Cross browser and cross framework solution for listening to XML Http requests. From http://stackoverflow.com/questions/23674175/in-javascript-how-can-i-test-if-any-ajax-call-is-running-in-the-background-at-a/23674587#23674587

Ajax_status.js

 var oldXHR = XMLHttpRequest.prototype.send;

    XMLHttpRequest.prototype.send = function () {
        //Insert code to run when new XHR request is created
        XHRCreated();
        oldXHR.apply(this, arguments);

        var oldReadSta = this.onreadystatechange;
        this.onreadystatechange = function () {
            oldReadSta.apply(this, arguments);
            if (this.readyState == 4 && this.status == 200) {
                //Insert code to run when the XHR request is completed
                XHRClosed();
            }
        }
    }
    
    function XHRCreated()
    {
      alert('XML HTTP request created');
    }
    
    function XHRClosed()
    {
      alert('XML HTTP request completed');
    }