[Zope] Sending an alarm message to all logged-in users

[Dennis Allison]

We have a fairly complex multi-frame presentation.  As I indicated, 
I could do it by doing a test, but that's costly in our particular 
situation.  I'm looking for something a bit lower overhead.

On Sun, 17 Oct 2004, Jens Vagelpohl wrote:

> On Oct 17, 2004, at 18:14, Tino Wildenhain wrote:
> 
> > Hi,
> >
> > Am So, den 17.10.2004 schrieb Dennis Allison um 17:52:
> >> Occasionally I have wished for a mechanism that would allow me to 
> >> write
> >> all logged-in users.  Of course, this could be acomplished with an
> >> explicit test, but making the test costs a lot of overhead.   Is 
> >> there a
> >> better way?
> >
> > HTTP is stateless. There is no such thing like "logged in".
> > Calls are only send from client to server, never the
> > other way round. Thus, you cannot "send" something to all
> > users.
> 
> One way to fake this out (as Tino already says, the concept of "logged 
> in user" is kind of meaningless) would be to have a slot in your main 
> template that would display something if...
> 
> - the current visitor has sent valid login information for the request 
> (meaning the user for the duration of the request is not "Anonymous 
> User")
> 
> - you fill some variable, maybe a property at the site root, or change 
> a script that returns something, with your message.
> 
> Those things can be tested for easily.
> 
> jens
> 
> _______________________________________________
> Zope maillist  -  Zope at zope.org
> http://mail.zope.org/mailman/listinfo/zope
> **   No cross posts or HTML encoding!  **
> (Related lists - 
>  http://mail.zope.org/mailman/listinfo/zope-announce
>  http://mail.zope.org/mailman/listinfo/zope-dev )
>