How can I elegantly handle devise's 401 status in AJAX?

Question

With devise one uses before_filter :authenticate_user! to restrict access to authenticated users only.

When an unauthenticated

Answer 1

As of Rails 5.1 and the new rails-ujs, all custom events return only one parameter: event. In this parameter, there is an additional attribute detail which contains an array of extra parameters. The parameters data, status, xhr have been bundled into event.detail. So handling the 401 error in ajax with the ajax:error event becomes:

document.body.addEventListener('ajax:error', function(event) {
  var detail = event.detail;
  var response = detail[0], status = detail[1], xhr = detail[2];
  if (xhr.status == 401) {
    // handle error
  }
})