--- /dev/null
+<?php
+
+/**
+ * EasyRdf
+ *
+ * LICENSE
+ *
+ * Copyright (c) 2009-2013 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) 2009-2013 Nicholas J Humfrey
+ * @license http://www.opensource.org/licenses/bsd-license.php
+ */
+
+/**
+ * Class to serialise an EasyRdf_Graph to Turtle
+ * with no external dependancies.
+ *
+ * http://www.w3.org/TR/turtle/
+ *
+ * @package EasyRdf
+ * @copyright Copyright (c) 2009-2013 Nicholas J Humfrey
+ * @license http://www.opensource.org/licenses/bsd-license.php
+ */
+class EasyRdf_Serialiser_Turtle extends EasyRdf_Serialiser
+{
+ private $outputtedBnodes = array();
+
+ /**
+ * Given a IRI string, escape and enclose in angle brackets.
+ *
+ * @param string $resourceIri
+ * @return string
+ */
+ public static function escapeIri($resourceIri)
+ {
+ $escapedIri = str_replace('>', '\\>', $resourceIri);
+ return "<$escapedIri>";
+ }
+
+ /**
+ * Given a string, enclose in quotes and escape any quotes in the string.
+ * Strings containing tabs, linefeeds or carriage returns will be
+ * enclosed in three double quotes (""").
+ *
+ * @param string $value
+ * @return string
+ */
+ public static function quotedString($value)
+ {
+ if (preg_match('/[\t\n\r]/', $value)) {
+ $escaped = str_replace(array('\\', '"""'), array('\\\\', '\\"""'), $value);
+ return '"""'.$escaped.'"""';
+ } else {
+ $escaped = str_replace(array('\\', '"'), array('\\\\', '\\"'), $value);
+ return '"'.$escaped.'"';
+ }
+ }
+
+ /**
+ * Given a an EasyRdf_Resource or URI, convert it into a string, suitable to
+ * be written to a Turtle document. URIs will be shortened into CURIES
+ * where possible.
+ *
+ * @param EasyRdf_Resource $resource The resource to convert to a Turtle string
+ * @param boolean $createNamespace If true, a new namespace may be created
+ * @return string
+ */
+ public function serialiseResource($resource, $createNamespace = false)
+ {
+ if (is_object($resource)) {
+ if ($resource->isBNode()) {
+ return $resource->getUri();
+ }
+
+ $resource = $resource->getUri();
+ }
+
+ $short = EasyRdf_Namespace::shorten($resource, $createNamespace);
+
+ if ($short) {
+ $this->addPrefix($short);
+ return $short;
+ }
+
+ return self::escapeIri($resource);
+ }
+
+ /**
+ * Given an EasyRdf_Literal object, convert it into a string, suitable to
+ * be written to a Turtle document. Supports multiline literals and literals with
+ * datatypes or languages.
+ *
+ * @param EasyRdf_Literal $literal
+ * @return string
+ */
+ public function serialiseLiteral($literal)
+ {
+ $value = strval($literal);
+ $quoted = self::quotedString($value);
+
+ if ($datatype = $literal->getDatatypeUri()) {
+ if ($datatype == 'http://www.w3.org/2001/XMLSchema#integer') {
+ return sprintf('%d', $value);
+ } elseif ($datatype == 'http://www.w3.org/2001/XMLSchema#decimal') {
+ return sprintf('%s', $value);
+ } elseif ($datatype == 'http://www.w3.org/2001/XMLSchema#double') {
+ return sprintf('%e', $value);
+ } elseif ($datatype == 'http://www.w3.org/2001/XMLSchema#boolean') {
+ return sprintf('%s', $value);
+ } else {
+ $escaped = $this->serialiseResource($datatype, true);
+ return sprintf('%s^^%s', $quoted, $escaped);
+ }
+ } elseif ($lang = $literal->getLang()) {
+ return $quoted . '@' . $lang;
+ } else {
+ return $quoted;
+ }
+ }
+
+ /**
+ * Convert an EasyRdf object into a string suitable to
+ * be written to a Turtle document.
+ *
+ * @param EasyRdf_Resource|EasyRdf_Literal $object
+ * @return string
+ */
+ public function serialiseObject($object)
+ {
+ if ($object instanceof EasyRdf_Resource) {
+ return $this->serialiseResource($object);
+ } elseif ($object instanceof EasyRdf_Literal) {
+ return $this->serialiseLiteral($object);
+ } else {
+ throw new InvalidArgumentException(
+ "serialiseObject() requires \$object to be ".
+ "of type EasyRdf_Resource or EasyRdf_Literal"
+ );
+ }
+ }
+
+
+ /**
+ * Protected method to serialise a RDF collection
+ * @ignore
+ */
+ protected function serialiseCollection($node, $indent)
+ {
+ $turtle = '(';
+ $count = 0;
+ while ($node) {
+ if ($id = $node->getBNodeId()) {
+ $this->outputtedBnodes[$id] = true;
+ }
+
+ $value = $node->get('rdf:first');
+ $node = $node->get('rdf:rest');
+ if ($node and $node->hasProperty('rdf:first')) {
+ $count++;
+ }
+
+ if ($value !== null) {
+ $serialised = $this->serialiseObject($value);
+ if ($count) {
+ $turtle .= "\n$indent $serialised";
+ } else {
+ $turtle .= " ".$serialised;
+ }
+ }
+ }
+ if ($count) {
+ $turtle .= "\n$indent)";
+ } else {
+ $turtle .= " )";
+ }
+ return $turtle;
+ }
+
+ /**
+ * Protected method to serialise the properties of a resource
+ * @ignore
+ */
+ protected function serialiseProperties($res, $depth = 1)
+ {
+ $properties = $res->propertyUris();
+ $indent = str_repeat(' ', ($depth*2)-1);
+
+ $turtle = '';
+ if (count($properties) > 1) {
+ $turtle .= "\n$indent";
+ }
+
+ $pCount = 0;
+ foreach ($properties as $property) {
+ if ($property === 'http://www.w3.org/1999/02/22-rdf-syntax-ns#type') {
+ $pStr = 'a';
+ } else {
+ $pStr = $this->serialiseResource($property, true);
+ }
+
+ if ($pCount) {
+ $turtle .= " ;\n$indent";
+ }
+
+ $turtle .= ' ' . $pStr;
+
+ $oCount = 0;
+ foreach ($res->all("<$property>") as $object) {
+ if ($oCount) {
+ $turtle .= ',';
+ }
+
+ if ($object instanceof EasyRdf_Collection) {
+ $turtle .= ' ' . $this->serialiseCollection($object, $indent);
+ } elseif ($object instanceof EasyRdf_Resource and $object->isBNode()) {
+ $id = $object->getBNodeId();
+ $rpcount = $this->reversePropertyCount($object);
+ if ($rpcount <= 1 and !isset($this->outputtedBnodes[$id])) {
+ // Nested unlabelled Blank Node
+ $this->outputtedBnodes[$id] = true;
+ $turtle .= ' [';
+ $turtle .= $this->serialiseProperties($object, $depth+1);
+ $turtle .= ' ]';
+ } else {
+ // Multiple properties pointing to this blank node
+ $turtle .= ' ' . $this->serialiseObject($object);
+ }
+ } else {
+ $turtle .= ' ' . $this->serialiseObject($object);
+ }
+ $oCount++;
+ }
+ $pCount++;
+ }
+
+ if ($depth == 1) {
+ $turtle .= " .";
+ if ($pCount > 1) {
+ $turtle .= "\n";
+ }
+ } elseif ($pCount > 1) {
+ $turtle .= "\n" . str_repeat(' ', (($depth-1)*2)-1);
+ }
+
+ return $turtle;
+ }
+
+ /**
+ * @ignore
+ */
+ protected function serialisePrefixes()
+ {
+ $turtle = '';
+ foreach ($this->prefixes as $prefix => $count) {
+ $url = EasyRdf_Namespace::get($prefix);
+ $turtle .= "@prefix $prefix: <$url> .\n";
+ }
+ return $turtle;
+ }
+
+ /**
+ * @ignore
+ */
+ protected function serialiseSubjects(EasyRdf_Graph $graph, $filterType)
+ {
+ $turtle = '';
+ foreach ($graph->resources() as $resource) {
+ /** @var $resource EasyRdf_Resource */
+ // If the resource has no properties - don't serialise it
+ $properties = $resource->propertyUris();
+ if (count($properties) == 0) {
+ continue;
+ }
+
+ // Is this node of the right type?
+ $thisType = $resource->isBNode() ? 'bnode' : 'uri';
+ if ($thisType != $filterType) {
+ continue;
+ }
+
+ if ($thisType == 'bnode') {
+ $id = $resource->getBNodeId();
+
+ if (isset($this->outputtedBnodes[$id])) {
+ // Already been serialised
+ continue;
+ }
+
+ $this->outputtedBnodes[$id] = true;
+ $rpcount = $this->reversePropertyCount($resource);
+
+ if ($rpcount == 0) {
+ $turtle .= '[]';
+ } else {
+ $turtle .= $this->serialiseResource($resource);
+ }
+ } else {
+ $turtle .= $this->serialiseResource($resource);
+ }
+
+ $turtle .= $this->serialiseProperties($resource);
+ $turtle .= "\n";
+ }
+ return $turtle;
+ }
+
+ /**
+ * Serialise an EasyRdf_Graph to Turtle.
+ *
+ * @param EasyRdf_Graph $graph An EasyRdf_Graph object.
+ * @param string $format The name of the format to convert to.
+ * @param array $options
+ * @throws EasyRdf_Exception
+ * @return string The RDF in the new desired format.
+ */
+ public function serialise($graph, $format, array $options = array())
+ {
+ parent::checkSerialiseParams($graph, $format);
+
+ if ($format != 'turtle' and $format != 'n3') {
+ throw new EasyRdf_Exception(
+ "EasyRdf_Serialiser_Turtle does not support: $format"
+ );
+ }
+
+ $this->prefixes = array();
+ $this->outputtedBnodes = array();
+
+ $turtle = '';
+ $turtle .= $this->serialiseSubjects($graph, 'uri');
+ $turtle .= $this->serialiseSubjects($graph, 'bnode');
+
+ if (count($this->prefixes)) {
+ return $this->serialisePrefixes() . "\n" . $turtle;
+ } else {
+ return $turtle;
+ }
+ }
+}
projects / yaffs-website / blobdiff