remoting/webapp/crd/js/third_party_host_permissions.js

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /**
   6  * @fileoverview
   7  * Obtains additional host permissions, showing a consent dialog if needed.
   8  *
   9  * When third party authentication is being used, the client must talk to a
  10  * third-party server. For that, once the URL is received from the host the
  11  * webapp must use Chrome's optional permissions API to check if it has the
  12  * "host" permission needed to access that URL. If the webapp hasn't already
  13  * been granted that permission, it shows a dialog explaining why it is being
  14  * requested, then uses the Chrome API ask the user for the new permission.
  15  */
  16
  17 'use strict';
  18
  19 /** @suppress {duplicate} */
  20 var remoting = remoting || {};
  21
  22 /**
  23  * @constructor
  24  * Encapsulates the UI to check/request permissions to a new host.
  25  *
  26  * @param {string} url The URL to request permission for.
  27  */
  28 remoting.ThirdPartyHostPermissions = function(url) {
  29   this.url_ = url;
  30   this.permissions_ = {'origins': [url]};
  31 };
  32
  33 /**
  34  * Get permissions to the URL, asking interactively if necessary.
  35  *
  36  * @param {function(): void} onOk Called if the permission is granted.
  37  * @param {function(): void} onError Called if the permission is denied.
  38  */
  39 remoting.ThirdPartyHostPermissions.prototype.getPermission = function(
  40     onOk, onError) {
  41   /** @type {remoting.ThirdPartyHostPermissions} */
  42   var that = this;
  43   chrome.permissions.contains(this.permissions_,
  44     /** @param {boolean} allowed Whether this extension has this permission. */
  45     function(allowed) {
  46       if (allowed) {
  47         onOk();
  48       } else {
  49         // Optional permissions must be requested in a user action context. This
  50         // is called from an asynchronous plugin callback, so we have to open a
  51         // confirmation dialog to perform the request on an interactive event.
  52         // In any case, we can use this dialog to explain to the user why we are
  53         // asking for the additional permission.
  54         that.showPermissionConfirmation_(onOk, onError);
  55       }
  56     });
  57 };
  58
  59 /**
  60  * Show an interactive dialog informing the user of the new permissions.
  61  *
  62  * @param {function(): void} onOk Called if the permission is granted.
  63  * @param {function(): void} onError Called if the permission is denied.
  64  * @private
  65  */
  66 remoting.ThirdPartyHostPermissions.prototype.showPermissionConfirmation_ =
  67     function(onOk, onError) {
  68   /** @type {HTMLElement} */
  69   var button = document.getElementById('third-party-auth-button');
  70   /** @type {HTMLElement} */
  71   var url = document.getElementById('third-party-auth-url');
  72   url.innerText = this.url_;
  73
  74   /** @type {remoting.ThirdPartyHostPermissions} */
  75   var that = this;
  76
  77   var consentGranted = function(event) {
  78     remoting.setMode(remoting.AppMode.CLIENT_CONNECTING);
  79     button.removeEventListener('click', consentGranted, false);
  80     that.requestPermission_(onOk, onError);
  81   };
  82
  83   button.addEventListener('click', consentGranted, false);
  84   remoting.setMode(remoting.AppMode.CLIENT_THIRD_PARTY_AUTH);
  85 };
  86
  87
  88 /**
  89  * Request permission from the user to access the token-issue URL.
  90  *
  91  * @param {function(): void} onOk Called if the permission is granted.
  92  * @param {function(): void} onError Called if the permission is denied.
  93  * @private
  94  */
  95 remoting.ThirdPartyHostPermissions.prototype.requestPermission_ = function(
  96     onOk, onError) {
  97   chrome.permissions.request(
  98     this.permissions_,
  99     /** @param {boolean} result Whether the permission was granted. */
 100     function(result) {
 101       if (result) {
 102         onOk();
 103       } else {
 104         onError();
 105       }
 106   });
 107 };