BUU has asked for the wisdom of the Perl Monks concerning the following question:

I spent an hour or two writing this up last night, it took a while for me to finally figure out exactly what I needed to do to acomplish my desires. The end result I desired was to create something involving nested nodes, much like the replies to this very node, except in a CSS compliant way that doesn't invovle table abuse. The idea I finally came up with to implement this was to nest divs, each div would have an offset of however much I wanted, that way the children would be offset by their offset + their parent offset and so on. This works beautifully. However this script was fairly complicated (atleast I thought so, etc) and I was wondering if any monks out there see any improvement or outright mistakes I made. Code follows..
First off, here is the datastructure that my %cats = $c->get_cats; gets, generated via: Dumper(\%cats);
$VAR1 = {
    '6' => {
       'parent' => '0',
       'title' => 'War3',
       'id' => '6',
       'descr' => 'I have no subcategories'
     },
    '1' => {
       'parent' => '0',
       'children' => [
           {
             'parent' => '1',
             'children' => [
                 {
                   'parent' => 3,
                   'children' => [
                       {
                   'parent' => 7,
                   'title' => 'main sub cat1 sub cat1 sub cat1',
                   'id' => '9',
                   'descr' => 'Wewt, more recursion of doom!'
                       }
                     ],
                   'title' => 'main sub cat1 sub cat1',
                   'id' => 7,
                   'descr' => 'Sub category for a sub category! wewt.'
                 }
               ],
             'title' => 'main sub cat1',
             'id' => 3,
             'descr' => 'This is a subcategory for the main column'
           },
           {
             'parent' => '1',
             'title' => 'main sub cat2',
             'id' => 4,
             'descr' => 'This is the second subcategory for the main c
+olumn'
           }
         ],
       'title' => 'Main',
       'id' => '1',
       'descr' => 'This is the main category, used for all stuff that 
+doesn\'t fit else where.'
     },
    '2' => {
       'parent' => '0',
       'children' => [
           {
             'parent' => '2',
             'children' => [
                 {
                   'parent' => 5,
                   'title' => 'd2 sub cat sub cat',
                   'id' => 8,
                   'descr' => 'Yet another sub sub category'
                 }
               ],
             'title' => 'Diablo subcategory',
             'id' => 5,
             'descr' => 'A subcategory for the diablo 2 section.'
           }
         ],
       'title' => 'Diablo',
       'id' => '2',
       'descr' => 'This is the main diablo category'
     }
  };

[download]

And here is the tmpl/Categories/per_cat.tmpl used in the creation of the $hpc html::Template object, $hpc; 
<div class='category' style='position:relative; left: 5em;'>
    <div class='title'><tmpl_var name='title'></div>
    <div class='descr'><tmpl_var name='descr'></div>
    <tmpl_var name='children'>
</div>

[download]

And finally, here is the code itself: 
#!/perl/bin/perl
use strict;
use lib 'lib';

require HTML::Template;
require Categories;

my $hpc = new HTML::Template(Filename=>'tmpl/Categories/per_cat.tmpl')
+;
my $c = new Categories;
my %cats = $c->get_cats;

print "Content-type: text/html\n\n";
print "<html><head></head><body>";

for(sort keys %cats)
{
  my @child_data;
  my $fhtml;
  if( $cats{ $_ }->{ children } )
  {
    for( @{ $cats{ $_ }->{ children } } )
    {
      my @children = _recurse( $_ );
      my $html;
      for( reverse @children )
      {
        $hpc->param
        (
          title => $_->{ title },
          descr => $_->{ descr },
          children => $html,
        );
        $html = $hpc->output;
        $hpc->clear_params;
      }
      $fhtml.=$html;;
    }
  }
  
  $hpc->param
  (
    title => $cats{ $_ }->{ title },
    descr => $cats{ $_ }->{ descr },
    children => $fhtml,
  );
  print $hpc->output;
  $hpc->clear_params;
}

print "</body></html>";

sub _recurse
{
  my $child = shift;
  my @data;

  if( ref($child->{ children }) eq 'ARRAY' )
  {
    for( @{ $_->{ children } } )
    {
      push @data, _recurse( $_ );
    }
  }
  
  unshift @data,$child;
  return @data;
}

[download]
With the important bits being the for loop and the _recurse subroutine.

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