in reply to Extracting XML data from a tree

Not Twig but Simple: 

use strict;
use warnings;
use XML::Simple;

my $xml = XMLin( 'CC.xml' );
for (@{ $xml->{Week}{Day} }) {
  print $_->{Times}{Time}{'start-time'},"\n" if $_->{'day-of-week'} eq
+ "Tuesday";
}

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Re^2: Extracting XML data from a tree
by Jenda (Abbot) on Jun 05, 2013 at 08:30 UTC

    See Simpler than XML::Simple.

    Your code would break if there were multiple <Time> tag in one <Times>. Here's one of the ways to do this with XML::Rules. It handles the multiple <Time> tags and stops processing the XML once it finds the requested day.

    use strict;
use XML::Rules;
use Data::Dumper;

my $parser = XML::Rules->new(
    strispaces => 7,
    rules => {
        Time => 'as array',
        Times => 'pass',
        'Day' => sub {
            my ($tag_name, $attrs, $context, $parent_data, $parser) = 
+@_;
            if ($attrs->{'day-of-week'} eq $parser->{parameters}) {
                $parser->return_this(join(', ', grep( defined($_), map
+ $_->{'start-time'}, @{$attrs->{Time}})));
            }
        },
        Month => sub{}
    }
);

my $time = $parser->parse(\*DATA, 'MondayX');

print "Time: $time\n";


__DATA__
<?xml version="1.0" encoding="utf-8"?>
  <Month>
    <Week>

    [download]

    Jenda
    Enoch was right!
    Enjoy the last years of Rome.

[reply]
[d/l]

      Agreed. The story does not look as favorable for XML::Simple anymore if the structure changes. If one makes it more robust using ForceArray => 1, then at least one more loop is required: 

      my $xml = XMLin( 'CC.xml', ( ForceArray => 1 ) );
for my $day (@{ $xml->{Week}[0]{Day} }) {
  next unless $day->{'day-of-week'} eq "Tuesday";
  for my $time ( @{ $day->{Times}[0]{Time} } ) {
    print $time->{'start-time'},"\n" if exists $time->{'start-time'};
  }
}

      [download]

      Not really so "simple" anymore...

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