Re: setHandler question

On 12/15/2012 01:30 PM, André Warnier wrote:
> And somehow the $r->add_config() looks a bit like a roundabout way of
> achieving what I want.  If I can, kind of, "stuff" an additional
> SetHandler configuration directive into the Apache configuration for my
> request, telling Apache "now do as if the <Location> contained a
> SetHandler directive", then why does the simpler $r->setHandler() not
> work ?

Perhaps that was the reason for ->add_config instead of ->handler. The
former sets the handler at the point in the request cycle when
SetHandler works, which I think is fixup. The latter acts at the point
of the call.

The point here is that modperl's PerlFixupHandler is registered with
APR_HOOK_REALLY_FIRST meaning it is called before (almost) all other
handlers. So, even if you use ->handler to set the handler to modperl
another module may decide to override your decision.

There is another glitch with mod_proxy here. A normal response handler
checks the content of ->handler to see if it is responsible to generate
the response. Not so mod_proxy. It relies on ->proxyreq:

In fact, where other modules do something like this to decide if they
are to generate the response:

    if(strcmp(r->handler, CGI_MAGIC_TYPE) &&
       strcmp(r->handler, "cgi-script"))
        return DECLINED;

mod_proxy does this:

    /* is this for us? */
    if (!r->proxyreq || !r->filename ||
        strncmp(r->filename, "proxy:", 6) != 0)
        return DECLINED;

I think what you want to do is to reconfigure a request previously set
up to be handled by mod_proxy, right? So, in that case you have to
either reset $r->proxyreq to 0 or reset $r->filename to NULL or to
change $r->filename to not start with "proxy:".

Torsten