IE ajax methods don't return XMLHttpRequest in v1.4.x

[chris.raethke]

From v1.4.0 onwards, any calls to $.ajax(), $.get(), $.getJSON() and $.post() return null instead of an XMLHttpRequest under Internet Explorer 7.

[chris.raethke]

example of failure under ie

[copleykj]

This issue seems to be that IE doesn't properly implement the XMLHttpRequest object. Upon testing if window.XMLHttpRequest exists it is reported as true but upon trying to create a new instance it reports that it doesn't. I have personally fixed this for myself with a simple modification.

This code starts on line 4952 in the development version if you want to modify so it's useable. If you do, I would recommend using something like  http://refresh-sf.com/yui/ to compress it before you use it on your site

* Original Code *

xhr: window.XMLHttpRequest && (window.location.protocol !== "file:"

!window.ActiveXObject) ?

function() {

return new window.XMLHttpRequest();

} : function() {

try {

return new window.ActiveXObject("Microsoft.XMLHTTP");

} catch(e) {}

},

* New Function *

xhr: window.ActiveXObject ?

function() {

try {

return new window.ActiveXObject("Microsoft.XMLHTTP");

} catch(e) {}

} : function() {

return new window.XMLHttpRequest();

},

With the modification it checks to see if the browser implements the activex object xmlhttp instead and if available uses it first and XMLHttpRequest as a last resort. This may not be the best fix, BUT I need my sites to work in ALL major browsers as most people do.

[dmethvin]

Dup of #6298.