Merge branch 'master' into subject-filter-by-tag

view/perspectiveBeta/app.js

@@ -63,6 +63,8 @@ const ONE = 1;
 
 const DEBUG_REALTIME = window.location.href.split(/[&\?]/)
   .includes('debug=REALTIME');
+const WEBSOCKET_ONLY = window.location.href.split(/[&\?]/)
+  .includes('protocol=websocket');
 
 const REQ_HEADERS = {
   Authorization: u.getCookie('Authorization'),
@@ -131,11 +133,36 @@ function handleEvent(eventData, eventTypeName) {
 function setupSocketIOClient(persBody) {
   const namespace = u.getNamespaceString(persBody);
 
+  /*
+   * if the transprotocol is set, initialize the socketio client with
+   *  the transport protocol options. The transProtocol variable is set in
+   *  perspective.pug
+   */
+  const options = {};
+  const clientProtocol = transProtocol;
+  if (clientProtocol) {
+    /*
+     * options is used here to set the transport type. For example to only use
+     * websockets as the transport protocol the options object will be
+     * { transports: ['websocket'] }. The regex is used to trim the white spaces
+     * and since clientProtocol is a string of comma seperated values,
+     * the split function is used to split them out by comma and convert
+     * it to an array.
+     */
+    options.transports = clientProtocol.replace(/\s*,\s*/g, ',').split(',');
+  }
+
   /*
    * Note: The "io" variable is defined by the "/socket.io.js" script included
    * in perspective.pug.
    */
-  const socket = io(namespace);
+  let socket;
+  if (WEBSOCKET_ONLY) {
+    socket = io(namespace, { transports: ['websocket'] });
+  } else {
+    socket = io(namespace, options);
+  }
+
   socket.on(eventsQueue.eventType.INTRNL_SUBJ_ADD, (data) => {
     handleEvent(data, eventsQueue.eventType.INTRNL_SUBJ_ADD);
   });

view/perspectiveBeta/perspective.pug

@@ -30,6 +30,8 @@ html(lang = 'en')
   script(src='/static/socket.io.js')
   script.
     var realtimeEventThrottleMilliseconds = #{eventThrottle};
+  script.
+    var transProtocol = '#{transportProtocol}';
   script
       if queryParams
           | var queryParams = !{queryParams}