/**
* Creates a value node for $value, and attaches it to the current subject of $writer.
* If a value node for $value was already created, null is returned. Otherwise, the
* value node's lname is returned, which should be used to generate detailed about the
* value into the writer returned by getValueNodeWriter().
*
* When this method returns a non-null lname, the current subject of the RdfWriter returned by
* getValueNodeWriter() will the be value node with that lname.
*
* @param RdfWriter $writer
* @param string $propertyValueNamespace Property value relation namespace
* @param string $propertyValueLName Property value relation name
* @param string $dataType Property data type (unused, passed here for symmetry
* with the signature of ValueSnakRdfBuilder::addValue).
* @param DataValue $value
*
* @return string|null The LName of the value node (in the RdfVocabulary::NS_VALUE namespace),
* or null if the value node should not be processed (generally, because it already has
* been processed).
*/
public function attachValueNode(RdfWriter $writer, $propertyValueNamespace, $propertyValueLName, $dataType, DataValue $value)
{
$valueLName = $value->getHash();
$writer->say(RdfVocabulary::$claimToValue[$propertyValueNamespace], $propertyValueLName)->is(RdfVocabulary::NS_VALUE, $valueLName);
if ($this->dedupeBag->alreadySeen($valueLName, 'V') !== false) {
return null;
}
$this->valueNodeWriter->about(RdfVocabulary::NS_VALUE, $valueLName)->a(RdfVocabulary::NS_ONTOLOGY, $this->vocabulary->getValueTypeName($value));
return $valueLName;
}
/**
* Adds the given Statement from the given Entity to the RDF graph.
*
* @param EntityId $entityId
* @param Statement $statement
* @param bool $isBest Is this best ranked statement?
*/
private function addStatement(EntityId $entityId, Statement $statement, $isBest)
{
$statementLName = $this->vocabulary->getStatementLName($statement);
$this->addMainSnak($entityId, $statementLName, $statement, $isBest);
// XXX: separate builder for qualifiers?
if ($this->produceQualifiers) {
// this assumes statement was added by addMainSnak
foreach ($statement->getQualifiers() as $q) {
$this->snakBuilder->addSnak($this->statementWriter, $q, RdfVocabulary::NSP_QUALIFIER);
}
}
// XXX: separate builder for references?
if ($this->produceReferences) {
/** @var Reference $reference */
foreach ($statement->getReferences() as $reference) {
//FIXME: split body into separate method
$hash = $reference->getSnaks()->getHash();
$refLName = $hash;
$this->statementWriter->about(RdfVocabulary::NS_STATEMENT, $statementLName)->say(RdfVocabulary::NS_PROV, 'wasDerivedFrom')->is(RdfVocabulary::NS_REFERENCE, $refLName);
if ($this->dedupeBag->alreadySeen($hash, 'R') !== false) {
continue;
}
$this->referenceWriter->about(RdfVocabulary::NS_REFERENCE, $refLName)->a(RdfVocabulary::NS_ONTOLOGY, 'Reference');
foreach ($reference->getSnaks() as $refSnak) {
$this->snakBuilder->addSnak($this->referenceWriter, $refSnak, RdfVocabulary::NSP_REFERENCE);
}
}
}
}