2 package Moose::Meta::Role;
9 use Scalar::Util 'blessed';
10 use B 'svref_2object';
12 use Moose::Meta::Class;
14 our $VERSION = '0.04';
18 ## the meta for the role package
20 __PACKAGE__->meta->add_attribute('_role_meta' => (
21 reader => '_role_meta',
22 init_arg => ':role_meta'
27 __PACKAGE__->meta->add_attribute('roles' => (
28 reader => 'get_roles',
34 __PACKAGE__->meta->add_attribute('excluded_roles_map' => (
35 reader => 'get_excluded_roles_map',
41 __PACKAGE__->meta->add_attribute('attribute_map' => (
42 reader => 'get_attribute_map',
48 __PACKAGE__->meta->add_attribute('required_methods' => (
49 reader => 'get_required_methods_map',
55 __PACKAGE__->meta->add_attribute('before_method_modifiers' => (
56 reader => 'get_before_method_modifiers_map',
57 default => sub { {} } # (<name> => [ (CODE) ])
60 __PACKAGE__->meta->add_attribute('after_method_modifiers' => (
61 reader => 'get_after_method_modifiers_map',
62 default => sub { {} } # (<name> => [ (CODE) ])
65 __PACKAGE__->meta->add_attribute('around_method_modifiers' => (
66 reader => 'get_around_method_modifiers_map',
67 default => sub { {} } # (<name> => [ (CODE) ])
70 __PACKAGE__->meta->add_attribute('override_method_modifiers' => (
71 reader => 'get_override_method_modifiers_map',
72 default => sub { {} } # (<name> => CODE)
80 $options{':role_meta'} = Moose::Meta::Class->initialize(
82 ':method_metaclass' => 'Moose::Meta::Role::Method'
83 ) unless defined $options{':role_meta'} &&
84 $options{':role_meta'}->isa('Moose::Meta::Class');
85 my $self = $class->meta->new_object(%options);
92 my ($self, $role) = @_;
93 (blessed($role) && $role->isa('Moose::Meta::Role'))
94 || confess "Roles must be instances of Moose::Meta::Role";
95 push @{$self->get_roles} => $role;
99 my ($self, $role_name) = @_;
101 || confess "You must supply a role name to look for";
102 # if we are it,.. then return true
103 return 1 if $role_name eq $self->name;
104 # otherwise.. check our children
105 foreach my $role (@{$self->get_roles}) {
106 return 1 if $role->does_role($role_name);
113 sub add_excluded_roles {
114 my ($self, @excluded_role_names) = @_;
115 $self->get_excluded_roles_map->{$_} = undef foreach @excluded_role_names;
118 sub get_excluded_roles_list {
120 keys %{$self->get_excluded_roles_map};
124 my ($self, $role_name) = @_;
125 exists $self->get_excluded_roles_map->{$role_name} ? 1 : 0;
130 sub add_required_methods {
131 my ($self, @methods) = @_;
132 $self->get_required_methods_map->{$_} = undef foreach @methods;
135 sub remove_required_methods {
136 my ($self, @methods) = @_;
137 delete $self->get_required_methods_map->{$_} foreach @methods;
140 sub get_required_method_list {
142 keys %{$self->get_required_methods_map};
145 sub requires_method {
146 my ($self, $method_name) = @_;
147 exists $self->get_required_methods_map->{$method_name} ? 1 : 0;
150 sub _clean_up_required_methods {
152 foreach my $method ($self->get_required_method_list) {
153 $self->remove_required_methods($method)
154 if $self->has_method($method);
161 # we delegate to some role_meta methods for convience here
162 # the Moose::Meta::Role is meant to be a read-only interface
163 # to the underlying role package, if you want to manipulate
164 # that, just use ->role_meta
166 sub name { (shift)->_role_meta->name }
167 sub version { (shift)->_role_meta->version }
169 sub get_method { (shift)->_role_meta->get_method(@_) }
170 sub has_method { (shift)->_role_meta->has_method(@_) }
171 sub alias_method { (shift)->_role_meta->alias_method(@_) }
172 sub get_method_list {
176 # this is a kludge for now,... these functions
177 # should not be showing up in the list at all,
178 # but they do, so we need to switch Moose::Role
179 # and Moose to use Sub::Exporter to prevent this
180 !/^(meta|has|extends|blessed|confess|augment|inner|override|super|before|after|around|with|requires)$/
181 } $self->_role_meta->get_method_list;
184 # ... however the items in statis (attributes & method modifiers)
185 # can be removed and added to through this API
193 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
199 $self->get_attribute_map->{$name} = $attr_desc;
203 my ($self, $name) = @_;
204 exists $self->get_attribute_map->{$name} ? 1 : 0;
208 my ($self, $name) = @_;
209 $self->get_attribute_map->{$name}
212 sub remove_attribute {
213 my ($self, $name) = @_;
214 delete $self->get_attribute_map->{$name}
217 sub get_attribute_list {
219 keys %{$self->get_attribute_map};
224 # mimic the metaclass API
225 sub add_before_method_modifier { (shift)->_add_method_modifier('before', @_) }
226 sub add_around_method_modifier { (shift)->_add_method_modifier('around', @_) }
227 sub add_after_method_modifier { (shift)->_add_method_modifier('after', @_) }
229 sub _add_method_modifier {
230 my ($self, $modifier_type, $method_name, $method) = @_;
231 my $accessor = "get_${modifier_type}_method_modifiers_map";
232 $self->$accessor->{$method_name} = []
233 unless exists $self->$accessor->{$method_name};
234 my $modifiers = $self->$accessor->{$method_name};
236 # check to see that we aren't adding the
237 # same code twice. We err in favor of the
238 # first on here, this may not be as expected
239 foreach my $modifier (@{$modifiers}) {
240 return if $modifier == $method;
242 push @{$modifiers} => $method;
245 sub add_override_method_modifier {
246 my ($self, $method_name, $method) = @_;
247 (!$self->has_method($method_name))
248 || confess "Cannot add an override of method '$method_name' " .
249 "because there is a local version of '$method_name'";
250 $self->get_override_method_modifiers_map->{$method_name} = $method;
253 sub has_before_method_modifiers { (shift)->_has_method_modifiers('before', @_) }
254 sub has_around_method_modifiers { (shift)->_has_method_modifiers('around', @_) }
255 sub has_after_method_modifiers { (shift)->_has_method_modifiers('after', @_) }
257 # override just checks for one,..
258 # but we can still re-use stuff
259 sub has_override_method_modifier { (shift)->_has_method_modifiers('override', @_) }
261 sub _has_method_modifiers {
262 my ($self, $modifier_type, $method_name) = @_;
263 my $accessor = "get_${modifier_type}_method_modifiers_map";
265 # for now we assume that if it exists,..
266 # it has at least one modifier in it
267 (exists $self->$accessor->{$method_name}) ? 1 : 0;
270 sub get_before_method_modifiers { (shift)->_get_method_modifiers('before', @_) }
271 sub get_around_method_modifiers { (shift)->_get_method_modifiers('around', @_) }
272 sub get_after_method_modifiers { (shift)->_get_method_modifiers('after', @_) }
274 sub _get_method_modifiers {
275 my ($self, $modifier_type, $method_name) = @_;
276 my $accessor = "get_${modifier_type}_method_modifiers_map";
277 @{$self->$accessor->{$method_name}};
280 sub get_override_method_modifier {
281 my ($self, $method_name) = @_;
282 $self->get_override_method_modifiers_map->{$method_name};
285 sub get_method_modifier_list {
286 my ($self, $modifier_type) = @_;
287 my $accessor = "get_${modifier_type}_method_modifiers_map";
288 keys %{$self->$accessor};
291 ## applying a role to a class ...
293 sub _check_excluded_roles {
294 my ($self, $other) = @_;
295 if ($other->excludes_role($self->name)) {
296 confess "Conflict detected: " . $other->name . " excludes role '" . $self->name . "'";
298 foreach my $excluded_role_name ($self->get_excluded_roles_list) {
299 if ($other->does_role($excluded_role_name)) {
300 confess "The class " . $other->name . " does the excluded role '$excluded_role_name'";
303 if ($other->isa('Moose::Meta::Role')) {
304 $other->add_excluded_roles($excluded_role_name);
306 # else -> ignore it :)
311 sub _check_required_methods {
312 my ($self, $other) = @_;
314 # we might need to move this down below the
315 # the attributes so that we can require any
316 # attribute accessors. However I am thinking
317 # that maybe those are somehow exempt from
318 # the require methods stuff.
319 foreach my $required_method_name ($self->get_required_method_list) {
320 unless ($other->has_method($required_method_name)) {
321 if ($other->isa('Moose::Meta::Role')) {
322 $other->add_required_methods($required_method_name);
325 confess "'" . $self->name . "' requires the method '$required_method_name' " .
326 "to be implemented by '" . $other->name . "'";
331 # we need to make sure that the method is
332 # not a method modifier, because those do
333 # not satisfy the requirements ...
334 my $method = $other->get_method($required_method_name);
335 # check if it is an override or a generated accessor ..
336 (!$method->isa('Moose::Meta::Method::Overriden') &&
337 !$method->isa('Class::MOP::Attribute::Accessor'))
338 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
339 "to be implemented by '" . $other->name . "', the method is only a method modifier";
340 # before/after/around methods are a little trickier
341 # since we wrap the original local method (if applicable)
342 # so we need to check if the original wrapped method is
343 # from the same package, and not a wrap of the super method
344 if ($method->isa('Class::MOP::Method::Wrapped')) {
345 ($method->get_original_method->package_name eq $other->name)
346 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
347 "to be implemented by '" . $other->name . "', the method is only a method modifier";
353 sub _apply_attributes {
354 my ($self, $other) = @_;
355 foreach my $attribute_name ($self->get_attribute_list) {
356 # it if it has one already
357 if ($other->has_attribute($attribute_name) &&
358 # make sure we haven't seen this one already too
359 $other->get_attribute($attribute_name) != $self->get_attribute($attribute_name)) {
360 # see if we are being composed
362 if ($other->isa('Moose::Meta::Role')) {
363 # all attribute conflicts between roles
364 # result in an immediate fatal error
365 confess "Role '" . $self->name . "' has encountered an attribute conflict " .
366 "during composition. This is fatal error and cannot be disambiguated.";
369 # but if this is a class, we
370 # can safely skip adding the
371 # attribute to the class
376 $other->add_attribute(
378 $self->get_attribute($attribute_name)
385 my ($self, $other) = @_;
386 foreach my $method_name ($self->get_method_list) {
387 # it if it has one already
388 if ($other->has_method($method_name) &&
389 # and if they are not the same thing ...
390 $other->get_method($method_name) != $self->get_method($method_name)) {
391 # see if we are composing into a role
392 if ($other->isa('Moose::Meta::Role')) {
393 # method conflicts between roles result
394 # in the method becoming a requirement
395 $other->add_required_methods($method_name);
397 # we have to remove the method from our
398 # role, if this is being called from combine()
399 # which means the meta is an anon class
400 # this *may* cause problems later, but it
401 # is probably fairly safe to assume that
402 # anon classes will only be used internally
403 # or by people who know what they are doing
404 $other->_role_meta->remove_method($method_name)
405 if $other->_role_meta->name =~ /__ANON__/;
412 # add it, although it could be overriden
413 $other->alias_method(
415 $self->get_method($method_name)
421 sub _apply_override_method_modifiers {
422 my ($self, $other) = @_;
423 foreach my $method_name ($self->get_method_modifier_list('override')) {
424 # it if it has one already then ...
425 if ($other->has_method($method_name)) {
426 # if it is being composed into another role
427 # we have a conflict here, because you cannot
428 # combine an overriden method with a locally
430 if ($other->isa('Moose::Meta::Role')) {
431 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
432 "during composition (A local method of the same name as been found). This " .
436 # if it is a class, then we
437 # just ignore this here ...
442 # if no local method is found, then we
443 # must check if we are a role or class
444 if ($other->isa('Moose::Meta::Role')) {
445 # if we are a role, we need to make sure
446 # we dont have a conflict with the role
447 # we are composing into
448 if ($other->has_override_method_modifier($method_name) &&
449 $other->get_override_method_modifier($method_name) != $self->get_override_method_modifier($method_name)) {
450 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
451 "during composition (Two 'override' methods of the same name encountered). " .
452 "This is fatal error.";
455 # if there is no conflict,
456 # just add it to the role
457 $other->add_override_method_modifier(
459 $self->get_override_method_modifier($method_name)
464 # if this is not a role, then we need to
465 # find the original package of the method
466 # so that we can tell the class were to
467 # find the right super() method
468 my $method = $self->get_override_method_modifier($method_name);
469 my $package = svref_2object($method)->GV->STASH->NAME;
470 # if it is a class, we just add it
471 $other->add_override_method_modifier($method_name, $method, $package);
477 sub _apply_method_modifiers {
478 my ($self, $modifier_type, $other) = @_;
479 my $add = "add_${modifier_type}_method_modifier";
480 my $get = "get_${modifier_type}_method_modifiers";
481 foreach my $method_name ($self->get_method_modifier_list($modifier_type)) {
485 ) foreach $self->$get($method_name);
489 sub _apply_before_method_modifiers { (shift)->_apply_method_modifiers('before' => @_) }
490 sub _apply_around_method_modifiers { (shift)->_apply_method_modifiers('around' => @_) }
491 sub _apply_after_method_modifiers { (shift)->_apply_method_modifiers('after' => @_) }
494 my ($self, $other) = @_;
496 $self->_check_excluded_roles($other);
497 $self->_check_required_methods($other);
499 $self->_apply_attributes($other);
500 $self->_apply_methods($other);
502 $self->_apply_override_method_modifiers($other);
503 $self->_apply_before_method_modifiers($other);
504 $self->_apply_around_method_modifiers($other);
505 $self->_apply_after_method_modifiers($other);
507 $other->add_role($self);
511 my ($class, @roles) = @_;
513 my $combined = $class->new(
514 ':role_meta' => Moose::Meta::Class->create_anon_class()
517 foreach my $role (@roles) {
518 $role->apply($combined);
521 $combined->_clean_up_required_methods;
526 package Moose::Meta::Role::Method;
531 our $VERSION = '0.01';
533 use base 'Class::MOP::Method';
543 Moose::Meta::Role - The Moose Role metaclass
547 Moose's Roles are being actively developed, please see L<Moose::Role>
548 for more information. For the most part, this has no user-serviceable
549 parts inside. It's API is still subject to some change (although
550 probably not that much really).
588 =item B<add_excluded_roles>
590 =item B<excludes_role>
592 =item B<get_excluded_roles_list>
594 =item B<get_excluded_roles_map>
604 =item B<alias_method>
606 =item B<get_method_list>
612 =item B<add_attribute>
614 =item B<has_attribute>
616 =item B<get_attribute>
618 =item B<get_attribute_list>
620 =item B<get_attribute_map>
622 =item B<remove_attribute>
628 =item B<add_required_methods>
630 =item B<remove_required_methods>
632 =item B<get_required_method_list>
634 =item B<get_required_methods_map>
636 =item B<requires_method>
642 =item B<add_after_method_modifier>
644 =item B<add_around_method_modifier>
646 =item B<add_before_method_modifier>
648 =item B<add_override_method_modifier>
654 =item B<has_after_method_modifiers>
656 =item B<has_around_method_modifiers>
658 =item B<has_before_method_modifiers>
660 =item B<has_override_method_modifier>
666 =item B<get_after_method_modifiers>
668 =item B<get_around_method_modifiers>
670 =item B<get_before_method_modifiers>
672 =item B<get_method_modifier_list>
678 =item B<get_override_method_modifier>
680 =item B<get_after_method_modifiers_map>
682 =item B<get_around_method_modifiers_map>
684 =item B<get_before_method_modifiers_map>
686 =item B<get_override_method_modifiers_map>
692 All complex software has bugs lurking in it, and this module is no
693 exception. If you find a bug please either email me, or add the bug
698 Stevan Little E<lt>stevan@iinteractive.comE<gt>
700 =head1 COPYRIGHT AND LICENSE
702 Copyright 2006 by Infinity Interactive, Inc.
704 L<http://www.iinteractive.com>
706 This library is free software; you can redistribute it and/or modify
707 it under the same terms as Perl itself.