my @columns = qw(parentNodeId nodeId level canode label);

my $CSV = <<'*END*';
0,1,0,blah,bloh
1,2,1,foo,faaa
1,3,1,bar,barrar
2,4,2,baz,bazbaz
2,5,2,aaa,aaaaa
3,6,2,bbb,bbbbbbab
4,7,3,zzz,zzzzz
*END*

my (%sections, $root);

my @navmod = split /\n/, $CSV;

foreach my $line (@navmod) {
	my %current;
	@current{@columns} = split /,/, $line;

	delete $current{level};

	my $nodeId = $current{nodeId};
	$sections{$nodeId} = \%current;

	my $parentNodeId = delete $current{parentNodeId};
	if ($parentNodeId) {
		push @{$sections{$parentNodeId}{section}}, \%current;
	} else {
		$root = \%current;
	}
}

use XML::Rules;

my $parser = XML::Rules->new( rules => []);

print $parser->ToXML(section => $root, 0, '  ');

##</code><code>##

my @columns = qw(parentNodeId nodeId level canode label);

my (%sections, $root);

while (my $line = <DATA>) {
	chomp($line);
	my %current;
	@current{@columns} = split /,/, $line;

	delete $current{level};

	my $nodeId = $current{nodeId};
	my $parentNodeId = delete $current{parentNodeId};

	if ($sections{$nodeId}) {
		%{$sections{$nodeId}} = ( %current, %{$sections{$nodeId}});
	} else {
		$sections{$nodeId} = \%current;
	}

	if ($parentNodeId) {
		push @{$sections{$parentNodeId}{section}}, $sections{$nodeId};
	} else {
		$root = $sections{$nodeId};
	}
}

use XML::Rules;

my $parser = XML::Rules->new( rules => []);

print $parser->ToXML(section => $root, 0, '  ');

__DATA__
3,6,2,bbb,bbbbbbab
1,2,1,foo,faaa
2,4,2,baz,bazbaz
2,5,2,aaa,aaaaa
1,3,1,bar,barrar
4,7,3,zzz,zzzzz
0,1,0,blah,bloh