--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/server/src/app/Helpers/RdfHelper.php	Mon Oct 31 14:24:23 2016 +0100
@@ -0,0 +1,130 @@
+<?php
+namespace CorpusParole\Helpers;
+
+use EasyRdf\Resource;
+use EasyRdf\Literal;
+use EasyRdf\RdfNamespace;
+
+use EasyRdf\Serialiser\Turtle;
+
+/**
+ * Globally Inspired by EasyRdf\Serialiser\Turtle::serialiseResource
+ */
+class RdfHelper {
+
+    private $prefixes = [];
+
+    public function getPrefixes() {
+        return $this->prefixes;
+    }
+
+    /**
+     * Keep track of the prefixes used while serialising
+     * @ignore
+     */
+    public function addPrefix($qname)
+    {
+        list ($prefix) = explode(':', $qname);
+        $this->prefixes[$prefix] = true;
+        return $prefix;
+    }
+
+
+    /**
+     * Given a IRI string, escape and enclose in angle brackets.
+     *
+     * @param  string $resourceIri
+     *
+     * @return string
+     */
+    public function escapeIri($resourceIri) {
+        $escapedIri = str_replace('>', '\\>', $resourceIri);
+        return "<span class=\"corpus-rdf-resource\"><span class=\"corpus-rdf-resource-delimiter\">&lt;</span><a class=\"corpus-rdf-resource-link\" href=\"$resourceIri\" target=\"_blank\">".htmlentities($escapedIri)."</a><span class=\"corpus-rdf-resource-delimiter\">&gt;</span></span>";
+    }
+
+    /**
+     * Insprired by EasyRdf\Serialiser\Turtle::serialiseLiteral
+     * 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 $value
+     *
+     * @return string
+     */
+    public function serialiseLiteral($literal)
+    {
+        $value = strval($literal);
+        $quoted = Turtle::quotedString($value);
+
+        if ($datatype = $literal->getDatatypeUri()) {
+            if ($datatype == 'http://www.w3.org/2001/XMLSchema#integer') {
+                return sprintf('<span class="corpus-rdf-literal corpus-rdf-literal-value">%d</span>', $value);
+            } elseif ($datatype == 'http://www.w3.org/2001/XMLSchema#decimal') {
+                return sprintf('<span class="corpus-rdf-literal corpus-rdf-literal-value">%s</span>', $value);
+            } elseif ($datatype == 'http://www.w3.org/2001/XMLSchema#double') {
+                return sprintf('<span class="corpus-rdf-literal corpus-rdf-literal-value">%e</span>', $value);
+            } elseif ($datatype == 'http://www.w3.org/2001/XMLSchema#boolean') {
+                return sprintf('<span class="corpus-rdf-literal corpus-rdf-literal-value">%s</span>', $value);
+            } else {
+                $escaped = $this->serialiseResource($datatype, false);
+                return sprintf('<span class="corpus-rdf-literal"><span class="corpus-rdf-literal-value corpus-rdf-literal-value-str">%s</span><span class="corpus-rdf-literal-type-separator">^^</span><span class="corpus-rdf-literal-type">%s</span></span>', $quoted, $escaped);
+            }
+        } elseif ($lang = $literal->getLang()) {
+            return sprintf('<span class="corpus-rdf-literal"><span class="corpus-rdf-literal-value corpus-rdf-literal-value-str">%s</span><span class="corpus-rdf-literal-lang-separator">@</span><span class="corpus-rdf-literal-lang">%s</span></span>',$quoted, $lang);
+        } else {
+            return "<span class=\"corpus-rdf-literal corpus-rdf-literal-value\">$quoted</span>";
+        }
+    }
+
+    /**
+     * 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  Resource|string $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()) {
+                $uri = preg_replace("/^_\:/", "", $resource->getUri(), 1);
+                return "<span class=\"corpus-rdf-blank-node\"><span class=\"corpus-rdf-blank-node-prefix\">_:</span>".htmlentities($uri)."</span>";
+            }
+
+            $resource = $resource->getUri();
+        }
+
+        $short = RdfNamespace::shorten($resource, $createNamespace);
+
+        if ($short) {
+            $prefix = $this->addPrefix($short);
+            $shortVal = substr($short, strlen($prefix)+1);
+            $namespaceVal = RdfNamespace::namespaces()[$prefix];
+
+            return "<span class=\"corpus-rdf-resource\"><span class=\"corpus-rdf-resource-prefix\" title=\"$namespaceVal\">$prefix</span><span class=\"corpus-rdf-resource-short-separator\">:</span><a class=\"corpus-rdf-resource-link\" href=\"$resource\" target=\"_blank\" title=\"$resource\">".htmlentities($shortVal)."</a></span>";
+        }
+
+        return $this->escapeIri($resource);
+    }
+
+
+    public function serialiseValue($val) {
+
+        if($val instanceof Resource) {
+            return $this->serialiseResource($val, false);
+        } elseif($val instanceof Literal) {
+            return $this->serialiseLiteral($val);
+        } else {
+            throw new \InvalidArgumentException(
+                "serialiseObject() requires \$object to be ".
+                'of type EasyRdf\Resource or EasyRdf\Literal'
+            );
+        }
+
+    }
+
+}