Handle authentication failures in the v2 app by restarting the app

remoting/webapp/crd/js/identity.js

Index: remoting/webapp/crd/js/identity.js
diff --git a/remoting/webapp/crd/js/identity.js b/remoting/webapp/crd/js/identity.js
index aef0f2c6f984444844d7002e1f4d827a90dfb09b..58115e15f54a0f9e2694af66efe974df19379d71 100644
--- a/remoting/webapp/crd/js/identity.js
+++ b/remoting/webapp/crd/js/identity.js
@@ -16,19 +16,17 @@ var remoting = remoting || {};
  * TODO(jamiewalch): Remove remoting.OAuth2 from this type annotation when
  * the Apps v2 work is complete.
  *
- * @type {remoting.Identity|remoting.OAuth2}
+ * @type {remoting.Identity}
  */
 remoting.identity = null;
 
 /**
- * @param {function(function():void):void} consentCallback Callback invoked if
- *     user consent is required. The callback is passed a continuation function
- *     which must be called from an interactive event handler (e.g. "click").
+ * @param {remoting.Identity.ConsentDialog} consentDialog
  * @constructor
  */
-remoting.Identity = function(consentCallback) {
+remoting.Identity = function(consentDialog) {
   /** @private */
-  this.consentCallback_ = consentCallback;
+  this.consentDialog_ = consentDialog;
   /** @type {string} @private */
   this.email_ = '';
   /** @type {string} @private */
@@ -38,6 +36,21 @@ remoting.Identity = function(consentCallback) {
 };
 
 /**
+ * chrome.identity.getAuthToken must be initiated from user interactions if
+ * called with interactive equals true.  This interface prompts a dialog for
+ * the user's consent.
+ *
+ * @interface
+ */
+remoting.Identity.ConsentDialog = function() {};
+
+/**
+ * @return {Promise} A Promise that resolves when permission to start an
+ *   interactive flow is granted.
+ */
+remoting.Identity.ConsentDialog.prototype.show = function() {};
+
+/**
  * Call a function with an access token.
  *
  * @param {function(string):void} onOk Function to invoke with access token if
@@ -75,7 +88,7 @@ remoting.Identity.prototype.callWithNewToken = function(onOk, onError) {
     chrome.identity.removeCachedAuthToken(
         {'token': token },
         that.callWithToken.bind(that, onOk, onError));
-  };
+  }
 
   this.callWithToken(revokeToken, onError);
 };
@@ -206,19 +219,12 @@ remoting.Identity.prototype.onAuthComplete_ = function(interactive, token) {
   }
 
   // If there's no token, but we haven't yet prompted for permission, do so
-  // now. The consent callback is responsible for continuing the auth flow.
-  this.consentCallback_(this.onAuthContinue_.bind(this));
-};
-
-/**
- * Called in response to the user signing in to the web-app.
- *
- * @private
- */
-remoting.Identity.prototype.onAuthContinue_ = function() {
-  chrome.identity.getAuthToken(
-      { 'interactive': true },
-      this.onAuthComplete_.bind(this, true));
+  // now.
+  var that = this;
+  this.consentDialog_.show().then(function() {

[Jamie, 2015/01/29 01:52:34]

I really like this new Promise-based approach. As discussed, however, please
verify that {interactive: true} is expected to work if invoked asynchronously
(via Promise.resolve()) from a UI event handler.

[kelvinp, 2015/01/29 19:40:31]

Courage replied.  Turns out the user interaction is merely a UX guideline rather
than a restriction. Done.

+    chrome.identity.getAuthToken({'interactive': true},
+                                 that.onAuthComplete_.bind(that, true));
+  });
 };
 
 /**