Jquery Ajax post success/error function

Question

I have a post function that is not being caught on error.

Here's the value being returned from postride.php.

if ($group_id==0) {
echo 'No group selected';
return false;
exit;
}

Here's the jquery code:

$(document).ready(function(){
$('#postride').submit(function(event) {
     event.preventDefault();
     dataString = $("#postride").serialize();
     $.ajax({
        type: "post",
        url: "postride.php",
        data:dataString,
        error: function(returnval) {
            $(".message").text(returnval + " failure");
            $(".message").fadeIn("slow");
            $(".message").delay(2000).fadeOut(1000);
        },
        success: function (returnval) {
            $(".message").text(returnval + " success");
            $(".message").fadeIn("slow");
            $(".message").delay(2000).fadeOut(1000);    
            //setTimeout( function() { top.location.href="view.php" }, 3000 );  
        }
    })
    return false;
});

});

The post function returns false, but the error function does not fire, only the success function. It will post "No group selected success".

Thanks for any help!

Answer 1

wsanville is correct: "success" or "failure" refers to the success/failure of the ajax request.

Rather than changing up the HTTP header, though, I find it useful to return information in a json response. So for instance, I would have postride.php respond like so:

$error = false;
if ($group_id==0) {
    $error = 'No group selected';
}
$response = array('error'=>$error);
echo json_encode($response);

Then in the "success" callback of the JS, I would do this:

success: function (returnval) {
    if (returnval.error) {
      $(".message").text(returnval + " failure")
        .fadeIn("slow",function(){
            $(this).delay(2000).fadeOut(1000);
        });
    } else {
      //do whatever user should see for succcess
    }

Answer 2

The error option in jQuery ajax methods is for errors caused by a bad connection, timeout, invalid url, things of that nature. It's not the kind of error that you're thinking.

What most people do is something like this...

php

if ($group_id == 0) {
echo json_encode(array(
    'status' => 'error',
    'message'=> 'error message'
));
}
else
{
echo json_encode(array(
    'status' => 'success',
    'message'=> 'success message'
));
}

javascript

$(document).ready(function(){
$('#postride').submit(function(event) {
     event.preventDefault();
     dataString = $("#postride").serialize();
     $.ajax({
        type: "post",
        url: "postride.php",
        dataType:"json",
        data: dataString,
        success: function (response) {
            if(response.status === "success") {
                // do something with response.message or whatever other data on success
            } else if(response.status === "error") {
                // do something with response.message or whatever other data on error
            }
        }
    })
    return false;
});