/**
* Check if this element encodes an RDF list, and if yes return an
* array of SMWExpElements corresponding to the collection elements in
* the specified order. Otherwise return false.
* The method only returns lists that can be encoded using
* parseType="Collection" in RDF/XML, i.e. only lists of non-literal
* resources.
*
* @return mixed array of SMWExpElement (but not SMWExpLiteral) or false
*/
public function getCollection()
{
$rdftypeUri = SMWExporter::getInstance()->getSpecialNsResource('rdf', 'type')->getUri();
$rdffirstUri = SMWExporter::getInstance()->getSpecialNsResource('rdf', 'first')->getUri();
$rdfrestUri = SMWExporter::getInstance()->getSpecialNsResource('rdf', 'rest')->getUri();
$rdfnilUri = SMWExporter::getInstance()->getSpecialNsResource('rdf', 'nil')->getUri();
// first check if we are basically an RDF List:
if ($this->m_subject->isBlankNode() && count($this->m_children) == 3 && array_key_exists($rdftypeUri, $this->m_children) && count($this->m_children[$rdftypeUri]) == 1 && array_key_exists($rdffirstUri, $this->m_children) && count($this->m_children[$rdffirstUri]) == 1 && !end($this->m_children[$rdffirstUri]) instanceof SMWExpLiteral && array_key_exists($rdfrestUri, $this->m_children) && count($this->m_children[$rdfrestUri]) == 1) {
$typedata = end($this->m_children[$rdftypeUri]);
$rdflistUri = SMWExporter::getInstance()->getSpecialNsResource('rdf', 'List')->getUri();
if ($typedata->getSubject()->getUri() == $rdflistUri) {
$first = end($this->m_children[$rdffirstUri]);
$rest = end($this->m_children[$rdfrestUri]);
if ($rest instanceof SMWExpData) {
$restlist = $rest->getCollection();
if ($restlist === false) {
return false;
} else {
array_unshift($restlist, $first);
return $restlist;
}
} elseif ($rest instanceof SMWExpResource && $rest->getUri() == $rdfnilUri) {
return array($first);
} else {
return false;
}
} else {
return false;
}
} elseif (count($this->m_children) == 0 && $this->m_subject->getUri() == $rdfnilUri) {
return array();
} else {
return false;
}
}
/**
* Add to the output a serialization of a property assignment where an
* SMWExpResource is the object. It is assumed that a suitable subject
* block has already been openend.
*
* @param $expResourceProperty SMWExpNsResource the property to use
* @param $expResource SMWExpResource the data value to use
* @param $indent string specifying a prefix for indentation (usually a sequence of tabs)
* @param $isClassTypeProp boolean whether the resource must be declared as a class
*/
protected function serializeExpResource(SMWExpNsResource $expResourceProperty, SMWExpResource $expResource, $indent, $isClassTypeProp)
{
$this->post_ns_buffer .= $indent . '<' . $expResourceProperty->getQName();
if (!$expResource->isBlankNode()) {
if ($expResource instanceof SMWExpNsResource && $expResource->getNamespaceID() == 'wiki') {
// very common case, reduce bandwidth
$this->post_ns_buffer .= ' rdf:resource="&wiki;' . $expResource->getLocalName() . '"';
} else {
$uriValue = $this->makeAttributeValueString($expResource->getUri());
$this->post_ns_buffer .= ' rdf:resource="' . $uriValue . '"';
}
}
$this->post_ns_buffer .= "/>\n";
if ($isClassTypeProp) {
$this->requireDeclaration($expResource, SMW_SERIALIZER_DECL_CLASS);
}
}
/**
* State that a certain declaration is needed. The method checks if the
* declaration is already available, and records a todo otherwise.
*/
protected function requireDeclaration(SMWExpResource $resource, $decltype)
{
// Do not declare predefined OWL language constructs:
if ($resource instanceof SMWExpNsResource) {
$nsId = $resource->getNamespaceId();
if ($nsId == 'owl' || $nsId == 'rdf' || $nsId == 'rdfs') {
return;
}
}
// Do not declare blank nodes:
if ($resource->isBlankNode()) {
return;
}
$name = $resource->getUri();
if (array_key_exists($name, $this->decl_done) && $this->decl_done[$name] & $decltype) {
return;
}
if (!array_key_exists($name, $this->decl_todo)) {
$this->decl_todo[$name] = $decltype;
} else {
$this->decl_todo[$name] = $this->decl_todo[$name] | $decltype;
}
}
