Not necessarily true. It can actually make code easier to work with.

my %validation_for = (
  foo => qr/^\d+$/, # foo must be an integer
  bar => \&validate,
}:

sub attr {
  my ( $self, $attr ) = splice @_, 0, 2;

  croak "No such attribute $attr" unless exists $validation_for{$attr}
+;

  return $self->{$attr} unless @_;

  # set the value
  my $validation = $validation_for{$attr};
  my $new_val    = shift;

  if ('Regexp' eq ref $validation) {
    croak "$new_val doesn't match $validation"
      if $new_val !~ $validation;
  }
  else {
    $self->$validation($new_val); # we'll assume it throws an error
  }
  $self->{$attr} = $new_val;
  return $self;
}

[download]

With that quick hack, adding a new attribute is as simple as adding a new key/value pair to the validation lookup.

You can then use a single method for getter/setters for everything and still have validation. Whether or not that's appropriate for your needs depends on your requirements. Also, "extra" behavior can easily be added to the validation subroutine, though at that point you'd probably want to rename the hash.

Cheers,
Ovid

New address of my CGI Course.

In reply to Re^2: Class attribute get/set approach flaws? by Ovid
in thread Class attribute get/set approach flaws? by radiantmatrix

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