Fellow monks showed you how to do it with Moo. I will show you how to do it without any OO system.

# Simple OO example with inheritance
# author: bliako
# for https://perlmonks.org/?node_id=11113260
# 02-20-2020

package Class1 {
    use warnings;
    use strict;

    sub new {
        my ($class, $config) = @_;
        print "Class1 called.\n";
        my $self = {
                   # set an error handler to be used by error().
                   # NOTE: anonymous subs are not member subs, so you 
+can't access $self...
           on_error => sub { print "on_error() : exiting with msg '$_[
+0]'\n"; exit(1); },
           name => "<no-name-set>",
        };
        bless $self => $class; # my idiomatic way to remember bless or
+der, i.e. bless $self, $class

        $self->_init_from_config($config);
        return $self;
    }
    sub _init_from_config {
        my $self = shift;
        my $config = shift; # a hashref of config params
        return unless defined $config;
        for (keys %$config){
            $self->{$_} = $config->{$_}, print "config: set '".$_."'.\
+n" if exists $self->{$_}
        }
    }

    sub myname { return $_[0]->{name} }
    sub error {
        my $self = shift;
        print "error() : called with $self, my name is ".$self->myname
+()."\n";
        $self->{on_error}->(@_);
    }
}
package Class2 {
    use warnings;
    use strict;
    use parent -norequire, 'Class1';

    sub new {
        my ($class,$config) = @_;
        print "Class2 called.\n";
        my $self = $class->SUPER::new($config);

        $self->{name} = "my name is Class2";
        return $self;
    }
}
package Class3 {
    use warnings;
    use strict;

    use parent -norequire, 'Class2';

    sub new {
        my ($class,$config) = @_;
        print "Class3 called.\n";
        my $self = $class->SUPER::new($config);

        $self->{on_error} = sub {
            print "on_error() : warning with msg '$_[0]'\n";
        };
        return $self;
    }
}

package main;

use warnings;
use strict;

use Data::Dumper;

my $c2 = Class2->new();
my $c3 = Class3->new({
  name => 'my name is Jack'
});
print "here is c2:\n".Dumper($c2);
$c3->error("oops for c3");
$c2->error("oops for c2");

print "you will not see this (because c2's error handler inherits c1's
+ which will exit()).\n";
[download]

bw, bliako

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