Question

my task is to do a long running JS code. This routine generate a POST request, and when its over and need to, generates another according to the answer:

function routine (a)
{
    var answer = createPostRequest (bla bla bla);
    if (answer)
    {
        routine (a);
    }
}

so it recursively calls itself as long as the answer is true. So far its good, but then browser freezes, or hangs too much. After a time, Firefox will tell me that script is running too long, and offers to stop it.
Instead of doing routine (a); I tried to do with a setTimeout with timing 1. The same things, but when I set 100 for timing, it looks ok. But there are unnecessarry waitings, plus its a subjective number (what if even that 100 causes problems?)
I need some kind of “message based” thing, like in Delphi/Windows programming: a program sends a message to itself. How can it be achived in JS?

Edit: the way I generating the request:

var ajax = createXmlHttp();
ajax.open ('POST', 'dsdsdsad.adsf', false);
var parameters = 'param=1';
ajax.setRequestHeader ('Content-type', 'application/x-www-form-urlencoded');
ajax.setRequestHeader ("Content-length", parameters.length);
ajax.setRequestHeader ("Connection", "close");
ajax.send (parameters);
try
{
    var answer = eval('(' + ajax.responseText + ')');
}
catch (error)
{
    alert ('Error in the answer: '+ajax.responseText);
    return;
}

Answer 1

I would assume your createPostRequest makes an AJAX call that can handle a callback.

If so, make sure the request is asynchronous and pass it a callback that tests the condition and makes the next call if needed.

function createPostRequest(address, callback) {
    var ajax = createXmlHttp();
    ajax.open ('POST', address, true); // make it async

    var parameters = 'param=1';
    ajax.setRequestHeader ('Content-type', 'application/x-www-form-urlencoded');
    ajax.setRequestHeader ("Content-length", parameters.length);
    ajax.setRequestHeader ("Connection", "close");

        // handle the async response
    ajax.onreadystatechange = function() {
                                if (ajax.readystate == 4) {
                                   try {
                                       callback(eval('(' + ajax.responseText + ')'));
                                   } catch {
                                       callback(null);
                                   }
                                }
                              };
    ajax.send (parameters);
}

---

function routine (a) {
    createPostRequest (bla bla bla, function(answer) {
        if (answer) {
            routine (a);
        }
    }
}