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} => $role;
98 sub calculate_all_roles {
101 grep { !$seen{$_->name}++ } $self, map { $_->calculate_all_roles } @{ $self->get_roles };
105 my ($self, $role_name) = @_;
107 || confess "You must supply a role name to look for";
108 # if we are it,.. then return true
109 return 1 if $role_name eq $self->name;
110 # otherwise.. check our children
111 foreach my $role (@{$self->get_roles}) {
112 return 1 if $role->does_role($role_name);
119 sub add_excluded_roles {
120 my ($self, @excluded_role_names) = @_;
121 $self->get_excluded_roles_map->{$_} = undef foreach @excluded_role_names;
124 sub get_excluded_roles_list {
126 keys %{$self->get_excluded_roles_map};
130 my ($self, $role_name) = @_;
131 exists $self->get_excluded_roles_map->{$role_name} ? 1 : 0;
136 sub add_required_methods {
137 my ($self, @methods) = @_;
138 $self->get_required_methods_map->{$_} = undef foreach @methods;
141 sub remove_required_methods {
142 my ($self, @methods) = @_;
143 delete $self->get_required_methods_map->{$_} foreach @methods;
146 sub get_required_method_list {
148 keys %{$self->get_required_methods_map};
151 sub requires_method {
152 my ($self, $method_name) = @_;
153 exists $self->get_required_methods_map->{$method_name} ? 1 : 0;
156 sub _clean_up_required_methods {
158 foreach my $method ($self->get_required_method_list) {
159 $self->remove_required_methods($method)
160 if $self->has_method($method);
167 # we delegate to some role_meta methods for convience here
168 # the Moose::Meta::Role is meant to be a read-only interface
169 # to the underlying role package, if you want to manipulate
170 # that, just use ->role_meta
172 sub name { (shift)->_role_meta->name }
173 sub version { (shift)->_role_meta->version }
175 sub get_method { (shift)->_role_meta->get_method(@_) }
176 sub has_method { (shift)->_role_meta->has_method(@_) }
177 sub alias_method { (shift)->_role_meta->alias_method(@_) }
178 sub get_method_list {
182 # this is a kludge for now,... these functions
183 # should not be showing up in the list at all,
184 # but they do, so we need to switch Moose::Role
185 # and Moose to use Sub::Exporter to prevent this
186 !/^(meta|has|extends|blessed|confess|augment|inner|override|super|before|after|around|with|requires)$/
187 } $self->_role_meta->get_method_list;
190 # ... however the items in statis (attributes & method modifiers)
191 # can be removed and added to through this API
199 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
205 $self->get_attribute_map->{$name} = $attr_desc;
209 my ($self, $name) = @_;
210 exists $self->get_attribute_map->{$name} ? 1 : 0;
214 my ($self, $name) = @_;
215 $self->get_attribute_map->{$name}
218 sub remove_attribute {
219 my ($self, $name) = @_;
220 delete $self->get_attribute_map->{$name}
223 sub get_attribute_list {
225 keys %{$self->get_attribute_map};
230 # mimic the metaclass API
231 sub add_before_method_modifier { (shift)->_add_method_modifier('before', @_) }
232 sub add_around_method_modifier { (shift)->_add_method_modifier('around', @_) }
233 sub add_after_method_modifier { (shift)->_add_method_modifier('after', @_) }
235 sub _add_method_modifier {
236 my ($self, $modifier_type, $method_name, $method) = @_;
237 my $accessor = "get_${modifier_type}_method_modifiers_map";
238 $self->$accessor->{$method_name} = []
239 unless exists $self->$accessor->{$method_name};
240 my $modifiers = $self->$accessor->{$method_name};
242 # check to see that we aren't adding the
243 # same code twice. We err in favor of the
244 # first on here, this may not be as expected
245 foreach my $modifier (@{$modifiers}) {
246 return if $modifier == $method;
248 push @{$modifiers} => $method;
251 sub add_override_method_modifier {
252 my ($self, $method_name, $method) = @_;
253 (!$self->has_method($method_name))
254 || confess "Cannot add an override of method '$method_name' " .
255 "because there is a local version of '$method_name'";
256 $self->get_override_method_modifiers_map->{$method_name} = $method;
259 sub has_before_method_modifiers { (shift)->_has_method_modifiers('before', @_) }
260 sub has_around_method_modifiers { (shift)->_has_method_modifiers('around', @_) }
261 sub has_after_method_modifiers { (shift)->_has_method_modifiers('after', @_) }
263 # override just checks for one,..
264 # but we can still re-use stuff
265 sub has_override_method_modifier { (shift)->_has_method_modifiers('override', @_) }
267 sub _has_method_modifiers {
268 my ($self, $modifier_type, $method_name) = @_;
269 my $accessor = "get_${modifier_type}_method_modifiers_map";
271 # for now we assume that if it exists,..
272 # it has at least one modifier in it
273 (exists $self->$accessor->{$method_name}) ? 1 : 0;
276 sub get_before_method_modifiers { (shift)->_get_method_modifiers('before', @_) }
277 sub get_around_method_modifiers { (shift)->_get_method_modifiers('around', @_) }
278 sub get_after_method_modifiers { (shift)->_get_method_modifiers('after', @_) }
280 sub _get_method_modifiers {
281 my ($self, $modifier_type, $method_name) = @_;
282 my $accessor = "get_${modifier_type}_method_modifiers_map";
283 @{$self->$accessor->{$method_name}};
286 sub get_override_method_modifier {
287 my ($self, $method_name) = @_;
288 $self->get_override_method_modifiers_map->{$method_name};
291 sub get_method_modifier_list {
292 my ($self, $modifier_type) = @_;
293 my $accessor = "get_${modifier_type}_method_modifiers_map";
294 keys %{$self->$accessor};
297 ## applying a role to a class ...
299 sub _check_excluded_roles {
300 my ($self, $other) = @_;
301 if ($other->excludes_role($self->name)) {
302 confess "Conflict detected: " . $other->name . " excludes role '" . $self->name . "'";
304 foreach my $excluded_role_name ($self->get_excluded_roles_list) {
305 if ($other->does_role($excluded_role_name)) {
306 confess "The class " . $other->name . " does the excluded role '$excluded_role_name'";
309 if ($other->isa('Moose::Meta::Role')) {
310 $other->add_excluded_roles($excluded_role_name);
312 # else -> ignore it :)
317 sub _check_required_methods {
318 my ($self, $other) = @_;
320 # we might need to move this down below the
321 # the attributes so that we can require any
322 # attribute accessors. However I am thinking
323 # that maybe those are somehow exempt from
324 # the require methods stuff.
325 foreach my $required_method_name ($self->get_required_method_list) {
326 unless ($other->has_method($required_method_name)) {
327 if ($other->isa('Moose::Meta::Role')) {
328 $other->add_required_methods($required_method_name);
331 confess "'" . $self->name . "' requires the method '$required_method_name' " .
332 "to be implemented by '" . $other->name . "'";
337 # we need to make sure that the method is
338 # not a method modifier, because those do
339 # not satisfy the requirements ...
340 my $method = $other->get_method($required_method_name);
341 # check if it is an override or a generated accessor ..
342 (!$method->isa('Moose::Meta::Method::Overriden') &&
343 !$method->isa('Class::MOP::Attribute::Accessor'))
344 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
345 "to be implemented by '" . $other->name . "', the method is only a method modifier";
346 # before/after/around methods are a little trickier
347 # since we wrap the original local method (if applicable)
348 # so we need to check if the original wrapped method is
349 # from the same package, and not a wrap of the super method
350 if ($method->isa('Class::MOP::Method::Wrapped')) {
351 ($method->get_original_method->package_name eq $other->name)
352 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
353 "to be implemented by '" . $other->name . "', the method is only a method modifier";
359 sub _apply_attributes {
360 my ($self, $other) = @_;
361 foreach my $attribute_name ($self->get_attribute_list) {
362 # it if it has one already
363 if ($other->has_attribute($attribute_name) &&
364 # make sure we haven't seen this one already too
365 $other->get_attribute($attribute_name) != $self->get_attribute($attribute_name)) {
366 # see if we are being composed
368 if ($other->isa('Moose::Meta::Role')) {
369 # all attribute conflicts between roles
370 # result in an immediate fatal error
371 confess "Role '" . $self->name . "' has encountered an attribute conflict " .
372 "during composition. This is fatal error and cannot be disambiguated.";
375 # but if this is a class, we
376 # can safely skip adding the
377 # attribute to the class
382 $other->add_attribute(
384 $self->get_attribute($attribute_name)
391 my ($self, $other) = @_;
392 foreach my $method_name ($self->get_method_list) {
393 # it if it has one already
394 if ($other->has_method($method_name) &&
395 # and if they are not the same thing ...
396 $other->get_method($method_name) != $self->get_method($method_name)) {
397 # see if we are composing into a role
398 if ($other->isa('Moose::Meta::Role')) {
399 # method conflicts between roles result
400 # in the method becoming a requirement
401 $other->add_required_methods($method_name);
403 # we have to remove the method from our
404 # role, if this is being called from combine()
405 # which means the meta is an anon class
406 # this *may* cause problems later, but it
407 # is probably fairly safe to assume that
408 # anon classes will only be used internally
409 # or by people who know what they are doing
410 $other->_role_meta->remove_method($method_name)
411 if $other->_role_meta->name =~ /__ANON__/;
418 # add it, although it could be overriden
419 $other->alias_method(
421 $self->get_method($method_name)
427 sub _apply_override_method_modifiers {
428 my ($self, $other) = @_;
429 foreach my $method_name ($self->get_method_modifier_list('override')) {
430 # it if it has one already then ...
431 if ($other->has_method($method_name)) {
432 # if it is being composed into another role
433 # we have a conflict here, because you cannot
434 # combine an overriden method with a locally
436 if ($other->isa('Moose::Meta::Role')) {
437 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
438 "during composition (A local method of the same name as been found). This " .
442 # if it is a class, then we
443 # just ignore this here ...
448 # if no local method is found, then we
449 # must check if we are a role or class
450 if ($other->isa('Moose::Meta::Role')) {
451 # if we are a role, we need to make sure
452 # we dont have a conflict with the role
453 # we are composing into
454 if ($other->has_override_method_modifier($method_name) &&
455 $other->get_override_method_modifier($method_name) != $self->get_override_method_modifier($method_name)) {
456 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
457 "during composition (Two 'override' methods of the same name encountered). " .
458 "This is fatal error.";
461 # if there is no conflict,
462 # just add it to the role
463 $other->add_override_method_modifier(
465 $self->get_override_method_modifier($method_name)
470 # if this is not a role, then we need to
471 # find the original package of the method
472 # so that we can tell the class were to
473 # find the right super() method
474 my $method = $self->get_override_method_modifier($method_name);
475 my $package = svref_2object($method)->GV->STASH->NAME;
476 # if it is a class, we just add it
477 $other->add_override_method_modifier($method_name, $method, $package);
483 sub _apply_method_modifiers {
484 my ($self, $modifier_type, $other) = @_;
485 my $add = "add_${modifier_type}_method_modifier";
486 my $get = "get_${modifier_type}_method_modifiers";
487 foreach my $method_name ($self->get_method_modifier_list($modifier_type)) {
491 ) foreach $self->$get($method_name);
495 sub _apply_before_method_modifiers { (shift)->_apply_method_modifiers('before' => @_) }
496 sub _apply_around_method_modifiers { (shift)->_apply_method_modifiers('around' => @_) }
497 sub _apply_after_method_modifiers { (shift)->_apply_method_modifiers('after' => @_) }
500 my ($self, $other) = @_;
502 $self->_check_excluded_roles($other);
503 $self->_check_required_methods($other);
505 $self->_apply_attributes($other);
506 $self->_apply_methods($other);
508 $self->_apply_override_method_modifiers($other);
509 $self->_apply_before_method_modifiers($other);
510 $self->_apply_around_method_modifiers($other);
511 $self->_apply_after_method_modifiers($other);
513 $other->add_role($self);
517 my ($class, @roles) = @_;
519 my $combined = $class->new(
520 ':role_meta' => Moose::Meta::Class->create_anon_class()
523 foreach my $role (@roles) {
524 $role->apply($combined);
527 $combined->_clean_up_required_methods;
532 package Moose::Meta::Role::Method;
537 our $VERSION = '0.01';
539 use base 'Class::MOP::Method';
549 Moose::Meta::Role - The Moose Role metaclass
553 Moose's Roles are being actively developed, please see L<Moose::Role>
554 for more information. For the most part, this has no user-serviceable
555 parts inside. It's API is still subject to some change (although
556 probably not that much really).
594 =item B<add_excluded_roles>
596 =item B<excludes_role>
598 =item B<get_excluded_roles_list>
600 =item B<get_excluded_roles_map>
610 =item B<alias_method>
612 =item B<get_method_list>
618 =item B<add_attribute>
620 =item B<has_attribute>
622 =item B<get_attribute>
624 =item B<get_attribute_list>
626 =item B<get_attribute_map>
628 =item B<remove_attribute>
634 =item B<add_required_methods>
636 =item B<remove_required_methods>
638 =item B<get_required_method_list>
640 =item B<get_required_methods_map>
642 =item B<requires_method>
648 =item B<add_after_method_modifier>
650 =item B<add_around_method_modifier>
652 =item B<add_before_method_modifier>
654 =item B<add_override_method_modifier>
660 =item B<has_after_method_modifiers>
662 =item B<has_around_method_modifiers>
664 =item B<has_before_method_modifiers>
666 =item B<has_override_method_modifier>
672 =item B<get_after_method_modifiers>
674 =item B<get_around_method_modifiers>
676 =item B<get_before_method_modifiers>
678 =item B<get_method_modifier_list>
684 =item B<get_override_method_modifier>
686 =item B<get_after_method_modifiers_map>
688 =item B<get_around_method_modifiers_map>
690 =item B<get_before_method_modifiers_map>
692 =item B<get_override_method_modifiers_map>
698 All complex software has bugs lurking in it, and this module is no
699 exception. If you find a bug please either email me, or add the bug
704 Stevan Little E<lt>stevan@iinteractive.comE<gt>
706 =head1 COPYRIGHT AND LICENSE
708 Copyright 2006 by Infinity Interactive, Inc.
710 L<http://www.iinteractive.com>
712 This library is free software; you can redistribute it and/or modify
713 it under the same terms as Perl itself.