[core] error reporting/logging

[Chuck Hagenbuch]

[moving to dev]

Quoting Jon Parise <jon@horde.org>:

> > I think it is worth holding up 2.4.0 to do a _thorough_ revamp
> > of how we handle errors, and to at least make sure that they
> > are logged somewhere with as much information as possible.
> > Troubleshooting a lot of things is unnecessarily hard for
> > people at this point.
> 
> I agree.  Where would you like to start?

There are two areas in which we need to improve. One is how errors are 
displayed on the front end. That one I'm not as worried about; we can do that 
incrementally. What I think we need to do before release is to make sure that 
whenever there is an error, we log it to a global Horde log source. Not errors 
like being unable to create a folder - we already give the user the necessary 
information in that case, and I don't see a need to duplicate the IMAP server 
logs there (though I could be swayed). But when we fail to run a query, can't 
send mail, can't connect to a database, ldap server, etc. - then we need to log 
the error details so that admins have a place to get better information.

So, I propose:

1. a global Horde log source. Just a configuration section. I'll do it in a few.
2. a static method, Horde::logError(), which would hide the Log:: handle from 
   the global namespace, make sure it was instantiated, etc. Also easy, but 
   I'll wait for feedback.
3. Then we need to audit the code and add lots of calls to said method, 
   including error details, messages, anything we can.

Thoughts?

-chuck

--
Charles Hagenbuch, <chuck@horde.org>
"What was and what may be lie, like children whose faces we cannot see, in the 
arms of silence. All we ever have is here, now." - Ursula K. Le Guin