diff --git a/h5p.classes.php b/h5p.classes.php
index b6d3b37..c54a92c 100644
--- a/h5p.classes.php
+++ b/h5p.classes.php
@@ -14,6 +14,7 @@ interface H5PFrameworkInterface {
    *   - h5pVersion: The version of the H5P plugin/module
    */
   public function getPlatformInfo();
+  
 
   /**
    * Fetches a file from a remote server using HTTP GET
@@ -1589,7 +1590,8 @@ class H5PCore {
   public static $scripts = array(
     'js/jquery.js',
     'js/h5p.js',
-    'js/h5p-event-dispatcher.js',
+    'js/event-dispatcher.js',
+    'js/x-api.js',
   );
   public static $adminScripts = array(
     'js/jquery.js',
@@ -2645,6 +2647,9 @@ class H5PContentValidator {
         $found = FALSE;
         foreach ($semantics->fields as $field) {
           if ($field->name == $key) {
+            if (isset($semantics->optional) && $semantics->optional) {
+              $field->optional = TRUE;
+            }
             $function = $this->typeMap[$field->type];
             $found = TRUE;
             break;
@@ -2669,11 +2674,13 @@ class H5PContentValidator {
         }
       }
     }
-    foreach ($semantics->fields as $field) {
-      if (!(isset($field->optional) && $field->optional)) {
-        // Check if field is in group.
-        if (! property_exists($group, $field->name)) {
-          $this->h5pF->setErrorMessage($this->h5pF->t('No value given for mandatory field ' . $field->name));
+    if (!(isset($semantics->optional) && $semantics->optional)) {
+      foreach ($semantics->fields as $field) {
+        if (!(isset($field->optional) && $field->optional)) {
+          // Check if field is in group.
+          if (! property_exists($group, $field->name)) {
+            $this->h5pF->setErrorMessage($this->h5pF->t('No value given for mandatory field ' . $field->name));
+          }
         }
       }
     }
diff --git a/js/h5p-event-dispatcher.js b/js/event-dispatcher.js
similarity index 53%
rename from js/h5p-event-dispatcher.js
rename to js/event-dispatcher.js
index fb7f5ef..7a86962 100644
--- a/js/h5p-event-dispatcher.js
+++ b/js/event-dispatcher.js
@@ -1,8 +1,13 @@
 /** @namespace H5P */
 var H5P = H5P || {};
 
-H5P.EventDispatcher = (function () {
+H5P.Event = function(type, data) {
+  this.type = type;
+  this.data = data;
+};
 
+H5P.EventDispatcher = (function () {
+  
   /**
    * The base of the event system.
    * Inherit this class if you want your H5P to dispatch events.
@@ -12,11 +17,11 @@ H5P.EventDispatcher = (function () {
     var self = this;
 
     /**
-     * Keep track of events and listeners for each event.
+     * Keep track of listeners for each event.
      * @private
      * @type {Object}
      */
-    var events = {};
+    var triggers = {};
 
     /**
      * Add new event listener.
@@ -26,21 +31,24 @@ H5P.EventDispatcher = (function () {
      * @param {String} type Event type
      * @param {Function} listener Event listener
      */
-    self.on = function (type, listener) {
+    self.on = function (type, listener, scope) {
+      if (scope === undefined) {
+        scope = self;
+      }
       if (!(listener instanceof Function)) {
         throw TypeError('listener must be a function');
       }
 
       // Trigger event before adding to avoid recursion
-      self.trigger('newListener', type, listener);
+      self.trigger('newListener', {'type': type, 'listener': listener});
 
-      if (!events[type]) {
+      if (!triggers[type]) {
         // First
-        events[type] = [listener];
+        triggers[type] = [{'listener': listener, 'scope': scope}];
       }
       else {
         // Append
-        events[type].push(listener);
+        triggers[type].push({'listener': listener, 'scope': scope});
       }
     };
 
@@ -52,17 +60,20 @@ H5P.EventDispatcher = (function () {
      * @param {String} type Event type
      * @param {Function} listener Event listener
      */
-    self.once = function (type, listener) {
+    self.once = function (type, listener, scope) {
+      if (scope === undefined) {
+        scope = self;
+      }
       if (!(listener instanceof Function)) {
         throw TypeError('listener must be a function');
       }
 
-      var once = function () {
-        self.off(type, once);
-        listener.apply(self, arguments);
+      var once = function (event) {
+        self.off(event, once);
+        listener.apply(scope, event);
       };
 
-      self.on(type, once);
+      self.on(type, once, scope);
     };
 
     /**
@@ -79,74 +90,58 @@ H5P.EventDispatcher = (function () {
         throw TypeError('listener must be a function');
       }
 
-      if (events[type] === undefined) {
+      if (triggers[type] === undefined) {
         return;
       }
 
       if (listener === undefined) {
         // Remove all listeners
-        delete events[type];
+        delete triggers[type];
         self.trigger('removeListener', type);
         return;
       }
 
       // Find specific listener
-      for (var i = 0; i < events[type].length; i++) {
-        if (events[type][i] === listener) {
-          events[type].unshift(i, 1);
-          self.trigger('removeListener', type, listener);
+      for (var i = 0; i < triggers[type].length; i++) {
+        if (triggers[type][i].listener === listener) {
+          triggers[type].unshift(i, 1);
+          self.trigger('removeListener', type, {'listener': listener});
           break;
         }
       }
 
       // Clean up empty arrays
-      if (!events[type].length) {
-        delete events[type];
+      if (!triggers[type].length) {
+        delete triggers[type];
       }
     };
 
-    /**
-     * Creates a copy of the arguments list. Skips the given number of arguments.
-     *
-     * @private
-     * @param {Array} args List of arguments
-     * @param {Number} skip Number of arguments to skip
-     * @param {Array} Copy og arguments list
-     */
-    var getArgs = function (args, skip) {
-      var left = [];
-      for (var i = skip; i < args.length; i++) {
-        left.push(args[i]);
-      }
-      return left;
-    };
-
     /**
      * Dispatch event.
      *
      * @public
-     * @param {String} type Event type
-     * @param {...*} args
+     * @param {String|Function}
+     *  
      */
-    self.trigger = function (type) {
-      if (self.debug !== undefined) {
-        // Class has debug enabled. Log events.
-        console.log(self.debug + ' - Firing event "' + type + '", ' + (events[type] === undefined ? 0 : events[type].length) + ' listeners.', getArgs(arguments, 1));
-      }
-
-      if (events[type] === undefined) {
+    self.trigger = function (event, eventData) {
+      if (event === undefined) {
+        return;
+      }
+      if (typeof event === 'string') {
+        event = new H5P.Event(event, eventData);
+      }
+      else if (eventData !== undefined) {
+        event.data = eventData;
+      }
+      if (triggers[event.type] === undefined) {
         return;
       }
-
-      // Copy all arguments except the first
-      var args = getArgs(arguments, 1);
-
       // Call all listeners
-      for (var i = 0; i < events[type].length; i++) {
-        events[type][i].apply(self, args);
+      for (var i = 0; i < triggers[event.type].length; i++) {
+        triggers[event.type][i].listener.call(triggers[event.type][i].scope, event);
       }
     };
   }
 
   return EventDispatcher;
-})();
+})();
\ No newline at end of file
diff --git a/js/h5p-embed.js b/js/h5p-embed.js
index b1b58c3..deeab96 100644
--- a/js/h5p-embed.js
+++ b/js/h5p-embed.js
@@ -90,7 +90,7 @@ var H5P = H5P || (function () {
       loadContent(contentId, h5ps[i]);
       contentId++;
     }
-  };
+  }
 
   /**
    * Return integration object
diff --git a/js/h5p.js b/js/h5p.js
index d53f8e2..5df3f2b 100644
--- a/js/h5p.js
+++ b/js/h5p.js
@@ -8,6 +8,8 @@ H5P.isFramed = (window.self !== window.top);
 // Useful jQuery object.
 H5P.$window = H5P.jQuery(window);
 
+H5P.instances = [];
+
 // Detect if we support fullscreen, and what prefix to use.
 if (document.documentElement.requestFullScreen) {
   H5P.fullScreenBrowserPrefix = '';
@@ -93,13 +95,6 @@ H5P.init = function () {
     // Keep track of when we started
     H5P.opened[contentId] = new Date();
 
-    // Handle events when the user finishes the content. Useful for logging exercise results.
-    instance.$.on('finish', function (event) {
-      if (event.data !== undefined) {
-        H5P.setFinished(contentId, event.data.score, event.data.maxScore, event.data.time);
-      }
-    });
-
     if (H5P.isFramed) {
       // Make it possible to resize the iframe when the content changes size. This way we get no scrollbars.
       var iframe = window.parent.document.getElementById('h5p-iframe-' + contentId);
@@ -123,28 +118,32 @@ H5P.init = function () {
       };
 
       var resizeDelay;
-      instance.$.on('resize', function () {
+      H5P.on(instance, 'resize', function () {
         // Use a delay to make sure iframe is resized to the correct size.
         clearTimeout(resizeDelay);
         resizeDelay = setTimeout(function () {
           resizeIframe();
         }, 1);
       });
+      H5P.instances.push(instance);
     }
 
+    H5P.on(instance, 'xAPI', H5P.xAPIListener);
+    H5P.on(instance, 'xAPI', H5P.xAPIEmitter);
+
     // Resize everything when window is resized.
     $window.resize(function () {
       if (window.parent.H5P.isFullscreen) {
         // Use timeout to avoid bug in certain browsers when exiting fullscreen. Some browser will trigger resize before the fullscreenchange event.
-          instance.$.trigger('resize');
+        H5P.trigger(instance, 'resize');
       }
       else {
-        instance.$.trigger('resize');
+        H5P.trigger(instance, 'resize');
       }
     });
 
     // Resize content.
-    instance.$.trigger('resize');
+    H5P.trigger(instance, 'resize');
   });
 
   // Insert H5Ps that should be in iframes.
@@ -156,6 +155,28 @@ H5P.init = function () {
   });
 };
 
+/*
+ * TODO xAPI:
+ * 1. Create a xAPI.js file and move xAPI code there (public)
+ * 2. Be able to listen for events from both div and iframe embedded content
+ * via the same API (this is about adding communication between the iframe and
+ * it's parent and make sure that the parent distributes the events from the
+ * iframe) (public)
+ * 3. Create a separate Drupal module that is able to listen for events from
+ * both div and iframe embedded content and send them to analytics (custom for Zavango)
+ * 4. Move the event system code to a separate file (public)
+ * 5. Make sure the helper functions provides all the relevant data, example values 
+ * and time spent (public)
+ * 6. Add documentation to the functions (public)
+ * 7. Add xAPI events to all the basic questiontype:
+ * 7.1 Multichoice
+ * 7.2 Fill in the blanks
+ * 7.3 Drag and drop
+ * 7.4 Drag the words
+ * 7.5 Mark the words
+ * 8. Add xAPI events to interactive video
+ */
+
 /**
  * Enable full screen for the given h5p.
  *
@@ -208,8 +229,8 @@ H5P.fullScreen = function ($element, instance, exitCallback, body) {
    */
   var entered = function () {
     // Do not rely on window resize events.
-    instance.$.trigger('resize');
-    instance.$.trigger('focus');
+    H5P.trigger(instance, 'resize');
+    H5P.trigger(instance, 'focus');
   };
 
   /**
@@ -223,8 +244,8 @@ H5P.fullScreen = function ($element, instance, exitCallback, body) {
     $classes.removeClass(classes);
 
     // Do not rely on window resize events.
-    instance.$.trigger('resize');
-    instance.$.trigger('focus');
+    H5P.trigger(instance, 'resize');
+    H5P.trigger(instance, 'focus');
 
     if (exitCallback !== undefined) {
       exitCallback();
@@ -353,6 +374,7 @@ H5P.classFromName = function (name) {
  * @param {Number} contentId
  * @param {jQuery} $attachTo An optional element to attach the instance to.
  * @param {Boolean} skipResize Optionally skip triggering of the resize event after attaching.
+ * @param {Object} The parent of this H5P
  * @return {Object} Instance.
  */
 H5P.newRunnable = function (library, contentId, $attachTo, skipResize) {
@@ -387,17 +409,27 @@ H5P.newRunnable = function (library, contentId, $attachTo, skipResize) {
   }
 
   var instance = new constructor(library.params, contentId);
-
+  
   if (instance.$ === undefined) {
     instance.$ = H5P.jQuery(instance);
   }
 
+  // Make xAPI events bubble
+//  if (parent !== null && parent.trigger !== undefined) {
+//    instance.on('xAPI', parent.trigger);
+//  }
+
+  // Automatically call resize on resize event if defined
+  if (typeof instance.resize === 'function') {
+    H5P.on(instance, 'resize', instance.resize);
+  }
+
   if ($attachTo !== undefined) {
     instance.attach($attachTo);
 
     if (skipResize === undefined || !skipResize) {
       // Resize content.
-      instance.$.trigger('resize');
+      H5P.trigger(instance, 'resize');
     }
   }
   return instance;
@@ -1055,7 +1087,7 @@ H5P.setFinished = function (contentId, score, maxScore, time) {
     var toUnix = function (date) {
       return Math.round(date.getTime() / 1000);
     };
-
+    
     // Post the results
     // TODO: Should we use a variable with the complete path?
     H5P.jQuery.post(H5P.ajaxPath + 'setFinished', {
@@ -1099,3 +1131,48 @@ if (H5P.jQuery) {
     }
   });
 }
+
+/**
+ * Trigger an event on an instance
+ * 
+ * Helper function that triggers an event if the instance supports event handling
+ * 
+ * @param {function} instance
+ *  An H5P instance
+ * @param {string} eventType
+ *  The event type
+ */
+H5P.trigger = function(instance, eventType) {
+  // Try new event system first
+  if (instance.trigger !== undefined) {
+    instance.trigger(eventType);
+  }
+  // Try deprecated event system
+  else if (instance.$ !== undefined && instance.$.trigger !== undefined) {
+    instance.$.trigger(eventType)
+  }
+};
+
+/**
+ * Register an event handler
+ * 
+ * Helper function that registers an event handler for an event type if
+ * the instance supports event handling
+ * 
+ * @param {function} instance
+ *  An h5p instance
+ * @param {string} eventType
+ *  The event type
+ * @param {function} handler
+ *  Callback that gets triggered for events of the specified type
+ */
+H5P.on = function(instance, eventType, handler) {
+  // Try new event system first
+  if (instance.on !== undefined) {
+    instance.on(eventType, handler);
+  }
+  // Try deprecated event system
+  else if (instance.$ !== undefined && instance.$.on !== undefined) {
+    instance.$.on(eventType, handler)
+  }
+};
\ No newline at end of file
diff --git a/js/x-api.js b/js/x-api.js
new file mode 100644
index 0000000..e94adf4
--- /dev/null
+++ b/js/x-api.js
@@ -0,0 +1,173 @@
+var H5P = H5P || {};
+
+H5P.xAPIListener = function(event) {
+  var statement = event.data.statement;
+  if ('verb' in statement) {
+    if (statement.verb.id === 'http://adlnet.gov/expapi/verbs/completed') {
+      var score = statement.result.score.raw;
+      var maxScore = statement.result.score.max;
+      var contentId = statement.object.extensions['http://h5p.org/x-api/h5p-local-content-id'];
+      H5P.setFinished(contentId, score, maxScore);
+    }
+  }
+};
+
+H5P.xAPIEmitter = function (event) {
+  if (event.data.statement !== undefined) {
+    for (var i = 0; i < H5P.xAPIListeners.length; i++) {
+      H5P.xAPIListeners[i](event.data.statement);
+    }
+  }
+};
+
+H5P.xAPIListeners = [];
+
+H5P.onXAPI = function(listener) {
+  H5P.xAPIListeners.push(listener);
+};
+
+H5P.onXAPI(function(statement) {
+  console.log(statement);
+});
+
+H5P.XAPIEvent = function() {
+  H5P.Event.call(this, 'xAPI', {'statement': {}});
+};
+
+H5P.XAPIEvent.prototype = Object.create(H5P.Event.prototype);
+H5P.XAPIEvent.prototype.constructor = H5P.XAPIEvent;
+
+H5P.XAPIEvent.prototype.setScoredResult = function(score, maxScore) {
+  this.data.statement.result = {
+    'score': {
+      'min': 0,
+      'max': maxScore,
+      'raw': score
+    }
+  };
+};
+
+H5P.XAPIEvent.prototype.setVerb = function(verb) {
+  if (H5P.jQuery.inArray(verb, H5P.XAPIEvent.allowedXAPIVerbs) !== -1) {
+    this.data.statement.verb = {
+      'id': 'http://adlnet.gov/expapi/verbs/' + verb,
+      'display': {
+        'en-US': verb
+      }
+    };
+  }
+  else {
+  console.log('illegal verb');
+  }
+  // Else: Fail silently...
+};
+
+H5P.XAPIEvent.prototype.getVerb = function(full) {
+  var statement = this.data.statement;
+  if ('verb' in statement) {
+    if (full === true) {
+      return statement.verb;
+    }
+    return statement.verb.id.slice(31);
+  }
+  else {
+    return null;
+  }
+}
+
+H5P.XAPIEvent.prototype.setObject = function(instance) {
+  this.data.statement.object = {
+    // TODO: Correct this. contentId might be vid
+    'id': window.location.origin + Drupal.settings.basePath + 'node/' + instance.contentId,
+    'objectType': 'Activity',
+    'extensions': {
+      'http://h5p.org/x-api/h5p-local-content-id': instance.contentId
+    }
+  };
+};
+
+H5P.XAPIEvent.prototype.setActor = function() {
+  this.data.statement.actor = H5P.getActor();
+};
+
+H5P.XAPIEvent.prototype.getMaxScore = function() {
+  return this.getVerifiedStatementValue(['result', 'score', 'max']);
+};
+
+H5P.XAPIEvent.prototype.getScore = function() {
+  return this.getVerifiedStatementValue(['result', 'score', 'raw']);
+};
+
+H5P.XAPIEvent.prototype.getVerifiedStatementValue = function(keys) {
+  var val = this.data.statement;
+  for (var i in keys) {
+    if (val[keys[i]] === undefined) {
+      return null;
+    }
+    val = val[keys[i]];
+  }
+  return val;
+}
+
+H5P.XAPIEvent.allowedXAPIVerbs = [
+  'answered',
+  'asked',
+  'attempted',
+  'attended',
+  'commented',
+  'completed',
+  'exited',
+  'experienced',
+  'failed',
+  'imported',
+  'initialized',
+  'interacted',
+  'launched',
+  'mastered',
+  'passed',
+  'preferred',
+  'progressed',
+  'registered',
+  'responded',
+  'resumed',
+  'scored',
+  'shared',
+  'suspended',
+  'terminated',
+  'voided'
+];
+
+H5P.EventDispatcher.prototype.triggerXAPI = function(verb, extra) {
+  this.trigger(this.createXAPIEventTemplate(verb, extra));
+};
+
+H5P.EventDispatcher.prototype.createXAPIEventTemplate = function(verb, extra) {
+  var event = new H5P.XAPIEvent();
+
+  event.setActor();
+  event.setVerb(verb);
+  if (extra !== undefined) {
+    for (var i in extra) {
+      event.data.statement[i] = extra[i];
+    }
+  }
+  if (!('object' in event)) {
+    event.setObject(this);
+  }
+  return event;
+};
+
+H5P.EventDispatcher.prototype.triggerXAPICompleted = function(score, maxScore) {
+  var event = this.createXAPIEventTemplate('completed');
+  event.setScoredResult(score, maxScore);
+  this.trigger(event);
+}
+
+H5P.getActor = function() {
+  var user = H5PIntegration.getUser();
+  return {
+    'name': user.name,
+    'mbox': 'mailto:' + user.mail,
+    'objectType': 'Agent'
+  };
+};
\ No newline at end of file