/**
* 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.');
}
}