[asterisk-dev] AEL, GoSub and DIALPLAN_EXISTS() do not like each other!

[Kirill Katsnelson]

AEL does not offer this feature of .conf scripts.

Practical example. We are using many customer "applications". An 
application name is also a queue name, among a few other things. Also, 
there is an optional per-customer set-up macro, invoked like this:

     if (${DIALPLAN_EXISTS("setup-${CUSTAPP}",s,1)}) {
       GoSub(setup-${CUSTAPP},s,1);
     }

Now, GoSub() causes a warning when compiling AEL file. Something we 
could live up to now. But the use of `s' here is relying on undocumented 
behavior of AEL.

So, between 1.8.1.1 and 1.8.3.rc2 it changed. Macros are no longer using 
the `s' extension as their entry point, rather `~~s~~'. That seems like 
a completely internal affair between AEL compiler and the dialplan, but 
thinking along these lines means there is no such an optional gosub 
feature in AEL at all.

Or I can test for both `s' and `~~s~~' in the script, to maintain the 
hack compatible both with 1.8.1 and 1.8.3, but obviously I do not like 
that either.

There should be a clean and documented way of doing exactly that. Going 
AEL should not mean self-limiting to fewer features of Asterisk.

  -kkm