$parser = librdf_new_parser($world, 'rdfxml', 'application/rdf+xml', null);
print "Redland parser created\n";
$uri = librdf_new_uri($world, 'file:../data/dc.rdf');
print "Parsing...\n";
librdf_parser_parse_into_model($parser, $uri, $uri, $model);
print "Done...\n";
librdf_free_uri($uri);
librdf_free_parser($parser);
$query = librdf_new_query($world, 'sparql', null, "PREFIX dc: <http://purl.org/dc/elements/1.1/> SELECT ?a ?c ?d WHERE { ?a dc:title ?c . OPTIONAL { ?a dc:related ?d } }", null);
print "Querying for dc:titles:\n";
$results = librdf_model_query_execute($model, $query);
$count = 1;
while ($results && !librdf_query_results_finished($results)) {
print "result {$count}: {\n";
for ($i = 0; $i < librdf_query_results_get_bindings_count($results); $i++) {
$val = librdf_query_results_get_binding_value($results, $i);
if ($val) {
$nval = librdf_node_to_string($val);
} else {
$nval = '(unbound)';
}
print " " . librdf_query_results_get_binding_name($results, $i) . "=" . $nval . "\n";
}
print "}\n";
librdf_query_results_next($results);
$count++;
}
if ($results) {
print "Returned {$count} results\n";
}
$results = null;
/**
* Return the current tuple of bindings.
*
* The result is an associative array using the binding names as the
* indices.
*
* @return array The current bindings tuple
* @throws LibRDF_Error If unable to get the current bindings tuple
* @access public
*/
public function current()
{
if ($this->isvalid and !librdf_query_results_finished($this->query_results)) {
$retarr = array();
$numbindings = librdf_query_results_get_bindings_count($this->query_results);
if ($numbindings < 0) {
throw new LibRDF_Error("Unable to get number of bindings in result");
}
for ($i = 0; $i < $numbindings; $i++) {
$key = librdf_query_results_get_binding_name($this->query_results, $i);
$value = librdf_query_results_get_binding_value($this->query_results, $i);
if (!$key or !$value) {
throw new LibRDF_Error("Failed to get current binding {$i}");
}
$retarr[$key] = LibRDF_Node::makeNode(librdf_new_node_from_node($value));
}
return $retarr;
} else {
return NULL;
}
}
