closure_preinit.js revision cedac228d2dd51db4b79ea1e72c7f249408ee061 
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 */
14window.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 */
20window.CLOSURE_NO_DEPS = true;
21
22/**
23 * Array of urls that should be included next, in order.
24 * @type {Array}
25 * @private
26 */
27window.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 */
34window.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};
95