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discuss » AJAX plugin does not work in IE6

Posted: Wed Mar 1 14:38:47 EST 2006
From: John Resig <jeresig at gmail.com >

Hmmm, yeah, that seems like a smart way to go about it - make things a
little bit quicker for everyone, I'd imagine. Alright, I'll see if I
can add this in, soon.

--John

On 3/1/06, Jim Dabell <jim-jquery.com at jimdabell.com> wrote:
>
> > So, I've adjusted the code to no longer use them, pushed the code live
> > - and I can confirm that it works in both browsers. You can check it
> > for yourself, here:
> > http://jquery.com/demo/ajax/
>
> I've had a look at the code, and have a couple of suggestions.
>
> Firstly, according to Yahoo's library¹, there's more than just two ProgIds to
> try and instantiate.
>
> Secondly, you might be able to make the code a bit smaller and quicker by
> checking for a native XMLHttpRequest constructor and generating an
> XMLHttpRequest function when it isn't there that just tries to instantiate
> the ActiveX objects.
>
> Something like the following (untested) should work:
>
> var progId = null;
> var progIds = [
> 'MSXML2.XMLHTTP.5.0',
> 'MSXML2.XMLHTTP.4.0',
> 'MSXML2.XMLHTTP.3.0',
> 'MSXML2.XMLHTTP',
> 'Microsoft.XMLHTTP'
> ];
>
> if (typeof XMLHttpRequest == "undefined") {
> function XMLHttpRequest() {
> var obj = null;
> if ( progId ) {
> return new ActiveXObject(progId);
> }
> for (var i = 0, id; id = progIds[i]; ++i) {
> try {
> obj = new ActiveXObject(id);
> progId = id;
> return obj;
> } catch ( e ) {}
> }
> return null;
> }
> }
>
> Then .xml() can be simplified to:
>
> $.xml = function( type, url, data, ret ) {
> type = type || "GET";
> var xmlhttp = new XMLHttpRequest();
>
> if ( !xmlhttp ) return;
>
> xmlhttp.open(type, url, true);
>
> if ( data )
> xmlhttp.setRequestHeader('Content-Type',
> 'application/x-www-form-urlencoded; charset=UTF-8');
>
> if ( ret )
> xmlhttp.onreadystatechange = function() {
> if ( xmlhttp.readyState == 4 ) ret(xmlhttp);
> };
>
> xmlhttp.send(data)
> };
>
> This is just off the top of my head to give you an idea of what I mean, you
> might have to bash it a bit to get it working.
>
> This means that Internet Explorer doesn't check for a native implementation
> every time it tries to instantiate an XMLHttpRequest object, and it remembers
> which ProgId is used so it doesn't have to search for the right one each
> time.
>
> ¹ Yahoo's XMLHttpRequest implementation (BSD licensed):
> <http://developer.yahoo.net/yui/connection/docs/overview-summary-connection.js.html>
> <http://developer.yahoo.net/yui/license.txt>
>
> --
> Jim
>
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> discuss at jquery.com
> http://jquery.com/discuss/
>


--
John Resig
http://ejohn.org/
jeresig at gmail.com