Intercept XHR requests for tracking ajax events.

intercept.js

(function(open){
	var targetURL = new RegExp('http://google.com');

	XMLHttpRequest.prototype.open = function(){
		this.addEventListener('readystatechange', function(){
			if(this.readyState !== 4) return;
			if(this.status < 200 || this.status >= 300) return;
			if(!targetURL.test(this.responseURL)) return;

      			// SUCCESS
			// code to execute here
		}, false);
		open.apply(this, arguments);
	}
})(XMLHttpRequest.prototype.open)