------
We are the carpenters and bricklayers of the Information Age.

The idea is a little like C++ templates, except not quite so brain-meltingly complicated. -- TheDamian, Exegesis 6

Please remember that I'm crufty and crochety. All opinions are purely mine and all code is untested, unless otherwise specified.

foreach my $entry (@{$self->{valuePair}})
{
     print "value=", $entry->{value}, $/;
     print "targetPo=", $entry->{targetPo}, $/;    
}
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Thanks for the advice about using parsers. I'll look into them once I've got this problem fixed. The xml is output from another program I wrote a while ago, so I understand what should be there. As for my current problem, when I run code, the Perl interpreter points to the first print line you had, and says: Not a HASH reference ... I went here with the debugger, and saw this

x $self
0  POSwitch=HASH(0x1bc4c8)
   'Id' => 'tp_incoming.vsd.10.Switch'
   'Object' => 'Mailbox.gender'
   'poName' => 'POSwitch'
   'valuePair' => ARRAY(0x1a7b94)
      0  SCALAR(0xc79d8)
         -> HASH(0xc7984)
            'targetPo' => 'ERROR000'
            'value' => 'xdefault'
      1  SCALAR(0xc7a5c)
         -> HASH(0xc79e4)
            'targetPo' => 'tp_incoming.vsd.10.Menu'
            'value' => 'Mailbox.GENDER_MALE'
      2  SCALAR(0xc7a8c)
         -> HASH(0xc7a68)
            'targetPo' => 'tp_incoming.vsd.10.Menu.9'
            'value' => 'Mailbox.GENDER_FEMALE'
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and

  DB<4> x $entry
0  SCALAR(0xc79d8)
   -> HASH(0xc7984)
      'targetPo' => 'ERROR000'
      'value' => 'xdefault'
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It's almost, but not quite there! ...regan

Trying to parse XML yourself isn't only non-productive, it's boring and tedious. Creating on the fly objects, however, is fun and exciting. Why bother with boring and tedious when you jump to fun stuff?

For example, let's run your sample XML through XML::Simple. I'll use the built-in DATA filehandle, so if you run this be sure you include it:

use XML::Simple;
use Data::Dumper;

my $xml = XMLin(\*DATA);
print Dumper $xml;

__DATA__
<ObjectType>
   <AppObject>hello</AppObject>
   <AppObjectField>gender</AppObjectField>
   <valueTargetPair value="MALE" targetPo="Incoming 1" />
   <valueTargetPair value="FEMALE" targetPo="Incoming 2" />
</ObjectType>
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When run on a computer that has XML::Simple installed, you should see something like:

$VAR1 = {
  'AppObject' => 'hello',
  'valueTargetPair' => [
    {
      'value' => 'MALE',
      'targetPo' => 'Incoming 1'
    },
    {
      'value' => 'FEMALE',
      'targetPo' => 'Incoming 2'
    }
  ],
  'AppObjectField' => 'gender'
};
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Now ... let's turn it into an object:

my $xml = XMLin(\*DATA);
bless $xml, $xml->{AppObject};
warn unless ref $xml eq 'hello';
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Done. ;) But don't be fooled. $xml is still a reference to an anonymous hash reference, it just also happens to "BE A" 'hello' object. Now, let's run tadman's code on this (with a couple of modifications), but this time i won't bother blessing it, since there is no reason to for this simple example:

my $xml = XMLin(\*DATA);
foreach my $entry (@{$xml->{valueTargetPair}})
{
     print "value=", $entry->{value}, $/;
     print "targetPo=", $entry->{targetPo}, $/;
}
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This prints:

value=MALE
targetPo=Incoming 1
value=FEMALE
targetPo=Incoming 2
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Hope this convinces you to stick with parsers for parsing XML. The work has not only already been done, it's been tried and tested. ;)

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

To get back to your original question, which is a data structure problem, a regex solution sort of like the following ought to work (and of course, filling the data structure via an official XML parser module should work in a similar way). I put this into a simple-minded harness to test it out -- you'll need to complicate it a bit, I'm sure.

#!/usr/bin/perl

use strict;
use Data::Dumper;

my %hash;
my $self = \%hash;

while (<DATA>) {  
    if ( m{<(\w+)>([^<]+)</\1>} ) { # a content element
        $$self{$1} = $2;  # store the content keyed by tag name
    }
    elsif ( m{<(\w+) ([^>]+)/>} ) { # an "empty" element
        my ($elem,$attr) = ($1,$2); # get tag name and attributes
        my %attrhash;
        while ( $attr =~ s/(\w+)="([^"]+)"// ) {
            $attrhash{$1} = $2;
        }
        push @{$$self{$elem}}, \%attrhash; # expect multiple instances
    }
}

print Dumper( $self );

# here's one way to access the structure's contents:

for my $tag ( sort keys %$self ) {
    if ( ref( $$self{$tag} ) eq 'ARRAY' ) {
        for ( @{$$self{$tag}} ) { # $_ is now an array element contain
+ing a hash ref
            for my $attr ( sort keys %{$_} ) {
                print "$tag : $attr = $$_{$attr}\n";
            }
        }
    }
    else {  # the tag had a plain string as content
        print "$tag = $$self{$tag}\n";
    }
}

__DATA__
<ObjectType>
   <AppObject>hello</AppObject>
   <AppObjectField>gender</AppObjectField>
   <valueTargetPair value="MALE" targetPo="Incoming 1" />
   <valueTargetPair value="FEMALE" targetPo="Incoming 2" />
</ObjectType>
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You'll want to study up on the "perlref" (and "perlreftut") man pages, if you haven't done that yet.

update: jeffa's solution is of course the correct one -- having studied that (as I should have done sooner), I conclude that my own proposed code is unnecessarily complicated and obscure. Do be sure to notice that jeffa solved the problem you were having with references.

Why push the hashes onto a list? You could just push the values and then refer to the list as a hash (right?) or you could just build a hashref and point $self->{valuePair} to it. If you want to have multiple values per key then just make it a hashref with lists as the values.

my $theHash;
if ($inline =~ /<valueTargetPair (.*)\/>/) {
   if ($inline =~ /value=\"(.*?)\" targetPo=\"(.*?)\"/) {
      push @{$theHash->{$1}},$2;
   }
}
$self->{valuePair} = $theHash;
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