[Javascript] AJAX and variable assignment?

Sun Apr 26 07:27:21 CDT 2009

Hello,

I'm using AJAX (prototype.js) and I'm having problems wrapping my head
around how to assign a variable in my code -- because no matter what I
try the variable remains undefined.  I assume this is because of AJAX
being asynchronous but am not quite sure how to assign variables in
this context.  Ideally I'd like to *not* set asynchronous to false
(and I'm not even convinced that asynch being false will work w/Firefox
3.0.x).

My end goal is to build a menu from innerHTML of an object that was
updated via AJAX.  Given what I've observed above, it appears that
while I can use AJAX to update the UI with the text/HTML that I'd
intended, when I look at object.innerHTML, it shows the *old* HTML not
the *new* HTML that I'd put inside of it.  For example:

<html>
 <head>
   <title>Ajax test</title>

   <script src="javascript/prototype.js"></script>
   <script type="text/javascript">
       var assign_it = null;

       function do_ajax() {
           var url = '/testjs1.cgi';
           var pars = 'ajax=1'
           var myAjax = new Ajax.Request(
               url,
               {
                   method: 'get',
                   parameters: pars,
                   onComplete: function(http) {
                       assign_it = http.responseText;
                       $('starter').innerHTML = assign_it;
                   }
               });
           alert("after " + " " + assign_it + " " + $('starter').innerHTML);
       }
   </script>
 </head>

 <body>
   <p id="starter">I am the start condition.</p>
   <input type="submit" onclick="do_ajax()"/>
 </body>
</html>

In the HTML above, do_ajax() updates the UI with the output of my CGI
program (the string "I've been touched by AJAX") but
$('starter').innerHTML still contains "I am the start condition".  The
same holds true when I look at the DOM Inspector in Firefox 3.0.x.
:-(

Does anyone have any suggestions as to how I can do the variable
assignment that I propose?

--
NP

-- 
Nathan Patwardhan