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