lib/MooseX/ClassAttribute/Trait/Application/ToRole.pm

   1 package MooseX::ClassAttribute::Trait::Application::ToRole;
   2
   3 use strict;
   4 use warnings;
   5
   6 use Moose::Util::MetaRole;
   7 use MooseX::ClassAttribute::Trait::Application::ToClass;
   8
   9 use namespace::autoclean;
  10 use Moose::Role;
  11
  12 with 'MooseX::ClassAttribute::Trait::Application';
  13
  14 sub _apply_class_attributes {
  15     my $self  = shift;
  16     my $role1 = shift;
  17     my $role2 = shift;
  18     $role2 = Moose::Util::MetaRole::apply_metaroles(
  19         for            => $role2,
  20         role_metaroles => {
  21             role => ['MooseX::ClassAttribute::Trait::Role'],
  22             application_to_class =>
  23                 ['MooseX::ClassAttribute::Trait::Application::ToClass'],
  24             application_to_role =>
  25                 ['MooseX::ClassAttribute::Trait::Application::ToRole'],
  26         },
  27     );
  28
  29     foreach my $attribute_name ( $role1->get_class_attribute_list() ) {
  30         if (   $role2->has_class_attribute($attribute_name)
  31             && $role2->get_class_attribute($attribute_name)
  32             != $role1->get_class_attribute($attribute_name) ) {
  33
  34             require Moose;
  35             Moose->throw_error( "Role '"
  36                     . $role1->name()
  37                     . "' has encountered a class attribute conflict "
  38                     . "during composition. This is fatal error and cannot be disambiguated."
  39             );
  40         }
  41         else {
  42             $role2->add_class_attribute(
  43                 $role1->get_class_attribute($attribute_name)->clone() );
  44         }
  45     }
  46 }
  47
  48 1;
  49
  50 # ABSTRACT: A trait that supports applying class attributes to roles
  51
  52 __END__
  53
  54 =pod
  55
  56 =head1 DESCRIPTION
  57
  58 This trait is used to allow the application of roles containing class
  59 attributes to roles.
  60
  61 =head1 BUGS
  62
  63 See L<MooseX::ClassAttribute> for details.
  64
  65 =cut