8 * Copyright (c) 2009-2013 Nicholas J Humfrey. All rights reserved.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 * 3. The name of the author 'Nicholas J Humfrey" may be used to endorse or
18 * promote products derived from this software without specific prior
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
25 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
34 * @copyright Copyright (c) 2009-2013 Nicholas J Humfrey
35 * @license http://www.opensource.org/licenses/bsd-license.php
39 * A pure-php class to parse RDF/JSON with no dependancies.
41 * http://n2.talis.com/wiki/RDF_JSON_Specification
42 * docs/appendix-a-rdf-formats-json.md
45 * @copyright Copyright (c) 2009-2013 Nicholas J Humfrey
46 * @license http://www.opensource.org/licenses/bsd-license.php
48 class EasyRdf_Parser_Json extends EasyRdf_Parser_RdfPhp
50 private $jsonLastErrorExists = false;
55 * @return object EasyRdf_Parser_Json
57 public function __construct()
59 $this->jsonLastErrorExists = function_exists('json_last_error');
62 /** Return the last JSON parser error as a string
64 * If json_last_error() is not available a generic message will be returned.
68 protected function jsonLastErrorString()
70 if ($this->jsonLastErrorExists) {
71 switch (json_last_error()) {
74 case JSON_ERROR_DEPTH:
75 return "JSON Parse error: the maximum stack depth has been exceeded";
76 case JSON_ERROR_STATE_MISMATCH:
77 return "JSON Parse error: invalid or malformed JSON";
78 case JSON_ERROR_CTRL_CHAR:
79 return "JSON Parse error: control character error, possibly incorrectly encoded";
80 case JSON_ERROR_SYNTAX:
81 return "JSON Parse syntax error";
83 return "JSON Parse error: malformed UTF-8 characters, possibly incorrectly encoded";
85 return "JSON Parse error: unknown";
88 return "JSON Parse error";
92 /** Parse the triple-centric JSON format, as output by libraptor
94 * http://librdf.org/raptor/api/serializer-json.html
98 protected function parseJsonTriples($data, $baseUri)
100 foreach ($data['triples'] as $triple) {
101 if ($triple['subject']['type'] == 'bnode') {
102 $subject = $this->remapBnode($triple['subject']['value']);
104 $subject = $triple['subject']['value'];
107 $predicate = $triple['predicate']['value'];
109 if ($triple['object']['type'] == 'bnode') {
112 'value' => $this->remapBnode($triple['object']['value'])
115 $object = $triple['object'];
118 $this->addTriple($subject, $predicate, $object);
121 return $this->tripleCount;
125 * Parse RDF/JSON into an EasyRdf_Graph
127 * @param object EasyRdf_Graph $graph the graph to load the data into
128 * @param string $data the RDF document data
129 * @param string $format the format of the input data
130 * @param string $baseUri the base URI of the data being parsed
131 * @return integer The number of triples added to the graph
133 public function parse($graph, $data, $format, $baseUri)
135 $this->checkParseParams($graph, $data, $format, $baseUri);
137 if ($format != 'json') {
138 throw new EasyRdf_Exception(
139 "EasyRdf_Parser_Json does not support: $format"
143 $decoded = @json_decode(strval($data), true);
144 if ($decoded === null) {
145 throw new EasyRdf_Parser_Exception(
146 $this->jsonLastErrorString()
150 if (array_key_exists('triples', $decoded)) {
151 return $this->parseJsonTriples($decoded, $baseUri);
153 return parent::parse($graph, $decoded, 'php', $baseUri);