Re: [TWiki-Dev] [SVN] HaraldJoerg r11384 - in twiki/branches/TWikiRelease04x00: lib lib/TWiki tools

[Harald J. <ha...@oo...>]

Crawford Currie writes:

> [...]
>>>Added:
>>>  twiki/branches/TWikiRelease04x00/lib/TWiki/Config.pm
>>>Modified:
>>>  twiki/branches/TWikiRelease04x00/lib/TWiki.pm
>>>  twiki/branches/TWikiRelease04x00/tools/MANIFEST
>>>Log:
>>>Item2826: Extract reading of config files into a module to facilitate benchmarking
>>>
>>Good idea! But shouldn't that same module be used by *everything* that
>>reads the config (e.g =configure=)?
>>
> There's another reason I want this; when I was rewriting configure, I
> moved all the "TWiki.cfg specific" stuff into a single module, on the
> assumption that someone might some day want to write - for example -
> YAML or XML versions of the config DB. No specific plans, just trying to
> keep stuff consistently pluggable.

To be honest, I deliberately wanted to stay out of the way of the
configure refactoring right now.

   * TWiki.pm needs a method to pull in configuration data reasonably
     fast, since this is done for every request (unless a persistent
     interpreter is in place).  Both filenames and format have been
     hardwired into TWiki.pm, and now are in TWiki::Config.pm.
   * The SVN configure code reads the configuration in
     TWiki/Configure/Checkers/BasicSanity.pm, and probably somewhere in
     TWiki/Configure/TWikiCfg.pm (though I failed to spot the line up to
     now).  Neither of those looks suitable for the simple needs of
     TWiki.pm, which boils down to "fill %TWiki::cfg" - without need for
     params, nor objects, nor the bunch of modules used by TWikiCfg.pm.
   * So, a new subroutine was needed anyway. I agree that I could/should
     have put it into the TWiki/Configure directory, maybe as
     TWiki/Configure/TWikiCfg/ReadConfig.pm?

BTW, is there a Codev topic to describe and discuss the rewrite (other
than the extensions installer)?  I have a faint feeling that the new
treatment of LocalSite.cfg is calling for trouble: Currently (i.e. up to
4.0.4) LocalSite.cfg is rather simple, and it is tempting for an admin
to add custom code there.  Plugins (I know one case of
TWiki:Plugins/LoginNameAliasesPlugin) may need a global variable set in
the config files, and I've always used LocalSite.cfg instead of
TWiki.cfg for that.  In TWikiRelease04x00 SVN, LocalSite.cfg is written
from scratch each time, retaining only the values from %TWiki::cfg, so
LoginNameAliasesPlugin will stop to work after each invocation of
configure.
-- 
Cheers,
haj