Recreating jQuery's ajaxStart and ajaxComplete functionality

Question

I\'m trying to reproduce jQuery\'s functions ajaxComplete and ajaxStart without jQuery so that they could be used in any environment with no library dependencies (it\'s a sp

Answer 1

Using .onreadystatechange wasn't working because I was testing with jQuery and jQuery's ajax methods manipulate and removes the onreadystatechange property.

However, adding an event listener for loadend works just fine everywhere but IE. For IE, I set up an interval instead - not the optimal solution, but it works for my needs. I only intended this script to work on IE8+ and modern browsers.

XMLHttpRequest.prototype.send = (function(orig){
    return function(){
        _core._fireAjaxEvents('pre', this._HREF);

        if (!/MSIE/.test(navigator.userAgent)){
            this.addEventListener("loadend", function(){
                _core._fireAjaxEvents('post', this._HREF);
            }, false);
        } else {
            var xhr = this,
            waiter = setInterval(function(){
                if(xhr.readyState && xhr.readyState == 4){
                    _core._fireAjaxEvents('post', xhr._HREF);
                    clearInterval(waiter);
                }
            }, 50);
        }

        return orig.apply(this, arguments);
    };
})(XMLHttpRequest.prototype.send);