Jesse Luehrs > Moose > Moose::Role

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Module Version: 2.0604   Source   Latest Release: Moose-2.1210

NAME ^

Moose::Role - The Moose Role

VERSION ^

version 2.0604

SYNOPSIS ^

  package Eq;
  use Moose::Role; # automatically turns on strict and warnings

  requires 'equal';

  sub no_equal {
      my ($self, $other) = @_;
      !$self->equal($other);
  }

  # ... then in your classes

  package Currency;
  use Moose; # automatically turns on strict and warnings

  with 'Eq';

  sub equal {
      my ($self, $other) = @_;
      $self->as_float == $other->as_float;
  }

  # ... and also

  package Comparator;
  use Moose;

  has compare_to => (
      is      => 'ro',
      does    => 'Eq',
      handles => 'Eq',
  );

  # ... which allows

  my $currency1 = Currency->new(...);
  my $currency2 = Currency->new(...);
  Comparator->new(compare_to => $currency1)->equal($currency2);

DESCRIPTION ^

The concept of roles is documented in Moose::Manual::Roles. This document serves as API documentation.

EXPORTED FUNCTIONS ^

Moose::Role currently supports all of the functions that Moose exports, but differs slightly in how some items are handled (see "CAVEATS" below for details).

Moose::Role also offers two role-specific keyword exports:

requires (@method_names)

Roles can require that certain methods are implemented by any class which does the role.

Note that attribute accessors also count as methods for the purposes of satisfying the requirements of a role.

excludes (@role_names)

Roles can exclude other roles, in effect saying "I can never be combined with these @role_names". This is a feature which should not be used lightly.

unimport

Moose::Role offers a way to remove the keywords it exports, through the unimport method. You simply have to say no Moose::Role at the bottom of your code for this to work.

METACLASS ^

When you use Moose::Role, you can specify traits which will be applied to your role metaclass:

    use Moose::Role -traits => 'My::Trait';

This is very similar to the attribute traits feature. When you do this, your class's meta object will have the specified traits applied to it. See "Metaclass and Trait Name Resolution" in Moose for more details.

APPLYING ROLES ^

In addition to being applied to a class using the 'with' syntax (see Moose::Manual::Roles) and using the Moose::Util 'apply_all_roles' method, roles may also be applied to an instance of a class using Moose::Util 'apply_all_roles' or the role's metaclass:

   MyApp::Test::SomeRole->meta->apply( $instance );

Doing this creates a new, mutable, anonymous subclass, applies the role to that, and reblesses. In a debugger, for example, you will see class names of the form Moose::Meta::Class::__ANON__::SERIAL::6 , which means that doing a 'ref' on your instance may not return what you expect. See Moose::Object for 'DOES'.

Additional params may be added to the new instance by providing 'rebless_params'. See Moose::Meta::Role::Application::ToInstance.

CAVEATS ^

Role support has only a few caveats:

BUGS ^

See "BUGS" in Moose for details on reporting bugs.

AUTHOR ^

Moose is maintained by the Moose Cabal, along with the help of many contributors. See "CABAL" in Moose and "CONTRIBUTORS" in Moose for details.

COPYRIGHT AND LICENSE ^

This software is copyright (c) 2012 by Infinity Interactive, Inc..

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

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