Re: Re7: Calling SUPER in MethodMaker-generated methods

Thanks. I rewrote it slightly:

#####################################################################
##  CustomMethodMaker
##  (must be in it's own file, due to the fact that it has to be 'used
+'.
#####################################################################
package Business::Shipping::CustomMethodMaker;
use base ( 'Class::MethodMaker' );

=head2 grouped_fields_inherit

Works like grouped_fields, except that it also calls the parent class.

=cut
sub grouped_fields_inherit {
  my ($class, %args) = @_;
  my %methods;
  foreach (keys %args) {
    my @slots = @{$args{$_}};
    $class->get_set(@slots);
    my $method_name = $_;
    my $caller = $class->find_target_class();
    $methods{$_} = sub {
        my $self = shift;
        #
        #print "installing $method_name() in $caller...\n";
        #
        # Without $caller and eval, the following line causes this err
+or:
        # 
        # Can't locate auto/CustomMethodMaker/SUPER/[METHOD].al in @IN
+C
        #
        my @parent_slots = eval "
            package $caller;
            if ( \$self->can( SUPER::$method_name ) ) {
                return \$self->SUPER::$method_name( \@_ );
            }
            else {
                return ( );
            }
            1;
        ";
        die $@ if $@;
        return ( @parent_slots, @slots );
    };
  }
  $class->install_methods(%methods);
}

1;
[download]

-Dan

Comment on Re: Re7: Calling SUPER in MethodMaker-generated methods Download Code

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Re9: Calling SUPER in MethodMaker-generated methods
by bbfu (Curate) on Jul 13, 2003 at 18:46 UTC

I was thinking about this a little over the weekend, and I realized why SUPER needs to check the current package's @ISA, instead of the package into which the object is blessed. It's to handle the case where the super-method also uses SUPER. If it just used the @ISA of the package the object was blessed into, SUPER in a super-method would start over at the bottom (top?) of the inheritance tree. So it has to use the current package, which is also the current position in the inheritance tree, except for the one case that you happened to run into. Anyway, that's the "why" of it.

I also realised that it's probably a bit more efficient to do the eval once, when creating the anonymous sub, instead of every time it's called (although it may be a case of premature optimization... I'm not entirely certain). Like so:

$methods{$_} = eval qq(
  package $caller;
  sub {
    my \$self = shift;
    #
    #print "installing $method_name() in $caller...\n";
    #
    # Without \$caller and eval, the following line causes this error:
    # 
    # Can't locate auto/CustomMethodMaker/SUPER/[METHOD].al in \@INC
    #
    my \@parent_slots;
    if ( \$self->can( SUPER::$method_name ) ) {
      \@parent_slots = \$self->SUPER::$method_name( \@_ );
    }
    return ( \@parent_slots, \@slots );
  }
);
die $@ if $@;
[download]

Just thought I'd share those, for completeness.

bbfu
Black flowers blossom
Fearless on my breath

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