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',
58 $options{':role_meta'} = Moose::Meta::Class->initialize(
60 ':method_metaclass' => 'Moose::Meta::Role::Method'
61 ) unless defined $options{':role_meta'} &&
62 $options{':role_meta'}->isa('Moose::Meta::Class');
63 my $self = $class->meta->new_object(%options);
70 my ($self, $role) = @_;
71 (blessed($role) && $role->isa('Moose::Meta::Role'))
72 || confess "Roles must be instances of Moose::Meta::Role";
73 push @{$self->get_roles} => $role;
76 sub calculate_all_roles {
79 grep { !$seen{$_->name}++ } $self, map { $_->calculate_all_roles } @{ $self->get_roles };
83 my ($self, $role_name) = @_;
85 || confess "You must supply a role name to look for";
86 # if we are it,.. then return true
87 return 1 if $role_name eq $self->name;
88 # otherwise.. check our children
89 foreach my $role (@{$self->get_roles}) {
90 return 1 if $role->does_role($role_name);
97 sub add_excluded_roles {
98 my ($self, @excluded_role_names) = @_;
99 $self->get_excluded_roles_map->{$_} = undef foreach @excluded_role_names;
102 sub get_excluded_roles_list {
104 keys %{$self->get_excluded_roles_map};
108 my ($self, $role_name) = @_;
109 exists $self->get_excluded_roles_map->{$role_name} ? 1 : 0;
114 sub add_required_methods {
115 my ($self, @methods) = @_;
116 $self->get_required_methods_map->{$_} = undef foreach @methods;
119 sub remove_required_methods {
120 my ($self, @methods) = @_;
121 delete $self->get_required_methods_map->{$_} foreach @methods;
124 sub get_required_method_list {
126 keys %{$self->get_required_methods_map};
129 sub requires_method {
130 my ($self, $method_name) = @_;
131 exists $self->get_required_methods_map->{$method_name} ? 1 : 0;
134 sub _clean_up_required_methods {
136 foreach my $method ($self->get_required_method_list) {
137 $self->remove_required_methods($method)
138 if $self->has_method($method);
145 # we delegate to some role_meta methods for convience here
146 # the Moose::Meta::Role is meant to be a read-only interface
147 # to the underlying role package, if you want to manipulate
148 # that, just use ->role_meta
150 sub name { (shift)->_role_meta->name }
151 sub version { (shift)->_role_meta->version }
153 sub get_method { (shift)->_role_meta->get_method(@_) }
154 sub has_method { (shift)->_role_meta->has_method(@_) }
155 sub alias_method { (shift)->_role_meta->alias_method(@_) }
156 sub get_method_list {
160 # this is a kludge for now,... these functions
161 # should not be showing up in the list at all,
162 # but they do, so we need to switch Moose::Role
163 # and Moose to use Sub::Exporter to prevent this
164 !/^(meta|has|extends|blessed|confess|augment|inner|override|super|before|after|around|with|requires)$/
165 } $self->_role_meta->get_method_list;
168 # ... however the items in statis (attributes & method modifiers)
169 # can be removed and added to through this API
177 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
183 $self->get_attribute_map->{$name} = $attr_desc;
187 my ($self, $name) = @_;
188 exists $self->get_attribute_map->{$name} ? 1 : 0;
192 my ($self, $name) = @_;
193 $self->get_attribute_map->{$name}
196 sub remove_attribute {
197 my ($self, $name) = @_;
198 delete $self->get_attribute_map->{$name}
201 sub get_attribute_list {
203 keys %{$self->get_attribute_map};
207 ## applying a role to a class ...
209 sub _check_excluded_roles {
210 my ($self, $other) = @_;
211 if ($other->excludes_role($self->name)) {
212 confess "Conflict detected: " . $other->name . " excludes role '" . $self->name . "'";
214 foreach my $excluded_role_name ($self->get_excluded_roles_list) {
215 if ($other->does_role($excluded_role_name)) {
216 confess "The class " . $other->name . " does the excluded role '$excluded_role_name'";
219 if ($other->isa('Moose::Meta::Role')) {
220 $other->add_excluded_roles($excluded_role_name);
222 # else -> ignore it :)
227 sub _check_required_methods {
228 my ($self, $other) = @_;
230 # we might need to move this down below the
231 # the attributes so that we can require any
232 # attribute accessors. However I am thinking
233 # that maybe those are somehow exempt from
234 # the require methods stuff.
235 foreach my $required_method_name ($self->get_required_method_list) {
238 # This should not call has_method, instead it should
239 # call find_method_by_name (to be added to Class::MOP)
240 unless ($other->has_method($required_method_name)) {
241 if ($other->isa('Moose::Meta::Role')) {
242 $other->add_required_methods($required_method_name);
245 confess "'" . $self->name . "' requires the method '$required_method_name' " .
246 "to be implemented by '" . $other->name . "'";
251 # we need to make sure that the method is
252 # not a method modifier, because those do
253 # not satisfy the requirements ...
256 # This should also call find_method_by_name
257 my $method = $other->get_method($required_method_name);
258 # check if it is an override or a generated accessor ..
259 (!$method->isa('Moose::Meta::Method::Overriden') &&
260 !$method->isa('Class::MOP::Attribute::Accessor'))
261 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
262 "to be implemented by '" . $other->name . "', the method is only a method modifier";
263 # before/after/around methods are a little trickier
264 # since we wrap the original local method (if applicable)
265 # so we need to check if the original wrapped method is
266 # from the same package, and not a wrap of the super method
267 if ($method->isa('Class::MOP::Method::Wrapped')) {
268 ($method->get_original_method->package_name eq $other->name)
269 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
270 "to be implemented by '" . $other->name . "', the method is only a method modifier";
276 sub _apply_attributes {
277 my ($self, $other) = @_;
278 foreach my $attribute_name ($self->get_attribute_list) {
279 # it if it has one already
280 if ($other->has_attribute($attribute_name) &&
281 # make sure we haven't seen this one already too
282 $other->get_attribute($attribute_name) != $self->get_attribute($attribute_name)) {
283 # see if we are being composed
285 if ($other->isa('Moose::Meta::Role')) {
286 # all attribute conflicts between roles
287 # result in an immediate fatal error
288 confess "Role '" . $self->name . "' has encountered an attribute conflict " .
289 "during composition. This is fatal error and cannot be disambiguated.";
292 # but if this is a class, we
293 # can safely skip adding the
294 # attribute to the class
299 $other->add_attribute(
301 $self->get_attribute($attribute_name)
308 my ($self, $other) = @_;
309 foreach my $method_name ($self->get_method_list) {
310 # it if it has one already
311 if ($other->has_method($method_name) &&
312 # and if they are not the same thing ...
313 $other->get_method($method_name) != $self->get_method($method_name)) {
314 # see if we are composing into a role
315 if ($other->isa('Moose::Meta::Role')) {
316 # method conflicts between roles result
317 # in the method becoming a requirement
318 $other->add_required_methods($method_name);
320 # we have to remove the method from our
321 # role, if this is being called from combine()
322 # which means the meta is an anon class
323 # this *may* cause problems later, but it
324 # is probably fairly safe to assume that
325 # anon classes will only be used internally
326 # or by people who know what they are doing
327 $other->_role_meta->remove_method($method_name)
328 if $other->_role_meta->name =~ /__ANON__/;
335 # add it, although it could be overriden
336 $other->alias_method(
338 $self->get_method($method_name)
345 my ($self, $other) = @_;
347 $self->_check_excluded_roles($other);
348 $self->_check_required_methods($other);
350 $self->_apply_attributes($other);
351 $self->_apply_methods($other);
353 $other->add_role($self);
357 my ($class, @roles) = @_;
359 my $combined = $class->new(
360 ':role_meta' => Moose::Meta::Class->create_anon_class()
363 foreach my $role (@roles) {
364 $role->apply($combined);
367 $combined->_clean_up_required_methods;
372 package Moose::Meta::Role::Method;
377 our $VERSION = '0.01';
379 use base 'Class::MOP::Method';
389 Moose::Meta::Role - The Moose Role metaclass
393 Moose's Roles are being actively developed, please see L<Moose::Role>
394 for more information. For the most part, this has no user-serviceable
395 parts inside. It's API is still subject to some change (although
396 probably not that much really).
434 =item B<add_excluded_roles>
436 =item B<excludes_role>
438 =item B<get_excluded_roles_list>
440 =item B<get_excluded_roles_map>
442 =item B<calculate_all_roles>
452 =item B<alias_method>
454 =item B<get_method_list>
460 =item B<add_attribute>
462 =item B<has_attribute>
464 =item B<get_attribute>
466 =item B<get_attribute_list>
468 =item B<get_attribute_map>
470 =item B<remove_attribute>
476 =item B<add_required_methods>
478 =item B<remove_required_methods>
480 =item B<get_required_method_list>
482 =item B<get_required_methods_map>
484 =item B<requires_method>
490 All complex software has bugs lurking in it, and this module is no
491 exception. If you find a bug please either email me, or add the bug
496 Stevan Little E<lt>stevan@iinteractive.comE<gt>
498 =head1 COPYRIGHT AND LICENSE
500 Copyright 2006 by Infinity Interactive, Inc.
502 L<http://www.iinteractive.com>
504 This library is free software; you can redistribute it and/or modify
505 it under the same terms as Perl itself.