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get a supported XHR instance
function(
a // cursor placeholder
){
for( // for all a
a = 3; // from 3
a--; // to 0,
) try { // try
return new( // returning a new
this.XMLHttpRequest // XMLHttpRequest (w3c)
|| // or
ActiveXObject // ActiveXObject (MS)
)([ // reflecting
"Msxml2", // the
"Msxml3", // various
"Microsoft"][a] + // MS flavors
".XMLHTTP" // and appropriate suffix,
)
}
catch(e){} // and ignore when it fails.
}
function(a){for(a=3;a--;)try{return new(this.XMLHttpRequest||ActiveXObject)(["Msxml2","Msxml3","Microsoft"][a]+".XMLHTTP")}catch(e){}}
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
Version 2, December 2004
Copyright (C) 2011 Jed Schmidt <http://jed.is>
Everyone is permitted to copy and distribute verbatim or modified
copies of this license document, and changing it is allowed as long
as the name is changed.
DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
0. You just DO WHAT THE FUCK YOU WANT TO.
{
"name": "getXHR",
"description": "get a supported XHR instance",
"keywords": [
"ajax",
"XHR",
"cross-browser",
"XmlHttpRequest"
]
}
@tsaniel
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tsaniel commented Jul 11, 2011

function(a){for(a=3;a--;)try{return new(this.XMLHttpRequest||ActiveXObject)(["Msxml2","Msxml3","Microsoft"][a]+".XMLHTTP")}catch(e){}}

My solution with saving 3 bytes.

@jed
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jed commented Jul 12, 2011

interesting... are you sure this won't interfere with normal operation of XMLHttpRequest?

@tsaniel
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tsaniel commented Jul 12, 2011

I am not sure but I think it won't because XMLHttpRequest.length returns 0 (just ignore the arguments object). Actually it seems working well.

@jed
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jed commented Jul 12, 2011

is the this needed for some reason?

@tsaniel
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tsaniel commented Jul 13, 2011

It is needed. If the XMLHttpRequest doesn't exist in the global object, the browsers will throw an error, but this.XMLHttpRequest(the this here is actually window) will be undefined instead and go to ActiveXObject.

@jed
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jed commented Jul 13, 2011

awesome, i've reflected the change. thanks @tsaniel!

@atk
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atk commented Jul 13, 2011

Just for the records, is there any IE version without a native XMLHttpRequest and support for Microsoft.XMLHTTP?

@tsaniel
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tsaniel commented Jul 13, 2011

It's quite confusing indeed. According to http://msdn.microsoft.com/en-us/library/ms537505(v=vs.85).aspx#_id , I think we can simply use new ActiveXObject('MSXML2.XMLHTTP.3.0').

@jed
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jed commented Jul 13, 2011

yikes, really? since this code was ported from PPK, i'm inclined to think it's good enough for now.

@tsaniel
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tsaniel commented Jul 13, 2011

So just keep the code unchanged... until someone finds another better solution.

@atk
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atk commented Jul 13, 2011

So instead of the current function, we could simply use

(function(){try{return new(this.XMLHttpRequest||ActiveXObject)('MSXML2.XMLHTTP.3.0')}catch(e){}}

@yckart
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yckart commented Jul 29, 2013

@atk It should be:

(function(){try{return new(this.XMLHttpRequest||ActiveXObject)('MSXML2.XMLHTTP.3.0')}catch(e){}}());

@Xeoncross
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Xeoncross commented Nov 26, 2013

I took the liberty to extend the code just a bit more (even if it isn't 140bytes anymore).

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