Manual automatic accessors in Perl

If you don't have Moose, Mo* or Class::Accessor:

package Foo;

=head1 SYNOPSIS

    my $f = Foo->new(
        bar => 'rab',
        qux => 'xuq',
    );

=cut

use constant ACCESSOR_MAP => {
    'get_bar' => 'bar',
    'get_qux' => 'qux',
};

use constant ACCESSOR_ITEM => qw(ping ting zing);

sub new {
    my ( $c, %args ) = @_;
    my $class = ref $c || $c;
    bless {%args}, $class;
}

sub __mk_accessor {
    my ( $c, $name, $key ) = @_;
    $key ||= $name;
    my $pkg = ref $c || $c;
    my $sym = join( '::', $pkg, $name );
    no strict 'refs';
    *{$sym} = sub {
        my ($self) = @_;
        $self->{$key};
    };
}

# set up ping(), ting(), zing()
__PACKAGE__->__mk_accessor($_) foreach __PACKAGE__->ACCESSOR_ITEM;

# set up get_bar(), get_qux()
for my $k ( keys %{ __PACKAGE__->ACCESSOR_MAP } ) {
    my $v = __PACKAGE__->ACCESSOR_MAP->{$k};
    __PACKAGE__->__mk_accessor( $k, $v );
}

# not tested

Perl: Fix DBI::db->disconnect invalidates 1 active statement handle

Add this subroutine to the module:

sub DESTROY {
    my ($self) = @_;
    # Finish off our statement handle, so we don't get warnings like:
    # DBI::db->disconnect invalidates 1 active statement handle
    my $sth = $self->{data_handle};
    if (blessed($sth) && $sth->can('finish')) {
        $sth->finish;
    }
}

Making a Perl module

Object oriented convention in Perl:

sub new
{  
    my ($class, %params) = @_;
    my $self = \%params;
    bless $self => $class;
    return $self;
}

Perl OO

our @ISA = ('MyParent');

sub new {

        my $proto = shift;

        my $class = ref($proto) || $proto;

        my $self  = {};

        $self->{NAME}   = undef;

        $self->{AGE}    = undef;

        $self->{PEERS}  = [];

        bless ($self, $class);

        return $self;

}