/**
* Try to find an SMWDataItem that the given SMWExpElement might
* represent. Returns null if this attempt failed.
*
* @param SMWExpElement $expElement
* @return SMWDataItem or null
*/
public static function findDataItemForExpElement(SMWExpElement $expElement)
{
global $wgContLang;
$dataItem = null;
if ($expElement instanceof SMWExpResource) {
$uri = $expElement->getUri();
$wikiNamespace = self::getNamespaceUri('wiki');
if (strpos($uri, $wikiNamespace) === 0) {
$localName = substr($uri, strlen($wikiNamespace));
$dbKey = urldecode(self::decodeURI($localName));
$parts = explode('-23', $dbKey, 2);
if (count($parts) == 2) {
$subobjectname = $parts[1];
} else {
$subobjectname = '';
}
$parts = explode(':', $dbKey, 2);
if (count($parts) == 1) {
$dataItem = new SMWDIWikiPage($dbKey, NS_MAIN, '', $subobjectname);
} else {
// try the by far most common cases directly before using Title
$namespaceName = str_replace('_', ' ', $parts[0]);
$namespaceId = -1;
foreach (array(SMW_NS_PROPERTY, NS_CATEGORY, NS_USER, NS_HELP) as $nsId) {
if ($namespaceName == $wgContLang->getNsText($nsId)) {
$namespaceId = $nsId;
break;
}
}
if ($namespaceId != -1) {
$dataItem = new SMWDIWikiPage($parts[1], $namespaceId, '', $subobjectname);
} else {
$title = Title::newFromDBkey($dbKey);
if (!is_null($title)) {
$dataItem = new SMWDIWikiPage($title->getDBkey(), $title->getNamespace(), $title->getInterwiki(), $subobjectname);
}
}
}
}
// else: not in wiki namespace -- TODO: this could be an imported URI
} else {
// TODO (currently not needed, but will be useful for displaying external SPARQL results)
}
return $dataItem;
}
/**
* Get the Turtle serialization string for the given SMWExpElement. The
* method just computes a name, and does not serialize triples, so the
* parameter must be an SMWExpResource or SMWExpLiteral, no SMWExpData.
*
* @param $expElement SMWExpElement being SMWExpLiteral or SMWExpResource
* @return string
*/
public static function getTurtleNameForExpElement(SMWExpElement $expElement)
{
if ($expElement instanceof SMWExpResource) {
if ($expElement->isBlankNode()) {
return '[]';
} elseif ($expElement instanceof SMWExpNsResource && $expElement->hasAllowedLocalName()) {
return $expElement->getQName();
} else {
return '<' . str_replace('>', '\\>', SMWExporter::getInstance()->expandURI($expElement->getUri())) . '>';
}
} elseif ($expElement instanceof SMWExpLiteral) {
$dataType = $expElement->getDatatype();
$lexicalForm = self::getCorrectLexicalForm($expElement);
if ($dataType !== '' && $dataType != 'http://www.w3.org/2001/XMLSchema#string') {
$count = 0;
$newdt = str_replace('http://www.w3.org/2001/XMLSchema#', 'xsd:', $dataType, $count);
return $count == 1 ? "{$lexicalForm}^^{$newdt}" : "{$lexicalForm}^^<{$dataType}>";
} else {
return $lexicalForm;
}
} else {
throw new InvalidArgumentException('The method can only serialize atomic elements of type SMWExpResource or SMWExpLiteral.');
}
}