2 package Moose::Meta::Role;
9 use Scalar::Util 'blessed';
10 use B 'svref_2object';
12 use Moose::Meta::Class;
14 our $VERSION = '0.03';
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 } $self->_role_meta->get_method_list;
184 # ... however the items in statis (attributes & method modifiers)
185 # can be removed and added to through this API
190 my ($self, $name, %attr_desc) = @_;
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 $self->get_override_method_modifiers_map->{$method_name} = $method;
242 sub has_before_method_modifiers { (shift)->_has_method_modifiers('before', @_) }
243 sub has_around_method_modifiers { (shift)->_has_method_modifiers('around', @_) }
244 sub has_after_method_modifiers { (shift)->_has_method_modifiers('after', @_) }
246 # override just checks for one,..
247 # but we can still re-use stuff
248 sub has_override_method_modifier { (shift)->_has_method_modifiers('override', @_) }
250 sub _has_method_modifiers {
251 my ($self, $modifier_type, $method_name) = @_;
252 my $accessor = "get_${modifier_type}_method_modifiers_map";
254 # for now we assume that if it exists,..
255 # it has at least one modifier in it
256 (exists $self->$accessor->{$method_name}) ? 1 : 0;
259 sub get_before_method_modifiers { (shift)->_get_method_modifiers('before', @_) }
260 sub get_around_method_modifiers { (shift)->_get_method_modifiers('around', @_) }
261 sub get_after_method_modifiers { (shift)->_get_method_modifiers('after', @_) }
263 sub _get_method_modifiers {
264 my ($self, $modifier_type, $method_name) = @_;
265 my $accessor = "get_${modifier_type}_method_modifiers_map";
266 @{$self->$accessor->{$method_name}};
269 sub get_override_method_modifier {
270 my ($self, $method_name) = @_;
271 $self->get_override_method_modifiers_map->{$method_name};
274 sub get_method_modifier_list {
275 my ($self, $modifier_type) = @_;
276 my $accessor = "get_${modifier_type}_method_modifiers_map";
277 keys %{$self->$accessor};
280 ## applying a role to a class ...
283 my ($self, $other) = @_;
285 if ($other->excludes_role($self->name)) {
286 confess "Conflict detected: " . $other->name . " excludes role '" . $self->name . "'";
289 # warn "... Checking " . $self->name . " for excluded methods";
290 foreach my $excluded_role_name ($self->get_excluded_roles_list) {
291 # warn "... Checking if '$excluded_role_name' is done by " . $other->name . " for " . $self->name;
292 if ($other->does_role($excluded_role_name)) {
293 confess "The class " . $other->name . " does the excluded role '$excluded_role_name'";
296 if ($other->isa('Moose::Meta::Role')) {
297 # warn ">>> The role " . $other->name . " does not do the excluded role '$excluded_role_name', so we are adding it in";
298 $other->add_excluded_roles($excluded_role_name);
301 # warn ">>> The class " . $other->name . " does not do the excluded role '$excluded_role_name', so we can just go about our business";
308 # we might need to move this down below the
309 # the attributes so that we can require any
310 # attribute accessors. However I am thinking
311 # that maybe those are somehow exempt from
312 # the require methods stuff.
313 foreach my $required_method_name ($self->get_required_method_list) {
314 unless ($other->has_method($required_method_name)) {
315 if ($other->isa('Moose::Meta::Role')) {
316 $other->add_required_methods($required_method_name);
319 confess "'" . $self->name . "' requires the method '$required_method_name' " .
320 "to be implemented by '" . $other->name . "'";
325 # we need to make sure that the method is
326 # not a method modifier, because those do
327 # not satisfy the requirements ...
328 my $method = $other->get_method($required_method_name);
329 # check if it is an override or a generated accessor ..
330 (!$method->isa('Moose::Meta::Method::Overriden') &&
331 !$method->isa('Class::MOP::Attribute::Accessor'))
332 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
333 "to be implemented by '" . $other->name . "', the method is only a method modifier";
334 # before/after/around methods are a little trickier
335 # since we wrap the original local method (if applicable)
336 # so we need to check if the original wrapped method is
337 # from the same package, and not a wrap of the super method
338 if ($method->isa('Class::MOP::Method::Wrapped')) {
339 ($method->get_original_method->package_name eq $other->name)
340 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
341 "to be implemented by '" . $other->name . "', the method is only a method modifier";
346 foreach my $attribute_name ($self->get_attribute_list) {
347 # it if it has one already
348 if ($other->has_attribute($attribute_name)) {
349 # see if we are being composed
351 if ($other->isa('Moose::Meta::Role')) {
354 # it is possible for these attributes
355 # to actually both be from the same
356 # origin (some common ancestor role)
357 # so we need to find a way to check this
359 # all attribute conflicts between roles
360 # result in an immediate fatal error
361 confess "Role '" . $self->name . "' has encountered an attribute conflict " .
362 "during composition. This is fatal error and cannot be disambiguated.";
365 # but if this is a class, we
366 # can safely skip adding the
367 # attribute to the class
372 # add it, although it could be overriden
373 $other->add_attribute(
375 %{$self->get_attribute($attribute_name)}
380 foreach my $method_name ($self->get_method_list) {
381 # it if it has one already
382 if ($other->has_method($method_name) &&
383 # and if they are not the same thing ...
384 $other->get_method($method_name) != $self->get_method($method_name)) {
385 # see if we are composing into a role
386 if ($other->isa('Moose::Meta::Role')) {
387 # method conflicts between roles result
388 # in the method becoming a requirement
389 $other->add_required_methods($method_name);
391 # we have to remove the method from our
392 # role, if this is being called from combine()
393 # which means the meta is an anon class
394 # this *may* cause problems later, but it
395 # is probably fairly safe to assume that
396 # anon classes will only be used internally
397 # or by people who know what they are doing
398 $other->_role_meta->remove_method($method_name)
399 if $other->_role_meta->name =~ /__ANON__/;
406 # add it, although it could be overriden
407 $other->alias_method(
409 $self->get_method($method_name)
414 foreach my $method_name ($self->get_method_modifier_list('override')) {
415 # it if it has one already then ...
416 if ($other->has_method($method_name)) {
417 # if it is being composed into another role
418 # we have a conflict here, because you cannot
419 # combine an overriden method with a locally
421 if ($other->isa('Moose::Meta::Role')) {
422 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
423 "during composition (A local method of the same name as been found). This " .
427 # if it is a class, then we
428 # just ignore this here ...
433 # if no local method is found, then we
434 # must check if we are a role or class
435 if ($other->isa('Moose::Meta::Role')) {
436 # if we are a role, we need to make sure
437 # we dont have a conflict with the role
438 # we are composing into
439 if ($other->has_override_method_modifier($method_name) &&
440 $other->get_override_method_modifier($method_name) != $self->get_override_method_modifier($method_name)) {
441 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
442 "during composition (Two 'override' methods of the same name encountered). " .
443 "This is fatal error.";
446 # if there is no conflict,
447 # just add it to the role
448 $other->add_override_method_modifier(
450 $self->get_override_method_modifier($method_name)
455 # if this is not a role, then we need to
456 # find the original package of the method
457 # so that we can tell the class were to
458 # find the right super() method
459 my $method = $self->get_override_method_modifier($method_name);
460 my $package = svref_2object($method)->GV->STASH->NAME;
461 # if it is a class, we just add it
462 $other->add_override_method_modifier($method_name, $method, $package);
467 foreach my $method_name ($self->get_method_modifier_list('before')) {
468 $other->add_before_method_modifier(
471 ) foreach $self->get_before_method_modifiers($method_name);
474 foreach my $method_name ($self->get_method_modifier_list('after')) {
475 $other->add_after_method_modifier(
478 ) foreach $self->get_after_method_modifiers($method_name);
481 foreach my $method_name ($self->get_method_modifier_list('around')) {
482 $other->add_around_method_modifier(
485 ) foreach $self->get_around_method_modifiers($method_name);
488 $other->add_role($self);
492 my ($class, @roles) = @_;
494 my $combined = $class->new(
495 ':role_meta' => Moose::Meta::Class->create_anon_class()
498 foreach my $role (@roles) {
499 $role->apply($combined);
502 $combined->_clean_up_required_methods;
507 package Moose::Meta::Role::Method;
512 our $VERSION = '0.01';
514 use base 'Class::MOP::Method';
524 Moose::Meta::Role - The Moose Role metaclass
528 Moose's Roles are being actively developed, please see L<Moose::Role>
529 for more information. For the most part, this has no user-serviceable
530 parts inside. It's API is still subject to some change (although
531 probably not that much really).
569 =item B<add_excluded_roles>
571 =item B<excludes_role>
573 =item B<get_excluded_roles_list>
575 =item B<get_excluded_roles_map>
585 =item B<alias_method>
587 =item B<get_method_list>
593 =item B<add_attribute>
595 =item B<has_attribute>
597 =item B<get_attribute>
599 =item B<get_attribute_list>
601 =item B<get_attribute_map>
603 =item B<remove_attribute>
609 =item B<add_required_methods>
611 =item B<remove_required_methods>
613 =item B<get_required_method_list>
615 =item B<get_required_methods_map>
617 =item B<requires_method>
623 =item B<add_after_method_modifier>
625 =item B<add_around_method_modifier>
627 =item B<add_before_method_modifier>
629 =item B<add_override_method_modifier>
635 =item B<has_after_method_modifiers>
637 =item B<has_around_method_modifiers>
639 =item B<has_before_method_modifiers>
641 =item B<has_override_method_modifier>
647 =item B<get_after_method_modifiers>
649 =item B<get_around_method_modifiers>
651 =item B<get_before_method_modifiers>
653 =item B<get_method_modifier_list>
659 =item B<get_override_method_modifier>
661 =item B<get_after_method_modifiers_map>
663 =item B<get_around_method_modifiers_map>
665 =item B<get_before_method_modifiers_map>
667 =item B<get_override_method_modifiers_map>
673 All complex software has bugs lurking in it, and this module is no
674 exception. If you find a bug please either email me, or add the bug
679 Stevan Little E<lt>stevan@iinteractive.comE<gt>
681 =head1 COPYRIGHT AND LICENSE
683 Copyright 2006 by Infinity Interactive, Inc.
685 L<http://www.iinteractive.com>
687 This library is free software; you can redistribute it and/or modify
688 it under the same terms as Perl itself.