Issue #1866858 by linclark, scor: Test RDFa by parsing RDFa (add the easyrdf library).

core/composer.json

@@ -15,7 +15,8 @@
     "doctrine/common": "2.3.*@stable",
     "guzzle/http": "*",
     "kriswallsmith/assetic": "1.1.*@alpha",
-    "symfony-cmf/routing": "1.0.*@dev"
+    "symfony-cmf/routing": "1.0.*@dev",
+    "njh/easyrdf": "0.8.*"
   },
   "minimum-stability": "dev"
 }

core/composer.lock

@@ -359,6 +359,39 @@
                 "routing"
             ]
         },
+        {
+            "name": "njh/easyrdf",
+            "description": "EasyRdf is a PHP library designed to make it easy to consume and produce RDF.",
+            "version": "0.8.0",
+            "type": "library",
+            "keywords": ["RDF", "Semantic Web", "Turtle", "RDFa"],
+            "homepage": "http://www.aelius.com/njh/easyrdf/",
+            "license": "BSD-3-Clause",
+            "authors": [
+                {
+                    "name": "Nicholas Humfrey",
+                    "email": "njh@aelius.com",
+                    "homepage": "http://www.aelius.com/njh/",
+                    "role": "Developer"
+                }
+            ],
+            "support": {
+                "forum": "http://groups.google.com/group/easyrdf/",
+                "issues": "http://github.com/njh/easyrdf/issues"
+            },
+            "require": {
+                "php": ">=5.2.8"
+            },
+            "repositories": [
+                {
+                    "type": "vcs",
+                    "url": "https://github.com/njh/easyrdf"
+                }
+            ],
+            "autoload": {
+                "psr-0": { "EasyRdf": "lib/" }
+            }
+        },
         {
             "name": "symfony/class-loader",
             "version": "dev-master",

core/vendor/composer/autoload_namespaces.php

@@ -23,4 +23,5 @@
     'Guzzle\\Common' => $vendorDir . '/guzzle/common/',
     'Doctrine\\Common' => $vendorDir . '/doctrine/common/lib/',
     'Assetic' => $vendorDir . '/kriswallsmith/assetic/src/',
+    'EasyRdf_' => $vendorDir . '/njh/easyrdf/lib/',
 );

core/vendor/njh/easyrdf/lib/EasyRdf.php

+<?php
+
+/**
+ * EasyRdf
+ *
+ * Use this file to load the core of EasyRdf, if you don't have an autoloader.
+ *
+ *
+ * LICENSE
+ *
+ * Copyright (c) 2009-2011 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) 2011 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ * @version    $Id$
+ */
+
+/**
+ * @see EasyRdf_Exception
+ */
+require_once "EasyRdf/Exception.php";
+
+/**
+ * @see EasyRdf_Format
+ */
+require_once "EasyRdf/Format.php";
+
+/**
+ * @see EasyRdf_Graph
+ */
+require_once "EasyRdf/Graph.php";
+
+/**
+ * @see EasyRdf_GraphStore
+ */
+require_once "EasyRdf/GraphStore.php";
+
+/**
+ * @see EasyRdf_Http
+ */
+require_once "EasyRdf/Http.php";
+
+/**
+ * @see EasyRdf_Http_Client
+ */
+require_once "EasyRdf/Http/Client.php";
+
+/**
+ * @see EasyRdf_Http_Response
+ */
+require_once "EasyRdf/Http/Response.php";
+
+/**
+ * @see EasyRdf_Namespace
+ */
+require_once "EasyRdf/Namespace.php";
+
+/**
+ * @see EasyRdf_Literal
+ */
+require_once "EasyRdf/Literal.php";
+
+/**
+ * @see EasyRdf_Literal_Boolean
+ */
+require_once "EasyRdf/Literal/Boolean.php";
+
+/**
+ * @see EasyRdf_Literal_Date
+ */
+require_once "EasyRdf/Literal/Date.php";
+
+/**
+ * @see EasyRdf_Literal_DateTime
+ */
+require_once "EasyRdf/Literal/DateTime.php";
+
+/**
+ * @see EasyRdf_Literal_Decimal
+ */
+require_once "EasyRdf/Literal/Decimal.php";
+
+/**
+ * @see EasyRdf_Literal_HexBinary
+ */
+require_once "EasyRdf/Literal/HexBinary.php";
+
+/**
+ * @see EasyRdf_Literal_HTML
+ */
+require_once "EasyRdf/Literal/HTML.php";
+
+/**
+ * @see EasyRdf_Literal_Integer
+ */
+require_once "EasyRdf/Literal/Integer.php";
+
+/**
+ * @see EasyRdf_Literal_XML
+ */
+require_once "EasyRdf/Literal/XML.php";
+
+/**
+ * @see EasyRdf_ParsedUri
+ */
+require_once "EasyRdf/ParsedUri.php";
+
+/**
+ * @see EasyRdf_Parser
+ */
+require_once "EasyRdf/Parser.php";
+
+/**
+ * @see EasyRdf_Parser_RdfPhp
+ */
+require_once "EasyRdf/Parser/RdfPhp.php";
+
+/**
+ * @see EasyRdf_Parser_Ntriples
+ */
+require_once "EasyRdf/Parser/Ntriples.php";
+
+/**
+ * @see EasyRdf_Parser_Json
+ */
+require_once "EasyRdf/Parser/Json.php";
+
+/**
+ * @see EasyRdf_Parser_Rdfa
+ */
+require_once "EasyRdf/Parser/Rdfa.php";
+
+/**
+ * @see EasyRdf_Parser_RdfXml
+ */
+require_once "EasyRdf/Parser/RdfXml.php";
+
+/**
+ * @see EasyRdf_Parser_Turtle
+ */
+require_once "EasyRdf/Parser/Turtle.php";
+
+/**
+ * @see EasyRdf_Resource
+ */
+require_once "EasyRdf/Resource.php";
+
+/**
+ * @see EasyRdf_Serialiser
+ */
+require_once "EasyRdf/Serialiser.php";
+
+/**
+ * @see EasyRdf_Serialiser_GraphViz
+ */
+require_once "EasyRdf/Serialiser/GraphViz.php";
+
+/**
+ * @see EasyRdf_Serialiser_RdfPhp
+ */
+require_once "EasyRdf/Serialiser/RdfPhp.php";
+
+/**
+ * @see EasyRdf_Serialiser_Ntriples
+ */
+require_once "EasyRdf/Serialiser/Ntriples.php";
+
+/**
+ * @see EasyRdf_Serialiser_Json
+ */
+require_once "EasyRdf/Serialiser/Json.php";
+
+/**
+ * @see EasyRdf_Serialiser_RdfXml
+ */
+require_once "EasyRdf/Serialiser/RdfXml.php";
+
+/**
+ * @see EasyRdf_Serialiser_Turtle
+ */
+require_once "EasyRdf/Serialiser/Turtle.php";
+
+/**
+ * @see EasyRdf_Sparql_Client
+ */
+require_once "EasyRdf/Sparql/Client.php";
+
+/**
+ * @see EasyRdf_Sparql_Result
+ */
+require_once "EasyRdf/Sparql/Result.php";
+
+/**
+ * @see EasyRdf_TypeMapper
+ */
+require_once "EasyRdf/TypeMapper.php";
+
+/**
+ * @see EasyRdf_Utils
+ */
+require_once "EasyRdf/Utils.php";

core/vendor/njh/easyrdf/lib/EasyRdf/Exception.php

+<?php
+
+/**
+ * EasyRdf
+ *
+ * LICENSE
+ *
+ * Copyright (c) 2009-2010 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) 2009-2010 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ * @version    $Id$
+ */
+
+/**
+ * EasyRdf Exception class
+ *
+ * All exceptions thrown by EasyRdf are an instance of this class.
+ *
+ * @package    EasyRdf
+ * @copyright  Copyright (c) 2009-2010 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ */
+class EasyRdf_Exception extends Exception
+{
+    // Comment to make PHP CodeSniffer happy
+}

core/vendor/njh/easyrdf/lib/EasyRdf/GraphStore.php

+<?php
+
+/**
+ * EasyRdf
+ *
+ * LICENSE
+ *
+ * Copyright (c) 2009-2011 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) 2009-2011 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ * @version    $Id$
+ */
+
+/**
+ * A class for fetching, saving and deleting graphs to a Graph Store.
+ * Implementation of the SPARQL 1.1 Graph Store HTTP Protocol.
+ *
+ * @package    EasyRdf
+ * @copyright  Copyright (c) 2009-2011 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ */
+class EasyRdf_GraphStore
+{
+    /** The address of the GraphStore endpoint */
+    private $uri = null;
+    private $parsedUri = null;
+
+
+    /** Create a new SPARQL Graph Store client
+     *
+     * @param string $uri The address of the graph store endpoint
+     */
+    public function __construct($uri)
+    {
+        $this->uri = $uri;
+        $this->parsedUri = new EasyRdf_ParsedUri($uri);
+    }
+
+    /** Get the URI of the graph store
+     *
+     * @return string The URI of the graph store
+     */
+    public function getUri()
+    {
+        return $this->uri;
+    }
+
+    /** Fetch a named graph from the graph store
+     *
+     * The URI can either be a full absolute URI or
+     * a URI relative to the URI of the graph store.
+     *
+     * @param string $uriRef The URI of graph desired
+     * @return object EasyRdf_Graph The graph requested
+     */
+    public function get($uriRef)
+    {
+        $graphUri = $this->parsedUri->resolve($uriRef)->toString();
+        $dataUrl = $this->urlForGraph($graphUri);
+        $graph = new EasyRdf_Graph($graphUri);
+        $graph->load($dataUrl);
+        return $graph;
+    }
+
+    /** Send some graph data to the graph store
+     *
+     * This method is used by insert() and replace()
+     *
+     * @ignore
+     */
+    protected function sendGraph($method, $graph, $uriRef, $format)
+    {
+        if (is_object($graph) and $graph instanceof EasyRdf_Graph) {
+            if ($uriRef == null) {
+                $uriRef = $graph->getUri();
+            }
+            $data = $graph->serialise($format);
+        } else {
+            $data = $graph;
+        }
+
+        $formatObj = EasyRdf_Format::getFormat($format);
+        $mimeType = $formatObj->getDefaultMimeType();
+
+        $graphUri = $this->parsedUri->resolve($uriRef)->toString();
+        $dataUrl = $this->urlForGraph($graphUri);
+
+        $client = EasyRdf_Http::getDefaultHttpClient();
+        $client->resetParameters(true);
+        $client->setUri($dataUrl);
+        $client->setMethod($method);
+        $client->setRawData($data);
+        $client->setHeaders('Content-Type', $mimeType);
+        $client->setHeaders('Content-Length', strlen($data));
+        $response = $client->request();
+        if (!$response->isSuccessful()) {
+            throw new EasyRdf_Exception(
+                "HTTP request for $dataUrl failed: ".$response->getMessage()
+            );
+        }
+        return $response;
+    }
+
+    /** Replace the contents of a graph in the graph store with new data
+     *
+     * The $graph parameter is the EasyRdf_Graph object to be sent to the
+     * graph store. Alternatively it can be a string, already serialised.
+     *
+     * The URI can either be a full absolute URI or
+     * a URI relative to the URI of the graph store.
+     *
+     * The $format parameter can be given to specify the serialisation
+     * used to send the graph data to the graph store.
+     *
+     * @param object EasyRdfGraph $graph The URI of graph desired
+     * @param string $uriRef The URI of graph to be replaced
+     * @param string $format The format of the data to send to the graph store
+     * @return object EasyRdf_Http_Response The response from the graph store
+     */
+    public function replace($graph, $uriRef = null, $format = 'ntriples')
+    {
+        return $this->sendGraph('PUT', $graph, $uriRef, $format);
+    }
+
+    /** Add data to a graph in the graph store
+     *
+     * The $graph parameter is the EasyRdf_Graph object to be sent to the
+     * graph store. Alternatively it can be a string, already serialised.
+     *
+     * The URI can either be a full absolute URI or
+     * a URI relative to the URI of the graph store.
+     *
+     * The $format parameter can be given to specify the serialisation
+     * used to send the graph data to the graph store.
+     *
+     * @param object EasyRdfGraph $graph The URI of graph desired
+     * @param string $uriRef The URI of graph to be added to
+     * @param string $format The format of the data to send to the graph store
+     * @return object EasyRdf_Http_Response The response from the graph store
+     */
+    public function insert($graph, $uriRef = null, $format = 'ntriples')
+    {
+        return $this->sendGraph('POST', $graph, $uriRef, $format);
+    }
+
+    /** Delete a graph from the graph store
+     *
+     * The URI can either be a full absolute URI or
+     * a URI relative to the URI of the graph store.
+     *
+     * @param string $uriRef The URI of graph to be added to
+     * @return object EasyRdf_Http_Response The response from the graph store
+     */
+    public function delete($uriRef)
+    {
+        $graphUri = $this->parsedUri->resolve($uriRef)->toString();
+        $dataUrl = $this->urlForGraph($graphUri);
+
+        $client = EasyRdf_Http::getDefaultHttpClient();
+        $client->resetParameters(true);
+        $client->setUri($dataUrl);
+        $client->setMethod('DELETE');
+        $response = $client->request();
+        if (!$response->isSuccessful()) {
+            throw new EasyRdf_Exception(
+                "HTTP request to delete $dataUrl failed: ".$response->getMessage()
+            );
+        }
+        return $response;
+    }
+
+    /** Work out the full URL for a graph store request.
+     *  by checking if if it is a direct or indirect request.
+     *  @ignore
+     */
+    protected function urlForGraph($url)
+    {
+        if (strpos($url, $this->uri) === false) {
+            $url = $this->uri."?graph=".urlencode($url);
+        }
+        return $url;
+    }
+
+    /** Magic method to return URI of the graph store when casted to string
+     *
+     * @return string The URI of the graph store
+     */
+    public function __toString()
+    {
+        return empty($this->uri) ? '' : $this->uri;
+    }
+}

core/vendor/njh/easyrdf/lib/EasyRdf/Http.php

+<?php
+
+/**
+ * EasyRdf
+ *
+ * LICENSE
+ *
+ * Copyright (c) 2009-2011 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) 2009-2011 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ * @version    $Id$
+ */
+
+
+/**
+ * Static class to set the HTTP client used by EasyRdf
+ *
+ * @package    EasyRdf
+ * @copyright  Copyright (c) 2009-2011 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ */
+class EasyRdf_Http
+{
+    /** The default HTTP Client object */
+    private static $defaultHttpClient = null;
+
+    /** Set the HTTP Client object used to fetch RDF data
+     *
+     * @param  object mixed $httpClient The new HTTP client object
+     * @return object mixed The new HTTP client object
+     */
+    public static function setDefaultHttpClient($httpClient)
+    {
+        if (!is_object($httpClient) or
+            !($httpClient instanceof Zend_Http_Client or
+              $httpClient instanceof EasyRdf_Http_Client)) {
+            throw new InvalidArgumentException(
+                "\$httpClient should be an object of class Zend_Http_Client or EasyRdf_Http_Client"
+            );
+        }
+        return self::$defaultHttpClient = $httpClient;
+    }
+
+    /** Get the HTTP Client object used to fetch RDF data
+     *
+     * If no HTTP Client has previously been set, then a new
+     * default (EasyRdf_Http_Client) client will be created.
+     *
+     * @return object mixed The HTTP client object
+     */
+    public static function getDefaultHttpClient()
+    {
+        if (!isset(self::$defaultHttpClient)) {
+            self::$defaultHttpClient = new EasyRdf_Http_Client();
+        }
+        return self::$defaultHttpClient;
+    }
+}

core/vendor/njh/easyrdf/lib/EasyRdf/Literal/Boolean.php

+<?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    $Id$
+ */
+
+/**
+ * Class that represents an RDF Literal of datatype xsd:boolean
+ *
+ * @package    EasyRdf
+ * @link       http://www.w3.org/TR/xmlschema-2/#boolean
+ * @copyright  Copyright (c) 2009-2012 Nicholas J Humfrey
+ * @license    http://www.opensource.org/licenses/bsd-license.php
+ */
+class EasyRdf_Literal_Boolean extends EasyRdf_Literal
+{
+    /** Constructor for creating a new boolean literal
+     *
+     * If the value is not a string, then it will be converted to 'true' or 'false'.
+     *
+     * @param  mixed  $value     The value of the literal
+     * @param  string $lang      Should be null (literals with a datatype can't have a language)
+     * @param  string $datatype  Optional datatype (default 'xsd:boolean')
+     * @return object EasyRdf_Literal_Boolean
+     */
+    public function __construct($value, $lang = null, $datatype = null)
+    {
+        if (!is_string($value)) {
+            $value = $value ? 'true' : 'false';
+        }
+        parent::__construct($value, null, $datatype);
+    }
+
+    /** Return the value of the literal cast to a PHP bool
+     *
+     * If the value is 'true' or '1' return true, otherwise returns false.
+     *
+     * @return bool
+     */
+    public function getValue()
+    {
+        return strtolower($this->value) === 'true' or $this->value === '1';
+    }
+