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Standard Class

Posted by admin (Graham Ellis), 17 January 2003
The ultimate "standard" class in Perl ... a constuctor and a set method each of which takes its parameters as a hash of settings to make, a get method to get any property, and an AUTOLOAD that lets you call any non-existatnt set or get method that you like and it will do what you mean.

Code:
# The ultimate standard class!

package animal;
use Carp;

use Exporter;
@ISA = qw(Exporter);
@EXPORT = qw($counter);
$counter = 0;

sub new {
       my ($class,@params) = @_ ;
       my %info;
       $counter++;
       set(\%info,@params);
       bless \%info,$class;
       }

sub set {
       my ($obj,@params) = @_;
       if (@params%2) {
               croak("Snuffed it it set ... ");
               }
       %setup = @params;
       foreach $p (keys %setup) {
               $q = $p;
               $p =~ s/^-//;
               unless ($pnv{$p}) {
                       carp("Can't set $p. Not a valid property");
               } else {
                       $$obj{$p} = $setup{$q};
                       }
               }
       1;
       }

sub get {
       my ($obj,$what) = @_;
       unless ($pnv{$what}) {
               carp("Can't get $what. Not a valid property");
               return 0;
               }
       return $$obj{$what};
       }

sub AUTOLOAD {
       my ($obj,$value) = @_;
       ($dirn,$what) = ($AUTOLOAD =~ /.*:(...)(.*)/);
       if ($dirn eq "set") {
               unless ($pnv{$what}) {
                       carp("Can't set $what. Not a valid property");
                       return 0;
                       }
               $$obj{$what} = $value;
               return 1;
       }
       if ($dirn eq "get") {
               unless ($pnv{$what}) {
                       carp("Can't get $what. Not a valid property");
                       return 0;
                       }
               return $$obj{$what};
               }
       # Check for anything else ;-)
       0;
       }

foreach $pname (qw(speed legs age weight comment colour)) {
       $pnv{$pname} = 1;
       }
print "Loaded in class, Copyright me, now\n";
1;




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