parameterizable packages with Package::Variant

By davewood on November 5, 2013 9:14 AM

Yesterday I tried to port a Moose App to Moo but got stuck when I found out it is using MooseX::Role::Parameterizable, a module not available in Moo. A quick visit in channel #moose on perl.irc.org later and I was told to give Package::Variant a try.

Few lines of conversation/debugging later and here is my parameterizable HTML::FormHandler role. Package::Variant is an extremly promising module to me that is really helpful when refactoring your code.

declare the HFH role

package MyApp::Role::Form::Step::Value;

use Package::Variant

    importing => ['HTML::FormHandler::Moose::Role'],

    subs      => [ qw/ has_field requires has around before after with / ];

sub make_variant {

    my ( $class, $target_package, %arguments ) = @_;

    my $name = exists $arguments{name} ? $arguments{name} : 'value';

    has_field $name => (

        type         => 'Text',

        required     => 0,

        noupdate     => 1,

        not_nullable => 1,

        element_attr => { class => 'detect_whitespace' },

    );

    around '_build_parameter_fields' => sub {

        my ( $orig, $self ) = @_;

        return [ @{ $self->$orig }, $name ];

    };

}

1;

And here is how you would use it.



package MyApp::Form::Step::CondSubTest;

use HTML::FormHandler::Moose;

use MyApp::Role::Form::Step::Value;

extends 'MyApp::Form::Step::Base';

with

  'MyApp::Role::Form::Step::SubTest',

  Value( name => 'value_a' ),

  Value( name => 'value_b' ),

  ;

1;