Ajax: How to prevent jQuery from calling the success event after executing xmlHttpRequest.abort();

Question

Using jQuery\'s $.ajax() function. Wherether the request has been purposely aborted, or if the server is down (not responding) it appears the same outcome happens;

Answer 1

The best solution to have only one request is assigning the return value of your $.ajax call to a variable, e.g. currentRequest, and then, inside your success(data, responseCode, xhr) function, checking if(xhr == currentRequest) and returning early if the check failed. When aborting you simply set currentRequest to null so the check fails.

This ensures an old request is never handled which is especially important if you do e.g. long polling and restart the request as soon as it has finished (you really don't want two "pollers" running at the same time due to an aborted request starting a new one).