/**
* check and manipulate the declared FROMs according to the access control
*/
protected function _prepareQuery($queryObject, &$options = array())
{
/*
* clone the Query2 Object to not modify the original one
* could be used elsewhere, could have side-effects
*/
if ($queryObject instanceof Erfurt_Sparql_Query2) {
//always clone
//the query will be altered here to implement AC and owl:imports
//dont make these changes global
$queryObject = clone $queryObject;
//bring triples etc. to canonical order
// $queryObject->optimize();
}
$defaultOptions = array(Erfurt_Store::RESULTFORMAT => Erfurt_Store::RESULTFORMAT_PLAIN, Erfurt_Store::USE_AC => true, Erfurt_Store::USE_OWL_IMPORTS => true, Erfurt_Store::USE_ADDITIONAL_IMPORTS => true);
if (!is_array($options)) {
$options = array();
}
$options = array_merge($defaultOptions, $options);
//typechecking
if (is_string($queryObject)) {
$queryObject = Erfurt_Sparql_SimpleQuery::initWithString($queryObject);
}
if (!($queryObject instanceof Erfurt_Sparql_Query2 || $queryObject instanceof Erfurt_Sparql_SimpleQuery)) {
throw new Erfurt_Store_Exception('Argument 1 passed to Erfurt_Store::sparqlQuery must be instance of ' . 'Erfurt_Sparql_Query2, Erfurt_Sparql_SimpleQuery or string', 1);
}
/*
if ($options[Erfurt_Store::USE_AC] == false) {
//we are done preparing early
return $queryObject;
}
*/
$logger = $this->_getQueryLogger();
$noBindings = false;
//get available models (readable)
$available = array();
if ($options[Erfurt_Store::USE_AC] === true) {
$logger->debug('AC: use ac ');
$availablepre = $this->getAvailableModels(true);
//all readable (with ac)
foreach ($availablepre as $key => $true) {
$available[] = array('uri' => $key, 'named' => false);
}
} else {
$logger->debug('AC: dont use ac ');
$allpre = $this->_backendAdapter->getAvailableModels();
//really all (without ac)
foreach ($allpre as $key => $true) {
$available[] = array('uri' => $key, 'named' => false);
}
}
$logger->debug('AC: available models ' . $this->toStr($available));
// examine froms (for access control and imports) in 5 steps
// 1. extract froms for easier handling
$froms = array();
if ($queryObject instanceof Erfurt_Sparql_Query2) {
foreach ($queryObject->getFroms() as $graphClause) {
$uri = $graphClause->getGraphIri()->getIri();
$froms[] = array('uri' => $uri, 'named' => $graphClause->isNamed());
}
} else {
//SimpleQuery
foreach ($queryObject->getFrom() as $graphClause) {
$froms[] = array('uri' => $graphClause, 'named' => false);
}
foreach ($queryObject->getFromNamed() as $graphClause) {
$froms[] = array('uri' => $graphClause, 'named' => true);
}
}
$logger->debug('AC: requested FROMs' . $this->toStr($froms));
// 2. no froms in query -> froms = availableModels
if (empty($froms)) {
$logger->debug('AC: no requested FROM -> take all available: ' . $this->toStr($available));
$froms = $available;
}
// 3. filter froms by availability and existence - if filtering deletes all -> give empty result back
if ($options[Erfurt_Store::USE_AC] === true) {
$froms = $this->_maskModelList($froms, $available);
$logger->debug('AC: after filtering (read-rights and existence): ' . $this->toStr($froms));
if (empty($froms)) {
$logger->debug('AC: all disallowed - empty result');
$noBindings = true;
}
}
// 4. get import closure for every remaining from
if ($options[Erfurt_Store::USE_OWL_IMPORTS] === true) {
foreach ($froms as $from) {
$importsClosure = $this->getImportsClosure($from['uri'], $options[Erfurt_Store::USE_ADDITIONAL_IMPORTS], $options[Erfurt_Store::USE_AC]);
$logger->debug('AC: import ' . $from['uri'] . ' -> ' . (empty($importsClosure) ? 'none' : implode(' ', $importsClosure)));
foreach ($importsClosure as $importedGraphUri) {
$addCandidate = array('uri' => $importedGraphUri, 'named' => false);
//avoid duplicates
if (in_array($addCandidate, $available) && array_search($addCandidate, $froms) === false) {
$froms[] = $addCandidate;
}
}
}
}
$logger->debug('AC: after imports: ' . $this->toStr($froms));
// 5. put froms back
if ($queryObject instanceof Erfurt_Sparql_Query2) {
$queryObject->setFroms(array());
foreach ($froms as $from) {
$queryObject->addFrom($from['uri'], $from['named']);
}
} else {
$queryObject->setFrom(array());
$queryObject->setFromNamed(array());
foreach ($froms as $from) {
if (!$from['named']) {
$queryObject->addFrom($from['uri']);
} else {
$queryObject->addFromNamed($from['uri']);
}
}
}
// if there were froms and all got deleted due to access controll - give back empty result set
// this is achieved by replacing the where-part with an unsatisfiable one
// i think this is efficient because otherwise we would have to deal with result formating und variables
if ($noBindings) {
$logger->debug('AC: force no bindings');
if ($queryObject instanceof Erfurt_Sparql_SimpleQuery) {
$queryObject->setWherePart('{FILTER(false)}');
} else {
if ($queryObject instanceof Erfurt_Sparql_Query2) {
$ggp = new Erfurt_Sparql_Query2_GroupGraphPattern();
$ggp->addFilter(false);
//unsatisfiable
$queryObject->removeAllProjectionVars();
$queryObject->setWhere($ggp);
}
}
}
return (string) $queryObject;
}
/**
* Moves resource to new URI
* renaming all occurences of the resource.
*
* @param string $oldUri The URI that identifies the resource.
* @param string $newUri The URI to move resource to.
*
* @return void
*/
public function renameResource($oldUri, $newUri)
{
$query = new Erfurt_Sparql_Query2();
$query->setDistinct(true);
$vars = array();
foreach (array('s', 'p', 'o') as $varName) {
$vars[$varName] = new Erfurt_Sparql_Query2_Var($varName);
$query->addProjectionVar($vars[$varName]);
}
$oldUriRef = new Erfurt_Sparql_Query2_IriRef($oldUri);
$union = new Erfurt_Sparql_Query2_GroupOrUnionGraphPattern();
foreach ($vars as $var) {
$group = new Erfurt_Sparql_Query2_GroupGraphPattern();
$group->addTriple($vars['s'], $vars['p'], $vars['o']);
$group->addFilter(new Erfurt_Sparql_Query2_sameTerm($var, $oldUriRef));
$union->addElement($group);
}
$query->addElement($union);
$result = $this->sparqlQuery($query, array('result_format' => 'extended'));
$removed = array();
$added = array();
foreach ($result['results']['bindings'] as $s) {
// result format from sparqlQuery
// isn't the same as format for delete/addMultipleStatements
if (array_key_exists('xml:lang', $s['o'])) {
$s['o']['lang'] = $s['o']['xml:lang'];
unset($s['o']['xml:lang']);
}
$removed[$s['s']['value']][$s['p']['value']][] = $s['o'];
foreach (array('s', 'p', 'o') as $varName) {
if ($s[$varName]['type'] === 'uri' && $s[$varName]['value'] === $oldUri) {
$s[$varName]['value'] = $newUri;
}
}
$added[$s['s']['value']][$s['p']['value']][] = $s['o'];
}
$this->deleteMultipleStatements($removed);
$this->addMultipleStatements($added);
}
