#!/usr/bin/perl -w
package MP3;
use Plugin;
use strict;

# get a plugin object so we can access its methods
# we could pass config details to the plugin object
# here if we want.....
my $p = new Plugin( config_var => 'some config var' );

# use closures to make truly private lexical vars that 
# can only be accessed by the get and set methods
{
    my $var1;
    sub set_var1 { $var1 = $_[0] }
    sub get_var1 { return $var1 }
}

{
    my $var2;
    sub set_var2 { $var2 = $_[0] }
    sub get_var2 { return $var2 }
}

{
    my $var3;
    sub set_var3 { $var3 = $_[0] }
    sub get_var3 { return $var3 }
}

sub say_gday { print "G'day World!\n" }

set_var1(123456);
print 'Get \$var1 ', get_var1(), "\n";
print "\$var1 is very private '$var1'\n";
# now call some of the Plugin functions....
$p->func1();        # sets $var1 to 123 and prints it...
$p->func2();        # calls a function in MP3 package
print $p->func3();  # return a config var

package Plugin;

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

sub func1 {
   MP3::set_var1(123);
   print MP3::get_var1(), "\n";
}

sub func2 {
   MP3::say_gday();
}

sub func3 {
   my $self = shift;
  return $self->{config_var};
}

1;