/**
* Loads a remote document or context
*
* @param string $url The URL of the document to load.
*
* @return RemoteDocument The remote document.
*
* @throws JsonLdException If loading the document failed.
*/
public static function loadDocument($url)
{
// if input looks like a file, try to retrieve it
$input = trim($url);
if (false == (isset($input[0]) && "{" === $input[0] || "[" === $input[0])) {
$remoteDocument = new RemoteDocument($url);
$streamContextOptions = array('method' => 'GET', 'header' => "Accept: application/ld+json, application/json; q=0.9, */*; q=0.1\r\n", 'timeout' => Processor::REMOTE_TIMEOUT);
$context = stream_context_create(array('http' => $streamContextOptions, 'https' => $streamContextOptions));
$httpHeadersOffset = 0;
stream_context_set_params($context, array('notification' => function ($code, $severity, $msg, $msgCode, $bytesTx, $bytesMax) use(&$remoteDocument, &$http_response_header, &$httpHeadersOffset) {
if ($code === STREAM_NOTIFY_MIME_TYPE_IS) {
$remoteDocument->mediaType = $msg;
} elseif ($code === STREAM_NOTIFY_REDIRECTED) {
$remoteDocument->documentUrl = $msg;
$remoteDocument->mediaType = null;
$httpHeadersOffset = count($http_response_header);
}
}));
if (false === ($input = @file_get_contents($url, false, $context))) {
throw new JsonLdException(JsonLdException::LOADING_DOCUMENT_FAILED, sprintf('Unable to load the remote document "%s".', $url), $http_response_header);
}
// Extract HTTP Link headers
$linkHeaderValues = array();
for ($i = count($http_response_header) - 1; $i > $httpHeadersOffset; $i--) {
if (0 === substr_compare($http_response_header[$i], 'Link:', 0, 5, true)) {
$value = substr($http_response_header[$i], 5);
$linkHeaderValues[] = $value;
}
}
$linkHeaderValues = self::parseContextLinkHeaders($linkHeaderValues, new IRI($url));
if (count($linkHeaderValues) === 1) {
$remoteDocument->contextUrl = reset($linkHeaderValues);
} elseif (count($linkHeaderValues) > 1) {
throw new JsonLdException(JsonLdException::MULTIPLE_CONTEXT_LINK_HEADERS, 'Found multiple contexts in HTTP Link headers', $http_response_header);
}
// If we got a media type, we verify it
if ($remoteDocument->mediaType) {
// Drop any media type parameters such as profiles
if (false !== ($pos = strpos($remoteDocument->mediaType, ';'))) {
$remoteDocument->mediaType = substr($remoteDocument->mediaType, 0, $pos);
}
$remoteDocument->mediaType = trim($remoteDocument->mediaType);
if ('application/ld+json' === $remoteDocument->mediaType) {
$remoteDocument->contextUrl = null;
} elseif ('application/json' !== $remoteDocument->mediaType && 0 !== substr_compare($remoteDocument->mediaType, '+json', -5)) {
throw new JsonLdException(JsonLdException::LOADING_DOCUMENT_FAILED, 'Invalid media type', $remoteDocument->mediaType);
}
}
$remoteDocument->document = Processor::parse($input);
return $remoteDocument;
}
return new RemoteDocument($url, Processor::parse($input));
}
