Fix broken analytics stopping page transitions

Change-Id: If1ef4cff33e92181ec8eab9a79c8e4fa93ad247c

Author: ewpatton

scripts/tutorialPage.js

@@ -1,4 +1,4 @@
-// -*- mode: javascript; js-indent-offset: 2; -*-
+// -*- mode: javascript; js-indent-level: 2; -*-
 // Copyright © 2017-2019 Massachusetts Institute of Technology, All rights reserved.
 // Released under the Apache License, Version 2.0
 // http://www.apache.org/licenses/LICENSE-2.0
@@ -295,8 +295,14 @@ $(document).ready(function() {
 
 sendAnalyticsEvent = function(eventObject) {
   if(document.getElementById("hasAnalytics") && document.getElementById("hasAnalytics").innerHTML === "1") {
-    ga('send', eventObject);
-    //console.log(eventObject);
+    if (gtag) {
+      try {
+        var eventAction = eventObject.eventAction || 'custom_event';
+        gtag('event', eventAction, eventObject);
+      } catch (e) {
+        // Throwing an error here breaks page transitions.
+      }
+    }
   }
 };
 enlargeVideo = function (youtubeid) {