use Module (LIST) and 'import'

eXile has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I'm trying to make some stuff in my module configurable via AppConfig but can't get it to work. What I'd like to do is give it a configfile like this:

use Blah ( Config => '/home/me/config.txt' );
[download]

My code: module Blah:

package Blah;
use AppConfig;
my $config = AppConfig->new();

sub import {
        my (%args) = @_;
        if ( $args{'Config'} ) {
                $config->file($args{'Config'});
        }
        #### next few lines for testing only
        use Data::Dumper;
        print Dumper(\%args);
}

use Othermodule ( Config => $config );
[download]

If I add 'use Blah (Config => "/configfile")' to my code it doesn't seem to pass the config to 'Othermodule'. Where am I going wrong?

Comment on use Module (LIST) and 'import' Select or Download Code

Replies are listed 'Best First'.
Re: use Module (LIST) and 'import' by duff (Parson) on Nov 30, 2004 at 21:08 UTC
You don't understand the order in which things are executed I think. The `use OtherModule` part happens before `$config` is modified by `import`. Remember that `use Blah qw(foo)` is shorthand for `BEGIN { require Blah; import Blah qw(foo); }`. The `use Othermodule` happens when you `require Blah` which is before `import` has had a chance to run. duff	[reply] [d/l] [select]
Re^2: use Module (LIST) and 'import' by eXile (Priest) on Nov 30, 2004 at 22:04 UTC
OK that's clear, thanks! Is there some other way to achieve my goal of being able to specify a config-parameter in a 'use'-statement and be able to pass it to other modules?	[reply]
Re^3: use Module (LIST) and 'import' by Stevie-O (Friar) on Dec 01, 2004 at 00:32 UTC
This can be done like so: `package Blah; use AppConfig; my $config = AppConfig->new(); sub import { my (%args) = @_; if ( $args{'Config'} ) { $config->file($args{'Config'}); } require OtherModule; OtherModule->import(Config => $config); #### next few lines for testing only use Data::Dumper; print Dumper(\%args); }` [download] --Stevie-O `$"=$,,$_=q>\|\p4<6 8p<M/_\|<('=> .q>.<4-KI<l\|2$<6%s!<qn#F<>;$, .=pack'N',"@{[unpack'C',$_] }"for split/</;$_=$,,y[A-Z a-z] {}cd;print lc` [download]	[reply] [d/l] [select]
Re: use Module (LIST) and 'import' by ysth (Canon) on Dec 01, 2004 at 05:45 UTC
In addition to the execution order problem, you also need to adjust for the fact that import is called as a method call (e.g. Blah->import(Config=>'/home/me/config.txt') in your case), so the first thing in @_ is the name of the used module. You should have: `my ($pkg, %args) = @_;`	[reply] [d/l]
Re: use Module (LIST) and 'import' by rrwo (Friar) on Dec 02, 2004 at 01:00 UTC
The use line is called during compilation, so $config is not yet set. Try the following: `BEGIN { $config = AppConfig->new(); } use Othermodule ( Config => $config );` [download]	[reply] [d/l]