gistfile1.txt

(function() {
  var originalRequest = Ext.Ajax.request;
  
  Ext.Ajax.request = function(o) {
    if (!(/config\/environment/.test(o.url))) {
      o.url = String.format("/myprependString/{0}", o.url.replace(/^\//, ''));
    }
    
    return originalRequest.call(this, o);
  };
})();