implement user logout

conference.js

     }
 }
 
+/**
+ * Disconnect from the conference and optionally request user feedback.
+ * @param {boolean} [requestFeedback=false] if user feedback should be requested
+ */
+function hangup (requestFeedback = false) {
+    let promise = Promise.resolve();
+
+    if (requestFeedback) {
+        promise = APP.UI.requestFeedback();
+    }
+
+    promise.then(function () {
+        connection.disconnect();
+
+        if (!config.enableWelcomePage) {
+            return;
+        }
+        // redirect to welcome page
+        setTimeout(() => {
+            APP.settings.setWelcomePageEnabled(true);
+            window.location.pathname = "/";
+        }, 3000);
+    }, function (err) {
+        console.error('Failed to hangup the call:', err);
+    });
+}
+
 /**
  * Create local tracks of specified types.
  * @param {string[]} devices required track types ('audio', 'video' etc.)
 
         // call hangup
         APP.UI.addListener(UIEvents.HANGUP, () => {
-            APP.UI.requestFeedback().then(() => {
-                connection.disconnect();
-                config.enableWelcomePage && setTimeout(() => {
-                        window.localStorage.welcomePageDisabled = false;
-                        window.location.pathname = "/";
-                    }, 3000);
-            }, (err) => {console.error(err);});
+            hangup(true);
         });
 
         // logout
         APP.UI.addListener(UIEvents.LOGOUT, () => {
-            // FIXME handle logout
-            // APP.xmpp.logout(function (url) {
-            //     if (url) {
-            //         window.location.href = url;
-            //     } else {
-            //         hangup();
-            //     }
-            // });
+            AuthHandler.logout(room).then(function (url) {
+                if (url) {
+                    window.location.href = url;
+                } else {
+                    hangup(true);
+                }
+            });
         });
 
         APP.UI.addListener(UIEvents.SIP_DIAL, (sipNumber) => {

modules/UI/UI.js

     document.title = interfaceConfig.APP_NAME;
     var setupWelcomePage = null;
     if(config.enableWelcomePage && window.location.pathname == "/" &&
-        (!window.localStorage.welcomePageDisabled ||
-            window.localStorage.welcomePageDisabled == "false")) {
+       Settings.isWelcomePageEnabled()) {
         $("#videoconference_page").hide();
         if (!setupWelcomePage)
             setupWelcomePage = require("./welcome_page/WelcomePage");

modules/UI/authentication/AuthHandler.js

                     APP.translation.translateString('connection.GOT_SESSION_ID')
                 );
 
+                // authenticate conference on the fly
                 room.join(lockPassword);
 
                 loginDialog.close();
     }
 }
 
+/**
+ * De-authenticate local user.
+ *
+ * @param {JitsiConference} room
+ * @param {string} [lockPassword] password to use if the conference is locked
+ * @returns {Promise}
+ */
+function logout (room) {
+    return new Promise(function (resolve) {
+        room.room.moderator.logout(resolve);
+    }).then(function (url) {
+        // de-authenticate conference on the fly
+        if (room.isJoined()) {
+            room.join();
+        }
+
+        return url;
+    });
+}
+
 /**
  * Notify user that authentication is required to create the conference.
  * @param {JitsiConference} room
 export default {
     authenticate,
     requireAuth,
-    closeAuth
+    closeAuth,
+    logout
 };

modules/UI/welcome_page/WelcomePage.js

-/* global $, interfaceConfig */
+/* global $, interfaceConfig, APP */
 var animateTimeout, updateTimeout;
 
 var RoomnameGenerator = require("../../util/RoomnameGenerator");
     }
 
     $("#disable_welcome").click(function () {
-        window.localStorage.welcomePageDisabled =
-            $("#disable_welcome").is(":checked");
+        APP.settings.setWelcomePageEnabled(
+            !$("#disable_welcome").is(":checked")
+        );
     });
 
 }
 
-module.exports = setupWelcomePage;
+module.exports = setupWelcomePage;

modules/settings/Settings.js

 let language = null;
 let cameraDeviceId = '';
 let micDeviceId = '';
+let welcomePageDisabled = false;
 
 function supportsLocalStorage() {
     try {
     language = window.localStorage.language;
     cameraDeviceId = window.localStorage.cameraDeviceId || '';
     micDeviceId = window.localStorage.micDeviceId || '';
+    welcomePageDisabled = JSON.parse(
+        window.localStorage.welcomePageDisabled || false
+    );
 } else {
     console.log("local storage is not supported");
     userId = generateUniqueId();
     setMicDeviceId: function (newId = '') {
         micDeviceId = newId;
         window.localStorage.micDeviceId = newId;
+    },
+
+    /**
+     * Check if welcome page is enabled or not.
+     * @returns {boolean}
+     */
+    isWelcomePageEnabled () {
+        return !welcomePageDisabled;
+    },
+
+    /**
+     * Enable or disable welcome page.
+     * @param {boolean} enabled if welcome page should be enabled or not
+     */
+    setWelcomePageEnabled (enabled) {
+        welcomePageDisabled = !enabled;
+        window.localStorage.welcomePageDisabled = welcomePageDisabled;
     }
 };