Webapp changes to support third party authentication

remoting/webapp/third_party_host_permissions.js

+// Copyright 2013 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
+ * Obtains additional host permissions, showing a consent dialog if needed.
+ *
+ * When third party authentication is being used, the client must talk to a
+ * third-party server. For that, once the URL is received from the host the
+ * webapp must use Chrome's optional permissions API to check if it has the
+ * "host" permission needed to access that URL. If the webapp hasn't already
+ * been granted that permission, it shows a dialog explaining why it is being
+ * requested, then uses the Chrome API ask the user for the new permission.
+ */
+
+'use strict';
+
+/** @suppress {duplicate} */
+var remoting = remoting || {};
+
+/**
+ * @constructor
+ * Encapsulates the UI to check/request permissions to a new host.
+ *
+ * @param {string} url The URL to request permission for.
+ */
+remoting.ThirdPartyHostPermissions = function(url) {
+  this.url_ = url;
+  this.permissions_ = {'origins': [url]};
+};
+
+/**
+ * Get permissions to the URL, asking interactively if necessary.
+ *
+ * @param {function(): void} onOk Called if the permission is granted.
+ * @param {function(): void} onError Called if the permission is denied.
+ */
+remoting.ThirdPartyHostPermissions.prototype.getPermission = function(
+    onOk, onError) {
+  /** @type {remoting.ThirdPartyHostPermissions} */
+  var that = this;
+  chrome.permissions.contains(this.permissions_,
+    /** @param {boolean} allowed Whether this extension has this permission. */
+    function(allowed) {
+      if (allowed) {
+        onOk();
+      } else {
+        // Optional permissions must be requested in a user action context. This
+        // is called from an asynchronous plugin callback, so we have to open a
+        // confirmation dialog to perform the request on an interactive event.
+        // In any case, we can use this dialog to explain to the user why we are
+        // asking for the additional permission.
+        that.showPermissionConfirmation_(onOk, onError);
+      }
+    });
+};
+
+/**
+ * Show an interactive dialog informing the user of the new permissions.
+ *
+ * @param {function(): void} onOk Called if the permission is granted.
+ * @param {function(): void} onError Called if the permission is denied.
+ * @private
+ */
+remoting.ThirdPartyHostPermissions.prototype.showPermissionConfirmation_ =
+    function(onOk, onError) {
+  /** @type {HTMLElement} */
+  var button = document.getElementById('third-party-auth-button');
+  /** @type {HTMLElement} */
+  var url = document.getElementById('third-party-auth-url');
+  url.innerText = this.url_;
+
+  /** @type {remoting.ThirdPartyHostPermissions} */
+  var that = this;
+
+  var consentGranted = function(event) {
+    remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
+    button.removeEventListener('click', consentGranted, false);
+    that.requestPermission_(onOk, onError);
+  };
+
+  button.addEventListener('click', consentGranted, false);
+  remoting.setMode(remoting.AppMode.CLIENT_THIRD_PARTY_AUTH);
+};
+
+
+/**
+ * Request permission from the user to access the token-issue URL.
+ *
+ * @param {function(): void} onOk Called if the permission is granted.
+ * @param {function(): void} onError Called if the permission is denied.
+ * @private
+ */
+remoting.ThirdPartyHostPermissions.prototype.requestPermission_ = function(
+    onOk, onError) {
+  chrome.permissions.request(
+    this.permissions_,
+    /** @param {boolean} result Whether the permission was granted. */
+    function(result) {
+      if (result) {
+        onOk();
+      } else {
+        onError();
+      }
+  });
+};