Refactored HostList to better support bookmarking.

remoting/webapp/me2mom/client_screen.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * Functions related to the 'client screen' for Chromoting.
  */
 
 'use strict';
@@ skipping 18 matching lines @@
  * @type {string} The normalized access code.
  */
 remoting.accessCode = '';
 
 /**
  * @type {string} The host's JID, returned by the server.
  */
 remoting.hostJid = '';
 
 /**
+ * @type {string} For Me2Me connections, the id of the current host, used to
+ *     facilitate refresh/reconnect if the cached host information is stale.

[Wez, 2011/12/03 01:26:33]

nit: the Id is used when re-connecting, since the JID may have changed

[Jamie, 2011/12/05 20:49:08]

Done.

+ */
+remoting.hostId = '';
+
+/**
  * @type {string} The host's public key, returned by the server.
  */
 remoting.hostPublicKey = '';
 
 /**
  * @type {XMLHttpRequest} The XHR object corresponding to the current
  *     support-hosts request, if there is one outstanding.
  */
 remoting.supportHostsXhr_ = null;
 
@@ skipping 193 matching lines @@
       // only with older client plugins. Current version should go the
       // FAILED state when connection fails.
       showConnectError_(remoting.Error.INVALID_ACCESS_CODE);
     }
 
   } else if (newState == remoting.ClientSession.State.CONNECTION_FAILED) {
     remoting.debug.log('Client plugin reported connection failed: ' +
                        remoting.clientSession.error);
     if (remoting.clientSession.error ==
         remoting.ClientSession.ConnectionError.HOST_IS_OFFLINE) {
-      showConnectError_(remoting.Error.HOST_IS_OFFLINE);
+      retryConnectOrReportOffline_();
     } else if (remoting.clientSession.error ==
                remoting.ClientSession.ConnectionError.SESSION_REJECTED) {
       showConnectError_(remoting.Error.INVALID_ACCESS_CODE);
     } else if (remoting.clientSession.error ==
                remoting.ClientSession.ConnectionError.INCOMPATIBLE_PROTOCOL) {
       showConnectError_(remoting.Error.INCOMPATIBLE_PROTOCOL);
     } else if (remoting.clientSession.error ==
                remoting.ClientSession.ConnectionError.NETWORK_FAILURE) {
       showConnectError_(remoting.Error.GENERIC);
     } else {
       showConnectError_(remoting.Error.GENERIC);
     }
 
   } else {
     remoting.debug.log('Unexpected client plugin state: ' + newState);
     // This should only happen if the web-app and client plugin get out of
     // sync, and even then the version check should allow compatibility.
     showConnectError_(remoting.Error.MISSING_PLUGIN);
   }
 }
 
 /**
+ * If we have a hostId to retry, try refreshing it and connecting again. If not,
+ * then show the 'host offline' error message.
+ *
+ * @return {void} Nothing.
+ */
+function retryConnectOrReportOffline_() {
+  if (remoting.hostId) {
+    console.log('Connection failed. Retrying.');
+    /** @param {boolean} success True if the refresh was successful. */
+    var onDone = function(success) {
+      if (success) {
+        remoting.connectHost(remoting.hostId, false);
+      } else {
+        showConnectError_(remoting.Error.HOST_IS_OFFLINE);
+      }
+    };
+    remoting.hostList.refresh(onDone);
+  } else {
+    console.log('Connection failed. Not retrying.');
+    showConnectError_(remoting.Error.HOST_IS_OFFLINE);
+  }
+}
+
+/**
  * Create the client session object and initiate the connection.
  *
  * @return {void} Nothing.
  */
 function startSession_() {
   remoting.debug.log('Starting session...');
   var accessCode = document.getElementById('access-code-entry');
   accessCode.value = '';  // The code has been validated and won't work again.
   remoting.clientSession =
       new remoting.ClientSession(
@@ skipping 120 matching lines @@
 /**
  * Update the horizontal position of the tool-bar to center it.
  */
 function recenterToolbar_() {
   var toolbar = document.getElementById('session-toolbar');
   var toolbarX = (window.innerWidth - toolbar.clientWidth) / 2;
   toolbar.style['left'] = toolbarX + 'px';
 }
 
 /**
- * Start a connection to the specified host, using the stored details.
+ * Start a connection to the specified host, using the cached details.
  *
- * @param {string} hostJid The jabber Id of the host.
- * @param {string} hostPublicKey The public key of the host.
- * @param {string} hostName The name of the host.
+ * @param {string} hostId The unique id of the host.
+ * @param {boolean} retryIfOffline If true and the host can't be contacted,
+ *     refresh the host list and try again. This allows bookmarked hosts to
+ *     work even if they reregister with Talk and get a different Jid.
  * @return {void} Nothing.
  */
-remoting.connectHost = function(hostJid, hostPublicKey, hostName) {
-  // TODO(jamiewalch): Instead of passing the jid in the URL, cache it in local
-  // storage so that host bookmarks can be implemented efficiently.
-  remoting.hostJid = hostJid;
-  remoting.hostPublicKey = hostPublicKey;
-  document.getElementById('connected-to').innerText = hostName;
-  document.title = document.title + ': ' + hostName;
-
+remoting.connectHost = function(hostId, retryIfOffline) {
   remoting.debug.log('Connecting to host...');
   remoting.currentConnectionType = remoting.ConnectionType.Me2Me;

[Wez, 2011/12/03 01:26:33]

nit: blank line here?

[Jamie, 2011/12/05 20:49:08]

Done.

+  // Storing the hostId indicates that it should be retried on failure.
+  remoting.hostId = retryIfOffline ? hostId : '';
   remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
 
+  var host = remoting.hostList.getHostForId(hostId);

[Wez, 2011/12/03 01:26:33]

Presumably this will return null if the Host Id is no longer valid, e.g. if the
Host was removed?  We should detect that case and not retry, I think?

[Jamie, 2011/12/05 20:49:08]

I'm not so sure. It's possible that a deleted host can come back, in which case
it's reasonable for bookmarks to that host to continue to work. If we don't
retry if the host is NULL, then the bookmark will work in this case iff the user
has visited the main host screen in the interim, which I don't think is very
intuitive. The cost of not optimising for the case is that it will take a couple
more seconds to fail if the bookmark is genuinely stale.

[Wez, 2011/12/05 20:59:38]

For a deleted host to "come back" it would have to be re-registered, so it'll
have a different key pair => not the same host.  So I don't think that can ever
happen.

+  if (!host) {
+    retryConnectOrReportOffline_();
+    return;
+  }
+  remoting.hostJid = host.jabberId;
+  remoting.hostPublicKey = host.publicKey;
+  document.getElementById('connected-to').innerText = host.hostName;
+  document.title = document.title + ': ' + host.hostName;
+
   if (!remoting.wcsLoader) {
     remoting.wcsLoader = new remoting.WcsLoader();
   }
   /** @param {function(string):void} setToken The callback function. */
   var callWithToken = function(setToken) {
     remoting.oauth2.callWithToken(setToken);
   };
   remoting.wcsLoader.startAsync(callWithToken, remoting.connectHostWithWcs);
 }
 
 /**
  * Continue making the connection to a host, once WCS has initialized.
  *
  * @return {void} Nothing.
  */
 remoting.connectHostWithWcs = function() {
   remoting.clientSession =
-  new remoting.ClientSession(
-      remoting.hostJid, remoting.hostPublicKey,
-      '', /** @type {string} */ (remoting.oauth2.getCachedEmail()),
-      onClientStateChange_);
+      new remoting.ClientSession(
+          remoting.hostJid, remoting.hostPublicKey,
+          '', /** @type {string} */ (remoting.oauth2.getCachedEmail()),
+          onClientStateChange_);
   /** @param {string} token The auth token. */
   var createPluginAndConnect = function(token) {
     remoting.clientSession.createPluginAndConnect(
         document.getElementById('session-mode'),
         token);
   };
 
   remoting.oauth2.callWithToken(createPluginAndConnect);
 }
 
 }());