25 Sep
2009
25 Sep
'09
9:10 p.m.
On Fri, Sep 25, 2009 at 1:04 PM, Jan Janak <jan(a)ryngle.com> wrote:
On Fri, Sep 25, 2009 at 12:17 AM, Grzegorz
Stanislawski
<stangrze(a)netitel.pl> wrote:
That's not trivial to implement anymore, unlike my simplified proposal
with '$' above. It's not only about the parser, you have to change the
way how you pass parameters to the query in the module and that's the
more complicated part. I am not saying that it is difficult to do, but
it takes some planning and coding.
And if we eventually do something like this, I'd prefer to do that one
little extra step and implement support for selects, PVs, and AVPs
instead of escape sequences like %1 and %2. The query from your
example might then look like this:
select ... where user=(a)authorization.username and domain=(a)from.uri.host
Internally escape sequences like %1 and %2 would almost always be
resolved to selects or PVs anyway simply because there are so many of
them, they are convenient to use and they can extract almost anything
from SIP messages or the proxy environment.
And I forgot to mention that patches are very much welcome, so if you
implement any of this, I'd be happy to include it.
Thanks! Jan.
Maybe we
could start by implementing the easier
version, that would give us the possibility to configure the query
string but not its parameters. That's trivial to implement. Later we
could add support for arbitrary parameters that are resolved to AVPs,
selects, PVs, whatever.
Version capable of resolving variables would be very useful for accounting,
and this is actually already done for db_extra modparam.
While having variable resolving for lookup queries might be overkill
especially that in some cases some PVs or AVPs are not yet known which may
lead to errors and confusion, i'd suggest not to trivialize it to syntax of
mysql_prepare. Having well defined %1 %2 or something like this, would allow
to for example use
"select .. from credentials where user=%1 and domain=%2" when multidomain
support is enabled and "select .. .. where user=%1" when not.
simple parser in module init could change % macros to ? and add certain keys
to list for further execution.