Re: common build function

[Jesse Luehrs]

On Mon, Nov 08, 2010 at 10:12:16PM +0000, Adam Guthrie wrote:
> Hi,
> 
> I've the following class
> 
> package AG::Dirs;
> 
> use Moose;
> use namespace::autoclean;
> use Path::Class::Dir;
> use MooseX::Types::Path::Class;
> 
> has 'root_dir' => ( isa => 'Path::Class::Dir', is => 'ro', coerce => 1,
> required => 1 );
> 
> has [ qw/
>         upload_dir
>         dynamic_data_cache_dir
>         static_image_dir
>         user_image_dir
>     / ]
> => ( isa => 'Path::Class::Dir', is => 'ro', coerce => 1, lazy_build => 1 );
> 
> sub _build_update_dir { $_[0]->root_dir->subdir('upload') };
> sub _build_dynamic_data_cache_dir {
> $_[0]->root_dir->subdir('dynamic_data_cache') };
> sub _build_static_image_dir { $_[0]->root_dir->subdir('static_image') };
> sub _build_user_image_dir { $_[0]->root_dir->subdir('user_image') };
> 
> __PACKAGE__->meta->make_immutable;
> 
> Is there a better way than the multiple _build functions?  A function that
> uses the attribute name perhaps?
> 
> Any help much appreciated,
> 
> Adam

  for $dir in (qw(upload dynamic_data_cache static_image user_image)) {
      has $dir => (
          isa        => 'Path::Class::Dir',
          is         => 'ro',
          coerce     => 1,
          lazy_build => 1,
      );
      __PACKAGE__->meta->add_method("_build_${dir}_dir" => sub {
          $_[0]->root_dir->subdir($dir);
      });
  }

or

  for $dir in (qw(upload dynamic_data_cache static_image user_image)) {
      has $dir => (
          isa     => 'Path::Class::Dir',
          is      => 'ro',
          coerce  => 1,
          default => sub {
              $_[0]->root_dir->subdir($dir);
          }
      );
  }

if you don't really need predicates or clearers.

-doy