/**
* Find the redirect target of an ExpNsResource
*
* Returns an SMWExpNsResource object the input redirects to, the input
* itself if there is no redirect (or it cannot be used for making a resource
* with a prefix).
*
* @since 1.6
*
* @param ExpNsResource $expNsResource string URI to check
* @param boolean $existsthat is set to true if $expNsResource is in the
* store; always false for blank nodes; always true for subobjects
*
* @return ExpNsResource
* @throws RuntimeException
*/
public function findRedirectTargetResource(ExpNsResource $expNsResource, &$exists)
{
$exists = true;
if ($expNsResource->isBlankNode() || $this->isNonRedirectableResource($expNsResource)) {
$exists = false;
return $expNsResource;
}
if ($expNsResource->getDataItem() instanceof DIWikiPage && $expNsResource->getDataItem()->getSubobjectName() !== '') {
return $expNsResource;
}
$firstRow = $this->doLookupResourceUriTargetFor($expNsResource);
if ($firstRow === false) {
$exists = false;
return $expNsResource;
}
if (count($firstRow) > 1 && !is_null($firstRow[1])) {
return $this->getResourceForTargetElement($expNsResource, $firstRow[1]);
}
return $expNsResource;
}
/**
* Find the redirect target of an SMWExpNsResource.
* Returns an SMWExpNsResource object the input redirects to,
* the input itself if there is no redirect (or it cannot be
* used for making a resource with a prefix).
*
* @since 1.6
* @param $expNsResource string URI to check
* @param $exists boolean that is set to true if $expNsResource is in the
* store; always false for blank nodes; always true for subobjects
* @return SMWExpNsResource
*/
protected function getSparqlRedirectTarget(SMWExpNsResource $expNsResource, &$exists)
{
if ($expNsResource->isBlankNode()) {
$exists = false;
return $expNsResource;
} elseif ($expNsResource->getDataItem() instanceof SMWDIWikiPage && $expNsResource->getDataItem()->getSubobjectName() !== '') {
$exists = true;
return $expNsResource;
}
$resourceUri = SMWTurtleSerializer::getTurtleNameForExpElement($expNsResource);
$rediUri = SMWTurtleSerializer::getTurtleNameForExpElement(SMWExporter::getSpecialPropertyResource('_REDI'));
$skeyUri = SMWTurtleSerializer::getTurtleNameForExpElement(SMWExporter::getSpecialPropertyResource('_SKEY'));
$sparqlResult = smwfGetSparqlDatabase()->select('*', "{$resourceUri} {$skeyUri} ?s OPTIONAL { {$resourceUri} {$rediUri} ?r }", array('LIMIT' => 1), array($expNsResource->getNamespaceId() => $expNsResource->getNamespace()));
$firstRow = $sparqlResult->current();
if ($firstRow === false) {
$exists = false;
return $expNsResource;
} elseif (count($firstRow) > 1 && !is_null($firstRow[1])) {
$exists = true;
$rediTargetElement = $firstRow[1];
$rediTargetUri = $rediTargetElement->getUri();
$wikiNamespace = SMWExporter::getNamespaceUri('wiki');
if (strpos($rediTargetUri, $wikiNamespace) === 0) {
return new SMWExpNsResource(substr($rediTargetUri, 0, strlen($wikiNamespace)), $wikiNamespace, 'wiki');
} else {
return $expNsResource;
}
} else {
$exists = true;
return $expNsResource;
}
}
