in reply to Re: Re: Calling SUPER in MethodMaker-generated methods
in thread Calling SUPER in MethodMaker-generated methods

$class vs. $self.
Consider this most trivial class: 
package Trivial;
sub new {
   my $class = shift @_;
   ...
   return bless $self, $class;
}

sub some_method {
   my $self = shift @_;
   ...
}
...

# in your program that uses Trivial:

my $instance = Trivial->new(..);
my $instance->some_method(..);

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In the constructor (new), @_ is shifted into $class. This is the name of the package, in this case Trivial.

When calling some_method(), @_ is shifted into $self. Here, $self is a reference to the calling object, $instance, which is of class Trivial.

Although i didn't specifically look, there is surely much more detailed documentation on perlmonks. In any case, a good way to remember what is being sent, look at what is to the left of the arrow "->" operator.

But really, that is a quick and dirty answer that doesnt really tell whats going on. So check out the docs, or Damian Conway's Object Oriented Perl for some very detailed explanations.

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Re: Re: Re: Re: Calling SUPER in MethodMaker-generated methods
by danb (Friar) on Jul 08, 2003 at 20:11 UTC

    Thanks again for the input. I'm familiar with everything you said, and I do have Damian Conways' OOP (although I haven't read it all yet).

    In fact, without using Class::MethodMaker, I can write everything by hand and it works like I want it to. Here is (nearly) the same code, but without MethodMaker: 

    #!/usr/bin/perl
use strict;
use warnings;

#####################################################################
##  Bug
#####################################################################
package Bug;
sub new { bless {}, shift }
sub required
{ 
    my @required = ( 'id', 'type', 'description' ); 
    return @required;
}

#####################################################################
##  FixedBug
#####################################################################
package FixedBug;
use base ( 'Bug' );
sub new { bless {}, shift }
sub required
{
    my @required = ( 
                    'date_fixed', 'repairer', 
                    shift->SUPER::required() 
                   );
    return @required;
}

#####################################################################
##  Main
#####################################################################
package Main;
my $fixed_bug = FixedBug->new();
print join( ', ', $fixed_bug->required() ) . "\n";

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    See?

    -Dan

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[d/l]

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