Mouse::Util::MetaRole(3pm)				User Contributed Perl Documentation				Mouse::Util::MetaRole(3pm)

NAME

       Mouse::Util::MetaRole - Apply roles to any metaclass, as well as the object base class

SYNOPSIS

	 package MyApp::Mouse;

	 use Mouse ();
	 use Mouse::Exporter;
	 use Mouse::Util::MetaRole;

	 use MyApp::Role::Meta::Class;
	 use MyApp::Role::Meta::Method::Constructor;
	 use MyApp::Role::Object;

	 Mouse::Exporter->setup_import_methods( also => 'Mouse' );

	 sub init_meta {
	     shift;
	     my %args = @_;

	     Mouse->init_meta(%args);

	     Mouse::Util::MetaRole::apply_metaroles(
		 for		 => $args{for_class},
		 class_metaroles => {
		     class	 => ['MyApp::Role::Meta::Class'],
		     constructor => ['MyApp::Role::Meta::Method::Constructor'],
		 },
	     );

	     Mouse::Util::MetaRole::apply_base_class_roles(
		 for   => $args{for_class},
		 roles => ['MyApp::Role::Object'],
	     );

	     return $args{for_class}->meta();
	 }

DESCRIPTION

       This utility module is designed to help authors of Mouse extensions write extensions that are able to cooperate with other Mouse
       extensions. To do this, you must write your extensions as roles, which can then be dynamically applied to the caller's metaclasses.

       This module makes sure to preserve any existing superclasses and roles already set for the meta objects, which means that any number of
       extensions can apply roles in any order.

USAGE

       It is very important that you only call this module's functions when your module is imported by the caller. The process of applying roles
       to the metaclass reinitializes the metaclass object, which wipes out any existing attributes already defined. However, as long as you do
       this when your module is imported, the caller should not have any attributes defined yet.

       The easiest way to ensure that this happens is to use Mouse::Exporter, which can generate the appropriate "init_meta" method for you, and
       make sure it is called when imported.

FUNCTIONS

       This module provides two functions.

   apply_metaroles( ... )
       This function will apply roles to one or more metaclasses for the specified class. It accepts the following parameters:

       o   for => $name

	   This specifies the class or for which to alter the meta classes. This can be a package name, or an appropriate meta-object (a
	   Mouse::Meta::Class or Mouse::Meta::Role).

       o   class_metaroles => \%roles

	   This is a hash reference specifying which metaroles will be applied to the class metaclass and its contained metaclasses and helper
	   classes.

	   Each key should in turn point to an array reference of role names.

	   It accepts the following keys:

	   class
	   attribute
	   method
	   constructor
	   destructor
       o   role_metaroles => \%roles

	   This is a hash reference specifying which metaroles will be applied to the role metaclass and its contained metaclasses and helper
	   classes.

	   It accepts the following keys:

	   role
	   method

   apply_base_class_roles( for => $class, roles => @roles )
       This function will apply the specified roles to the object's base class.

SEE ALSO

       Moose::Util::MetaRole

perl v5.14.2							    2012-06-30						Mouse::Util::MetaRole(3pm)