so far the best hack is :
sub location;
has location => (...);
On Sun, Jan 18, 2009 at 3:40 AM, Paul Fenwick <p...@perltraining.com.au> wrote:
> G'day Moosers,
>
> I'm currently working on some quick lightning talks demonstrating Moose and
> why it's useful. One of the examples I'm using for roles looks like this:
>
> package SunSmart;
>
> use Moose::Role;
> use Weather::Google;
>
> use constant HOT => 28; # Deg C.
>
> requires 'go_outside';
> requires 'location';
>
> before 'go_outside' => sub {
> my ($self) = @_;
>
> my $weather = Weather::Google->new(
> $self->location
> );
>
> if ($weather->current->{temp_c} > HOT) {
> print "Don't forget your hat!\n";
> }
> }
>
> In short, if something has a location, and the ability to go_outside, then
> we can give it the SunSmart role, and it won't forget its hat if it's too hot.
>
> Unfortunately for me, `location` is an attribute on practically all of my
> classes, and Moose doesn't seem to like having an attribute to satisfy a
> 'requires':
>
> 'SunSmart' requires the method 'location' to be implemented by
> 'Person::Social'but the method is only an attribute accessor at
> /usr/lib/perl5/site_perl/5.8/Moose/Meta/Role/Application.pm line 59
>
> This makes me sad, since I really *do* require a location method, but it's
> absolutely fine if it's an attribute.
>
> I know there have been some discussions about this in the past, with the
> possibility of a 'requires_attr' or similar keyword, although to the best of
> my knowledge this is not yet implemented.
>
> In the meantime, is there any easy[1] way to tell Moose that attributes are
> just fine to satisify 'requires' dependencies?
>
> Many thanks,
>
> Paul
>
> [1] Since I'm writing short talks for mixed audiences, I can't show anything
> too scary. Sure, I'm willing to dig around in the guts of all sorts of
> things, but I'm trying to dispel the myth that as a regular Perl programmer
> you should have to.
>
> --
> Paul Fenwick <p...@perltraining.com.au> | http://perltraining.com.au/
> Director of Training | Ph: +61 3 9354 6001
> Perl Training Australia | Fax: +61 3 9354 2681
>
>
--
benh~
http://three.sentenc.es/
