Smarty jQuery/Ajax call barrier - ajax

Question

I'm modifying an existing system which uses Smarty. This particular problem is causing a major stumbling block as I just can't find a way around it.
I have a data-grid, each record has an action which calls ?module=the_module&action=the_action.
My corresponding function function the_module_the_action($postData, $getData) is used to perform the particular request.
The request for this module comes through from a jQuery $.ajax({}) request, simply because I don't want to loose the search form variables. So on success, I'll redirect the page using document.location='index.php?module=&action='.
This is fine as it allows me to detect that the action has been successful whilst maintaining the search filters on the grid.
But, I have a problem when the user action fails. The method the_module_the_action($postData, $getData) return echo 'success'; exit() on success but on a failure it should print out the Smarty template i.e. details of the record.
I believe the problem occurs because of a call through Ajax. The template is being served but because it is a call made using Ajax it isn't displayed.
How can I get around this problem?
Update:-
This is my function which Ajax calls:
public function module_action($post_data) {
$object=new Class((int)$post_data["id"]);
if($object->method()) {
echo "success";
exit();
}
else {
$this->assignToSmarty('_someSmartyVar', $someData);
$this->assignToSmarty('_data', $class->getData());
echo "failed";
}
}
The Ajax used to call this is:-
$(document).ready(function() {
$(".revokeButton").click(function(){
var selected=$(this).attr('id');
var filterBu = $('#filter_bu').val();
var filterJc = $('#filter_jc').val();
if(confirm("Are you sure you want to r.....")) {
$.ajax({
beforeSend: function() { },
url: 'index.php?module=module&action=action',
type: 'POST',
data: ({ bid:selected }),
cache: false,
success: function(data, textStatus) {
if(data == 'success') {
success_message = 'success';
} else if(data == 'failed') {
success_message = 'failed';
}
document.location='index.php?module=module&message='+success_message+'&filter_bu='+filterBu+'&filter_jc='+filterJc;
}
});
}
});
});
The success and failure are echoing out successfully, but the smarty stuff isn't.

Answer 1

I see two problems. First of all, you seem to have forgotten the smarty->display() function call in the failure leg of the module_action function. Secondly, you wrote:
if(data == 'success') {
success_message = 'success';
} else if(data == 'failed') {
success_message = 'failed';
}
This will always only output success or failure. You probably want to do something more like the following:
if(data == 'success') {
success_message = 'success';
} else {
// if got here, 'data' doesn't contain "success!", so it must contain
// something else, likely error data. You could either just display
// data as it is or first do some sort of check to ensure that it
// does, in fact, contain error data, and then display it.
success_message = 'error!<br \>\n' + data;
}