<?php
/**
* EasyRdf
*
* LICENSE
*
* Copyright (c) 2009-2012 Nicholas J Humfrey. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author 'Nicholas J Humfrey" may be used to endorse or
* promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* @package EasyRdf
* @copyright Copyright (c) 2009-2012 Nicholas J Humfrey
* @license http://www.opensource.org/licenses/bsd-license.php
* @version $Id$
*/
/**
* A pure-php class to parse RDF/JSON with no dependancies.
*
* http://n2.talis.com/wiki/RDF_JSON_Specification
*
* @package EasyRdf
* @copyright Copyright (c) 2009-2012 Nicholas J Humfrey
* @license http://www.opensource.org/licenses/bsd-license.php
*/
class EasyRdf_Parser_Json extends EasyRdf_Parser_RdfPhp {
private $jsonLastErrorExists = false;
/**
* Constructor
*
* @return object EasyRdf_Parser_Json
*/
public function __construct() {
$this->jsonLastErrorExists = function_exists('json_last_error');
}
/** Return the last JSON parser error as a string
*
* If json_last_error() is not available a generic message will be returned.
*
* @ignore
*/
protected function jsonLastErrorString() {
if ($this->jsonLastErrorExists) {
switch (json_last_error()) {
case JSON_ERROR_NONE:
return null;
case JSON_ERROR_DEPTH:
return "JSON Parse error: the maximum stack depth has been exceeded";
case JSON_ERROR_STATE_MISMATCH:
return "JSON Parse error: invalid or malformed JSON";
case JSON_ERROR_CTRL_CHAR:
return "JSON Parse error: control character error, possibly incorrectly encoded";
case JSON_ERROR_SYNTAX:
return "JSON Parse syntax error";
case JSON_ERROR_UTF8:
return "JSON Parse error: malformed UTF-8 characters, possibly incorrectly encoded";
default:
return "JSON Parse error: unknown";
}
}
else {
return "JSON Parse error";
}
}
/** Parse the triple-centric JSON format, as output by libraptor
*
* http://librdf.org/raptor/api/serializer-json.html
*
* @ignore
*/
protected function parseJsonTriples($data, $baseUri) {
foreach ($data['triples'] as $triple) {
if ($triple['subject']['type'] == 'bnode') {
$subject = $this
->remapBnode($triple['subject']['value']);
}
else {
$subject = $triple['subject']['value'];
}
$predicate = $triple['predicate']['value'];
if ($triple['object']['type'] == 'bnode') {
$object = array(
'type' => 'bnode',
'value' => $this
->remapBnode($triple['object']['value']),
);
}
else {
$object = $triple['object'];
}
$this
->addTriple($subject, $predicate, $object);
}
return $this->tripleCount;
}
/**
* Parse RDF/JSON into an EasyRdf_Graph
*
* @param object EasyRdf_Graph $graph the graph to load the data into
* @param string $data the RDF document data
* @param string $format the format of the input data
* @param string $baseUri the base URI of the data being parsed
* @return integer The number of triples added to the graph
*/
public function parse($graph, $data, $format, $baseUri) {
$this
->checkParseParams($graph, $data, $format, $baseUri);
if ($format != 'json') {
throw new EasyRdf_Exception("EasyRdf_Parser_Json does not support: {$format}");
}
$decoded = @json_decode(strval($data), true);
if ($decoded === null) {
throw new EasyRdf_Exception($this
->jsonLastErrorString());
}
if (array_key_exists('triples', $decoded)) {
return $this
->parseJsonTriples($decoded, $baseUri);
}
else {
return parent::parse($graph, $decoded, 'php', $baseUri);
}
}
}
Name | Description |
---|---|
EasyRdf_Parser_Json | A pure-php class to parse RDF/JSON with no dependancies. |