Active viewer PING controller. Closes #790 (#990)

webroot/js/app-video-only.js

@@ -19,6 +19,7 @@ import {
 import {
   URL_CONFIG,
   URL_STATUS,
+  URL_VIEWER_PING,
   TIMER_STATUS_UPDATE,
   TIMER_STREAM_DURATION_COUNTER,
   TEMP_IMAGE,
@@ -117,6 +118,12 @@ export default class VideoOnly extends Component {
         this.handleOfflineMode();
         this.handleNetworkingError(`Stream status: ${error}`);
       });
+
+      // Ping the API to let them know we're an active viewer
+      fetch(URL_VIEWER_PING).catch((error) => {
+        this.handleOfflineMode();
+        this.handleNetworkingError(`Viewer PING error: ${error}`);
+      });
   }
 
   setConfigData(data = {}) {