$.ajaxSetup Global Defaults or $.when Deferred Aggregation for jQuery Upgrade Recovery
Global AJAX defaults or deferred aggregation after a jQuery upgrade The goal is to recover AJAX error handling safely after upgrading jQuery without breaking unrelated scripts on the same page. One option is $.ajaxSetup to set timeout, headers, or error handling globally; the other is $.when to wrap multiple jqXHR objects and handle failures through a single