#!/usr/bin/perl

use strict;
use warnings;
use Template;

my $container = Container->new();
$container->add( 
  Object->new( name => 'foo', value => 10, usefulness => 0 )
);
$container->add(
  Object->new( name => 'bar', value => 20, meaning => 42 )
);

my $vars = {
  'container' => $container
};

my $template = <<EOT;
container=[% container %]
all:
[% FOREACH element IN container.all.sort('name') %]
[% element %] name is [% element.name %]
[% END %]
one:
[% FOREACH element IN container.one(10).sort('name') %]
[% element %] name is [% element.name %]
[% END %]
EOT

my $tt = Template->new();
$tt->process(\$template, $vars);

package Object;

sub new {
  my $class = shift;
  my $self = {@_};
  return bless($self, $class); 
}


package Container;

sub new {
  my $class = shift;
  my $self = {@_};
  return bless($self, $class); 
}

sub add {
  my $self = shift;
  my $new = shift;
  push @{$self->{'objects'}}, $new;
}

sub all {
  my $self = shift;
  return @{$self->{'objects'}};
}

sub one {
  my $self = shift;
  my $filter = shift;
  return grep { $_->{'value'} == $filter } @{$self->{'objects'}}; 
}