I have code like:

            try {
                LoadingStart();
                const result = await $.ajax({
                    type: 'Get',
                    url: url,
                    data: data,
                });
                LoadingEnd();
                window.location.replace(result.redirectUrl);
            } catch (err) {
                LoadingEnd();
                console.error('MyFunction', err);
            }

The exception, when logged comes out like

Object { readyState: 0, getResponseHeader: getResponseHeader(a), getAllResponseHeaders: getAllResponseHeaders(), setRequestHeader: setRequestHeader(a, b), overrideMimeType: overrideMimeType(a), statusCode: statusCode(a), abort: abort(a), state: state(), always: always(), catch: catch(a), … }

How do I get the detail of an await AJAX exception?

I have tried 'err.message' but it seems to be undefined. I was expecting a text showing the error reason. I found detail by not using await with try/catch, instead using the AJAX error function that takes in the xhr and the exception. I would like the same kind of detail in the exception caught.

I have code like:

            try {
                LoadingStart();
                const result = await $.ajax({
                    type: 'Get',
                    url: url,
                    data: data,
                });
                LoadingEnd();
                window.location.replace(result.redirectUrl);
            } catch (err) {
                LoadingEnd();
                console.error('MyFunction', err);
            }

The exception, when logged comes out like

Object { readyState: 0, getResponseHeader: getResponseHeader(a), getAllResponseHeaders: getAllResponseHeaders(), setRequestHeader: setRequestHeader(a, b), overrideMimeType: overrideMimeType(a), statusCode: statusCode(a), abort: abort(a), state: state(), always: always(), catch: catch(a), … }

How do I get the detail of an await AJAX exception?

I have tried 'err.message' but it seems to be undefined. I was expecting a text showing the error reason. I found detail by not using await with try/catch, instead using the AJAX error function that takes in the xhr and the exception. I would like the same kind of detail in the exception caught.

• javascript
• ajax

• 2 Have you checked the response in your network tab? – mykaf Commented 4 hours ago
• Your LoadingEnd() call (or something like it) probably should be in a finally clause. – Pointy Commented 3 hours ago

1 Answer 1

When using await $.ajax(...), a failure doesn’t throw a typical JavaScript Error object but instead rejects with the jqXHR object returned by jQuery. That object doesn’t include a standard message property, so trying to access err.message returns undefined.

To get the error details, inspect the jqXHR object’s properties. For example:

err.status – The HTTP status code (e.g., 404, 500). err.statusText – The corresponding status text (e.g., "Not Found", "Internal Server Error"). err.responseText – The text of the response from the server (often contains the error message). You can modify your catch block like this:

catch (err) {
    LoadingEnd();
    console.error('AJAX error:', err.status, err.statusText);
    console.error('Response:', err.responseText);
}