frodo2014 has asked for the wisdom of the Perl Monks concerning the following question:

As the title suggests, I (think) I know what I'm doing wrong, but I haven't got the foggiest idea how to fix it. I humbly present my .pl : 
#!/usr/bin/perl

use 5.014;
use strict;
use warnings;
use autodie;
use AppConfig qw(:all);
use Data::Dumper;

$AppConfig::configFile='/home/john/tmp/config.xml';

my %config=getAPPConfig();

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and my .pm 
#!/usr/bin/perl

package AppConfig;

use 5.014;
use strict;
use warnings;
use autodie;

use Exporter qw(import);

# Module specific imports
use XML::Twig;

our $VERSION     = 1.00;
our @ISA         = qw(Exporter);
our @EXPORT_OK   = qw(getAppConfig);
our %EXPORT_TAGS = (
               'all' => \@EXPORT_OK,
           ); 

our $configFile;

sub getAppConfig {

my (%config,$twig,$root);
say $AppConfig::configFile;
$twig = XML::Twig->new();
$twig->parsefile->($AppConfig::configFile);
$root = $twig->root;

$config{'ppSK'}=$root->first_child('pp')->first_child('ppSK')->text;

return \%config;

}

# End.....
1;

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Now... when I run it, I get this.... 
/home/john/tmp/config.xml
Use of uninitialized value in -f at /usr/share/perl5/XML/Twig.pm line 
+697.
Couldn't open :
No such file or directory at AppConfig.pm line 30
 at AppConfig.pm line 30

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So the variable scope seems to be ok because "say $AppConfig::configFile;" outputs.... but then the same variable passed to XML::Twig seems to cause all hell to break loose. So here I am, submitting myself to the lions as another newbie to be devoured.

Replies are listed 'Best First'.
Re: Another noob making a mess of variable scope....
by toolic (Bishop) on Feb 17, 2014 at 15:23 UTC
    The problem has nothing to do with scope. You are calling parsefile incorrectly. Change: 
    $twig->parsefile->($AppConfig::configFile);

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    to: 

    $twig->parsefile($AppConfig::configFile);

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Re: Another noob making a mess of variable scope....
by tobyink (Canon) on Feb 17, 2014 at 16:04 UTC

    As well as what toolic said, your function is returning a reference to a hash (i.e. a scalar), but when you call your function you assign it to a hash.

    Either replace return \%config with return %config, or replace my %config=getAPPConfig() with my %config=%{getAPPConfig()} (but don't do both).

    use Moops; class Cow :rw { has name => (default => 'Ermintrude') }; say Cow->new->name
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Re: Another noob making a mess of variable scope....
by frodo2014 (Initiate) on Feb 17, 2014 at 21:09 UTC
    Thanks all !
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Re: Another noob making a mess of variable scope....
by walto (Pilgrim) on Feb 18, 2014 at 17:28 UTC
    If you want a more object oriented approach you can modify App::Config like this 
    #!/usr/bin/perl
#
#
use strict;
use warnings;

package AppConfig;

use 5.014;
use strict;
use warnings;
use autodie;
use Carp;
use Exporter qw(import);

# Module specific imports
use XML::Twig;

our $VERSION     = 1.00;
our @ISA         = qw(Exporter);
our @EXPORT_OK   = qw(getAppConfig);
our %EXPORT_TAGS = ( 'all' => \@EXPORT_OK, );

sub new {
    my $class         = shift;
    my $self          = {};
    my %passed_params = @_;
    croak "Please provide filename\n" unless (defined $passed_params{f
+ilename});
    $self->{filename}= $passed_params{filename};
    
    bless( $self, $class );
    return $self;
}

sub getAppConfig {
    my ($self) = @_;
    my ( %config, $twig, $root );
    $twig = XML::Twig->new();
    $twig->parsefile->( $self->{filename} );
    $root = $twig->root;

    $config{'ppSK'} =
      $root->first_child('pp')->first_child('ppSK')->text;

    return \%config;
}
# End.....
1;

    [download]

    And use the module like this
    #!/usr/bin/perl

use 5.014;
use strict;
use warnings;
use autodie;
use AppConfig qw(:all);
use Data::Dumper;

my $app_config = AppConfig->new('filename' => '/home/john/tmp/config.x
+ml');

my %config=getAPPConfig();

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Re: Another noob making a mess of variable scope....
by fishmonger (Chaplain) on Feb 17, 2014 at 16:18 UTC

    In addition to the already mentioned issues, you've declared $configFile but never assigned it a value so the $twig->parsefile statement won't have a file to parse.

    Oops, I missed the assignment statement in the script. Forget what I said.

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