#!/usr/bin/perl

use strict;
use warnings;

use XML::Twig;

my $t= XML::Twig->new( twig_roots => { 'Collection[@Type="CustomProperty"]' => \&collection},
                       twig_print_outside_roots => 1,   
                     );
$t->parsefile( $ARG[0]);

exit;

sub collection
  { my ($t, $collection)= @_;
    foreach my $sub_record ($collection->children( 'SubRecord'))
      { my $name  = $sub_record->field( 'Property[@Name="Name"]');
        my $value = $sub_record->field( 'Property[@Name="Value"]');
        # we want to keep thæ attributes (except Name of course)
        my $atts  = $sub_record->first_child( 'Property[@Name="Value"]')->atts;
        delete $atts->{Name};
        my $property= XML::Twig::Elt->new( $name, $atts, $value);
        $property->replace( $sub_record);
      }
     $collection->print;
  }