Chas Owens wrote:
> On 6/22/07, Mathew Snyder <[EMAIL PROTECTED]> wrote:
> snip
>> I'm not sure what you mean by "Change your new() in a new() and init()".
> snip
>> What do you mean by "set/get approach"?
> snip
>
> Some people believe that new should just create a new blank object and
> call an init method to do setup. There are good arguments both ways.
>
> Manually writing Accessor, Mutator, Getter, or Setter methods sucks
> and is error prone. It is often better to write one getter and one
> setter that gets or sets the field(s) passed to it. Another method is
> to use Perl's autoload capability to magically create subroutines for
> you. Starting with some Perl in the 5.8 line the autoload function
> gained the ability to be an lvalue, so I have written it that way.
>
> Perl script:
> #!/usr/bin/perl
>
> use strict;
> use warnings;
> use Report;
>
> my $rpt = Report->new;
>
> $rpt->set({id => 5, queue => 10});
> print $rpt->printable;
>
> my ($id, $queue) = $rpt->get(qw(id queue));
>
> print "id is $id and queue is $queue\n";
>
> #same thing, but I like the => better
> $rpt->set("id", 6);
> $rpt->set(id => 6);
>
> print "id is now ", $rpt->get("id"), "\n";
>
> $rpt->id = 7;
> print "id is now ", $rpt->id, "\n";
>
> Module:
> package Report;
>
> use strict;
> use warnings;
> use Carp;
>
> our $AUTOLOAD;
> our %fields = (
> _id => 1,
> _queue => 1,
> _owner => 1,
> _priority => 1,
> _worked => 1,
> _timeLeft => 1,
> _due => 1,
> _created => 1,
> _updated => 1,
> _severity => 1,
> _ccl => 1,
> );
>
> #minimal new
> sub new {
> my $class = shift;
> my $self = bless {}, $class;
> $self->init(@_);
> return $self;
> }
>
> #real object creation happens here
> sub init {
> my $self = shift;
> my @fields = keys %fields;
> @[EMAIL PROTECTED] = (undef) x @fields;
> }
>
> sub _validate_field {
> my ($self, $k) = @_;
> croak "$k is not a valid field for " . ref $self
> unless $fields{"_$k"};
> }
>
> #Getter/setter method 1
> sub get {
> my ($self, @k) = @_;
> my @ret;
> for my $k (@k) {
> $self->_validate_field($k);
> push @ret, $self->{"_$k"};
> }
> local $" = ' ::: ';
> return @ret
> }
>
> sub set {
> my $self = shift;
> croak "bad number of arguments" unless @_ == 2 or @_ == 1;
> if (@_ == 2) {
> $self->_validate_field($_[0]);
> return $self->{"_$_[0]"} = $_[1];
> }
> croak "not a hash reference" unless ref $_[0] eq 'HASH';
> my $h = $_[0];
> my @ret;
> for my $k (keys %$h) {
> $self->_validate_field($k);
> push @ret, $self->{"_$k"} = $h->{$k};
> }
> return @ret;
> }
>
> #another form of setter/getter
>
> sub AUTOLOAD : lvalue {
> my ($k) = $AUTOLOAD =~ /::(.*?)$/;
> return if $k eq 'DESTROY';
> my $self = shift;
> $self->_validate_field($k);
> $self->{"_$k"};
> }
>
> sub printable {
> my ($self) = @_;
>
> # return Printable Report info
> return $self->id . " " . $self->queue . "\n";
> }
>
> 1;
>
I pretty much have a very small idea of what is going on up there.
Mathew
Keep up with me and what I'm up to: http://theillien.blogspot.com
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
http://learn.perl.org/
