jQuery ajax generic error handling and on a case-by-case basis

Question

I have a generic ajax Error handler written like so:

$('html').ajaxError(function(e, xhr, settings, exception) {

    var message = '';

    if (xhr.status == 0) {
        message = 'You are offline!\n Please check your network.';
    }
    else if (xhr.status == 403) {
        window.location.href = $('#logon').attr('href');
    }
    else if (xhr.status == 404) {
        message = 'Requested URL not found.';
    }
    else if (xhr.status == 500) {

        message = xhr.responseText;

        $('#cboxLoadedContent div.news_article_content').append('<p>' + message + '</p>');

        try {//Error handling for POST calls
            message = JSON.parse(xhr.responseText);
        }

        catch (ex) {//Error handling for GET calls
            message = xhr.responseText;
        }

    }
    else if (errStatus == 'parsererror') {
        message = 'Error.\nParsing JSON Request failed.';

    }
    else if (errStatus == 'timeout') {
        message = 'Request timed out.\nPlease try later';
    }
    else {
        message = ('Unknown Error.\n' + xhr.responseText);
    }

    if (message != '' && xhr.status != 500) {
        message = message;
    }

    if (xhr.status != 403) {

        $('#icis_dashboard').append('<p id="ajax_error_msg" class="offScreen">' + message + '</p>');

        errorBox({
            inline: true,
            width: 0,
            href: '#ajax_error_msg',
            onLoadCall: function() { $('#cboxLoadedContent').jScrollPaneRemove(); },
            onCleanupCall: function() { $('#ajax_error_msg').remove(); }
        });
    }

});

So when the error is not 403 a dialog is shown with text relating to the error.

This is fine but what iwould like to do is have the generic handler as a backup and then deal with each error on an individual basis within the original ajax call.

so as the backup handler alerts "bar" on a 404 i would like to alert "foo" instead:

            error: function(xhr) {
            if (xhr.status == 404) {
                //window.location.href = $('#logon').attr('href');
                alert("foo");    
            }
        }

I sthere anyway to do this? I don't know how to prevent the backup from firing as they both seem to trigger at the moment.

Answer 1

You can set the ajax property "global" to false in the ajax function that does it's own error handling. That should prevent global error handling. Check: http://api.jquery.com/jQuery.ajax#toptions.

Answer 2

I don't think you can control this with jQuery. The global ajaxError gets called on any error that happens during an ajax call. However, the "local" error callback gets called before the global callback so you could set a variable that tells the global callback not to run.

For instance:

var handledLocally = false;

$('html').ajaxError(function(e, xhr, settings, exception) {
    if (!handledLocally){
        //run the normal error callback code and the reset handledLocally
    }
});

error: function(){
    //set handledLocally to true to let the global callback it has been taken care of
    handledLocally = true;
}

You can view this jsFiddle that shows how this can be accomplished (be sure to click run at the top before clicking the links): http://jsfiddle.net/e7By8/