#!/usr/bin/perl
use warnings;
use strict;
use XML::Twig;

my $twig= XML::Twig->new( twig_handlers =>
                          { 'RDF/Topic' => \&topic,
                            'RDF/ExternalPage' => \&extpage
                          }
                        );
$twig->parsefile( './sample.xml');
# my $base_dir = 'F:/httpserv';
# chdir $base_dir or die "Failed to chdir to $base_dir: $!\n";

{
  my %links;
  sub topic {
    my ( $twig, $topic ) = @_;
    if ( $topic->children('link')) {
#      my $dir = $topic->att('r:id');
#      chdir $dir or "Failed to chdir to $dir: $!\n";
      $links{ $_->att('r:resource') } = $_ for $topic->children('link');
    }
    else {
      %links = ();
    }
    $twig->purge;
  }

  sub extpage {
    my ( $twig, $extpage ) = @_;
    if ( exists $links{ $extpage->att( 'about' ) } ) {
      print $extpage->first_child_text('d:Title'), "\n";
      print $extpage->first_child_text('d:Description'), "\n";
    }
    $twig->purge;
#    chdir $base_dir or die "Failed to chdir to $base_dir: $!";
  }
}
__END__
British Horror Films: 10 Rillington Place
Review which looks at plot especially the shocking features of it.
MMI Movie Review: 10 Rillington Place
Review includes plot, real life story behind the film and realism in the film.