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 %options = @_;
Mouse->init_meta(%options);
Mouse::Util::MetaRole::apply_metaclass_roles(
for_class => $options{for_class},
metaclass_roles => ['MyApp::Role::Meta::Class'],
constructor_class_roles => ['MyApp::Role::Meta::Method::Constructor'],
);
Mouse::Util::MetaRole::apply_base_class_roles(
for_class => $options{for_class},
roles => ['MyApp::Role::Object'],
);
return $options{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_metaclass_roles( ... )
This function will apply roles to one or more metaclasses for the specified class. It accepts the following parameters:
for_class => $name
This specifies the class for which to alter the meta classes.
metaclass_roles => \@roles
attribute_metaclass_roles => \@roles
method_metaclass_roles => \@roles
constructor_class_roles => \@roles
destructor_class_roles => \@roles
These parameter all specify one or more roles to be applied to the specified metaclass. You can pass any or all of these parameters at once.
apply_base_class_roles( for_class => $class, roles => \@roles )
This function will apply the specified roles to the object's base class.