/**
* Loads an ontology from configuration files using the DBpedia mapping language.
*
* @param $pages Array of PageNode instances containing the configuration files
* @return Ontology The ontology
*/
public function read(array $pages)
{
$ontology = new Ontology();
$ontology->addClass(new OntologyClass("owl:Thing"));
OntologyDataTypes::addDataTypes($ontology);
// TODO: range should be rdfs:Class
$ontology->addProperty(new OntologyProperty("rdf:type", $ontology->getClass("owl:Thing")));
foreach ($pages as $pageNode) {
OntologyReader::createClasses($ontology, $pageNode);
}
foreach ($pages as $pageNode) {
OntologyReader::linkClasses($ontology, $pageNode);
}
return $ontology;
}
/**
* Loads the ontology
*/
private function loadOntology()
{
if ($this->allowCaching && file_exists(self::ONTOLOGY_FILE)) {
$this->logger->info('Loading ontology from file.');
$this->ontology = unserialize(file_get_contents(self::ONTOLOGY_FILE));
} else {
//Parse ontology schema pages
$this->logger->info('Reading ontology...');
$ontologyPages = $this->loadAllPages($this->ontologySource);
//Load ontology
$ontologyReader = new OntologyReader();
$this->ontology = $ontologyReader->read($ontologyPages);
LabelExtractor::addProperties($this->ontology);
AbstractExtractor::addProperties($this->ontology);
$this->destroyAllPages($ontologyPages);
file_put_contents(self::ONTOLOGY_FILE, serialize($this->ontology));
//Show the extracted ontology
$writer = new ontology\OWLOntologyWriter();
echo $writer->toOWL($this->ontology);
}
}
private function processOntology()
{
$path = $this->ontologyPath();
if ($path === false) {
return false;
}
try {
$name = OntologyReader::getName($path);
// check that namespace is known
OntologyNamespaces::getUri($name, 'http://example.com/');
} catch (\Exception $e) {
$this->response(400, 'Invalid ontology page title ' . $path);
return true;
// we're done, give up
}
// TODO: add the following two lines? or at least the first line?
// if (! $this->parsePage()) return true; // we're done, give up
// if (! $this->hasTemplate(self::$ontologyTemplates)) ignore data? send error response?
// forward source to ultrapedia
// Ontology pages don't exist @ Ultrapedia
//if (! $this->sendWiki()) return true; // error response already sent
try {
$configHolder = $this->configHandler->updateOntology($path, $this->rawPage);
} catch (\Exception $e) {
$this->response(500, 'Internal server error', 'Failed to update ontology: ' . $e);
return true;
// give up
}
$writer = new OWLOntologyWriter();
$owl = $writer->toOWL($configHolder->ontology);
if (!$this->sendOwl($owl)) {
return true;
}
// error response already sent
return $this->response(200, 'Successfully updated ontology schema');
}
/**
* @param $abstracts should properties for AbstractExtractor be added to ontology?
* TODO: Create an interface ExtractorBuilder with methods addProperties() and createExtractor().
* Give this method an array of ExtractorBuilders.
*/
public function loadOntology($abstracts = true)
{
$ontologyPages = $this->loadAllPages($this->ontologyDir);
$ontologyReader = new OntologyReader();
$ontology = $ontologyReader->read($ontologyPages);
\dbpedia\mapping\LabelExtractor::addProperties($ontology);
if ($abstracts) {
\dbpedia\mapping\AbstractExtractor::addProperties($ontology);
}
$this->destroyAllPages($ontologyPages);
return $ontology;
}
