There's a hook for processing your configuration and making any changes (offhand, post-config?). If any of this is done on a file or directory level, you can do that in your configuration merge callbacks. I have to do something similar where a forwarding capability might be enabled, but the location to forward is still null, etc.
Thanks, Rick Houser Auto-Owners Insurance Systems Support (517)703-2580 > -----Original Message----- > From: Ray Morris [mailto:supp...@bettercgi.com] > Sent: Thursday, August 13, 2009 10:13 AM > To: modules-dev@httpd.apache.org > Subject: Re: Defining mandatory parameters for Apache modules > > This may be a level problem. Are you thinking of throwing > an error if it's unset, or simply disabling the module for that > VirtualHost, directory, etc.? Pretty much any module must do > a check with each request to see if it should handle the request - > for example the module may be wanted in one virtual host and > ot another, so you typically have an "enable" directive like > RewriteEngine On. At configuration time, if you don't have > your required directive you don't enable your module. That's > how most standard modules work, it seems. For example if you > don't use AuthUserFile you simply don't authenticate against > any file. You say you don't want to check with each request, > but you already have to check whether or not your enabled with > each request, for most any module. Of course, if this required > directive is the only required directive, you can use it as > your "enabling" directive, without needing any "MeEnabled" > directive. > > However, I have a feeling, based on little but intuition, > that you can solve your actual problem by looking it from one > level higher or lower. Not knowing what your module is supposed > to do or what the directive is, I can't give any example of > looking at the problem from a higher level. At a lower level, > ask "how can I make a missing or default value work?". You've > said you don't want to do that, but think about it again. At > the higher level, back up to whatever the module is supposed > to accomplish - the business goal. How can that goal be > accomplished in a different manner that doesn' need the > directive? (IE, instead of asking "how can I buy a car to > get to work when I haven't gotten paid yet?", ask "how can I > get to work without having a car?"). > -- > Ray Morris > supp...@bettercgi.com > > Strongbox - The next generation in site security: > http://www.bettercgi.com/strongbox/ > > Throttlebox - Intelligent Bandwidth Control > http://www.bettercgi.com/throttlebox/ > > Strongbox / Throttlebox affiliate program: > http://www.bettercgi.com/affiliates/user/register.php > > > On 08/13/2009 08:34:42 AM, Raj Iyer wrote: > > > > > > Hello, > > > > > > > > The Apache web server on start up iterates through the list of > > configuration directives and invokes the associated module handler > > for > > each directive. > > > > > > > > For e.g. if module A has handlers for directives D1 and D2, then the > > httpd process on start up will invoke the handlers within module A > > when > > it encounters D1 and D2 in httpd.conf. > > > > > > > > However, what is the best way to find out missing mandatory > > parameters > > from within the module. For e.g. if a directive D3 is mandatory for > > the > > module to work, then how can the module on initialization guarantee > > that > > this configuration parameter is provided? > > > > > > > > I do not want to provide a default value for this mandatory > > configuration directive and also, I do not want to check > whether this > > mandatory directive is defined or not while handling each request. > > > > > > > > Thanks in advance, > > > > Best regards, > > > > Raj Iyer > > > > > > > > > > > >
