Moose::Meta::Role(3p)

NAME
Moose::Meta::Role - The Moose Role metaclass

VERSION
version 2.4000

DESCRIPTION
This class is a subclass of Class::MOP::Module that provides additional Moose-specific functionality.

Its API looks a lot like Moose::Meta::Class, but internally it implements many things differently. This may change in the future.

INHERITANCE
"Moose::Meta::Role" is a subclass of Class::MOP::Module.

METHODS

  Construction
Moose::Meta::Role->initialize($role_name)

This method creates a new role object with the provided name.

Moose::Meta::Role->combine( [ $role => { ... } ], [ $role ], ... )

This method accepts a list of array references. Each array reference should contain a role name or Moose::Meta::Role object as its first element. The second element is an optional hash reference. The hash reference can contain "-excludes" and "-alias" keys to control how methods are composed from the role.

The return value is a new Moose::Meta::Role::Composite that represents the combined roles.

$metarole->composition_class_roles

When combining multiple roles using "combine", this method is used to obtain a list of role names to be applied to the Moose::Meta::Role::Composite instance returned by "combine". The default implementation returns an empty list. Extensions that need to hook into role combination may wrap this method to return additional role names.

Moose::Meta::Role->create($name, %options)

This method is identical to the Moose::Meta::Class "create" method.

Moose::Meta::Role->create_anon_role

This method is identical to the Moose::Meta::Class "create_anon_class" method.

$metarole->is_anon_role

Returns true if the role is an anonymous role.

$metarole->consumers

Returns a list of names of classes and roles which consume this role.

  Role application
$metarole->apply( $thing, @options )

This method applies a role to the given $thing. That can be another Moose::Meta::Role, object, a Moose::Meta::Class object, or a (non-meta) object instance.

The options are passed directly to the constructor for the appropriate Moose::Meta::Role::Application subclass.

Note that this will apply the role even if the $thing in question already "does" this role. "does_role" in Moose::Util is a convenient wrapper for finding out if role application is necessary.

  Roles and other roles
$metarole->get_roles

This returns an array reference of roles which this role does. This list may include duplicates.

$metarole->calculate_all_roles

This returns a unique list of all roles that this role does, and all the roles that its roles do.

$metarole->does_role($role)

Given a role name or Moose::Meta::Role object, returns true if this role does the given role.

$metarole->add_role($role)

Given a Moose::Meta::Role object, this adds the role to the list of roles that the role does.

$metarole->get_excluded_roles_list

Returns a list of role names which this role excludes.

$metarole->excludes_role($role_name)

Given a role name, returns true if this role excludes the named role.

$metarole->add_excluded_roles(@role_names)

Given one or more role names, adds those roles to the list of excluded roles.

  Methods
The methods for dealing with a role's methods are all identical in API and behavior to the same methods in Class::MOP::Class.

$metarole->method_metaclass

Returns the method metaclass name for the role. This defaults to Moose::Meta::Role::Method.

$metarole->get_method($name)

$metarole->has_method($name)

$metarole->add_method( $name, $body )

$metarole->get_method_list

$metarole->find_method_by_name($name)

These methods are all identical to the methods of the same name in Class::MOP::Class

  Attributes
As with methods, the methods for dealing with a role's attribute are all identical in API and behavior to the same methods in Class::MOP::Class.

However, attributes stored in this class are not stored as objects. Rather, the attribute definition is stored as a hash reference. When a role is composed into a class, this hash reference is passed directly to the metaclass's "add_attribute" method.

This is quite likely to change in the future.

$metarole->get_attribute($attribute_name)

$metarole->has_attribute($attribute_name)

$metarole->get_attribute_list

$metarole->add_attribute($name, %options)

$metarole->remove_attribute($attribute_name)

  Overload introspection and creation
The methods for dealing with a role's overloads are all identical in API and behavior to the same methods in Class::MOP::Class.

$metarole->is_overloaded

$metarole->get_overloaded_operator($op)

$metarole->has_overloaded_operator($op)

$metarole->get_overload_list

$metarole->get_all_overloaded_operators

$metarole->add_overloaded_operator($op, $impl)

$metarole->remove_overloaded_operator($op)

  Required methods
$metarole->get_required_method_list

Returns the list of methods required by the role.

$metarole->requires_method($name)

Returns true if the role requires the named method.

$metarole->add_required_methods(@names)

Adds the named methods to the role's list of required methods.

$metarole->remove_required_methods(@names)

Removes the named methods from the role's list of required methods.

$metarole->add_conflicting_method(%params)

Instantiate the parameters as a Moose::Meta::Role::Method::Conflicting object, then add it to the required method list.

  Method modifiers
These methods act like their counterparts in Class::MOP::Class and Moose::Meta::Class.

However, method modifiers are simply stored internally, and are not applied until the role itself is applied to a class or object.

$metarole->add_after_method_modifier($method_name, $method)

$metarole->add_around_method_modifier($method_name, $method)

$metarole->add_before_method_modifier($method_name, $method)

$metarole->add_override_method_modifier($method_name, $method)

These methods all add an appropriate modifier to the internal list of modifiers.

$metarole->has_after_method_modifiers

$metarole->has_around_method_modifiers

$metarole->has_before_method_modifiers

$metarole->has_override_method_modifier

Return true if the role has any modifiers of the given type.

$metarole->get_after_method_modifiers($method_name)

$metarole->get_around_method_modifiers($method_name)

$metarole->get_before_method_modifiers($method_name)

Given a method name, returns a list of the appropriate modifiers for that method.

$metarole->get_override_method_modifier($method_name)

Given a method name, returns the override method modifier for that method, if it has one.

  Introspection
Moose::Meta::Role->meta

This will return a Class::MOP::Class instance for this class.

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

AUTHORS

•   Stevan Little <stevan@cpan.org>

•   Dave Rolsky <autarch@urth.org>

•   Jesse Luehrs <doy@cpan.org>

•   Shawn M Moore <sartak@cpan.org>

•   יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>

•   Karen Etheridge <ether@cpan.org>

•   Florian Ragwitz <rafl@debian.org>

•   Hans Dieter Pearcey <hdp@cpan.org>

•   Chris Prather <chris@prather.org>

•   Matt S Trout <mstrout@cpan.org>

COPYRIGHT AND LICENSE
This software is copyright (c) 2006 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.