Pooya Karimian

I posted about the new PersianJS code in the Persian Computing mailing list. What I've done is to change the code to work in Firefox/Mozilla browsers besides IE, this means allowing Linux/Mac users to use it too.

For catching keypress events and changing them to another key with javascript in Internet Explorer, there's a variable named window.event.keyCode that can both be used both for reading the pressed key and also for changing it to another key.

In Mozilla/Firefox the key code is in a variable named event.which which is defined only in the context of event handler.

The following examples only work in Firefox/Mozilla. The first one shows how to read the key value:

<input type="text" size=20 onkeypress="alert(event.which);">

<script type="text/javascript">
 function newKey(event) {
     if (event.which==0x23) return;
     var new_event=document.createEvent("KeyEvents");
     new_event.initKeyEvent("keypress", false, true, document.defaultView, false, false, false, false, 0, 0x23);
     event.preventDefault();
     event.target.dispatchEvent(new_event);
 }
</script>
<form action=""><input type="text" size="20" onkeypress="newKey(event)"></form>

Using a simple method for detecting browser type, such as testing for the existance of window.event object, it is possible to write multibrowser codes. PersianJS is a complete example.

Update Aug 5, 2005: Seems like because of a vulnerability initKeyEvent is disabled from Firefox 1.0.6 as you can see in bug #289940. I'm too busy but I will try to write a complete description and comment on that bug hoping that this feature return back to Firefox.

Update March 1, 2007: It's been a while that the bug is fixed. But the syntax for initKeyEvent is changed. You can no longer change the current event but instead you can create a new event and cancel the old one. I fixed the above code to reflect that.