lib/goog/labs/useragent/engine.js

1// Copyright 2013 The Closure Library Authors. All Rights Reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//      http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS-IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15/**
16 * @fileoverview Closure user agent detection.
17 * @see http://en.wikipedia.org/wiki/User_agent
18 * For more information on browser brand, platform, or device see the other
19 * sub-namespaces in goog.labs.userAgent (browser, platform, and device).
20 *
21 */
22
23goog.provide('goog.labs.userAgent.engine');
24
25goog.require('goog.array');
26goog.require('goog.labs.userAgent.util');
27goog.require('goog.string');
28
29
30/**
31 * @return {boolean} Whether the rendering engine is Presto.
32 */
33goog.labs.userAgent.engine.isPresto = function() {
34  return goog.labs.userAgent.util.matchUserAgent('Presto');
35};
36
37
38/**
39 * @return {boolean} Whether the rendering engine is Trident.
40 */
41goog.labs.userAgent.engine.isTrident = function() {
42  // IE only started including the Trident token in IE8.
43  return goog.labs.userAgent.util.matchUserAgent('Trident') ||
44      goog.labs.userAgent.util.matchUserAgent('MSIE');
45};
46
47
48/**
49 * @return {boolean} Whether the rendering engine is WebKit.
50 */
51goog.labs.userAgent.engine.isWebKit = function() {
52  return goog.labs.userAgent.util.matchUserAgentIgnoreCase('WebKit');
53};
54
55
56/**
57 * @return {boolean} Whether the rendering engine is Gecko.
58 */
59goog.labs.userAgent.engine.isGecko = function() {
60  return goog.labs.userAgent.util.matchUserAgent('Gecko') &&
61      !goog.labs.userAgent.engine.isWebKit() &&
62      !goog.labs.userAgent.engine.isTrident();
63};
64
65
66/**
67 * @return {string} The rendering engine's version or empty string if version
68 *     can't be determined.
69 */
70goog.labs.userAgent.engine.getVersion = function() {
71  var userAgentString = goog.labs.userAgent.util.getUserAgent();
72  if (userAgentString) {
73    var tuples = goog.labs.userAgent.util.extractVersionTuples(
74        userAgentString);
75
76    var engineTuple = tuples[1];
77    if (engineTuple) {
78      // In Gecko, the version string is either in the browser info or the
79      // Firefox version.  See Gecko user agent string reference:
80      // http://goo.gl/mULqa
81      if (engineTuple[0] == 'Gecko') {
82        return goog.labs.userAgent.engine.getVersionForKey_(
83            tuples, 'Firefox');
84      }
85
86      return engineTuple[1];
87    }
88
89    // IE has only one version identifier, and the Trident version is
90    // specified in the parenthetical.
91    var browserTuple = tuples[0];
92    var info;
93    if (browserTuple && (info = browserTuple[2])) {
94      var match = /Trident\/([^\s;]+)/.exec(info);
95      if (match) {
96        return match[1];
97      }
98    }
99  }
100  return '';
101};
102
103
104/**
105 * @param {string|number} version The version to check.
106 * @return {boolean} Whether the rendering engine version is higher or the same
107 *     as the given version.
108 */
109goog.labs.userAgent.engine.isVersionOrHigher = function(version) {
110  return goog.string.compareVersions(goog.labs.userAgent.engine.getVersion(),
111                                     version) >= 0;
112};
113
114
115/**
116 * @param {!Array.<!Array.<string>>} tuples Version tuples.
117 * @param {string} key The key to look for.
118 * @return {string} The version string of the given key, if present.
119 *     Otherwise, the empty string.
120 * @private
121 */
122goog.labs.userAgent.engine.getVersionForKey_ = function(tuples, key) {
123  // TODO(nnaze): Move to util if useful elsewhere.
124
125  var pair = goog.array.find(tuples, function(pair) {
126    return key == pair[0];
127  });
128
129  return pair && pair[1] || '';
130};