GUACAMOLE-1744: Merge automatically clean up UI if session has expired in the background.

guacamole/src/main/frontend/src/app/auth/service/authenticationService.js

@@ -261,6 +261,43 @@ angular.module('auth').factory('authenticationService', ['$injector',
 
     };
 
+    /**
+     * Determines whether the session associated with a particular token is
+     * still valid, without performing an operation that would result in that
+     * session being marked as active. If no token is provided, the session of
+     * the current user is checked.
+     *
+     * @param {string} [token]
+     *     The authentication token to pass with the "Guacamole-Token" header.
+     *     If omitted, and the user is logged in, the user's current
+     *     authentication token will be used.
+     *
+     * @returns {Promise.<!boolean>}
+     *     A promise that resolves with the boolean value "true" if the session
+     *     is valid, and resolves with the boolean value "false" otherwise,
+     *     including if an error prevents session validity from being
+     *     determined. The promise is never rejected.
+     */
+    service.getValidity = function getValidity(token) {
+
+        // NOTE: Because this is a HEAD request, we will not receive a JSON
+        // response body. We will only have a simple yes/no regarding whether
+        // the auth token can be expected to be usable.
+        return service.request({
+            method: 'HEAD',
+            url: 'api/session'
+        }, token)
+
+        .then(function sessionIsValid() {
+            return true;
+        })
+
+        ['catch'](function sessionIsNotValid() {
+            return false;
+        });
+
+    };
+
     /**
      * Makes a request to revoke an authentication token using the token REST
      * API endpoint, returning a promise that succeeds only if the token was

guacamole/src/main/frontend/src/app/index/controllers/indexController.js

@@ -23,14 +23,30 @@
 angular.module('index').controller('indexController', ['$scope', '$injector',
         function indexController($scope, $injector) {
 
+    /**
+     * The number of milliseconds that should elapse between client-side
+     * session checks. This DOES NOT impact whether a session expires at all;
+     * such checks will always be server-side. This only affects how quickly
+     * the client-side view can recognize that a user's session has expired
+     * absent any action taken by the user.
+     *
+     * @type {!number}
+     */
+    const SESSION_VALIDITY_RECHECK_INTERVAL = 15000;
+
+    // Required types
+    const ManagedClientState = $injector.get('ManagedClientState');
+
     // Required services
-    const $document         = $injector.get('$document');
-    const $location         = $injector.get('$location');
-    const $route            = $injector.get('$route');
-    const $window           = $injector.get('$window');
-    const clipboardService  = $injector.get('clipboardService');
-    const guacNotification  = $injector.get('guacNotification');
-    const guacClientManager = $injector.get('guacClientManager');
+    const $document              = $injector.get('$document');
+    const $interval              = $injector.get('$interval');
+    const $location              = $injector.get('$location');
+    const $route                 = $injector.get('$route');
+    const $window                = $injector.get('$window');
+    const authenticationService  = $injector.get('authenticationService');
+    const clipboardService       = $injector.get('clipboardService');
+    const guacNotification       = $injector.get('guacNotification');
+    const guacClientManager      = $injector.get('guacClientManager');
 
     /**
      * The error that prevents the current page from rendering at all. If no
@@ -202,6 +218,48 @@ angular.module('index').controller('indexController', ['$scope', '$injector',
         keyboard.reset();
     };
 
+    /**
+     * Returns whether the current user has at least one active connection
+     * running within the current tab.
+     *
+     * @returns {!boolean}
+     *     true if the current user has at least one active connection running
+     *     in the current browser tab, false otherwise.
+     */
+    var hasActiveTunnel = function hasActiveTunnel() {
+
+        var clients = guacClientManager.getManagedClients();
+        for (var id in clients) {
+
+            switch (clients[id].clientState.connectionState) {
+                case ManagedClientState.ConnectionState.CONNECTING:
+                case ManagedClientState.ConnectionState.WAITING:
+                case ManagedClientState.ConnectionState.CONNECTED:
+                    return true;
+            }
+
+        }
+
+        return false;
+
+    };
+
+    // If we're logged in and not connected to anything, periodically check
+    // whether the current session is still valid. If the session has expired,
+    // refresh the auth state to reshow the login screen (rather than wait for
+    // the user to take some action and discover that they are not logged in
+    // after all). There is no need to do this if a connection is active as
+    // that connection activity will already automatically check session
+    // validity.
+    $interval(function cleanUpViewIfSessionInvalid() {
+        if ($scope.applicationState === ApplicationState.READY && !hasActiveTunnel()) {
+            authenticationService.getValidity().then(function validityDetermined(valid) {
+                if (!valid)
+                    $scope.reAuthenticate();
+            });
+        }
+    }, SESSION_VALIDITY_RECHECK_INTERVAL);
+
     // Release all keys upon form submission (there may not be corresponding
     // keyup events for key presses involved in submitting a form)
     $document.on('submit', function formSubmitted() {