Okay, why is the subclass's new() not required? Is it because the
DBLogon's additional field (DBNAME) is added via the _init() method? So
you end up with something like this:
# Base class Logon new()
sub new {
my $that = shift;
my $class = ref($that) || $that;
my $self = {};
bless $self, $class;
$self->_init();
return $self;
}
# Base class Logon _init()
sub _init {
my $self = shift;
$self->{USERID} = undef;
$self->{SERVER} = undef;
}
Then the subclass DBLogon would no longer have a new() method, but would
retain its _init() method, which would be modified to call the SUPER's
_init as well, right?
# Subclass DBLogon init()
sub _init {
my $self = shift;
$self->SUPER::_init();
$self->{DBNAME} = undef;
}
Just to clarify, the only reason I don't need a new() method in the
subclass is because any class-specific logic is contained in the _init()
method for both parent and subclass. If there were no _init() method,
then both classes would have a new(), right?
-----Original Message-----
From: Bob Showalter [mailto:[EMAIL PROTECTED]
Sent: Friday, April 01, 2005 10:44 AM
To: '[EMAIL PROTECTED]'; beginners@perl.org
Subject: RE: Attempting OO with Perl - New() method in subclass not
working
[EMAIL PROTECTED] wrote:
> I am trying to build an inheritable object, and I am using examples
> from the Perl Cookbook, 2nd edition, mostly Recipe 13.1, using the new
> and _init methods.
Your subclass does not need (and should not have) a new() method; it can
use the one from the base class.
As Randal pointed out, the subclass _init needs to call
$self->SUPER::_init(), and then do any additional initialization. If
there is no additional initialization in the subclass, you don't need an
_init method there either.
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