2 package Moose::Meta::Role;
9 use Scalar::Util 'blessed';
10 use B 'svref_2object';
12 our $VERSION = '0.05';
14 use Moose::Meta::Class;
15 use Moose::Meta::Role::Method;
17 use base 'Class::MOP::Module';
23 __PACKAGE__->meta->add_attribute('roles' => (
24 reader => 'get_roles',
30 __PACKAGE__->meta->add_attribute('excluded_roles_map' => (
31 reader => 'get_excluded_roles_map',
37 __PACKAGE__->meta->add_attribute('attribute_map' => (
38 reader => 'get_attribute_map',
44 __PACKAGE__->meta->add_attribute('required_methods' => (
45 reader => 'get_required_methods_map',
51 __PACKAGE__->meta->add_attribute('before_method_modifiers' => (
52 reader => 'get_before_method_modifiers_map',
53 default => sub { {} } # (<name> => [ (CODE) ])
56 __PACKAGE__->meta->add_attribute('after_method_modifiers' => (
57 reader => 'get_after_method_modifiers_map',
58 default => sub { {} } # (<name> => [ (CODE) ])
61 __PACKAGE__->meta->add_attribute('around_method_modifiers' => (
62 reader => 'get_around_method_modifiers_map',
63 default => sub { {} } # (<name> => [ (CODE) ])
66 __PACKAGE__->meta->add_attribute('override_method_modifiers' => (
67 reader => 'get_override_method_modifiers_map',
68 default => sub { {} } # (<name> => CODE)
73 sub method_metaclass { 'Moose::Meta::Role::Method' }
78 my ($self, $role) = @_;
79 (blessed($role) && $role->isa('Moose::Meta::Role'))
80 || confess "Roles must be instances of Moose::Meta::Role";
81 push @{$self->get_roles} => $role;
84 sub calculate_all_roles {
87 grep { !$seen{$_->name}++ } $self, map { $_->calculate_all_roles } @{ $self->get_roles };
91 my ($self, $role_name) = @_;
93 || confess "You must supply a role name to look for";
94 # if we are it,.. then return true
95 return 1 if $role_name eq $self->name;
96 # otherwise.. check our children
97 foreach my $role (@{$self->get_roles}) {
98 return 1 if $role->does_role($role_name);
105 sub add_excluded_roles {
106 my ($self, @excluded_role_names) = @_;
107 $self->get_excluded_roles_map->{$_} = undef foreach @excluded_role_names;
110 sub get_excluded_roles_list {
112 keys %{$self->get_excluded_roles_map};
116 my ($self, $role_name) = @_;
117 exists $self->get_excluded_roles_map->{$role_name} ? 1 : 0;
122 sub add_required_methods {
123 my ($self, @methods) = @_;
124 $self->get_required_methods_map->{$_} = undef foreach @methods;
127 sub remove_required_methods {
128 my ($self, @methods) = @_;
129 delete $self->get_required_methods_map->{$_} foreach @methods;
132 sub get_required_method_list {
134 keys %{$self->get_required_methods_map};
137 sub requires_method {
138 my ($self, $method_name) = @_;
139 exists $self->get_required_methods_map->{$method_name} ? 1 : 0;
142 sub _clean_up_required_methods {
144 foreach my $method ($self->get_required_method_list) {
145 $self->remove_required_methods($method)
146 if $self->has_method($method);
153 # this is an UGLY hack
156 $self->{'%!methods'} ||= {};
157 $self->Moose::Meta::Class::get_method_map()
161 # Yes, this is a really really UGLY hack
162 # but it works, and until I can figure
163 # out a better way, this is gonna be it.
165 sub get_method { (shift)->Moose::Meta::Class::get_method(@_) }
166 sub has_method { (shift)->Moose::Meta::Class::has_method(@_) }
167 sub alias_method { (shift)->Moose::Meta::Class::alias_method(@_) }
168 sub get_method_list {
171 } (shift)->Moose::Meta::Class::get_method_list(@_)
174 sub find_method_by_name { (shift)->has_method(@_) }
176 # ... however the items in statis (attributes & method modifiers)
177 # can be removed and added to through this API
185 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
191 $self->get_attribute_map->{$name} = $attr_desc;
195 my ($self, $name) = @_;
196 exists $self->get_attribute_map->{$name} ? 1 : 0;
200 my ($self, $name) = @_;
201 $self->get_attribute_map->{$name}
204 sub remove_attribute {
205 my ($self, $name) = @_;
206 delete $self->get_attribute_map->{$name}
209 sub get_attribute_list {
211 keys %{$self->get_attribute_map};
216 # mimic the metaclass API
217 sub add_before_method_modifier { (shift)->_add_method_modifier('before', @_) }
218 sub add_around_method_modifier { (shift)->_add_method_modifier('around', @_) }
219 sub add_after_method_modifier { (shift)->_add_method_modifier('after', @_) }
221 sub _add_method_modifier {
222 my ($self, $modifier_type, $method_name, $method) = @_;
223 my $accessor = "get_${modifier_type}_method_modifiers_map";
224 $self->$accessor->{$method_name} = []
225 unless exists $self->$accessor->{$method_name};
226 my $modifiers = $self->$accessor->{$method_name};
228 # check to see that we aren't adding the
229 # same code twice. We err in favor of the
230 # first on here, this may not be as expected
231 foreach my $modifier (@{$modifiers}) {
232 return if $modifier == $method;
234 push @{$modifiers} => $method;
237 sub add_override_method_modifier {
238 my ($self, $method_name, $method) = @_;
239 (!$self->has_method($method_name))
240 || confess "Cannot add an override of method '$method_name' " .
241 "because there is a local version of '$method_name'";
242 $self->get_override_method_modifiers_map->{$method_name} = $method;
245 sub has_before_method_modifiers { (shift)->_has_method_modifiers('before', @_) }
246 sub has_around_method_modifiers { (shift)->_has_method_modifiers('around', @_) }
247 sub has_after_method_modifiers { (shift)->_has_method_modifiers('after', @_) }
249 # override just checks for one,..
250 # but we can still re-use stuff
251 sub has_override_method_modifier { (shift)->_has_method_modifiers('override', @_) }
253 sub _has_method_modifiers {
254 my ($self, $modifier_type, $method_name) = @_;
255 my $accessor = "get_${modifier_type}_method_modifiers_map";
257 # for now we assume that if it exists,..
258 # it has at least one modifier in it
259 (exists $self->$accessor->{$method_name}) ? 1 : 0;
262 sub get_before_method_modifiers { (shift)->_get_method_modifiers('before', @_) }
263 sub get_around_method_modifiers { (shift)->_get_method_modifiers('around', @_) }
264 sub get_after_method_modifiers { (shift)->_get_method_modifiers('after', @_) }
266 sub _get_method_modifiers {
267 my ($self, $modifier_type, $method_name) = @_;
268 my $accessor = "get_${modifier_type}_method_modifiers_map";
269 @{$self->$accessor->{$method_name}};
272 sub get_override_method_modifier {
273 my ($self, $method_name) = @_;
274 $self->get_override_method_modifiers_map->{$method_name};
277 sub get_method_modifier_list {
278 my ($self, $modifier_type) = @_;
279 my $accessor = "get_${modifier_type}_method_modifiers_map";
280 keys %{$self->$accessor};
283 ## applying a role to a class ...
285 sub _check_excluded_roles {
286 my ($self, $other) = @_;
287 if ($other->excludes_role($self->name)) {
288 confess "Conflict detected: " . $other->name . " excludes role '" . $self->name . "'";
290 foreach my $excluded_role_name ($self->get_excluded_roles_list) {
291 if ($other->does_role($excluded_role_name)) {
292 confess "The class " . $other->name . " does the excluded role '$excluded_role_name'";
295 if ($other->isa('Moose::Meta::Role')) {
296 $other->add_excluded_roles($excluded_role_name);
298 # else -> ignore it :)
303 sub _check_required_methods {
304 my ($self, $other) = @_;
306 # we might need to move this down below the
307 # the attributes so that we can require any
308 # attribute accessors. However I am thinking
309 # that maybe those are somehow exempt from
310 # the require methods stuff.
311 foreach my $required_method_name ($self->get_required_method_list) {
313 unless ($other->find_method_by_name($required_method_name)) {
314 if ($other->isa('Moose::Meta::Role')) {
315 $other->add_required_methods($required_method_name);
318 confess "'" . $self->name . "' requires the method '$required_method_name' " .
319 "to be implemented by '" . $other->name . "'";
324 # we need to make sure that the method is
325 # not a method modifier, because those do
326 # not satisfy the requirements ...
327 my $method = $other->get_method($required_method_name);
328 # check if it is an override or a generated accessor ..
329 (!$method->isa('Moose::Meta::Method::Overriden') &&
330 !$method->isa('Class::MOP::Method::Accessor'))
331 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
332 "to be implemented by '" . $other->name . "', the method is only a method modifier";
333 # before/after/around methods are a little trickier
334 # since we wrap the original local method (if applicable)
335 # so we need to check if the original wrapped method is
336 # from the same package, and not a wrap of the super method
337 if ($method->isa('Class::MOP::Method::Wrapped')) {
338 ($method->get_original_method->package_name eq $other->name)
339 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
340 "to be implemented by '" . $other->name . "', the method is only a method modifier";
346 sub _apply_attributes {
347 my ($self, $other) = @_;
348 foreach my $attribute_name ($self->get_attribute_list) {
349 # it if it has one already
350 if ($other->has_attribute($attribute_name) &&
351 # make sure we haven't seen this one already too
352 $other->get_attribute($attribute_name) != $self->get_attribute($attribute_name)) {
353 # see if we are being composed
355 if ($other->isa('Moose::Meta::Role')) {
356 # all attribute conflicts between roles
357 # result in an immediate fatal error
358 confess "Role '" . $self->name . "' has encountered an attribute conflict " .
359 "during composition. This is fatal error and cannot be disambiguated.";
362 # but if this is a class, we
363 # can safely skip adding the
364 # attribute to the class
369 $other->add_attribute(
371 $self->get_attribute($attribute_name)
378 my ($self, $other) = @_;
379 foreach my $method_name ($self->get_method_list) {
380 # it if it has one already
381 if ($other->has_method($method_name) &&
382 # and if they are not the same thing ...
383 $other->get_method($method_name)->body != $self->get_method($method_name)->body) {
384 # see if we are composing into a role
385 if ($other->isa('Moose::Meta::Role')) {
386 # method conflicts between roles result
387 # in the method becoming a requirement
388 $other->add_required_methods($method_name);
390 # we have to remove the method from our
391 # role, if this is being called from combine()
392 # which means the meta is an anon class
393 # this *may* cause problems later, but it
394 # is probably fairly safe to assume that
395 # anon classes will only be used internally
396 # or by people who know what they are doing
397 $other->Moose::Meta::Class::remove_method($method_name)
398 if $other->name =~ /__COMPOSITE_ROLE_SANDBOX__/;
405 # add it, although it could be overriden
406 $other->alias_method(
408 $self->get_method($method_name)
414 sub _apply_override_method_modifiers {
415 my ($self, $other) = @_;
416 foreach my $method_name ($self->get_method_modifier_list('override')) {
417 # it if it has one already then ...
418 if ($other->has_method($method_name)) {
419 # if it is being composed into another role
420 # we have a conflict here, because you cannot
421 # combine an overriden method with a locally
423 if ($other->isa('Moose::Meta::Role')) {
424 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
425 "during composition (A local method of the same name as been found). This " .
429 # if it is a class, then we
430 # just ignore this here ...
435 # if no local method is found, then we
436 # must check if we are a role or class
437 if ($other->isa('Moose::Meta::Role')) {
438 # if we are a role, we need to make sure
439 # we dont have a conflict with the role
440 # we are composing into
441 if ($other->has_override_method_modifier($method_name) &&
442 $other->get_override_method_modifier($method_name) != $self->get_override_method_modifier($method_name)) {
443 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
444 "during composition (Two 'override' methods of the same name encountered). " .
445 "This is fatal error.";
448 # if there is no conflict,
449 # just add it to the role
450 $other->add_override_method_modifier(
452 $self->get_override_method_modifier($method_name)
457 # if this is not a role, then we need to
458 # find the original package of the method
459 # so that we can tell the class were to
460 # find the right super() method
461 my $method = $self->get_override_method_modifier($method_name);
462 my $package = svref_2object($method)->GV->STASH->NAME;
463 # if it is a class, we just add it
464 $other->add_override_method_modifier($method_name, $method, $package);
470 sub _apply_method_modifiers {
471 my ($self, $modifier_type, $other) = @_;
472 my $add = "add_${modifier_type}_method_modifier";
473 my $get = "get_${modifier_type}_method_modifiers";
474 foreach my $method_name ($self->get_method_modifier_list($modifier_type)) {
478 ) foreach $self->$get($method_name);
482 sub _apply_before_method_modifiers { (shift)->_apply_method_modifiers('before' => @_) }
483 sub _apply_around_method_modifiers { (shift)->_apply_method_modifiers('around' => @_) }
484 sub _apply_after_method_modifiers { (shift)->_apply_method_modifiers('after' => @_) }
486 my $anon_counter = 0;
489 my ($self, $other) = @_;
491 unless ($other->isa('Moose::Meta::Class') || $other->isa('Moose::Meta::Role')) {
493 # Runtime Role mixins
496 # We really should do this better, and
497 # cache the results of our efforts so
498 # that we don't need to repeat them.
500 my $pkg_name = __PACKAGE__ . "::__RUNTIME_ROLE_ANON_CLASS__::" . $anon_counter++;
501 eval "package " . $pkg_name . "; our \$VERSION = '0.00';";
506 $other = Moose::Meta::Class->initialize($pkg_name);
507 $other->superclasses(blessed($object));
509 bless $object => $pkg_name;
512 $self->_check_excluded_roles($other);
513 $self->_check_required_methods($other);
515 $self->_apply_attributes($other);
516 $self->_apply_methods($other);
518 $self->_apply_override_method_modifiers($other);
519 $self->_apply_before_method_modifiers($other);
520 $self->_apply_around_method_modifiers($other);
521 $self->_apply_after_method_modifiers($other);
523 $other->add_role($self);
527 my ($class, @roles) = @_;
529 my $pkg_name = __PACKAGE__ . "::__COMPOSITE_ROLE_SANDBOX__::" . $anon_counter++;
530 eval "package " . $pkg_name . "; our \$VERSION = '0.00';";
533 my $combined = $class->initialize($pkg_name);
535 foreach my $role (@roles) {
536 $role->apply($combined);
539 $combined->_clean_up_required_methods;
552 Moose::Meta::Role - The Moose Role metaclass
556 Moose's Roles are being actively developed, please see L<Moose::Role>
557 for more information. For the most part, this has no user-serviceable
558 parts inside. It's API is still subject to some change (although
559 probably not that much really).
597 =item B<add_excluded_roles>
599 =item B<excludes_role>
601 =item B<get_excluded_roles_list>
603 =item B<get_excluded_roles_map>
605 =item B<calculate_all_roles>
611 =item B<method_metaclass>
613 =item B<find_method_by_name>
619 =item B<alias_method>
621 =item B<get_method_list>
623 =item B<get_method_map>
629 =item B<add_attribute>
631 =item B<has_attribute>
633 =item B<get_attribute>
635 =item B<get_attribute_list>
637 =item B<get_attribute_map>
639 =item B<remove_attribute>
645 =item B<add_required_methods>
647 =item B<remove_required_methods>
649 =item B<get_required_method_list>
651 =item B<get_required_methods_map>
653 =item B<requires_method>
659 =item B<add_after_method_modifier>
661 =item B<add_around_method_modifier>
663 =item B<add_before_method_modifier>
665 =item B<add_override_method_modifier>
671 =item B<has_after_method_modifiers>
673 =item B<has_around_method_modifiers>
675 =item B<has_before_method_modifiers>
677 =item B<has_override_method_modifier>
683 =item B<get_after_method_modifiers>
685 =item B<get_around_method_modifiers>
687 =item B<get_before_method_modifiers>
689 =item B<get_method_modifier_list>
695 =item B<get_override_method_modifier>
697 =item B<get_after_method_modifiers_map>
699 =item B<get_around_method_modifiers_map>
701 =item B<get_before_method_modifiers_map>
703 =item B<get_override_method_modifiers_map>
709 All complex software has bugs lurking in it, and this module is no
710 exception. If you find a bug please either email me, or add the bug
715 Stevan Little E<lt>stevan@iinteractive.comE<gt>
717 =head1 COPYRIGHT AND LICENSE
719 Copyright 2006, 2007 by Infinity Interactive, Inc.
721 L<http://www.iinteractive.com>
723 This library is free software; you can redistribute it and/or modify
724 it under the same terms as Perl itself.