AJAX pass custom field to jqXHR

Question

Is there a way to pass an extra field to the jqXHR object? Here my situation:

I'm returning a HttpResponseMessage like so:

response.ReasonPhrase = "someString " + Resources.Messages.NoData;
response.StatusCode = HttpStatusCode.NoContent;
return response;

But there are some cases I need to pass another StatusCode = HttpStatusCode.NoContent;, for a different reason:

response.ReasonPhrase = "anotherString " + Resources.Messages.NoMoreData;
response.StatusCode = HttpStatusCode.NoContent;
return response;

Because the messages are all localized (Resources.Messages) to the users language, I need an extra field to check for example if it equals to "someString " or "anotherString " or "...." in the AJAX success call back:

$.ajax({
type: 'POST',
url: '/api/testing/test',
data: jobject,
contentType: 'application/json',
success: function (data, status, xhr) {
    if (status == "nocontent" && xhr.statusText.startsWith("someString")) {
        // do something
    }
    if (status == "nocontent" && xhr.statusText.startsWith("anotherString")) {
        // do something
    }

error: function (xhr) {
    debugger;
    if (xhr.responseJSON == 'UnableToParseDateTime') {
        // do something
    }
}
});

The weird thing is, is that xhr.statusText doesn't support xhr.statusText.startsWith(). So equality checks on "someString " or "anotherString " or "...." doesn't work.

I've noticed that responseText is always empty in the success call back. If I can 'fill' that one from the server would be nice. If not, how can I have an extra field for the jqXHR object? Or define a few new custom HttpStatusCode?

Answer 1

I'm not sure if startsWith is standard javascript, but you can always add your own function to the String prototype (see this SO):

if (typeof String.prototype.startsWith != 'function') {
  String.prototype.startsWith = function(str) {
    return this.lastIndexOf(str, 0) === 0;
  };
}

Which will allow you to check any String with startsWith.

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To help with the question on adding to the jqXHR object, have you taken a look at the docs? You can modify the jqXHR object in the beforeSend function of the AJAX call.