/**
* It gets all statements of a given graph which match the following conditions:
* - statement's subject is either equal to the subject of the same statement of the graph or
* it is null.
* - statement's predicate is either equal to the predicate of the same statement of the graph or
* it is null.
* - statement's object is either equal to the object of a statement of the graph or it is null.
*
* @param Statement $Statement It can be either a concrete or pattern-statement.
* @param Node $graph optional Overrides target graph. If set, you will get all
* matching statements of that graph.
* @param array $options optional It contains key-value pairs and should provide
* additional introductions for the store and/or its
* adapter(s).
* @return StatementIterator It contains Statement instances of all matching statements of the
* given graph.
* @todo check if graph URI is valid
* @todo make it possible to read graphUri from $statement, if given $graphUri is null
*/
public function getMatchingStatements(Statement $statement, Node $graph = null, array $options = array())
{
// otherwise check, if graph was set in the statement and it is a named node and use it, if so.
if (null === $graph && $statement->isQuad()) {
$graph = $statement->getGraph();
}
/*
* Build query
*/
$query = 'SELECT ?s ?p ?o { ?s ?p ?o ';
if ($graph !== null) {
$query = 'SELECT ?s ?p ?o ?g { graph ?g { ?s ?p ?o } ';
}
// create shortcuts for S, P and O
$subject = $statement->getSubject();
$predicate = $statement->getPredicate();
$object = $statement->getObject();
// add filter, if subject is a named node or literal
if (!$subject->isVariable()) {
$query .= 'FILTER (?s = ' . $subject->toNQuads() . ') ';
}
// add filter, if predicate is a named node or literal
if (!$predicate->isVariable()) {
$query .= 'FILTER (?p = ' . $predicate->toNQuads() . ') ';
}
// add filter, if object is a named node or literal
if (!$object->isVariable()) {
$query .= 'FILTER (?o = ' . $object->toNQuads() . ') ';
}
// add filter, if graph is a named node or literal
if ($graph !== null && !$graph->isVariable()) {
$query .= 'FILTER (?g = ' . $graph->toNQuads() . ') ';
}
$query .= '}';
// execute query and save result
// TODO transform getMatchingStatements into lazy loading, so a batch loading is possible
$result = $this->query($query, $options);
/*
* Transform SetResult entries to Statement instances.
*/
$statementList = array();
if ($graph !== null) {
foreach ($result as $entry) {
$statementList[] = $this->statementFactory->createStatement($entry['s'], $entry['p'], $entry['o'], $entry['g']);
}
} else {
foreach ($result as $entry) {
$statementList[] = $this->statementFactory->createStatement($entry['s'], $entry['p'], $entry['o']);
}
}
// return a StatementIterator which contains the matching statements
return $this->statementIteratorFactory->createIteratorFromArray($statementList);
}
/**
* Transforms a statement array given by EasyRdf to a Saft StatementIterator instance.
*
* @param array $rdfPhp
* @return StatementIterator
*/
protected function rdfPhpToStatementIterator(array $rdfPhp)
{
$statements = array();
// go through all subjects
foreach ($rdfPhp as $subject => $predicates) {
// predicates associated with the subject
foreach ($predicates as $property => $objects) {
// object(s)
foreach ($objects as $object) {
/**
* Create subject node
*/
if (true === NodeUtils::simpleCheckURI($subject)) {
$s = $this->nodeFactory->createNamedNode($subject);
} else {
$s = $this->nodeFactory->createLiteral($subject);
}
/**
* Create predicate node
*/
if (true === NodeUtils::simpleCheckURI($property)) {
$p = $this->nodeFactory->createNamedNode($property);
} else {
$p = $this->nodeFactory->createLiteral($property);
}
/*
* Create object node
*/
// URI
if (NodeUtils::simpleCheckURI($object['value'])) {
$o = $this->nodeFactory->createNamedNode($object['value']);
// datatype set
} elseif (isset($object['datatype'])) {
$o = $this->nodeFactory->createLiteral($object['value'], $object['datatype']);
// lang set
} elseif (isset($object['lang'])) {
$o = $this->nodeFactory->createLiteral($object['value'], 'http://www.w3.org/1999/02/22-rdf-syntax-ns#langString', $object['lang']);
} else {
$o = $this->nodeFactory->createLiteral($object['value']);
}
// build and add statement
$statements[] = $this->statementFactory->createStatement($s, $p, $o);
}
}
}
return new ArrayStatementIteratorImpl($statements);
}
/**
* Removes all statements from a (default-) graph which match with given statement.
*
* @param Statement $statement It can be either a concrete or pattern-statement.
* @param Node $graph optional Overrides target graph. If set, all statements will
* be delete in that graph.
* @param array $options optional Key-value pairs which provide additional introductions
* for the store and/or its adapter(s).
*/
public function deleteMatchingStatements(Statement $statement, Node $graph = null, array $options = array())
{
// given $graph forces usage of it and not the graph from the statement instance
if (null !== $graph) {
// use given $graph
// use graphUri from statement
} elseif (null === $graph && null !== $statement->getGraph()) {
$graph = $statement->getGraph();
}
// create triple statement, because we have to handle the graph extra
$tripleStatement = $this->statementFactory->createStatement($statement->getSubject(), $statement->getPredicate(), $statement->getObject());
$statementIterator = $this->statementIteratorFactory->createIteratorFromArray(array($tripleStatement));
$triple = $this->sparqlFormat($statementIterator);
$query = 'DELETE ';
if (null !== $graph) {
$query .= 'FROM <' . $graph->getUri() . '> ';
}
$query .= '{' . $triple . '} WHERE {' . $triple . '}';
$this->query($query);
}
/**
* Create statements from query.
*
* @param Query $queryObject Query object which represents a SPARQL query.
* @return StatementIterator StatementIterator object
*/
protected function getStatements(Query $queryObject)
{
$queryParts = $queryObject->getQueryParts();
$statementArray = array();
// if only triples, but no quads
if (true === isset($queryParts['triple_pattern']) && false === isset($queryParts['quad_pattern'])) {
foreach ($queryParts['triple_pattern'] as $pattern) {
/**
* Create Node instances for S, P and O to build a Statement instance later on
*/
$s = $this->createNodeByValueAndType($pattern['s'], $pattern['s_type']);
$p = $this->createNodeByValueAndType($pattern['p'], $pattern['p_type']);
$o = $this->createNodeByValueAndType($pattern['o'], $pattern['o_type']);
$g = null;
$statementArray[] = $this->statementFactory->createStatement($s, $p, $o, $g);
}
// if only quads, but not triples
} elseif (false === isset($queryParts['triple_pattern']) && true === isset($queryParts['quad_pattern'])) {
foreach ($queryParts['quad_pattern'] as $pattern) {
/**
* Create Node instances for S, P and O to build a Statement instance later on
*/
$s = $this->createNodeByValueAndType($pattern['s'], $pattern['s_type']);
$p = $this->createNodeByValueAndType($pattern['p'], $pattern['p_type']);
$o = $this->createNodeByValueAndType($pattern['o'], $pattern['o_type']);
$g = $this->createNodeByValueAndType($pattern['g'], $pattern['g_type']);
$statementArray[] = $this->statementFactory->createStatement($s, $p, $o, $g);
}
// found quads and triples
} elseif (true === isset($queryParts['triple_pattern']) && true === isset($queryParts['quad_pattern'])) {
throw new \Exception('Query contains quads and triples. That is not supported yet.');
// neither quads nor triples
} else {
throw new \Exception('Query contains neither quads nor triples.');
}
return $this->statementIteratorFactory->createIteratorFromArray($statementArray);
}
/**
* It basically returns all stored statements.
*
* @param Statement $Statement It can be either a concrete or pattern-statement.
* @param Node $graph optional Overrides target graph. If set, you will get all
* matching statements of that graph.
* @param array $options optional It contains key-value pairs and should provide additional
* introductions for the store and/or its adapter(s).
* @return StatementIterator It contains Statement instances of all matching statements of the given
* graph.
*/
public function getMatchingStatements(Statement $statement, Node $graph = null, array $options = array())
{
if (null !== $graph) {
$graphUri = $graph->getUri();
// no graph information given, use default graph
} elseif (null === $graph && null === $statement->getGraph()) {
$graphUri = 'http://saft/defaultGraph/';
// no graph given, use graph information from $statement
} elseif (null === $graph && $statement->getGraph()->isNamed()) {
$graphUri = $statement->getGraph()->getUri();
// no graph given, use graph information from $statement
} elseif (null === $graph && false == $statement->getGraph()->isNamed()) {
$graphUri = 'http://saft/defaultGraph/';
}
if (false == isset($this->statements[$graphUri])) {
$this->statements[$graphUri] = array();
}
// if not default graph was requested
if ('http://saft/defaultGraph/' != $graphUri) {
return new ArrayStatementIteratorImpl($this->statements[$graphUri]);
// if default graph was requested, return matching statements from all graphs
} else {
$_statements = array();
foreach ($this->statements as $graphUri => $statements) {
foreach ($statements as $statement) {
if ('http://saft/defaultGraph/' == $graphUri) {
$graph = null;
} else {
$graph = $this->nodeFactory->createNamedNode($graphUri);
}
$_statements[] = $this->statementFactory->createStatement($statement->getSubject(), $statement->getPredicate(), $statement->getObject(), $graph);
}
}
return new ArrayStatementIteratorImpl($_statements);
}
}