[feat] Add support for jiconop

.eslintignore

@@ -11,3 +11,6 @@ doc/example/libs/*
 # not seem to be a reason why we will want to risk being inconsistent with our
 # remaining JavaScript source code.
 !.eslintrc.js
+
+# Source code written in ES5 which is not processed through Babel.
+connection_optimization/external_connect.js

connection_optimization/external_connect.js

@@ -0,0 +1,69 @@
+/**
+ * Requests the given webservice that will create the connection and will return
+ * the necessary details(rid, sid and jid) to attach to this connection and
+ * start using it. This script can be used for optimizing the connection startup
+ * time. The function will send AJAX request to a webservice that should
+ * create the bosh session much faster than the client because the webservice
+ * can be started on the same machine as the XMPP serever.
+ *
+ * NOTE: It's vert important to execute this function as early as you can for
+ * optimal results.
+ *
+ * @param webserviceUrl the url for the web service that is going to create the
+ * connection.
+ * @param successCallback callback function called with the result of the AJAX
+ * request if the request was successfull. The callback will receive one
+ * parameter which will be JS Object with properties - rid, sid and jid. This
+ * result should be passed to JitsiConnection.attach method in order to use that
+ * connection.
+ * @param error_callback callback function called the AJAX request fail. This
+ * callback is going to receive one parameter which is going to be JS error
+ * object with a reason for failure in it.
+ */
+
+console.log('external_connect.js loaded');
+function createConnectionExternally( // eslint-disable-line no-unused-vars
+        webserviceUrl,
+        successCallback,    
+        error_callback) {
+    if (!window.XMLHttpRequest) {
+        error_callback(new Error('XMLHttpRequest is not supported!'));
+        return;
+    }
+
+    var HTTP_STATUS_OK = 200;
+
+    var xhttp = new XMLHttpRequest();
+
+    xhttp.onreadystatechange = function() {
+        if (xhttp.readyState == xhttp.DONE) {
+            var now = window.connectionTimes['external_connect.done']
+                = window.performance.now();
+            console.log('(TIME) external connect XHR done:\t', now);
+            if (xhttp.status == HTTP_STATUS_OK) {
+                try {
+                    var data = JSON.parse(xhttp.responseText);
+                    successCallback(data);
+                } catch (e) {
+                    error_callback(e);
+                }
+            } else {
+                error_callback(new Error('XMLHttpRequest error. Status: '
+                    + xhttp.status + '. Error message: ' + xhttp.statusText));
+            }
+        }
+    };
+
+    xhttp.open('GET', webserviceUrl, true);
+
+    // Fixes external connect for IE
+    // The timeout property may be set only after calling the open() method
+    // and before calling the send() method.
+    xhttp.timeout = 3000;
+
+    window.connectionTimes = {};
+    var now = window.connectionTimes['external_connect.sending']
+        = window.performance.now();
+    console.log('(TIME) Sending external connect XHR:\t', now);
+    xhttp.send();
+}

globals.d.ts

@@ -4,4 +4,6 @@ declare global {
     interface Window {
         connectionTimes: any;
     }
+    // function named createConnectionExternally
+    function createConnectionExternally(): void;
 }