public static function getBody($dataObj)
{
if ($dataObj->is_semantic) {
// Check if a configuration is given
$conf = array();
if (!empty($dataObj->semantic->conf)) {
$conf = $dataObj->semantic->conf;
foreach ($conf['ns'] as $prefix => $uri) {
RdfNamespace::set($prefix, $uri);
}
}
// Add the configured ontology prefixes
$ontologies = \App::make('Tdt\\Core\\Repositories\\Interfaces\\OntologyRepositoryInterface');
$context = array();
// Only add the common namespaces
$namespaces = array('hydra', 'rdf', 'rdfs', 'foaf', 'void', 'xsd', 'skos', 'xs');
foreach ($namespaces as $ns) {
$namespace = $ontologies->getByPrefix($ns);
if (!empty($namespace)) {
$context[$ns] = $namespace['uri'];
}
}
$output = $dataObj->data->serialise('jsonld');
// Next, encode the context as JSON
$jsonContext = json_encode($context);
// Compact the JsonLD by using @context -> Needs tweaking can only return the
// URI spaces that are used in the document.
$compacted = JsonLD::compact($output, $jsonContext);
// Print the resulting JSON-LD!
return JsonLD::toString($compacted, true);
} else {
\App::abort(400, "The data is not a semantically linked document, a linked data JSON representation is not possible.");
}
}
protected function open()
{
$this->graph = new Graph();
$rdfa_parser = new RdfaParser();
$json_parser = new JsonLd();
\EasyRdf\RdfNamespace::set('dcat', 'http://www.w3.org/ns/dcat#');
\EasyRdf\RdfNamespace::set('lbld', 'http://decisions.data.vlaanderen.be/ns#');
$data = file_get_contents($this->extractor->uri);
// Assume we have an rdfa document to begin with
$rdfa_parser->parse($this->graph, $data, 'rdfa', $this->extractor->base_uri);
// Check if we have properties we need to include into the current graph
$properties = explode(',', $this->extractor->follow_properties);
foreach ($this->graph->resources() as $resource) {
foreach ($properties as $property) {
$resolve_resources = $resource->allResources($property);
if (!empty($resolve_resources)) {
foreach ($resolve_resources as $resolve_resource) {
$data = file_get_contents($resolve_resource->getUri());
// Parse any rdfa data in the document into the existing graph
$this->graph->parse($data, 'rdfa', $resolve_resource->getUri());
$json = $this->parseJsonldSnippet($data);
if (!empty($json)) {
try {
$this->graph->parse($json, 'jsonld', $resolve_resource->getUri());
} catch (\Exception $ex) {
\Log::error("We could not parse json from the data, the data was:" . $json);
}
}
}
}
}
}
// We only return the graph once as a full datastructure
$this->has_next = true;
}
public function __construct($endpoint, $namespaces)
{
$this->endpoint = $endpoint;
$this->namespaces = $namespaces;
foreach ($namespaces as $namespace => $uri) {
\EasyRdf\RdfNamespace::set($namespace, $uri);
}
}
/**
* Create the DCAT document of the published (non-draft) resources
*
* @return mixed \Data object with a graph of DCAT information
*/
private function createDcat()
{
$ns = $this->dcat->getNamespaces();
foreach ($ns as $prefix => $uri) {
RdfNamespace::set($prefix, $uri);
}
// If limit is empty, provide a custom page size for the DCAT document
$limit = \Input::get('limit');
if (empty($limit)) {
\Input::merge(array('limit' => 100));
}
// Apply paging when fetching the definitions
list($limit, $offset) = Pager::calculateLimitAndOffset();
$definition_count = $this->definitions->countPublished();
$definitions = $this->definitions->getAllPublished($limit, $offset);
$oldest = $this->definitions->getOldest();
$describedDefinitions = array();
// Add the source type description to the definition
foreach ($definitions as $definition) {
$definition = array_merge($definition, $this->definitions->getFullDescription($definition['collection_uri'] . '/' . $definition['resource_name']));
array_push($describedDefinitions, $definition);
}
$graph = $this->dcat->getDcatDocument($describedDefinitions, $oldest);
// Return the dcat feed in our internal data object
$data_result = new Data();
$data_result->data = $graph;
$data_result->is_semantic = true;
$data_result->paging = Pager::calculatePagingHeaders($limit, $offset, $definition_count);
// Add the semantic configuration for the ARC graph
$data_result->semantic = new \stdClass();
$data_result->semantic->conf = array('ns' => $ns);
$data_result->definition = [];
$data_result->definition['resource_name'] = 'dcat';
$data_result->definition['collection_uri'] = 'info';
$data_result->definition['source_type'] = 'DCAT';
return $data_result;
}
protected function open()
{
// Perform XLST
$xsl_url = "https://webgate.ec.europa.eu/CITnet/stash/projects/ODCKAN/repos/iso-19139-to-dcat-ap/browse/iso-19139-to-dcat-ap.xsl?raw";
$proc = null;
try {
$xml = new DOMDocument();
$xml->load($this->extractor->uri);
$xsl = new DOMDocument();
$xsl->load($xsl_url);
$proc = new XSLTProcessor();
$proc->importStyleSheet($xsl);
} catch (\ErrorException $ex) {
$this->log('Something went wrong: ' . $ex->getMessage());
die;
}
$dcat_document = $proc->transformToXML($xml);
\EasyRdf\RdfNamespace::set('locn', 'http://www.w3.org/ns/locn#');
// Parse the dcat graph
$graph = new Graph();
$rdf_parser = new RdfXml();
$rdf_parser->parse($graph, $dcat_document, 'rdfxml', 'http://foo');
$this->datasets = $graph->allOfType('dcat:Dataset');
}
private function sparqlRetrieveTriplesForNotation($notation)
{
// alternative query (the fuseki's query is the same except that # must be encoded as %23 or it will be understood as eof
//$query = "prefix skos: <http://www.w3.org/2004/02/skos/core#> select ?s ?p ?o where {?s skos:notation '" . $notation . "' . }";
\EasyRdf\RdfNamespace::set('skos', 'http://www.w3.org/2004/02/skos/core#');
$query = "select ?s ?p ?o where {?s skos:notation '" . $notation . "' . }";
$sparqlClient = new \EasyRdf\Sparql\Client(BASE_URI_ . ':3030/openskos/query');
$result = $sparqlClient->query($query);
return $result;
}
/**
* Retrieve a Data object identified by $uri
*
* @param string $uri The identifier that identifies a resource
*
* @return \Response
*/
public function get($uri)
{
// Check permissions
Auth::requirePermissions('dataset.view');
// Split for an (optional) extension
list($uri, $extension) = self::processURI($uri);
$extension = strtolower($extension);
// Check for caching
// Based on: URI / Rest parameters / Query parameters / Paging headers
$cache_string = $uri;
list($limit, $offset) = Pager::calculateLimitAndOffset();
$cache_string .= '/limit=' . $limit . 'offset=' . $offset;
$omit = ['limit', 'offset', 'page', 'page_size'];
$query_string_params = \Input::get();
foreach ($query_string_params as $key => $val) {
if (in_array($key, $omit)) {
unset($query_string_params[$key]);
}
}
$cache_string .= http_build_query($query_string_params);
$cache_string = sha1($cache_string);
if (Cache::has($cache_string)) {
return ContentNegotiator::getResponse(Cache::get($cache_string), $extension);
} else {
// Get definition
$definition = $this->definition->getByIdentifier($uri);
if ($definition) {
// Get source definition
$source_definition = $this->definition->getDefinitionSource($definition['source_id'], $definition['source_type']);
if ($source_definition) {
$source_type = $source_definition['type'];
// KML can be formatted into different formats
if ($source_definition['type'] == 'XML' && $source_definition['geo_formatted'] == 1) {
$source_type == 'kml';
$source_definition['type'] = 'KML';
}
// Create the right datacontroller
$controller_class = 'Tdt\\Core\\DataControllers\\' . $source_type . 'Controller';
$data_controller = \App::make($controller_class);
// Get REST parameters
$uri_segments = explode('/', $uri);
$definition_segments = explode('/', $definition['collection_uri']);
array_push($definition_segments, $definition['resource_name']);
$rest_parameters = array_diff($uri_segments, $definition_segments);
$rest_parameters = array_values($rest_parameters);
$throttle_response = $this->applyThrottle($definition);
if (!empty($throttle_response)) {
return $throttle_response;
}
// Retrieve dataobject from datacontroller
$data = $data_controller->readData($source_definition, $rest_parameters);
// If the source type is XML, just return the XML contents, don't transform
if (strtolower($source_type) == 'xml' && $extension == 'xml') {
return $this->createXMLResponse($data->data);
} elseif (strtolower($source_type) == 'xml' && $extension == 'kml' && $data->geo_formatted) {
return $this->createXMLResponse($data->data);
} elseif (!$data->is_semantic && $extension == 'xml' && $source_type != 'xml') {
\App::abort(406, "The requested format for the datasource is not available.");
} elseif (strtolower($source_type) == 'xml' && !$data->geo_formatted && !empty($extension) && $extension != 'xml') {
\App::abort(406, "The requested format for the datasource is not available.");
} elseif (strtolower($source_type) == 'xml' && $data->geo_formatted && !empty($extension) && !in_array($extension, $data->preferred_formats)) {
\App::abort(406, "The requested format for the datasource is not available.");
}
$data->rest_parameters = $rest_parameters;
// REST filtering
if ($source_type != 'INSTALLED' && count($data->rest_parameters) > 0) {
$data->data = self::applyRestFilter($data->data, $data->rest_parameters);
}
// Semantic paging with the hydra voc
if ($data->is_semantic && !empty($data->paging)) {
RdfNamespace::set('hydra', 'http://www.w3.org/ns/hydra/core#');
$graph = $data->data;
$url = \URL::to($definition['collection_uri'] . '/' . $definition['resource_name']);
$request_url = \Request::url();
$graph->addResource($request_url, 'void:subset', $url);
foreach ($data->paging as $key => $val) {
$paged_url = $request_url . '?offset=' . $val[0] . '&limit=' . $val[1] . Pager::buildQuerystring();
switch ($key) {
case 'next':
$graph->addResource($request_url, 'hydra:nextPage', $paged_url);
break;
case 'previous':
$graph->addResource($request_url, 'hydra:previousPage', $paged_url);
break;
case 'last':
$graph->addResource($request_url, 'hydra:lastPage', $paged_url);
break;
case 'first':
$graph->addResource($request_url, 'hydra:firstPage', $paged_url);
break;
}
}
$graph->addResource($url, 'a', 'dcat:Dataset');
$title = null;
if (!empty($definition['title'])) {
$title = $definition['title'];
} else {
$title = $definition['collection_uri'] . '/' . $definition['resource_name'];
}
$graph->addLiteral($url, 'dc:title', $title);
$graph->addLiteral($url, 'dc:description', $source_definition['description']);
$graph->addResource($url, 'dcat:distribution', $url . '.json');
$data->data = $graph;
}
// Add definition to the object
$data->definition = $definition;
// Add source definition to the object
$data->source_definition = $source_definition;
// Add the available, supported formats to the object
$format_helper = new FormatHelper();
$data->formats = $format_helper->getAvailableFormats($data);
// Store in cache
if (!empty($definition['cache_minutes'])) {
Cache::put($cache_string, $data, $definition['cache_minutes']);
}
// Return the formatted response with content negotiation
return ContentNegotiator::getResponse($data, $extension);
} else {
\App::abort(404, "Source for the definition could not be found.");
}
} else {
// Coulnd't find a definition, but it might be a collection
$resources = $this->definition->getByCollection($uri);
if (count($resources) > 0) {
$data = new Data();
$data->data = new \stdClass();
$data->data->datasets = array();
$data->data->collections = array();
foreach ($resources as $res) {
// Check if it's a subcollection or a dataset
$collection_uri = rtrim($res['collection_uri'], '/');
if ($collection_uri == $uri) {
array_push($data->data->datasets, \URL::to($collection_uri . '/' . $res['resource_name']));
} else {
// Push the subcollection if it's not already in the array
if (!in_array(\URL::to($collection_uri), $data->data->collections)) {
array_push($data->data->collections, \URL::to($collection_uri));
}
}
}
// Fake a definition
$data->definition = new \Definition();
$uri_array = explode('/', $uri);
$last_chunk = array_pop($uri_array);
$data->definition->collection_uri = join('/', $uri_array);
$data->definition->resource_name = $last_chunk;
// Return the formatted response with content negotiation
return ContentNegotiator::getResponse($data, $extension);
} else {
\App::abort(404, "The dataset or collection you were looking for could not be found (URI: {$uri}).");
}
}
}
}
/**
* @param $prefix
* @param $long
*/
public function set($prefix, $long)
{
RdfNamespace::set($prefix, $long);
}
protected function open()
{
\EasyRdf\RdfNamespace::set('locn', 'http://www.w3.org/ns/locn#');
$graph = Graph::newAndLoad($this->extractor->uri, $this->extractor->format);
$this->datasets = $graph->allOfType('dcat:Dataset');
}
