use strict;
use CGI qw(header);
use HTML::Template;

my $cart_ref = {
   42 => {
      qty         => 5,
      price       => 5,
      description => 'widget 42',
   },
   77 => {
      qty         => 2,
      price       => 7,
      description => 'widget 77',
   },
};

my $html = do {local $/;<DATA>};
my $tmpl = HTML::Template->new(scalarref=> \$html);

my $rows = [ 
   map {
      { id => $_, %{$cart_ref->{$_}} }
   } keys %$cart_ref
];

$tmpl->param(rows => $rows);
print header, $tmpl->output;
   

__DATA__
<table>
   <tr>
      <th>Item</th>
      <th>Quantity</th>
      <th>Description</th>
      <th>Price</th>
   </tr>
   <tmpl_loop rows>
   <tr>
      <td><tmpl_var id></td>
      <td><tmpl_var qty></td>
      <td><tmpl_var description></td>
      <td><tmpl_var price></td>
   </tr>
   </tmpl_loop>
</table>