use strict;
use warnings;

use XML::Twig qw( );

my $xml = <<'__EOI__';
<?xml version="1.0" encoding="UTF-8" standalone="no" ?>
<root xmlns:foo="uri:foo">
  <ele id="a" />
  <ele id="b" xmlns="uri:foo"/>
  <foo:ele id="c" />
</root>
__EOI__


{
   my $seen = '';

   my $t = XML::Twig->new(
      twig_handlers => {
         'ele' => sub { $seen .= $_->att('id') },
      },
   );
   $t->parsestring($xml);

   print("$seen\n");
   print($seen eq 'a'                   ? "Standard\n"   : "Not standard\n");
   print($seen eq 'a' || $seen eq 'abc' ? "Consistent\n" : "Not consistent\n");
}

print("\n");

{
   my $seen_null = '';
   my $seen_foo  = '';

   my $t = XML::Twig->new(
      map_xmlns => {
         'uri:foo' => 'f',
      },
      twig_handlers => {
         'ele'     => sub { $seen_null .= $_->att('id') || $_->att('f:id') },
         'f:ele'   => sub { $seen_foo  .= $_->att('id') || $_->att('f:id') },
      },
   );
   $t->parsestring($xml);

   print("$seen_null:$seen_foo\n");
   print($seen_null eq 'a'                        ? "Standard\n"   : "Not standard\n");
   print($seen_null eq 'a' || $seen_null eq 'abc' ? "Consistent\n" : "Not consistent\n");
   print($seen_foo eq 'bc'                        ? "NS working\n" : "NS broken\n");
}

##</code><code>##

ab
Not standard
Not consistent

a:bc
Standard
Consistent
NS working