[CS3 JS] How to Create a Timer?

Question

Within InDesign I need to be able to fire a periodic process to examine links from a JavaScript script. I have my own script running in its own engine.
I can't figure out how to create a timer that will run in the background and call the appropriate callback function periodically.
I've created a little process like this:
* Sleeps for waitTime milliseconds then calls the callBack function.
function timer(callBack, waitTime) {
$.writeln("timer(): callBack=" + callBack + ", waitTime=" + waitTime);
if (waitTime == undefined) waitTime = 2000;
$.writeln("timer(): sleeping for " + waitTime + "...");
$.sleep(waitTime);
$.writeln("timer(): awake, calling callBack");
try {
return callBack();
} catch (e) {
$.writeln("timer(): Exception from callBack.exec(): " + e);
return undefined;
function myCallBack() {
return Window.confirm("Callback called", true, "Continue looping");
while (true) {
if (!timer(myCallBack)) break;
And this works in the sense that my timer runs, but it runs as a blocking process, which is not what I want.
Is there something I'm missing or is this simply not possible in CS3 JavaScript? A search on "timer" in the InDesign forums didn't reveal anything, nor did the InDesign JavaScript Guide nor the Scripting Tools Guide.
Thanks,
Eliot

Answer 1

1. Download and install Active Page Item Developer Toolkit.
http://www.rorohiko.com/wordpress/indesign-downloads/active-page-item-developer/
You'll have a demo period for 20 days or a month, I don't remember exactly.
2. Create a new document, open 'Active Page Item Developer' panel (Windows menu).
3. Copy the script from my previous post, draw an object - e.g. a rectangle and with the object selected enter 'idle' into Event Filter field, then press Tab and paste the script into the largest field.
You'll see an alert appearing every 10 seconds and the cursor flickering.