diff -r 2b3247d02769 -r f55970e41793 server/src/app/Models/Document.php
--- a/server/src/app/Models/Document.php	Wed Jun 24 01:36:46 2015 +0200
+++ b/server/src/app/Models/Document.php	Mon Oct 05 17:02:10 2015 +0200
@@ -4,16 +4,22 @@
 use Config;
 use CorpusParole\Libraries\Utils;
 use CorpusParole\Libraries\RdfModel\RdfModelResource;
+use JsonSerializable;
 use Log;
+use EasyRdf\Literal;
+use EasyRdf\Resource;
+use EasyRdf\Graph;
+use EasyRdf\Isomorphic;
+
 
 /**
- * Model class for Document. Inherit from EasyRdf_Resource
+ * Model class for Document. Inherit from EasyRd\Resource
  * SELECT DISTINCT ?g WHERE {GRAPH ?g {?s ?p ?o}}
  */
-class Document extends RdfModelResource {
+class Document extends RdfModelResource implements JsonSerializable {
 
     public function __construct($uri, $graph = null) {
-        parent::__construct($uri, $graph, 'foaf:primaryTopic');
+        parent::__construct($uri, $graph);
     }
 
     private $id = null;
@@ -26,40 +32,60 @@
     }
 
     public function getTitle() {
-        return $this->innerDocument->getLiteral('dc11:title');
+        try {
+            return $this->getLiteral('<http://purl.org/dc/elements/1.1/title>');
+        } catch(\Exception $e) {
+            return null;
+        }
     }
 
     public function getPublishers() {
-        return $this->innerDocument->allLiterals('dc11:publisher');
+        try {
+            return $this->allLiterals('dc11:publisher');
+        } catch(\Exception $e) {
+           return [];
+       }
     }
 
     public function getMediaArray() {
 
         //TODO: add media type
         $res = [];
-        $formats = $this->innerDocument->allResources("dc:isFormatOf");
+        $formats = [];
+        try {
+            $formats = $this->allResources("dc:isFormatOf");
+        } catch(\Exception $e) {
+            // do nothing
+        }
         foreach ($formats as $f) {
             $uri = $f->getUri();
             $mimetype = Utils::get_mimetype($uri);
             array_push($res, ["url" => $uri, "format" => $mimetype]);
         }
-        array_push($res, ["url" => $this->innerDocument->getUri(), "format" => $this->innerDocument->getLiteral('dc11:format')]);
+
+        $format = null;
+        try {
+            $format = $this->getLiteral('dc11:format');
+        } catch(\Exception $e) {
+            // do nothing
+        }
+        array_push($res, ["url" => $this->getUri(), "format" => $format]);
         return $res;
     }
 
     public function getTypes() {
-        return $this->innerDocument->all('dc11:type');
+        return $this->all('dc11:type');
     }
 
     public function getDiscourseTypes() {
         return array_values(array_filter($this->getTypes(), function($v) {
-            return $v instanceof \EasyRdf_Literal && $v->getDatatypeUri() === Config::get('constants.OLAC_DISCOURSE_TYPE')['uri'];
+            return $v instanceof Literal && $v->getDatatypeUri() === Config::get('constants.OLAC_DISCOURSE_TYPE')['uri'];
         }));
     }
 
     public function getOtherTypes() {
         $res = array_values(array_filter($this->getTypes(), function($v) {
-            return $v instanceof \EasyRdf_Resource || $v->getDatatypeUri() !== Config::get('constants.OLAC_DISCOURSE_TYPE')['uri'];
+            return $v instanceof Resource || $v->getDatatypeUri() !== Config::get('constants.OLAC_DISCOURSE_TYPE')['uri'];
         }));
         return $res;
     }
@@ -69,19 +95,19 @@
         $this->startDelta();
 
         foreach($this->getDiscourseTypes() as $discourseType) {
-            $this->innerDocument->delete('dc11:type', $discourseType);
-            $this->currentDelta->deletedGraph->add($this->innerDocument, 'dc11:type', $discourseType);
+            $this->delete('dc11:type', $discourseType);
+            $this->currentDelta->getDeletedGraph()->add($this, 'dc11:type', new Literal($discourseType, null, Config::get('constants.OLAC_DISCOURSE_TYPE')['uri']));
         }
         // re-add them
 
         foreach($discoursesTypes as $dType) {
-            $this->innerDocument->add('dc11:type', new \EasyRdf_Literal($dType, null, Config::get('constants.OLAC_DISCOURSE_TYPE')['uri']));
-            $this->currentDelta->addedGraph->add($this->innerDocument, 'dc11:type', $discourseType);
+            $this->add('dc11:type', new Literal($dType, null, Config::get('constants.OLAC_DISCOURSE_TYPE')['uri']));
+            $this->currentDelta->getAddedGraph()->add($this, 'dc11:type', new Literal($dType, null, Config::get('constants.OLAC_DISCOURSE_TYPE')['uri']));
         }
     }
 
     public function isIsomorphic($doc) {
-        return \EasyRdf_Isomorphic::isomorphic($this->graph, $doc->graph);
+        return Isomorphic::isomorphic($this->graph, $doc->graph);
     }
 
     /*
@@ -90,8 +116,35 @@
      */
     public function __clone() {
 
-        $this->graph = new \EasyRdf_Graph($this->graph->getUri(), $this->graph->toRdfPhp());
-        $this->innerDocument = $this->getResource('foaf:primaryTopic');
+        $this->graph = new Graph($this->graph->getUri(), $this->graph->toRdfPhp());
+    }
+
+    public function jsonSerialize() {
+        if(!$this->graph) {
+            return [
+                'id' => $this->getId(),
+            ];
+        } else {
+            $mediaArray = array_map(
+                function($m) {
+                    $f = Utils::process_literal_or_string($m['format']);
+                    return ['url' => $m['url'], 'format' => $f];},
+                $this->getMediaArray()
+            );
+
+            $publishers = array_map(
+                function($v) { return Utils::process_literal_or_string($v); },
+                $this->getPublishers()
+            );
+
+            return [
+                'id' => $this->getId(),
+                'uri' => $this->getUri(),
+                'title' => $this->getTitle()->getValue(),
+                'publishers' => $publishers,
+                'mediaArray'=> $mediaArray
+            ];
+        }
     }
 
 }