[Asterisk-Dev] Making a variable available to a dialplan

[Steven Critchfield]

On Thu, 2004-10-21 at 14:11 -0400, David Filion wrote:
> >On Thu, 2004-10-21 at 11:46 -0400, David Filion wrote:
> >  
> >
> >>Hi,
> >>
> >>I need to create a variable in an app "global" so that I can refer to 
> >>its value in a dial plan.  What functions should I look at to do this?  
> >>Searching the archives didn't turn anything up.
> >>    
> OK, the situation.  Our company is sharing * with multiple small 
> companies. Our dial plan makes heavy use of patterns and DB look ups 
> (postgresql) to avoid having to hard code values, especially since a lot 
> of the dial plan is common to all the different companies.  The problem 
> we're run into to with the employee directories.  The directory reads 
> its values from voicemail.conf, using the context in voicemail.conf as 
> the context to jump to in extensions. conf.  This means that we need to 
> create a context in extensions.conf for every company,  duplicating a 
> lot of code.  Now, we've found a way to still divide each company into 
> separate contexts in voicemail.conf and have them all just to the same 
> context in extensions.conf.  However, we need access to the actual 
> extension number, which does not appear to be passed when the jump to 
> extensions is made. This appears to result from forcing the context to 
> jump to in extensions.  Confused yet? I know I am.
> 
> So, the idea is to store the values somewhere before the jump to 
> extensions is made and then query the stored value one in extensions.  
> Now, if this can be done with out changing any code, great. If not, then 
> tips/pointers are welcome as I'm not real familiar with the inner 
> workings of Asterisk yet.

Okay, so to modify your original request, you do NOT want a global
variable. A global variable would be prone to a race condition where you
have multiple callers in the directory at once and both ending up at the
same extension as the variable is available in both places. You would
want a channel variable so that each channel gets it's own information
and holds it private.

That is why explaining a bit more about what you want to do is
important.

I leave the rest of the question for someone more knowledgable in the
directory app to answer the rest.

-- 
Steven Critchfield <critch at basesys.com>