chrome/browser/resources/cryptotoken/textfetcher.js

   1 // Copyright 2014 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 Implements a simple XmlHttpRequest-based text document
   7  * fetcher.
   8  *
   9  */
  10 'use strict';
  11
  12 /**
  13  * A fetcher of text files.
  14  * @interface
  15  */
  16 function TextFetcher() {}
  17
  18 /**
  19  * @param {string} url The URL to fetch.
  20  * @param {string?} opt_method The HTTP method to use (default GET)
  21  * @param {string?} opt_body The request body
  22  * @return {!Promise<string>} A promise for the fetched text. In case of an
  23  *     error, this promise is rejected with an HTTP status code.
  24  */
  25 TextFetcher.prototype.fetch = function(url, opt_method, opt_body) {};
  26
  27 /**
  28  * @constructor
  29  * @implements {TextFetcher}
  30  */
  31 function XhrTextFetcher() {
  32 }
  33
  34 /**
  35  * @param {string} url The URL to fetch.
  36  * @param {string?} opt_method The HTTP method to use (default GET)
  37  * @param {string?} opt_body The request body
  38  * @return {!Promise<string>} A promise for the fetched text. In case of an
  39  *     error, this promise is rejected with an HTTP status code.
  40  */
  41 XhrTextFetcher.prototype.fetch = function(url, opt_method, opt_body) {
  42   return new Promise(function(resolve, reject) {
  43     var xhr = new XMLHttpRequest();
  44     var method = opt_method || 'GET';
  45     xhr.open(method, url, true);
  46     xhr.onloadend = function() {
  47       if (xhr.status != 200) {
  48         reject(xhr.status);
  49         return;
  50       }
  51       resolve(xhr.responseText);
  52     };
  53     xhr.onerror = function() {
  54       // Treat any network-level errors as though the page didn't exist.
  55       reject(404);
  56     };
  57     if (opt_body)
  58       xhr.send(opt_body);
  59     else
  60       xhr.send();
  61   });
  62 };