chrome/browser/resources/chromeos/chromevox/closure/closure_preinit.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 Code to execute before Closure's base.js.
   7  *
   8  */
   9
  10 /**
  11  * Tell Closure to load JavaScript code from the extension root directory.
  12  * @type {boolean}
  13  */
  14 window.CLOSURE_BASE_PATH = chrome.extension.getURL('/closure/');
  15
  16 /**
  17  * Tell Closure not to load deps.js; it's included by manifest.json already.
  18  * @type {boolean}
  19  */
  20 window.CLOSURE_NO_DEPS = true;
  21
  22 /**
  23  * Array of urls that should be included next, in order.
  24  * @type {Array}
  25  * @private
  26  */
  27 window.queue_ = [];
  28
  29 /**
  30  * Custom function for importing ChromeVox scripts.
  31  * @param {string} src The JS file to import.
  32  * @return {boolean} Whether the script was imported.
  33  */
  34 window.CLOSURE_IMPORT_SCRIPT = function(src) {
  35   // Only run our version of the import script
  36   // when trying to inject ChromeVox scripts.
  37   if (src.indexOf('chrome-extension://') == 0) {
  38     if (!goog.inHtmlDocument_() ||
  39         goog.dependencies_.written[src]) {
  40       return false;
  41     }
  42     goog.dependencies_.written[src] = true;
  43     function loadNextScript() {
  44       if (goog.global.queue_.length == 0)
  45         return;
  46
  47       var src = goog.global.queue_[0];
  48
  49       if (window.CLOSURE_USE_EXT_MESSAGES) {
  50         var relativeSrc = src.substr(src.indexOf('closure/..') + 11);
  51         chrome.extension.sendMessage(
  52             {'srcFile': relativeSrc},
  53             function(response) {
  54               try {
  55                 eval(response['code']);
  56               } catch (e) {
  57                 console.error('Script error: ' + e + ' in ' + src);
  58               }
  59               goog.global.queue_ = goog.global.queue_.slice(1);
  60               loadNextScript();
  61             });
  62         return;
  63       }
  64       window.console.log('Using XHR');
  65
  66       // Load the script by fetching its source and running 'eval' on it
  67       // directly, with a magic comment that makes Chrome treat it like it
  68       // loaded normally. Wait until it's fetched before loading the
  69       // next script.
  70       var xhr = new XMLHttpRequest();
  71       var url = src + '?' + new Date().getTime();
  72       xhr.onreadystatechange = function() {
  73         if (xhr.readyState == 4) {
  74           var scriptText = xhr.responseText;
  75           // Add a magic comment to the bottom of the file so that
  76           // Chrome knows the name of the script in the JavaScript debugger.
  77           scriptText += '\n//# sourceURL=' + src + '\n';
  78           eval(scriptText);
  79           goog.global.queue_ = goog.global.queue_.slice(1);
  80           loadNextScript();
  81         }
  82       };
  83       xhr.open('GET', url, false);
  84       xhr.send(null);
  85     }
  86     goog.global.queue_.push(src);
  87     if (goog.global.queue_.length == 1) {
  88       loadNextScript();
  89     }
  90     return true;
  91   } else {
  92     return goog.writeScriptTag_(src);
  93   }
  94 };