bump version to 0.90
[gitmo/Moose.git] / lib / Moose / Meta / Role.pm
CommitLineData
e185c027 1
2package Moose::Meta::Role;
3
4use strict;
5use warnings;
6use metaclass;
7
21f1e231 8use Scalar::Util 'blessed';
b6a00b82 9use Carp 'confess';
9f2230e9 10use Sub::Name 'subname';
963c24e1 11use Devel::GlobalDestruction 'in_global_destruction';
bdabd620 12
eaf5a43e 13our $VERSION = '0.90';
e606ae5f 14$VERSION = eval $VERSION;
d44714be 15our $AUTHORITY = 'cpan:STEVAN';
e185c027 16
8ee73eeb 17use Moose::Meta::Class;
39b3bc94 18use Moose::Meta::Role::Method;
d67145ed 19use Moose::Meta::Role::Method::Required;
bb153262 20use Moose::Meta::Role::Method::Conflicting;
8ee73eeb 21
68efb014 22use base 'Class::MOP::Module';
80572233 23
fb1e11d5 24## ------------------------------------------------------------------
25## NOTE:
26## I normally don't do this, but I am doing
27## a whole bunch of meta-programmin in this
28## module, so it just makes sense. For a clearer
d03bd989 29## picture of what is going on in the next
30## several lines of code, look at the really
fb1e11d5 31## big comment at the end of this file (right
32## before the POD).
33## - SL
34## ------------------------------------------------------------------
80572233 35
21716c07 36my $META = __PACKAGE__->meta;
37
38## ------------------------------------------------------------------
39## attributes ...
e185c027 40
21716c07 41# NOTE:
42# since roles are lazy, we hold all the attributes
fb1e11d5 43# of the individual role in 'statis' until which
44# time when it is applied to a class. This means
45# keeping a lot of things in hash maps, so we are
21716c07 46# using a little of that meta-programmin' magic
d03bd989 47# here an saving lots of extra typin. And since
fb1e11d5 48# many of these attributes above require similar
49# functionality to support them, so we again use
50# the wonders of meta-programmin' to deliver a
21716c07 51# very compact solution to this normally verbose
52# problem.
53# - SL
54
55foreach my $action (
fb1e11d5 56 {
57 name => 'excluded_roles_map',
58 attr_reader => 'get_excluded_roles_map' ,
21716c07 59 methods => {
fb1e11d5 60 add => 'add_excluded_roles',
55f28f0a 61 get_keys => 'get_excluded_roles_list',
fb1e11d5 62 existence => 'excludes_role',
21716c07 63 }
64 },
fb1e11d5 65 {
66 name => 'required_methods',
21716c07 67 attr_reader => 'get_required_methods_map',
68 methods => {
7c62cb0a 69 remove => 'remove_required_methods',
70 get_values => 'get_required_method_list',
71 existence => 'requires_method',
21716c07 72 }
d03bd989 73 },
21716c07 74 {
fb1e11d5 75 name => 'attribute_map',
21716c07 76 attr_reader => 'get_attribute_map',
77 methods => {
78 get => 'get_attribute',
55f28f0a 79 get_keys => 'get_attribute_list',
21716c07 80 existence => 'has_attribute',
81 remove => 'remove_attribute',
82 }
83 }
84) {
fb1e11d5 85
21716c07 86 my $attr_reader = $action->{attr_reader};
87 my $methods = $action->{methods};
fb1e11d5 88
89 # create the attribute
90 $META->add_attribute($action->{name} => (
91 reader => $attr_reader,
92 default => sub { {} }
93 ));
94
95 # create some helper methods
21716c07 96 $META->add_method($methods->{add} => sub {
97 my ($self, @values) = @_;
fb1e11d5 98 $self->$attr_reader->{$_} = undef foreach @values;
21716c07 99 }) if exists $methods->{add};
fb1e11d5 100
55f28f0a 101 $META->add_method($methods->{get_keys} => sub {
21716c07 102 my ($self) = @_;
fb1e11d5 103 keys %{$self->$attr_reader};
55f28f0a 104 }) if exists $methods->{get_keys};
fb1e11d5 105
8a0bfed9 106 $META->add_method($methods->{get_values} => sub {
107 my ($self) = @_;
108 values %{$self->$attr_reader};
109 }) if exists $methods->{get_values};
110
21716c07 111 $META->add_method($methods->{get} => sub {
112 my ($self, $name) = @_;
fb1e11d5 113 $self->$attr_reader->{$name}
114 }) if exists $methods->{get};
115
21716c07 116 $META->add_method($methods->{existence} => sub {
117 my ($self, $name) = @_;
fb1e11d5 118 exists $self->$attr_reader->{$name} ? 1 : 0;
119 }) if exists $methods->{existence};
120
21716c07 121 $META->add_method($methods->{remove} => sub {
122 my ($self, @values) = @_;
123 delete $self->$attr_reader->{$_} foreach @values;
fb1e11d5 124 }) if exists $methods->{remove};
21716c07 125}
d79e62fd 126
b05518b2 127$META->add_attribute(
128 'method_metaclass',
129 reader => 'method_metaclass',
130 default => 'Moose::Meta::Role::Method',
131);
132
77ed8b8d 133$META->add_attribute(
134 'required_method_metaclass',
135 reader => 'required_method_metaclass',
136 default => 'Moose::Meta::Role::Method::Required',
137);
138
eec8ca8a 139$META->add_attribute(
bb153262 140 'conflicting_method_metaclass',
141 reader => 'conflicting_method_metaclass',
142 default => 'Moose::Meta::Role::Method::Conflicting',
eec8ca8a 143);
144
07de7559 145$META->add_attribute(
146 'application_to_class_class',
147 reader => 'application_to_class_class',
148 default => 'Moose::Meta::Role::Application::ToClass',
149);
150
151$META->add_attribute(
152 'application_to_role_class',
153 reader => 'application_to_role_class',
154 default => 'Moose::Meta::Role::Application::ToRole',
155);
156
157$META->add_attribute(
158 'application_to_instance_class',
159 reader => 'application_to_instance_class',
160 default => 'Moose::Meta::Role::Application::ToInstance',
161);
162
12d8c847 163$META->add_attribute(
164 'composition_class_roles',
165 reader => 'composition_class_roles',
166 predicate => 'has_composition_class_roles',
167);
168
21716c07 169## some things don't always fit, so they go here ...
80572233 170
21716c07 171sub add_attribute {
172 my $self = shift;
173 my $name = shift;
52ac1d4a 174 unless ( defined $name ) {
70ea9161 175 require Moose;
176 Moose->throw_error("You must provide a name for the attribute");
177 }
21716c07 178 my $attr_desc;
179 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
180 $attr_desc = $_[0];
181 }
182 else {
183 $attr_desc = { @_ };
184 }
185 $self->get_attribute_map->{$name} = $attr_desc;
186}
e185c027 187
16d721b3 188sub add_required_methods {
189 my $self = shift;
190
191 for (@_) {
192 my $method = $_;
c9d7e396 193 if (!blessed($method)) {
16d721b3 194 $method = $self->required_method_metaclass->new(
195 name => $method,
196 );
197 }
198 $self->get_required_methods_map->{$method->name} = $method;
199 }
200}
201
bb153262 202sub add_conflicting_method {
09eeab06 203 my $self = shift;
204
205 my $method;
206 if (@_ == 1 && blessed($_[0])) {
207 $method = shift;
208 }
209 else {
bb153262 210 $method = $self->conflicting_method_metaclass->new(@_);
09eeab06 211 }
212
213 $self->add_required_methods($method);
214}
215
21716c07 216## ------------------------------------------------------------------
217## method modifiers
218
21716c07 219# NOTE:
fb1e11d5 220# the before/around/after method modifiers are
21716c07 221# stored by name, but there can be many methods
222# then associated with that name. So again we have
223# lots of similar functionality, so we can do some
224# meta-programmin' and save some time.
225# - SL
226
227foreach my $modifier_type (qw[ before around after ]) {
fb1e11d5 228
229 my $attr_reader = "get_${modifier_type}_method_modifiers_map";
d03bd989 230
fb1e11d5 231 # create the attribute ...
232 $META->add_attribute("${modifier_type}_method_modifiers" => (
233 reader => $attr_reader,
234 default => sub { {} }
d03bd989 235 ));
fb1e11d5 236
237 # and some helper methods ...
21716c07 238 $META->add_method("get_${modifier_type}_method_modifiers" => sub {
239 my ($self, $method_name) = @_;
fb1e11d5 240 #return () unless exists $self->$attr_reader->{$method_name};
d9847263 241 my $mm = $self->$attr_reader->{$method_name};
242 $mm ? @$mm : ();
21716c07 243 });
fb1e11d5 244
21716c07 245 $META->add_method("has_${modifier_type}_method_modifiers" => sub {
246 my ($self, $method_name) = @_;
247 # NOTE:
fb1e11d5 248 # for now we assume that if it exists,..
21716c07 249 # it has at least one modifier in it
250 (exists $self->$attr_reader->{$method_name}) ? 1 : 0;
fb1e11d5 251 });
252
21716c07 253 $META->add_method("add_${modifier_type}_method_modifier" => sub {
254 my ($self, $method_name, $method) = @_;
fb1e11d5 255
256 $self->$attr_reader->{$method_name} = []
21716c07 257 unless exists $self->$attr_reader->{$method_name};
fb1e11d5 258
21716c07 259 my $modifiers = $self->$attr_reader->{$method_name};
fb1e11d5 260
21716c07 261 # NOTE:
fb1e11d5 262 # check to see that we aren't adding the
263 # same code twice. We err in favor of the
21716c07 264 # first on here, this may not be as expected
265 foreach my $modifier (@{$modifiers}) {
266 return if $modifier == $method;
267 }
fb1e11d5 268
21716c07 269 push @{$modifiers} => $method;
270 });
fb1e11d5 271
21716c07 272}
1331430a 273
21716c07 274## ------------------------------------------------------------------
275## override method mofidiers
0558683c 276
fb1e11d5 277$META->add_attribute('override_method_modifiers' => (
278 reader => 'get_override_method_modifiers_map',
279 default => sub { {} }
280));
281
21716c07 282# NOTE:
fb1e11d5 283# these are a little different because there
21716c07 284# can only be one per name, whereas the other
285# method modifiers can have multiples.
286# - SL
0558683c 287
21716c07 288sub add_override_method_modifier {
289 my ($self, $method_name, $method) = @_;
290 (!$self->has_method($method_name))
c245d69b 291 || Moose->throw_error("Cannot add an override of method '$method_name' " .
4c0b3599 292 "because there is a local version of '$method_name'");
fb1e11d5 293 $self->get_override_method_modifiers_map->{$method_name} = $method;
21716c07 294}
0558683c 295
21716c07 296sub has_override_method_modifier {
297 my ($self, $method_name) = @_;
298 # NOTE:
fb1e11d5 299 # for now we assume that if it exists,..
21716c07 300 # it has at least one modifier in it
fb1e11d5 301 (exists $self->get_override_method_modifiers_map->{$method_name}) ? 1 : 0;
21716c07 302}
0558683c 303
21716c07 304sub get_override_method_modifier {
305 my ($self, $method_name) = @_;
fb1e11d5 306 $self->get_override_method_modifiers_map->{$method_name};
21716c07 307}
0558683c 308
21716c07 309## general list accessor ...
80572233 310
21716c07 311sub get_method_modifier_list {
312 my ($self, $modifier_type) = @_;
fb1e11d5 313 my $accessor = "get_${modifier_type}_method_modifiers_map";
21716c07 314 keys %{$self->$accessor};
315}
e185c027 316
e606ae5f 317sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
318sub update_package_cache_flag {
319 my $self = shift;
320 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
321}
322
323
324
21716c07 325## ------------------------------------------------------------------
80572233 326## subroles
327
278ca49c 328$META->add_attribute('roles' => (
21716c07 329 reader => 'get_roles',
330 default => sub { [] }
331));
332
80572233 333sub add_role {
334 my ($self, $role) = @_;
335 (blessed($role) && $role->isa('Moose::Meta::Role'))
c245d69b 336 || Moose->throw_error("Roles must be instances of Moose::Meta::Role");
80572233 337 push @{$self->get_roles} => $role;
e606ae5f 338 $self->reset_package_cache_flag;
80572233 339}
340
b8aeb4dc 341sub calculate_all_roles {
342 my $self = shift;
343 my %seen;
fb1e11d5 344 grep {
345 !$seen{$_->name}++
346 } ($self, map {
347 $_->calculate_all_roles
348 } @{ $self->get_roles });
b8aeb4dc 349}
350
80572233 351sub does_role {
352 my ($self, $role_name) = @_;
353 (defined $role_name)
c245d69b 354 || Moose->throw_error("You must supply a role name to look for");
bdabd620 355 # if we are it,.. then return true
356 return 1 if $role_name eq $self->name;
357 # otherwise.. check our children
80572233 358 foreach my $role (@{$self->get_roles}) {
bdabd620 359 return 1 if $role->does_role($role_name);
80572233 360 }
361 return 0;
362}
363
1db8ecc7 364sub find_method_by_name { (shift)->get_method(@_) }
093b12c2 365
fb1e11d5 366sub alias_method {
8b7cb9ab 367 Carp::cluck("The alias_method method is deprecated. Use add_method instead.\n");
89e6757a 368
87e63626 369 my $self = shift;
fb1e11d5 370
87e63626 371 $self->add_method(@_);
fb1e11d5 372}
373
21716c07 374## ------------------------------------------------------------------
fb1e11d5 375## role construction
21716c07 376## ------------------------------------------------------------------
e185c027 377
21716c07 378sub apply {
bca01282 379 my ($self, $other, @args) = @_;
380
381 (blessed($other))
c245d69b 382 || Moose->throw_error("You must pass in an blessed instance");
d03bd989 383
07de7559 384 my $application_class;
1c9db35c 385 if ($other->isa('Moose::Meta::Role')) {
07de7559 386 $application_class = $self->application_to_role_class;
1c9db35c 387 }
388 elsif ($other->isa('Moose::Meta::Class')) {
07de7559 389 $application_class = $self->application_to_class_class;
d03bd989 390 }
1c9db35c 391 else {
07de7559 392 $application_class = $self->application_to_instance_class;
d03bd989 393 }
07de7559 394
395 Class::MOP::load_class($application_class);
396 return $application_class->new(@args)->apply($self, $other);
0558683c 397}
398
21716c07 399sub combine {
a4e516f6 400 my ($class, @role_specs) = @_;
d03bd989 401
d03bd989 402 require Moose::Meta::Role::Composite;
403
28412c0b 404 my (@roles, %role_params);
405 while (@role_specs) {
31d96c3e 406 my ($role_name, $params) = @{ splice @role_specs, 0, 1 };
407 my $requested_role = Class::MOP::class_of($role_name);
408
6bdef412 409 my $actual_role = $requested_role->_role_for_combination($params);
31d96c3e 410 push @roles => $actual_role;
411
28412c0b 412 next unless defined $params;
31d96c3e 413 $role_params{$actual_role->name} = $params;
28412c0b 414 }
d03bd989 415
fb1e11d5 416 my $c = Moose::Meta::Role::Composite->new(roles => \@roles);
7071e2cb 417 return $c->apply_params(\%role_params);
0558683c 418}
419
6bdef412 420sub _role_for_combination {
436d7a28 421 my ($self, $params) = @_;
422 return $self;
423}
424
b6a00b82 425sub create {
2d5f3fab 426 my ( $role, $package_name, %options ) = @_;
b6a00b82 427
2d5f3fab 428 $options{package} = $package_name;
b6a00b82 429
430 (ref $options{attributes} eq 'HASH')
431 || confess "You must pass a HASH ref of attributes"
432 if exists $options{attributes};
433
434 (ref $options{methods} eq 'HASH')
435 || confess "You must pass a HASH ref of methods"
436 if exists $options{methods};
437
2d5f3fab 438 my (%initialize_options) = %options;
b6a00b82 439 delete @initialize_options{qw(
440 package
441 attributes
442 methods
443 version
444 authority
445 )};
446
447 my $meta = $role->initialize( $package_name => %initialize_options );
448
6a4a7c31 449 $meta->_instantiate_module( $options{version}, $options{authority} );
450
b6a00b82 451 # FIXME totally lame
452 $meta->add_method('meta' => sub {
453 $role->initialize(ref($_[0]) || $_[0]);
454 });
455
456 if (exists $options{attributes}) {
457 foreach my $attribute_name (keys %{$options{attributes}}) {
458 my $attr = $options{attributes}->{$attribute_name};
459 $meta->add_attribute($attribute_name => $attr);
460 }
461 }
462
463 if (exists $options{methods}) {
464 foreach my $method_name (keys %{$options{methods}}) {
465 $meta->add_method($method_name, $options{methods}->{$method_name});
466 }
467 }
468
d1765290 469 Class::MOP::weaken_metaclass($meta->name)
470 if $meta->is_anon_role;
471
b6a00b82 472 return $meta;
473}
474
c9ee520d 475# anonymous roles. most of it is copied straight out of Class::MOP::Class.
476# an intrepid hacker might find great riches if he unifies this code with that
477# code in Class::MOP::Module or Class::MOP::Package
478{
479 # NOTE:
480 # this should be sufficient, if you have a
481 # use case where it is not, write a test and
482 # I will change it.
483 my $ANON_ROLE_SERIAL = 0;
484
485 # NOTE:
486 # we need a sufficiently annoying prefix
487 # this should suffice for now, this is
488 # used in a couple of places below, so
489 # need to put it up here for now.
490 my $ANON_ROLE_PREFIX = 'Moose::Meta::Role::__ANON__::SERIAL::';
491
492 sub is_anon_role {
493 my $self = shift;
494 no warnings 'uninitialized';
495 $self->name =~ /^$ANON_ROLE_PREFIX/;
496 }
497
498 sub create_anon_role {
499 my ($role, %options) = @_;
500 my $package_name = $ANON_ROLE_PREFIX . ++$ANON_ROLE_SERIAL;
501 return $role->create($package_name, %options);
502 }
503
504 # NOTE:
505 # this will only get called for
506 # anon-roles, all other calls
507 # are assumed to occur during
508 # global destruction and so don't
509 # really need to be handled explicitly
510 sub DESTROY {
511 my $self = shift;
512
963c24e1 513 return if in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
c9ee520d 514
515 no warnings 'uninitialized';
516 return unless $self->name =~ /^$ANON_ROLE_PREFIX/;
517
518 # XXX: is this necessary for us? I don't understand what it's doing
519 # -sartak
520
521 # Moose does a weird thing where it replaces the metaclass for
522 # class when fixing metaclass incompatibility. In that case,
523 # we don't want to clean out the namespace now. We can detect
524 # that because Moose will explicitly update the singleton
525 # cache in Class::MOP.
526 #my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
527 #return if $current_meta ne $self;
528
529 my ($serial_id) = ($self->name =~ /^$ANON_ROLE_PREFIX(\d+)/);
530 no strict 'refs';
531 foreach my $key (keys %{$ANON_ROLE_PREFIX . $serial_id}) {
532 delete ${$ANON_ROLE_PREFIX . $serial_id}{$key};
533 }
534 delete ${'main::' . $ANON_ROLE_PREFIX}{$serial_id . '::'};
535 }
536}
537
fb1e11d5 538#####################################################################
539## NOTE:
d03bd989 540## This is Moose::Meta::Role as defined by Moose (plus the use of
541## MooseX::AttributeHelpers module). It is here as a reference to
fb1e11d5 542## make it easier to see what is happening above with all the meta
543## programming. - SL
544#####################################################################
545#
546# has 'roles' => (
a40b446a 547# metaclass => 'Array',
fb1e11d5 548# reader => 'get_roles',
764a7831 549# isa => 'ArrayRef[Moose::Meta::Role]',
fb1e11d5 550# default => sub { [] },
551# provides => {
552# 'push' => 'add_role',
553# }
554# );
d03bd989 555#
fb1e11d5 556# has 'excluded_roles_map' => (
a40b446a 557# metaclass => 'Hash',
fb1e11d5 558# reader => 'get_excluded_roles_map',
559# isa => 'HashRef[Str]',
560# provides => {
561# # Not exactly set, cause it sets multiple
562# 'set' => 'add_excluded_roles',
563# 'keys' => 'get_excluded_roles_list',
564# 'exists' => 'excludes_role',
565# }
566# );
d03bd989 567#
fb1e11d5 568# has 'attribute_map' => (
a40b446a 569# metaclass => 'Hash',
fb1e11d5 570# reader => 'get_attribute_map',
d03bd989 571# isa => 'HashRef[Str]',
fb1e11d5 572# provides => {
573# # 'set' => 'add_attribute' # has some special crap in it
574# 'get' => 'get_attribute',
575# 'keys' => 'get_attribute_list',
576# 'exists' => 'has_attribute',
577# # Not exactly delete, cause it sets multiple
d03bd989 578# 'delete' => 'remove_attribute',
fb1e11d5 579# }
580# );
d03bd989 581#
fb1e11d5 582# has 'required_methods' => (
a40b446a 583# metaclass => 'Hash',
fb1e11d5 584# reader => 'get_required_methods_map',
72264f10 585# isa => 'HashRef[Moose::Meta::Role::Method::Required]',
d03bd989 586# provides => {
587# # not exactly set, or delete since it works for multiple
fb1e11d5 588# 'set' => 'add_required_methods',
589# 'delete' => 'remove_required_methods',
590# 'keys' => 'get_required_method_list',
d03bd989 591# 'exists' => 'requires_method',
fb1e11d5 592# }
593# );
d03bd989 594#
595# # the before, around and after modifiers are
596# # HASH keyed by method-name, with ARRAY of
fb1e11d5 597# # CODE refs to apply in that order
d03bd989 598#
fb1e11d5 599# has 'before_method_modifiers' => (
a40b446a 600# metaclass => 'Hash',
fb1e11d5 601# reader => 'get_before_method_modifiers_map',
602# isa => 'HashRef[ArrayRef[CodeRef]]',
603# provides => {
604# 'keys' => 'get_before_method_modifiers',
d03bd989 605# 'exists' => 'has_before_method_modifiers',
606# # This actually makes sure there is an
fb1e11d5 607# # ARRAY at the given key, and pushed onto
608# # it. It also checks for duplicates as well
d03bd989 609# # 'add' => 'add_before_method_modifier'
610# }
fb1e11d5 611# );
d03bd989 612#
fb1e11d5 613# has 'after_method_modifiers' => (
a40b446a 614# metaclass => 'Hash',
fb1e11d5 615# reader =>'get_after_method_modifiers_map',
616# isa => 'HashRef[ArrayRef[CodeRef]]',
617# provides => {
618# 'keys' => 'get_after_method_modifiers',
d03bd989 619# 'exists' => 'has_after_method_modifiers',
620# # This actually makes sure there is an
fb1e11d5 621# # ARRAY at the given key, and pushed onto
d03bd989 622# # it. It also checks for duplicates as well
623# # 'add' => 'add_after_method_modifier'
624# }
fb1e11d5 625# );
d03bd989 626#
fb1e11d5 627# has 'around_method_modifiers' => (
a40b446a 628# metaclass => 'Hash',
fb1e11d5 629# reader =>'get_around_method_modifiers_map',
630# isa => 'HashRef[ArrayRef[CodeRef]]',
631# provides => {
632# 'keys' => 'get_around_method_modifiers',
d03bd989 633# 'exists' => 'has_around_method_modifiers',
634# # This actually makes sure there is an
fb1e11d5 635# # ARRAY at the given key, and pushed onto
d03bd989 636# # it. It also checks for duplicates as well
637# # 'add' => 'add_around_method_modifier'
638# }
fb1e11d5 639# );
d03bd989 640#
fb1e11d5 641# # override is similar to the other modifiers
642# # except that it is not an ARRAY of code refs
643# # but instead just a single name->code mapping
d03bd989 644#
fb1e11d5 645# has 'override_method_modifiers' => (
a40b446a 646# metaclass => 'Hash',
fb1e11d5 647# reader =>'get_override_method_modifiers_map',
d03bd989 648# isa => 'HashRef[CodeRef]',
fb1e11d5 649# provides => {
650# 'keys' => 'get_override_method_modifier',
d03bd989 651# 'exists' => 'has_override_method_modifier',
652# 'add' => 'add_override_method_modifier', # checks for local method ..
fb1e11d5 653# }
654# );
d03bd989 655#
fb1e11d5 656#####################################################################
657
658
e185c027 6591;
660
661__END__
662
663=pod
664
665=head1 NAME
666
667Moose::Meta::Role - The Moose Role metaclass
668
669=head1 DESCRIPTION
670
705d4cfd 671This class is a subclass of L<Class::MOP::Module> that provides
672additional Moose-specific functionality.
673
674It's API looks a lot like L<Moose::Meta::Class>, but internally it
675implements many things differently. This may change in the future.
79592a54 676
cf3bb5c5 677=head1 INHERITANCE
678
679C<Moose::Meta::Role> is a subclass of L<Class::MOP::Module>.
680
e185c027 681=head1 METHODS
682
705d4cfd 683=head2 Construction
684
e185c027 685=over 4
686
705d4cfd 687=item B<< Moose::Meta::Role->initialize($role_name) >>
e185c027 688
705d4cfd 689This method creates a new role object with the provided name.
e185c027 690
705d4cfd 691=item B<< Moose::Meta::Role->combine( [ $role => { ... } ], [ $role ], ... ) >>
78cd1d3b 692
705d4cfd 693This method accepts a list of array references. Each array reference
694should contain a role name as its first element. The second element is
c8b8d92f 695an optional hash reference. The hash reference can contain C<-excludes>
696and C<-alias> keys to control how methods are composed from the role.
e606ae5f 697
705d4cfd 698The return value is a new L<Moose::Meta::Role::Composite> that
699represents the combined roles.
db1ab48d 700
705d4cfd 701=item B<< Moose::Meta::Role->create($name, %options) >>
e185c027 702
705d4cfd 703This method is identical to the L<Moose::Meta::Class> C<create>
704method.
705
706=item B<< Moose::Meta::Role->create_anon_role >>
e185c027 707
705d4cfd 708This method is identical to the L<Moose::Meta::Class>
709C<create_anon_class> method.
e185c027 710
705d4cfd 711=item B<< $metarole->is_anon_role >>
e185c027 712
705d4cfd 713Returns true if the role is an anonymous role.
e185c027 714
715=back
716
705d4cfd 717=head2 Role application
718
e185c027 719=over 4
720
705d4cfd 721=item B<< $metarole->apply( $thing, @options ) >>
80572233 722
705d4cfd 723This method applies a role to the given C<$thing>. That can be another
724L<Moose::Meta::Role>, object, a L<Moose::Meta::Class> object, or a
725(non-meta) object instance.
80572233 726
705d4cfd 727The options are passed directly to the constructor for the appropriate
728L<Moose::Meta::Role::Application> subclass.
80572233 729
d05235e1 730Note that this will apply the role even if the C<$thing> in question already
731C<does> this role. L<Moose::Util/does_role> is a convenient wrapper for
732finding out if role application is necessary.
733
80572233 734=back
735
705d4cfd 736=head2 Roles and other roles
737
80572233 738=over 4
739
705d4cfd 740=item B<< $metarole->get_roles >>
d79e62fd 741
705d4cfd 742This returns an array reference of roles which this role does. This
743list may include duplicates.
d79e62fd 744
705d4cfd 745=item B<< $metarole->calculate_all_roles >>
d79e62fd 746
705d4cfd 747This returns a I<unique> list of all roles that this role does, and
748all the roles that its roles do.
d79e62fd 749
705d4cfd 750=item B<< $metarole->does_role($role_name) >>
2b14ac61 751
705d4cfd 752Given a role I<name>, returns true if this role does the given
753role.
d79e62fd 754
705d4cfd 755=item B<< $metarole->add_role($role) >>
d79e62fd 756
705d4cfd 757Given a L<Moose::Meta::Role> object, this adds the role to the list of
758roles that the role does.
68efb014 759
705d4cfd 760=item B<< $metarole->get_excluded_roles_list >>
be4427d0 761
705d4cfd 762Returns a list of role names which this role excludes.
e185c027 763
705d4cfd 764=item B<< $metarole->excludes_role($role_name) >>
e185c027 765
705d4cfd 766Given a role I<name>, returns true if this role excludes the named
767role.
e606ae5f 768
705d4cfd 769=item B<< $metarole->add_excluded_roles(@role_names) >>
e606ae5f 770
705d4cfd 771Given one or more role names, adds those roles to the list of excluded
772roles.
bdabd620 773
705d4cfd 774=back
e185c027 775
705d4cfd 776=head2 Methods
093b12c2 777
705d4cfd 778The methods for dealing with a role's methods are all identical in API
779and behavior to the same methods in L<Class::MOP::Class>.
638853cb 780
705d4cfd 781=over 4
53dd42d8 782
705d4cfd 783=item B<< $metarole->method_metaclass >>
e185c027 784
705d4cfd 785Returns the method metaclass name for the role. This defaults to
786L<Moose::Meta::Role::Method>.
e185c027 787
705d4cfd 788=item B<< $metarole->get_method($name) >>
e185c027 789
705d4cfd 790=item B<< $metarole->has_method($name) >>
e185c027 791
705d4cfd 792=item B<< $metarole->add_method( $name, $body ) >>
e185c027 793
705d4cfd 794=item B<< $metarole->get_method_list >>
e185c027 795
705d4cfd 796=item B<< $metarole->find_method_by_name($name) >>
797
798These methods are all identical to the methods of the same name in
8f6cbfcd 799L<Class::MOP::Package>
e185c027 800
801=back
802
705d4cfd 803=head2 Attributes
804
805As with methods, the methods for dealing with a role's attribute are
806all identical in API and behavior to the same methods in
807L<Class::MOP::Class>.
808
809However, attributes stored in this class are I<not> stored as
810objects. Rather, the attribute definition is stored as a hash
811reference. When a role is composed into a class, this hash reference
812is passed directly to the metaclass's C<add_attribute> method.
813
814This is quite likely to change in the future.
815
e185c027 816=over 4
817
705d4cfd 818=item B<< $metarole->get_attribute($attribute_name) >>
819
820=item B<< $metarole->has_attribute($attribute_name) >>
1331430a 821
705d4cfd 822=item B<< $metarole->get_attribute_map >>
38f1204c 823
705d4cfd 824=item B<< $metarole->get_attribute_list >>
1331430a 825
705d4cfd 826=item B<< $metarole->add_attribute($name, %options) >>
1331430a 827
705d4cfd 828=item B<< $metarole->remove_attribute($attribute_name) >>
1331430a 829
830=back
831
705d4cfd 832=head2 Required methods
833
0558683c 834=over 4
835
705d4cfd 836=item B<< $metarole->get_required_method_list >>
0558683c 837
705d4cfd 838Returns the list of methods required by the role.
0558683c 839
705d4cfd 840=item B<< $metarole->requires_method($name) >>
0558683c 841
705d4cfd 842Returns true if the role requires the named method.
0558683c 843
0ecff16b 844=item B<< $metarole->add_required_methods(@names) >>
0558683c 845
b3c1586a 846Adds the named methods to the role's list of required methods.
0558683c 847
705d4cfd 848=item B<< $metarole->remove_required_methods(@names) >>
0558683c 849
2dda1d28 850Removes the named methods from the role's list of required methods.
0558683c 851
bb153262 852=item B<< $metarole->add_conflicting_method(%params) >>
09eeab06 853
bb153262 854Instantiate the parameters as a L<Moose::Meta::Role::Method::Conflicting>
09eeab06 855object, then add it to the required method list.
856
705d4cfd 857=back
858
859=head2 Method modifiers
0558683c 860
705d4cfd 861These methods act like their counterparts in L<Class::Mop::Class> and
862L<Moose::Meta::Class>.
863
864However, method modifiers are simply stored internally, and are not
865applied until the role itself is applied to a class.
0558683c 866
867=over 4
868
705d4cfd 869=item B<< $metarole->add_after_method_modifier($method_name, $method) >>
0558683c 870
705d4cfd 871=item B<< $metarole->add_around_method_modifier($method_name, $method) >>
0558683c 872
705d4cfd 873=item B<< $metarole->add_before_method_modifier($method_name, $method) >>
0558683c 874
705d4cfd 875=item B<< $metarole->add_override_method_modifier($method_name, $method) >>
0558683c 876
705d4cfd 877These methods all add an appropriate modifier to the internal list of
878modifiers.
0558683c 879
705d4cfd 880=item B<< $metarole->has_after_method_modifiers >>
0558683c 881
705d4cfd 882=item B<< $metarole->has_around_method_modifiers >>
883
884=item B<< $metarole->has_before_method_modifiers >>
885
886=item B<< $metarole->has_override_method_modifier >>
0558683c 887
705d4cfd 888Return true if the role has any modifiers of the given type.
0558683c 889
705d4cfd 890=item B<< $metarole->get_after_method_modifiers($method_name) >>
0558683c 891
705d4cfd 892=item B<< $metarole->get_around_method_modifiers($method_name) >>
0558683c 893
705d4cfd 894=item B<< $metarole->get_before_method_modifiers($method_name) >>
0558683c 895
705d4cfd 896Given a method name, returns a list of the appropriate modifiers for
897that method.
898
899=item B<< $metarole->get_override_method_modifier($method_name) >>
900
901Given a method name, returns the override method modifier for that
902method, if it has one.
0558683c 903
904=back
905
705d4cfd 906=head2 Introspection
505065c4 907
705d4cfd 908=over 4
505065c4 909
705d4cfd 910=item B<< Moose::Meta::Role->meta >>
505065c4 911
705d4cfd 912This will return a L<Class::MOP::Class> instance for this class.
505065c4 913
914=back
915
e185c027 916=head1 BUGS
917
fb1e11d5 918All complex software has bugs lurking in it, and this module is no
e185c027 919exception. If you find a bug please either email me, or add the bug
920to cpan-RT.
921
922=head1 AUTHOR
923
924Stevan Little E<lt>stevan@iinteractive.comE<gt>
925
926=head1 COPYRIGHT AND LICENSE
927
2840a3b2 928Copyright 2006-2009 by Infinity Interactive, Inc.
e185c027 929
930L<http://www.iinteractive.com>
931
932This library is free software; you can redistribute it and/or modify
fb1e11d5 933it under the same terms as Perl itself.
e185c027 934
b8aeb4dc 935=cut