protected function linkMetadata()
{
$ldpType = 'http://www.w3.org/ns/ldp#' . $this->type;
$this->weblinks[] = WebLink::factory($ldpType)->rel('type');
$metadata = $this->templateEngine->setTemplate($this->metadata ? $this->metadata : "<{pagedResourceUri}> a <{$ldpType}> .")->render();
$this->resultGraph->parse($metadata, 'turtle');
return $this;
}
public function get($resourceId = null)
{
// call the method that populate resultGraph
$this->linkData();
$hasNextPage = $this->detectIfHasNextPage();
// add metadata and weblinks to single-page resource
if ($this->context->isSinglePageResource()) {
// provide web links as required by LDP specifications
$this->weblinks[] = WebLink::factory('http://www.w3.org/ns/ldp-paging#Page')->rel('type');
// LDP servers may provide a first page link when responding to requests with any single-page
// resource as the Request-URI.
$this->weblinks[] = WebLink::factory($this->context->firstPageUri())->rel('first');
// LDP servers may provide a last page link in responses to GET requests with any single-page
// resource as the Request-URI.
// LDP servers must provide a next page link in responses to GET requests with any single-page
// resource other than the final page as the Request-URI. This is the mechanism by which clients c
// an discover the URL of the next page.
// LDP servers must not provide a next page link in responses to GET requests with the final
// single-page resource as the Request-URI. This is the mechanism by which clients can discover
// the end of the page sequence as currently known by the server.
if ($hasNextPage) {
$this->weblinks[] = WebLink::factory($this->context->nextPageUri())->rel('next');
}
// LDP servers may provide a previous page link in responses to GET requests with any
// single-page resource other than the first page as the Request-URI.
// This is one mechanism by which clients can discover the URL of the previous page.
// LDP servers must not provide a previous page link in responses to GET requests with the
// First single-page resource as the Request-URI. This is one mechanism by which clients
// can discover the beginning of the page sequence as currently known by the server.
if ($this->context->getPageNum() > 0) {
$this->weblinks[] = WebLink::factory($this->context->prevPageUri())->rel('prev');
}
// add metadata about linked Data Single page resource
$metadata = $this->templateEngine->setTemplate('
@base <{requestedUri}> .
@prefix ldp-paging: <http://www.w3.org/ns/ldp-paging#> .
<> a ldp-paging:Page; ldp-paging:pageOf <{pagedResourceUri}>.
')->render();
$this->resultGraph->parse($metadata, 'turtle');
} elseif ($hasNextPage) {
// Server side initiated page management:
// WARNING THI IMPLEMENTATION USES A LDP SPECIFICATIO FEATURE AT RISK:
// LDP servers should respond with HTTP status code 333 (Returning Related) to successful
// GET requests with any paged resource as the Request-URI, although any appropriate code may be used.
Http::setHttpResponseCode(333);
header('Location: ' . $this->context->firstPageUri());
// N.B. 333 code is not yet standarized..it is threathed as 302 by many agents
// In that case you coud return withoud any other payload setup.
// but if 333 will be standarized the payload is ready to serve first page
}
// add to result graph the metadata about Linked Data paged resource in first page
// Note that this apply both for Single-Page resource and for Paged Resource
if ($this->context->getPageNum() == 0) {
$this->linkMetadata();
}
return $this->stateTransfer($this->resultGraph, $this->weblinks);
}
public function get()
{
// sanitize request input
$username = filter_input(INPUT_GET, 'username', FILTER_SANITIZE_STRING);
$password = filter_input(INPUT_GET, 'password', FILTER_SANITIZE_STRING);
$endpoint = filter_input(INPUT_GET, 'endpoint', FILTER_SANITIZE_URL);
$query = filter_input(INPUT_GET, 'query', FILTER_UNSAFE_RAW);
// prepare request content model
if ($endpoint && $query) {
HttpClient::useIdentity($username, $password);
$sparql = new SparqlClient($endpoint);
$result = $sparql->query($query);
} else {
$result = new Graph($_SERVER['REQUEST_URI']);
}
return self::stateTransfer($result, WebLink::factory('sparqlForm.php?' . http_build_query($_GET))->rel('edit'));
}
public function get($to = 'World')
{
return $this->stateTransfer($hello = new Greeting($to), WebLink::factory($hello->by)->rel('next'));
}
/**
* An helper to setup content type and alternate web link headers
*/
public static function setContentType($contentType, $policyClass = null)
{
if (is_null($policyClass)) {
$policyClass = get_called_class();
}
header('Content-Type: ' . $contentType);
$selfUri = isset($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : '';
if ($selfUri && is_subclass_of($policyClass, __CLASS__)) {
$altenatives = array_keys($policyClass::$renderers);
header(WebLink::factory($selfUri)->rel('self')->httpSerializer(), false);
foreach ($altenatives as $type) {
if ($contentType != $type) {
header(WebLink::factory($selfUri)->rel('alternate')->type($type)->httpSerializer(), false);
}
}
}
}
