In the template code:

<script type="text/javascript">
var xmlhttp=false;
/*@cc_on @*/
if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
    xmlhttp = new XMLHttpRequest();
}
function myfunction(username) {
    var params = "rm=remove&username="+username;
    var objectlist = document.getElementById(objectlist);
    // rm is the node we want to remove from the DOM
    var rm = document.getElementById(username);
    // The true attribute means the script continues after
    // the post has been executed
    xmlhttp.open("POST", '/my/runmode/', true);
    xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-u
+rlencoded");
    xmlhttp.setRequestHeader("Connection","close");
    // Connection is to be closed after transfer
    xmlhttp.onreadystatechange=function() {
        if (xmlhttp.readyState==4) {
            // Delete the html node when request is complete
            rm.parentNode.removeChild(rm);
        }
    }
    xmlhttp.send(params);
}
</script>
<ul id="objectlist">
[% FOREACH object = objects %]
  <p id="[% object.username %]">[% object.username %] -
    <a href="#" 
      onclick="myfunction('[% object.username %]');">   
    remove</a>
  </p>
[% END %]
</ul>
[download]

Meanwhile in my CGI::App handler...

sub setup {
    my $self = shift;
    $self->start_mode('default');
    $self->run_modes( [ qw( default remove ) ] );
}

sub remove {
    my $self = shift;
    my $user =
    My::User->retrieve(
        username => $self->query->param('username')
    );
    $user->delete;
}
[download]

There exist some modules on CPAN for JSON conversion into and out of perl, but a) JSON doesn't fully work on older browsers (like IE's older than 6), and b) we'd written a version (which produces much uglier javascript that works on older versions of IE) well before JSON became a buzzword, itself.

I don't know what to tell you, exactly... some folks might be working on some clever tools, somewhere, that present a useful abstraction on AJAX, but I know that I (and my team) just deal with the complexities of it. Granted we've built some tools (you know, some simple javascript libraries to manage the synchronous and the asynchronous http requests and such). But these are just tools to make the task easier, nothing that really abstracts away the fact that there are these requests coming and going, triggered by DHTML events and so on. I don't know if anyone else has.

------------
:Wq
Not an editor command: Wq
[download]

There really isn't much difference to building a script that handles an AJAX request compared to a regular request. The main difference is that the AJAX request usually returns XML, or possibly just a small snippet of HTML.

The hard part around AJAX is the JavaScript side (since I am a perl developer, JavaScript is hard ;). There are already some JavaScript libraries out there that can really simplify this. I've used one called Sarissa that works pretty well, but I haven't done enough in this area to recommend the "best" JavaScript library out there. Just do some searching.

If you want an example using CGI::Application, then you can have a look at my attempt at building an Upload Meter (something like Apache::UploadMeter). It is just a prototype, so there isn't much in the way of documentation, but it does show how you can do AJAX with CGI::Application (as you will notice, it is no different from a regular CGI::Application module). Here is a tarball of the entire prototype.

I would like to wrap this up in a simple to use module at some point, but time is my enemy right now :)

The JS side is where things get interesting. I personally use HTML::Prototype and the Prototype JavaScript library for my AJAX work. (I have documentation for this forthcoming.)

Yep, I would say it is. I didn't phrase the question quite right--I just meant that I was looking for a general answer to what people were doing to apply AJAX-type thinking to their perl-based CGI applications.

I have tried the perl AJAX Module but I am not getting successful in this and finding it very complex.
I have tried the example given on link :
http://www.perl.com/pub/a/2006/03/02/ajax_and_perl.html?page=2
But it is not working completely.
It would be a great help if you could provide some working easy example to understand the basics of CGI::AJAX.
Many thanks
-Vivek