// browser shim for xmlhttprequest module
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var hasCORS = require('has-cors');
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var globalThis = require('../globalThis');
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module.exports = function (opts) {
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var xdomain = opts.xdomain;
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// scheme must be same when usign XDomainRequest
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// http://blogs.msdn.com/b/ieinternals/archive/2010/05/13/xdomainrequest-restrictions-limitations-and-workarounds.aspx
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var xscheme = opts.xscheme;
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// XDomainRequest has a flow of not sending cookie, therefore it should be disabled as a default.
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// https://github.com/Automattic/engine.io-client/pull/217
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var enablesXDR = opts.enablesXDR;
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// XMLHttpRequest can be disabled on IE
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try {
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if ('undefined' !== typeof XMLHttpRequest && (!xdomain || hasCORS)) {
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return new XMLHttpRequest();
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}
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} catch (e) { }
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// Use XDomainRequest for IE8 if enablesXDR is true
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// because loading bar keeps flashing when using jsonp-polling
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// https://github.com/yujiosaka/socke.io-ie8-loading-example
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try {
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if ('undefined' !== typeof XDomainRequest && !xscheme && enablesXDR) {
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return new XDomainRequest();
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}
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} catch (e) { }
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if (!xdomain) {
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try {
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return new globalThis[['Active'].concat('Object').join('X')]('Microsoft.XMLHTTP');
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} catch (e) { }
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}
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};
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