[Zope] Q: onLoad + onUnload...?

Mon, 30 Apr 2001 18:15:42 +0100

In tracking users online, in most applications you'd have a connection to
the server open, which the system can track to monitor who's online. Without
that, HTTP is a connectionless protocol, so you can't really track that.

An alternative to the onLoad and onUnload functions is to have registering
as online as part of the page loading, and to keep track of when someone was
last online - effectively set things up so that if there is no activity from
someone in a given period then they're online, and if they 'log out' of the
system then it explicitly marks them as offline.

That can provide some measure of functionality in itself, but you can set a
page to refresh regularly - often a zero size frame - which will then keep
someone signed in, and if they close the browser then after a minute or
whatever it recognises them as offline. It generates more traffic, but it
doesn't open any new windows.

David Burton

----- Original Message -----
From: "3dfestival - WebMaster" <thomas@3dfestival.com>
To: "zopeQ" <zope@zope.org>
Sent: Monday, April 30, 2001 12:14 PM
Subject: [Zope] Q: onLoad + onUnload...?

> My prob:
> I want to make a variable in DTML which counts the user online....
>
> I actually did do it, but in a crappy way:
>
>
> <body onLoad="addUser();" onUnload="subUser();">
>
> and I had made to functions in javscript:
>
> function addUser()
> {
> self.open('addU', 'counting users');
> }
>
> function subUser()
> {
> self.open('subU', 'counting users');
> }
>
> and to DTML-methods
>
> =====
> addU
> =====
> <html><head>
> <dtml-call "REQUEST.set ('uc, uc+1)">
> <script language="javascript">
> <!--self.close();--></script>
> </head><body></body></html>
> =====
> subU:
> =====
> <html><head>
> <dtml-call "REQUEST.set ('uc, uc-1)">
> <script language="javascript">
> <!--self.close();--></script>
> </head><body></body></html>
> =====
>
> and I added a porperty (integer) called uc...
>
> It worked fine, but it was very irritating for the users that a new window
> woukd open and then close every time the went from one place to
another....
>
> Now to my Q:
>
> Is there some way to do this javascript in DTML or PYTHON....?
> If so: How...?
>
> ( = Stoons = )
>  - Webmaster @ 3D festival (http://www.3dfestival.com)
>
>
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