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

[Jens Vagelpohl]

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