc_result($rset, 2);
                      $o = odbc_result($rset, 3);

                      if($p == "http://purl.org/ontology/bibo/uri"
                        || $p == "http://www.w3.org/2000/01/rdf-schema#label")
                      {
                        $reify = $xml->createReificationStatement($p, $o);
                        $object->appendChild($reify);
                      }
                    }
                  }

                  $pred->appendChild($object);
                  $subjectMeta->appendChild($pred);
                }
              }
            }
          }

          $resultset->appendChild($subjectMeta);
        }

        foreach($dd->contributors as $contributor)
        {
          if($contributor != "")
          {
            $pred = $xml->createPredicate("dcterms:contributor");
            $object = $xml->createObject("sioc:User", $contributor);
            $pred->appendChild($object);
            $subject->appendChild($pred);
          }
        }

        $resultset->appendChild($subject);
      }
    }

    return ($this->injectDoctype($xml->saveXML($resultset)));
  }

  public function injectDoctype($xmlDoc)
  {
    $posHeader = strpos($xmlDoc, '"?>') + 3;
    $xmlDoc = substr($xmlDoc, 0, $posHeader)
      . "\n<!DOCTYPE resultset PUBLIC \"-//Structured Dynamics LLC//Dataset Read DTD 0.1//EN\" \"" . $this->dtdBaseURL
        . $this->dtdURL . "\">" . substr($xmlDoc, $posHeader, strlen($xmlDoc) - $posHeader);

    return ($xmlDoc);
  }

  public function ws_conneg($accept, $accept_charset, $accept_encoding, $accept_language)
  {
    $this->conneg =
      new Conneg($accept, $accept_charset, $accept_encoding, $accept_language, DatasetRead::$supportedSerializations);

    // Validate query
    $this->validateQuery();

    // If the query is still valid
    if($this->conneg->getStatus() == 200)
    {
      // Check for errors
      if($this->uri == "")
      {
        $this->conneg->setStatus(400);
        $this->conneg->setStatusMsg("Bad Request");
        $this->conneg->setStatusMsgExt("No URI specified for any dataset");
        $this->conneg->setStatusMsgExt($this->errorMessenger->_200->name);
        $this->conneg->setError($this->errorMessenger->_200->id, $this->errorMessenger->ws,
          $this->errorMessenger->_200->name, $this->errorMessenger->_200->description, "",
          $this->errorMessenger->_200->level);

        return;
      }
    }
  }

  public function pipeline_conneg($accept, $accept_charset, $accept_encoding, $accept_language)
    { $this->ws_conneg($accept, $accept_charset, $accept_encoding, $accept_language); }

  public function pipeline_getResponseHeaderStatus() { return $this->conneg->getStatus(); }

  public function pipeline_getResponseHeaderStatusMsg() { return $this->conneg->getStatusMsg(); }

  public function pipeline_getResponseHeaderStatusMsgExt() { return $this->conneg->getStatusMsgExt(); }

  private function getNamespace($uri)
  {
    $pos = strrpos($uri, "#");

    if($pos !== FALSE)
    {
      return array (substr($uri, 0, $pos) . "#", substr($uri, $pos + 1, strlen($uri) - ($pos + 1)));
    }
    else
    {
      $pos = strrpos($uri, "/");

      if($pos !== FALSE)
      {
        return array (substr($uri, 0, $pos) . "/", substr($uri, $pos + 1, strlen($uri) - ($pos + 1)));
      }
      else
      {
        $pos = strpos($uri, ":");

        if($pos !== FALSE)
        {
          $nsUri = explode(":", $uri, 2);

          foreach($this->namespaces as $uri2 => $prefix2)
          {
            $uri2 = urldecode($uri2);

            if($prefix2 == $nsUri[0])
            {
              return (array ($uri2, $nsUri[1]));
            }
          }

          return explode(":", $uri, 2);
        }
      }
    }

    return (FALSE);
  }
  public function pipeline_serialize()
  {
    $rdf_part = "";

    switch($this->conneg->getMime())
    {
      case "application/json":
        $json_part = "";
        $xml = new ProcessorXML();
        $xml->loadXML($this->pipeline_getResultset());

        $subjects = $xml->getSubjects();

        foreach($subjects as $subject)
        {
          $subjectURI = $xml->getURI($subject);
          $subjectType = $xml->getType($subject);

          $json_part .= "      { \n";
          $json_part .= "        \"uri\": \"" . parent::jsonEncode($subjectURI) . "\", \n";
          $json_part .= "        \"type\": \"" . parent::jsonEncode($subjectType) . "\", \n";

          $predicates = $xml->getPredicates($subject);

          $nbPredicates = 0;

          foreach($predicates as $predicate)
          {
            $objects = $xml->getObjects($predicate);

            foreach($objects as $object)
            {
              $nbPredicates++;

              if($nbPredicates == 1)
              {
                $json_part .= "        \"predicate\": [ \n";
              }

              $objectType = $xml->getType($object);
              $predicateType = $xml->getType($predicate);

              if($objectType == "rdfs:Literal")
              {
                $objectValue = $xml->getContent($object);

                $json_part .= "          { \n";
                $json_part .= "            \"" . parent::jsonEncode($predicateType) . "\": \""
                  . parent::jsonEncode($objectValue) . "\" \n";
                $json_part .= "          },\n";
              }
              else
              {
                $objectURI = $xml->getURI($object);
                $rdf_part .= "          <$predicateType> <$objectURI> ;\n";

                $json_part .= "          { \n";
                $json_part .= "            \"" . parent::jsonEncode($predicateType) . "\": { \n";
                $json_part .= "                \"uri\": \"" . parent::jsonEncode($objectURI) . "\" \n";
                $json_part .= "                } \n";
                $json_part .= "          },\n";
              }
            }
          }

          if(strlen($json_part) > 0)
          {
            $json_part = substr($json_part, 0, strlen($json_part) - 2) . "\n";
          }

          if($nbPredicates > 0)
          {
            $json_part .= "        ]\n";
          }

          $json_part .= "      },\n";
        }

        if(strlen($json_part) > 0)
        {
          $json_part = substr($json_part, 0, strlen($json_part) - 2) . "\n";
        }

        return ($json_part);
      break;

      case "application/rdf+n3":
        $xml = new ProcessorXML();
        $xml->loadXML($this->pipeline_getResultset());

        $dataset = $xml->getSubjectsByType("void:Dataset");

        $dataset_uri = $xml->getURI($dataset->item(0));

        $rdf_part .= "<$dataset_uri> a void:Dataset ;\n";

        // Get title
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:title");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "dcterms:title \"\"\"" . $xml->getContent($objects->item(0)) . "\"\"\" ;\n";
        }

        // Get description
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:description");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "dcterms:description \"\"\"" . $xml->getContent($objects->item(0)) . "\"\"\" ;\n";
        }

        // Get created
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:created");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "dcterms:created \"\"\"" . $xml->getContent($objects->item(0)) . "\"\"\" ;\n";
        }

        // Get modified
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:modified");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "dcterms:modified \"\"\"" . $xml->getContent($objects->item(0)) . "\"\"\" ;\n";
        }

        // Get creator
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:creator");

        foreach($predicates as $predicate)
        {
          $objects = $xml->getObjectsByType($predicate, "sioc:User");
          $rdf_part .= "dcterms:creator <" . $xml->getURI($objects->item(0)) . "> ;\n";
        }

        // Get contributors
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:contributor");

        foreach($predicates as $predicate)
        {
          $objects = $xml->getObjectsByType($predicate, "sioc:User");
          $rdf_part .= "dcterms:contributor <" . $xml->getURI($objects->item(0)) . "> ;\n";
        }

        return ($rdf_part);

      break;

      case "application/rdf+xml":

        $xml = new ProcessorXML();
        $xml->loadXML($this->pipeline_getResultset());


        /*
                $nsId = 0;
        */

        $dataset = $xml->getSubjectsByType("void:Dataset");

        $dataset_uri = $xml->getURI($dataset->item(0));

        $rdf_part .= "<void:Dataset rdf:about=\"".$this->xmlEncode($dataset_uri)."\">\n";

        // Get title
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:title");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "<dcterms:title>" . $this->xmlEncode($xml->getContent($objects->item(0))) . "</dcterms:title>\n";
        }

        // Get description
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:description");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "<dcterms:description>" . $this->xmlEncode($xml->getContent($objects->item(0))) . 
                                                                                            "</dcterms:description>\n";
        }

        // Get created
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:created");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "<dcterms:created>" . $this->xmlEncode($xml->getContent($objects->item(0))) . 
                                                                                                "</dcterms:created>\n";
        }

        // Get modified
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:modified");

        if($predicates->item(0))
        {
          $objects = $xml->getObjectsByType($predicates->item(0), "rdfs:Literal");
          $rdf_part .= "<dcterms:modified>" . $this->xmlEncode($xml->getContent($objects->item(0))) . 
                                                                                                "</dcterms:modified>\n";
        }

        // Get creator
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:creator");

        foreach($predicates as $predicate)
        {
          $objects = $xml->getObjectsByType($predicate, "sioc:User");
          $rdf_part .= "<dcterms:creator rdf:resource=\"" . $this->xmlEncode($xml->getURI($objects->item(0))) . 
                                                                                                              "\" />\n";
        }

        // Get contributors
        $predicates = $xml->getPredicatesByType($dataset->item(0), "dcterms:contributor");

        foreach($predicates as $predicate)
        {
          $objects = $xml->getObjectsByType($predicate, "sioc:User");
          $rdf_part .= "<dcterms:contributor rdf:resource=\"" . $this->xmlEncode($xml->getURI($objects->item(0))) . 
                                                                                                              "\" />\n";
        }

        $rdf_part .= "</void:Dataset>\n";

        return ($rdf_part);
      break;
    }
  }

  public function pipeline_serialize_reification() { return ""; }

  public function ws_serialize()
  {
    switch($this->conneg->getMime())
    {
      case "application/rdf+n3":
        $rdf_document = "";
        $rdf_document .= "@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .\n";
        $rdf_document .= "@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .\n";
        $rdf_document .= "@prefix void: <http://rdfs.org/ns/void#> .\n";
        $rdf_document .= "@prefix dcterms: <http://purl.org/dc/terms/> .\n";
        $rdf_document .= "@prefix wsf: <http://purl.org/ontology/wsf#> .\n";

        $rdf_document .= $this->pipeline_serialize();

        $rdf_document = substr($rdf_document, 0, strlen($rdf_document) - 2) . ".\n";

        return $rdf_document;
      break;

      case "application/rdf+xml":
        $rdf_document = "";
        $rdf_document .= "<?xml version=\"1.0\"?>\n";
        $rdf_document
          .= "<rdf:RDF xmlns:wsf=\"http://purl.org/ontology/wsf#\" xmlns:void=\"http://rdfs.org/ns/void#\" xmlns:dcterms=\"http://purl.org/dc/terms/\" xmlns:rdfs=\"http://www.w3.org/2000/01/rdf-schema#\" xmlns:rdf=\"http://www.w3.org/1999/02/22-rdf-syntax-ns#\">\n\n";

        $rdf_document .= $this->pipeline_serialize();

        $rdf_document .= "</rdf:RDF>";

        return $rdf_document;
      break;

      case "text/xml":
        return $this->pipeline_getResultset();
      break;

      case "application/json":
        $json_document = "";
        $json_document .= "{\n";
        $json_document .= "  \"prefixes\": [ \n";
        $json_document .= "    {\n";
        $json_document .= "      \"rdf\": \"http:\/\/www.w3.org\/1999\/02\/22-rdf-syntax-ns#\",\n";
        $json_document .= "      \"rdfs\": \"http://www.w3.org/2000/01/rdf-schema#\",\n";
        $json_document .= "      \"void\": \"http://rdfs.org/ns/void#\",\n";
        $json_document .= "      \"dcterms\": \"http://purl.org/dc/terms/\"\n";
        $json_document .= "    } \n";
        $json_document .= "  ],\n";
        $json_document .= "  \"resultset\": {\n";
        $json_document .= "    \"subject\": [\n";
        $json_document .= $this->pipeline_serialize();
        $json_document .= "    ]\n";
        $json_document .= "  }\n";
        $json_document .= "}";

        return ($json_document);
      break;
    }
  }

  public function ws_respond($content)
  {
    // First send the header of the request
    $this->conneg->respond();

    // second, send the content of the request

    // Make sure there is no error.
    if($this->conneg->getStatus() == 200)
    {
      echo $content;
    }

    $this->__destruct();
  }


  public function process()
  {
    // Make sure there was no conneg error prior to this process call
    if($this->conneg->getStatus() == 200)
    {
      /*
        In the future, this single query should be used for that ALL purpose.
        There is currently a bug in virtuoso that doesnt return anything in the resultset (virtuoso v5.0.10)
        if one of the OPTIONAL pattern is not existing in the triple store (so, OPTIONAL doesn't work)
        
        sparql
        select * 
        from named </wsf/datasets/>
        from named </wsf/>
        where
        {
          graph </wsf/>
          {
            ?access <http://purl.org/ontology/wsf#registeredIP> "174.129.251.47::1" ;
            <http://purl.org/ontology/wsf#read> "True" ;
            <http://purl.org/ontology/wsf#datasetAccess> ?dataset .
          }
          
          graph </wsf/datasets/> 
          {
            ?dataset a <http://rdfs.org/ns/void#Dataset> ;
            <http://purl.org/dc/terms/created> ?created.
        
            OPTIONAL{?dataset <http://purl.org/dc/terms/title> ?title.}
            OPTIONAL{?dataset <http://purl.org/dc/terms/description> ?description.}
            OPTIONAL{?dataset <http://purl.org/dc/terms/creator> ?creator.}
            OPTIONAL{?dataset <http://purl.org/dc/terms/modified> ?modified.}
          }    
        };
      */

      $query = "";
      $datasets = array();

      if($this->datasetUri == "all")
      {
        $query = "  select distinct ?dataset ?title ?description ?creator ?created ?modified ?contributor ?meta
                  from named <" . $this->wsf_graph . ">
                  from named <" . $this->wsf_graph . "datasets/>
                  where
                  {
                    graph <" . $this->wsf_graph . ">
                    {
                      ?access <http://purl.org/ontology/wsf#registeredIP> ?ip ;
                            <http://purl.org/ontology/wsf#read> \"True\" ;
                      <http://purl.org/ontology/wsf#datasetAccess> ?dataset .
                      filter( str(?ip) = \"$this->registered_ip\" or str(?ip) = \"0.0.0.0\") .
                    }
                    
                    graph <"
          . $this->wsf_graph
          . "datasets/>
                    {
                      ?dataset a <http://rdfs.org/ns/void#Dataset> ;
                      <http://purl.org/dc/terms/created> ?created.
                  
                      OPTIONAL{?dataset <http://purl.org/ontology/wsf#meta> ?meta.}
                      OPTIONAL{?dataset <http://purl.org/dc/terms/title> ?title.}
                      OPTIONAL{?dataset <http://purl.org/dc/terms/description> ?description.}
                      OPTIONAL{?dataset <http://purl.org/dc/terms/modified> ?modified.}
                      OPTIONAL{?dataset <http://purl.org/dc/terms/contributor> ?contributor.}
                      OPTIONAL{?dataset <http://purl.org/dc/terms/creator> ?creator.}
                    }    
                  }";

        $resultset = @$this->db->query($this->db->build_sparql_query(str_replace(array ("\n", "\r", "\t"), " ", $query),
          array ("dataset", "title", "description", "creator", "created", "modified", "contributor", "meta"), FALSE));

        if(odbc_error())
        {
          $this->conneg->setStatus(500);
          $this->conneg->setStatusMsg("Internal Error");
          $this->conneg->setStatusMsgExt($this->errorMessenger->_300->name);
          $this->conneg->setError($this->errorMessenger->_300->id, $this->errorMessenger->ws,
            $this->errorMessenger->_300->name, $this->errorMessenger->_300->description, odbc_errormsg(),
            $this->errorMessenger->_300->level);

          return;
        }
        else
        {
          $dataset = "";
          $title = "";
          $description = "";
          $creator = "";
          $created = "";
          $modified = "";
          $contributors = array();
          $meta = "";

          while(odbc_fetch_row($resultset))
          {
            $dataset2 = odbc_result($resultset, 1);

            if($dataset2 != $dataset && $dataset != "")
            {
              array_push($this->datasetsDescription,
                new DatasetDescription($dataset, $title, $description, $creator, $created, $modified, $contributors));
              $contributors = array();
            }

            $dataset = $dataset2;

            $title = odbc_result($resultset, 2);
            $description = odbc_result($resultset, 3);
            $creator = odbc_result($resultset, 4);
            $created = odbc_result($resultset, 5);
            $modified = odbc_result($resultset, 6);
            array_push($contributors, odbc_result($resultset, 7));
            $meta = odbc_result($resultset, 8);
          }

          $metaDescription = array();

          // We have to add the meta information if available
          if($meta != "" && $this->addMeta == "true")
          {
            $query = "select ?p ?o (str(DATATYPE(?o))) as ?otype (LANG(?o)) as ?olang
                    from <" . $this->wsf_graph . "datasets/>
                    where
                    {
                      <$meta> ?p ?o.
                    }";

            $resultset =
              @$this->db->query($this->db->build_sparql_query(str_replace(array ("\n", "\r", "\t"), " ", $query),
                array ('p', 'o', 'otype', 'olang'), FALSE));

            $contributors = array();

            if(odbc_error())
            {
              $this->conneg->setStatus(500);
              $this->conneg->setStatusMsg("Internal Error");
              $this->conneg->setStatusMsgExt($this->errorMessenger->_305->name);
              $this->conneg->setError($this->errorMessenger->_305->id, $this->errorMessenger->ws,
                $this->errorMessenger->_305->name, $this->errorMessenger->_305->description, odbc_errormsg(),
                $this->errorMessenger->_305->level);

              return;
            }
            else
            {
              while(odbc_fetch_row($resultset))
              {
                $predicate = odbc_result($resultset, 1);
                $object = odbc_result($resultset, 2);
                $otype = odbc_result($resultset, 3);
                $olang = odbc_result($resultset, 4);

                if(isset($metaDescription[$predicate]))
                {
                  array_push($metaDescription[$predicate], $object);
                }
                else
                {
                  $metaDescription[$predicate] = array( $object );

                  if($olang && $olang != "")
                  {
                    /* If a language is defined for an object, we force its type to be xsd:string */
                    $metaDescription[$predicate]["type"] = "http://www.w3.org/2001/XMLSchema#string";
                  }
                  else
                  {
                    $metaDescription[$predicate]["type"] = $otype;
                  }
                }
              }
            }

            unset($resultset);
          }

          if($dataset != "")
          {
            array_push($this->datasetsDescription,
              new DatasetDescription($dataset, $title, $description, $creator, $created, $modified, $contributors,
                $meta, $metaDescription));
          }

          unset($resultset);
        }

      /*      
              // Get all datasets this user has access to
              $query = "select ?dataset 
                      from named <".$this->wsf_graph."datasets/>
                      from named <".$this->wsf_graph.">
                      where
                      {
                        graph <".$this->wsf_graph."datasets/>
                        {
                          ?dataset a <http://rdfs.org/ns/void#Dataset> .
                        }
                      
                        graph <".$this->wsf_graph.">
                        {
                          ?access <http://purl.org/ontology/wsf#registeredIP> \"$this->registered_ip\" ;
                                  <http://purl.org/ontology/wsf#read> \"True\" ;
                                  <http://purl.org/ontology/wsf#datasetAccess> ?dataset .
                        }
                      }";                
      
              $resultset = @$this->db->query($this->db->build_sparql_query(str_replace(array("\n", "\r", "\t"), " ", $query), array("dataset"), FALSE));
                          
              if (odbc_error())
              {
                $this->conneg->setStatus(500);
                $this->conneg->setStatusMsg("Internal Error");
                $this->conneg->setStatusMsgExt("Error #dataset-read-100");  
                return;
              }  
              else
              {
                while(odbc_fetch_row($resultset))
                {
                  array_push($datasets, odbc_result($resultset, 1));
                }
                
                unset($resultset);
              }
      */

      }
      else
      {
        $dataset = $this->datasetUri;

        $query =
          "select ?title ?description ?creator ?created ?modified ?meta
                from named <" . $this->wsf_graph . "datasets/>
                where
                {
                  graph <" . $this->wsf_graph
          . "datasets/>
                  {
                    <$dataset> a <http://rdfs.org/ns/void#Dataset> ;
                    <http://purl.org/dc/terms/created> ?created.
                    
                    OPTIONAL{<$dataset> <http://purl.org/dc/terms/title> ?title.} .
                    OPTIONAL{<$dataset> <http://purl.org/dc/terms/description> ?description.} .
                    OPTIONAL{<$dataset> <http://purl.org/dc/terms/creator> ?creator.} .
                    OPTIONAL{<$dataset> <http://purl.org/dc/terms/modified> ?modified.} .
                    OPTIONAL{<$dataset> <http://purl.org/ontology/wsf#meta> ?meta.} .
                  }
                }";

        $resultset = @$this->db->query($this->db->build_sparql_query(str_replace(array ("\n", "\r", "\t"), " ", $query),
          array ('title', 'description', 'creator', 'created', 'modified', 'meta'), FALSE));

        if(odbc_error())
        {
          $this->conneg->setStatus(500);
          $this->conneg->setStatusMsg("Internal Error");
          $this->conneg->setStatusMsgExt($this->errorMessenger->_301->name);
          $this->conneg->setError($this->errorMessenger->_301->id, $this->errorMessenger->ws,
            $this->errorMessenger->_301->name, $this->errorMessenger->_301->description, odbc_errormsg(),
            $this->errorMessenger->_301->level);

          return;
        }
        else
        {
          if(odbc_fetch_row($resultset))
          {
            $title = odbc_result($resultset, 1);
            $description = odbc_result($resultset, 2);
            $creator = odbc_result($resultset, 3);
            $created = odbc_result($resultset, 4);
            $modified = odbc_result($resultset, 5);
            $meta = odbc_result($resultset, 6);

            unset($resultset);

            $metaDescription = array();

            // We have to add the meta information if available
            if($meta != "" && $this->addMeta == "true")
            {
              $query = "select ?p ?o (str(DATATYPE(?o))) as ?otype (LANG(?o)) as ?olang
                      from <" . $this->wsf_graph . "datasets/>
                      where
                      {
                        <$meta> ?p ?o.
                      }";

              $resultset =
                @$this->db->query($this->db->build_sparql_query(str_replace(array ("\n", "\r", "\t"), " ", $query),
                  array ('p', 'o', 'otype', 'olang'), FALSE));

              $contributors = array();

              if(odbc_error())
              {
                $this->conneg->setStatus(500);
                $this->conneg->setStatusMsg("Internal Error");
                $this->conneg->setStatusMsgExt($this->errorMessenger->_302->name);
                $this->conneg->setError($this->errorMessenger->_302->id, $this->errorMessenger->ws,
                  $this->errorMessenger->_302->name, $this->errorMessenger->_302->description, odbc_errormsg(),
                  $this->errorMessenger->_302->level);

                return;
              }
              else
              {
                while(odbc_fetch_row($resultset))
                {
                  $predicate = odbc_result($resultset, 1);
                  $object = odbc_result($resultset, 2);
                  $otype = odbc_result($resultset, 3);
                  $olang = odbc_result($resultset, 4);

                  if(isset($metaDescription[$predicate]))
                  {
                    array_push($metaDescription[$predicate], $object);
                  }
                  else
                  {
                    $metaDescription[$predicate] = array( $object );

                    if($olang && $olang != "")
                    {
                      /* If a language is defined for an object, we force its type to be xsd:string */
                      $metaDescription[$predicate]["type"] = "http://www.w3.org/2001/XMLSchema#string";
                    }
                    else
                    {
                      $metaDescription[$predicate]["type"] = $otype;
                    }
                  }
                }
              }

              unset($resultset);
            }


            // Get all contributors (users that have CUD perissions over the dataset)
            $query =
              "select ?contributor 
                    from <" . $this->wsf_graph
              . "datasets/>
                    where
                    {
                      <$dataset> a <http://rdfs.org/ns/void#Dataset> ;
                      <http://purl.org/dc/terms/contributor> ?contributor.
                    }";

            $resultset =
              @$this->db->query($this->db->build_sparql_query(str_replace(array ("\n", "\r", "\t"), " ", $query),
                array( 'contributor' ), FALSE));

            $contributors = array();

            if(odbc_error())
            {
              $this->conneg->setStatus(500);
              $this->conneg->setStatusMsg("Internal Error");
              $this->conneg->setStatusMsgExt($this->errorMessenger->_303->name);
              $this->conneg->setError($this->errorMessenger->_303->id, $this->errorMessenger->ws,
                $this->errorMessenger->_303->name, $this->errorMessenger->_303->description, odbc_errormsg(),
                $this->errorMessenger->_303->level);

              return;
            }
            elseif(odbc_fetch_row($resultset))
            {
              array_push($contributors, odbc_result($resultset, 1));
            }

            array_push($this->datasetsDescription,
              new DatasetDescription($dataset, $title, $description, $creator, $created, $modified, $contributors,
                $meta, $metaDescription));
          }
        }
      }

      if(count($this->datasetsDescription) == 0 && $this->datasetUri != "all")
      {
        $this->conneg->setStatus(400);
        $this->conneg->setStatusMsg("Bad Request");
        $this->conneg->setStatusMsgExt("This dataset doesn't exist in this WSF");
        $this->conneg->setStatusMsgExt($this->errorMessenger->_304->name);
        $this->conneg->setError($this->errorMessenger->_304->id, $this->errorMessenger->ws,
          $this->errorMessenger->_304->name, $this->errorMessenger->_304->description, "",
          $this->errorMessenger->_304->level);
      }
    }
  }
}

class DatasetDescription
{
  public $uri = "";

  public $title = "";

  public $description = "";

  public $creator = "";

  public $created = "";

  public $modified = "";

  public $contributors = array();

  public $meta = "";

  public $metaDescription = "";

  function __construct($uri, $title, $description, $creator, $created, $modified, $contributors, $meta = "",
    $metaDescription = array())
  {
    $this->uri = $uri;
    $this->title = $title;
    $this->description = $description;
    $this->creator = $creator;
    $this->created = $created;
    $this->modified = $modified;
    $this->contributors = $contributors;
    $this->meta = $meta;
    $this->metaDescription = $metaDescription;
  }
}


?>