Question

Is there any common way, example or code template how to repeat a XHR that failed due to connection problems?
Preferably in jQuery but other ideas are welcome.

I need to send some application state data to a database server. This is initiated by the user clicking a button. If the XHR fails for some reason I need to make sure that the data is sent later (no interaction needed here) in the correct order (the user may press the button again).

Answer 1

jQuery provides an error callback in .ajax for this:

$.ajax({
    url: 'your/url/here.php',
    error: function(xhr, status, error) {
        //  The status returns a string, and error is the server error response.
        //  You want to check if there was a timeout:
        if(status == 'timeout') {
           $.ajax();
        }
    }
});

See the jQuery docs for more info.