in reply to bless!!

If a constructor is inherited, it needs to bless into a class that is not its own. As in: 
package CLASS_B;
sub new {
  my $class = shift; # critical here
  bless { @_ }, $class; # blesses to maybe CLASS_A
}
package CLASS_A;
@ISA = qw(CLASS_B);
...
my $object = CLASS_A->new;

[download]
This calls, CLASS_A::new, which inherits to CLASS_B::new, which blesses the hashref into CLASS_A, not CLASS_B. Does that help?

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

Replies are listed 'Best First'.
Re: •Re: bless!!
by bakunin (Scribe) on Jan 17, 2004 at 23:14 UTC
    Thank you for pointing out inheritance merlyn!
    I saw something like this a few weeks ago... wish I remembered where exactly. 
    package Class_A;

sub new {

  ## the usual:
  my $class = shift;
  my $self = {};  
  bless $self, $class;
}

sub newB {
  
  my $self = {};  
  bless $self, 'Class_B';
}

    [download]
    Does this ring any bells?
[reply]
[d/l]

In Section Seekers of Perl Wisdom