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1// NOTICE!! DO NOT USE ANY OF THIS JAVASCRIPT
2// IT'S JUST JUNK FOR OUR DOCS!
3// ++++++++++++++++++++++++++++++++++++++++++
4/*!
5 * Copyright 2014 Twitter, Inc.
6 *
7 * Licensed under the Creative Commons Attribution 3.0 Unported License. For
8 * details, see http://creativecommons.org/licenses/by/3.0/.
9 */
10// Intended to prevent false-positive bug reports about Bootstrap not working properly in old versions of IE due to folks testing using IE's unreliable emulation modes.
11(function () {
12 'use strict';
13
14 function emulatedIEMajorVersion() {
15 var groups = /MSIE ([0-9.]+)/.exec(window.navigator.userAgent)
16 if (groups === null) {
17 return null
18 }
19 var ieVersionNum = parseInt(groups[1], 10)
20 var ieMajorVersion = Math.floor(ieVersionNum)
21 return ieMajorVersion
22 }
23
24 function actualNonEmulatedIEMajorVersion() {
25 // Detects the actual version of IE in use, even if it's in an older-IE emulation mode.
26 // IE JavaScript conditional compilation docs: http://msdn.microsoft.com/en-us/library/ie/121hztk3(v=vs.94).aspx
27 // @cc_on docs: http://msdn.microsoft.com/en-us/library/ie/8ka90k2e(v=vs.94).aspx
28 var jscriptVersion = new Function('/*@cc_on return @_jscript_version; @*/')() // jshint ignore:line
29 if (jscriptVersion === undefined) {
30 return 11 // IE11+ not in emulation mode
31 }
32 if (jscriptVersion < 9) {
33 return 8 // IE8 (or lower; haven't tested on IE<8)
34 }
35 return jscriptVersion // IE9 or IE10 in any mode, or IE11 in non-IE11 mode
36 }
37
38 var ua = window.navigator.userAgent
39 if (ua.indexOf('Opera') > -1 || ua.indexOf('Presto') > -1) {
40 return // Opera, which might pretend to be IE
41 }
42 var emulated = emulatedIEMajorVersion()
43 if (emulated === null) {
44 return // Not IE
45 }
46 var nonEmulated = actualNonEmulatedIEMajorVersion()
47
48 if (emulated !== nonEmulated) {
49 window.alert('WARNING: You appear to be using IE' + nonEmulated + ' in IE' + emulated + ' emulation mode.\nIE emulation modes can behave significantly differently from ACTUAL older versions of IE.\nPLEASE DON\'T FILE BOOTSTRAP BUGS based on testing in IE emulation modes!')
50 }
51})();