foo
[gitmo/Moose.git] / lib / Moose / Meta / Role.pm
CommitLineData
e185c027 1
2package Moose::Meta::Role;
3
4use strict;
5use warnings;
6use metaclass;
7
bdabd620 8use Carp 'confess';
9use Scalar::Util 'blessed';
d30bc041 10use B 'svref_2object';
bdabd620 11
12use Moose::Meta::Class;
e185c027 13
061a963b 14our $VERSION = '0.03';
e185c027 15
bdabd620 16## Attributes
17
80572233 18## the meta for the role package
19
bdabd620 20__PACKAGE__->meta->add_attribute('_role_meta' => (
21 reader => '_role_meta',
22 init_arg => ':role_meta'
80572233 23));
24
25## roles
26
27__PACKAGE__->meta->add_attribute('roles' => (
28 reader => 'get_roles',
29 default => sub { [] }
e185c027 30));
31
d79e62fd 32## excluded roles
33
34__PACKAGE__->meta->add_attribute('excluded_roles_map' => (
35 reader => 'get_excluded_roles_map',
36 default => sub { {} }
37));
38
80572233 39## attributes
40
e185c027 41__PACKAGE__->meta->add_attribute('attribute_map' => (
42 reader => 'get_attribute_map',
43 default => sub { {} }
44));
45
1331430a 46## required methods
47
48__PACKAGE__->meta->add_attribute('required_methods' => (
49 reader => 'get_required_methods_map',
50 default => sub { {} }
51));
52
80572233 53## method modifiers
54
55__PACKAGE__->meta->add_attribute('before_method_modifiers' => (
56 reader => 'get_before_method_modifiers_map',
bdabd620 57 default => sub { {} } # (<name> => [ (CODE) ])
e185c027 58));
59
80572233 60__PACKAGE__->meta->add_attribute('after_method_modifiers' => (
61 reader => 'get_after_method_modifiers_map',
bdabd620 62 default => sub { {} } # (<name> => [ (CODE) ])
80572233 63));
64
65__PACKAGE__->meta->add_attribute('around_method_modifiers' => (
66 reader => 'get_around_method_modifiers_map',
bdabd620 67 default => sub { {} } # (<name> => [ (CODE) ])
80572233 68));
69
70__PACKAGE__->meta->add_attribute('override_method_modifiers' => (
71 reader => 'get_override_method_modifiers_map',
72 default => sub { {} } # (<name> => CODE)
73));
74
bdabd620 75## Methods
80572233 76
e185c027 77sub new {
78 my $class = shift;
79 my %options = @_;
bdabd620 80 $options{':role_meta'} = Moose::Meta::Class->initialize(
a7d0cd00 81 $options{role_name},
82 ':method_metaclass' => 'Moose::Meta::Role::Method'
db1ab48d 83 ) unless defined $options{':role_meta'} &&
84 $options{':role_meta'}->isa('Moose::Meta::Class');
e185c027 85 my $self = $class->meta->new_object(%options);
86 return $self;
87}
88
80572233 89## subroles
90
91sub add_role {
92 my ($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} => $role;
96}
97
98sub does_role {
99 my ($self, $role_name) = @_;
100 (defined $role_name)
101 || confess "You must supply a role name to look for";
bdabd620 102 # if we are it,.. then return true
103 return 1 if $role_name eq $self->name;
104 # otherwise.. check our children
80572233 105 foreach my $role (@{$self->get_roles}) {
bdabd620 106 return 1 if $role->does_role($role_name);
80572233 107 }
108 return 0;
109}
110
d79e62fd 111## excluded roles
112
113sub add_excluded_roles {
114 my ($self, @excluded_role_names) = @_;
115 $self->get_excluded_roles_map->{$_} = undef foreach @excluded_role_names;
116}
117
118sub get_excluded_roles_list {
119 my ($self) = @_;
120 keys %{$self->get_excluded_roles_map};
121}
122
123sub excludes_role {
124 my ($self, $role_name) = @_;
125 exists $self->get_excluded_roles_map->{$role_name} ? 1 : 0;
126}
127
1331430a 128## required methods
129
130sub add_required_methods {
131 my ($self, @methods) = @_;
132 $self->get_required_methods_map->{$_} = undef foreach @methods;
133}
134
38f1204c 135sub remove_required_methods {
136 my ($self, @methods) = @_;
137 delete $self->get_required_methods_map->{$_} foreach @methods;
138}
139
1331430a 140sub get_required_method_list {
141 my ($self) = @_;
142 keys %{$self->get_required_methods_map};
143}
144
145sub requires_method {
146 my ($self, $method_name) = @_;
147 exists $self->get_required_methods_map->{$method_name} ? 1 : 0;
148}
149
db1ab48d 150sub _clean_up_required_methods {
151 my $self = shift;
152 foreach my $method ($self->get_required_method_list) {
38f1204c 153 $self->remove_required_methods($method)
db1ab48d 154 if $self->has_method($method);
155 }
156}
157
80572233 158## methods
159
e185c027 160# NOTE:
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
165
bdabd620 166sub name { (shift)->_role_meta->name }
167sub version { (shift)->_role_meta->version }
e185c027 168
bdabd620 169sub get_method { (shift)->_role_meta->get_method(@_) }
170sub has_method { (shift)->_role_meta->has_method(@_) }
171sub alias_method { (shift)->_role_meta->alias_method(@_) }
e185c027 172sub get_method_list {
173 my ($self) = @_;
bdabd620 174 grep {
175 # NOTE:
176 # this is a kludge for now,... these functions
177 # should not be showing up in the list at all,
178 # but they do, so we need to switch Moose::Role
179 # and Moose to use Sub::Exporter to prevent this
1331430a 180 !/^(meta|has|extends|blessed|confess|augment|inner|override|super|before|after|around|with|requires)$/
bdabd620 181 } $self->_role_meta->get_method_list;
e185c027 182}
183
184# ... however the items in statis (attributes & method modifiers)
185# can be removed and added to through this API
186
187# attributes
188
189sub add_attribute {
a2eec5e7 190 my $self = shift;
191 my $name = shift;
192 my $attr_desc;
193 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
194 $attr_desc = $_[0];
195 }
196 else {
197 $attr_desc = { @_ };
198 }
199 $self->get_attribute_map->{$name} = $attr_desc;
e185c027 200}
201
202sub has_attribute {
203 my ($self, $name) = @_;
204 exists $self->get_attribute_map->{$name} ? 1 : 0;
205}
206
207sub get_attribute {
208 my ($self, $name) = @_;
209 $self->get_attribute_map->{$name}
210}
211
212sub remove_attribute {
213 my ($self, $name) = @_;
214 delete $self->get_attribute_map->{$name}
215}
216
217sub get_attribute_list {
218 my ($self) = @_;
219 keys %{$self->get_attribute_map};
220}
221
222# method modifiers
223
80572233 224# mimic the metaclass API
225sub add_before_method_modifier { (shift)->_add_method_modifier('before', @_) }
226sub add_around_method_modifier { (shift)->_add_method_modifier('around', @_) }
227sub add_after_method_modifier { (shift)->_add_method_modifier('after', @_) }
228
229sub _add_method_modifier {
e185c027 230 my ($self, $modifier_type, $method_name, $method) = @_;
80572233 231 my $accessor = "get_${modifier_type}_method_modifiers_map";
232 $self->$accessor->{$method_name} = []
233 unless exists $self->$accessor->{$method_name};
d30bc041 234 my $modifiers = $self->$accessor->{$method_name};
235 # NOTE:
236 # check to see that we aren't adding the
237 # same code twice. We err in favor of the
238 # first on here, this may not be as expected
239 foreach my $modifier (@{$modifiers}) {
240 return if $modifier == $method;
241 }
242 push @{$modifiers} => $method;
e185c027 243}
244
80572233 245sub add_override_method_modifier {
246 my ($self, $method_name, $method) = @_;
247 $self->get_override_method_modifiers_map->{$method_name} = $method;
e185c027 248}
249
80572233 250sub has_before_method_modifiers { (shift)->_has_method_modifiers('before', @_) }
251sub has_around_method_modifiers { (shift)->_has_method_modifiers('around', @_) }
252sub has_after_method_modifiers { (shift)->_has_method_modifiers('after', @_) }
253
254# override just checks for one,..
255# but we can still re-use stuff
256sub has_override_method_modifier { (shift)->_has_method_modifiers('override', @_) }
257
258sub _has_method_modifiers {
e185c027 259 my ($self, $modifier_type, $method_name) = @_;
80572233 260 my $accessor = "get_${modifier_type}_method_modifiers_map";
261 # NOTE:
262 # for now we assume that if it exists,..
263 # it has at least one modifier in it
264 (exists $self->$accessor->{$method_name}) ? 1 : 0;
e185c027 265}
266
80572233 267sub get_before_method_modifiers { (shift)->_get_method_modifiers('before', @_) }
268sub get_around_method_modifiers { (shift)->_get_method_modifiers('around', @_) }
269sub get_after_method_modifiers { (shift)->_get_method_modifiers('after', @_) }
270
271sub _get_method_modifiers {
e185c027 272 my ($self, $modifier_type, $method_name) = @_;
80572233 273 my $accessor = "get_${modifier_type}_method_modifiers_map";
274 @{$self->$accessor->{$method_name}};
275}
276
277sub get_override_method_modifier {
278 my ($self, $method_name) = @_;
279 $self->get_override_method_modifiers_map->{$method_name};
e185c027 280}
281
282sub get_method_modifier_list {
283 my ($self, $modifier_type) = @_;
80572233 284 my $accessor = "get_${modifier_type}_method_modifiers_map";
285 keys %{$self->$accessor};
e185c027 286}
287
bdabd620 288## applying a role to a class ...
289
a2eec5e7 290sub _check_excluded_roles {
bdabd620 291 my ($self, $other) = @_;
d79e62fd 292 if ($other->excludes_role($self->name)) {
293 confess "Conflict detected: " . $other->name . " excludes role '" . $self->name . "'";
294 }
d79e62fd 295 foreach my $excluded_role_name ($self->get_excluded_roles_list) {
9c429218 296 if ($other->does_role($excluded_role_name)) {
d79e62fd 297 confess "The class " . $other->name . " does the excluded role '$excluded_role_name'";
298 }
299 else {
300 if ($other->isa('Moose::Meta::Role')) {
d79e62fd 301 $other->add_excluded_roles($excluded_role_name);
302 }
a2eec5e7 303 # else -> ignore it :)
d79e62fd 304 }
305 }
a2eec5e7 306}
307
308sub _check_required_methods {
309 my ($self, $other) = @_;
1331430a 310 # NOTE:
311 # we might need to move this down below the
312 # the attributes so that we can require any
313 # attribute accessors. However I am thinking
314 # that maybe those are somehow exempt from
315 # the require methods stuff.
316 foreach my $required_method_name ($self->get_required_method_list) {
fa1be058 317 unless ($other->has_method($required_method_name)) {
318 if ($other->isa('Moose::Meta::Role')) {
319 $other->add_required_methods($required_method_name);
320 }
321 else {
322 confess "'" . $self->name . "' requires the method '$required_method_name' " .
323 "to be implemented by '" . $other->name . "'";
324 }
325 }
38f1204c 326 else {
327 # NOTE:
328 # we need to make sure that the method is
329 # not a method modifier, because those do
330 # not satisfy the requirements ...
331 my $method = $other->get_method($required_method_name);
332 # check if it is an override or a generated accessor ..
333 (!$method->isa('Moose::Meta::Method::Overriden') &&
334 !$method->isa('Class::MOP::Attribute::Accessor'))
335 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
336 "to be implemented by '" . $other->name . "', the method is only a method modifier";
337 # before/after/around methods are a little trickier
338 # since we wrap the original local method (if applicable)
339 # so we need to check if the original wrapped method is
340 # from the same package, and not a wrap of the super method
341 if ($method->isa('Class::MOP::Method::Wrapped')) {
342 ($method->get_original_method->package_name eq $other->name)
343 || confess "'" . $self->name . "' requires the method '$required_method_name' " .
344 "to be implemented by '" . $other->name . "', the method is only a method modifier";
345 }
346 }
a2eec5e7 347 }
348}
349
350sub _apply_attributes {
351 my ($self, $other) = @_;
bdabd620 352 foreach my $attribute_name ($self->get_attribute_list) {
db1ab48d 353 # it if it has one already
a2eec5e7 354 if ($other->has_attribute($attribute_name) &&
355 # make sure we haven't seen this one already too
356 $other->get_attribute($attribute_name) != $self->get_attribute($attribute_name)) {
db1ab48d 357 # see if we are being composed
358 # into a role or not
a2eec5e7 359 if ($other->isa('Moose::Meta::Role')) {
db1ab48d 360 # all attribute conflicts between roles
361 # result in an immediate fatal error
362 confess "Role '" . $self->name . "' has encountered an attribute conflict " .
363 "during composition. This is fatal error and cannot be disambiguated.";
364 }
365 else {
366 # but if this is a class, we
367 # can safely skip adding the
368 # attribute to the class
369 next;
370 }
371 }
372 else {
db1ab48d 373 $other->add_attribute(
374 $attribute_name,
a2eec5e7 375 $self->get_attribute($attribute_name)
db1ab48d 376 );
377 }
a2eec5e7 378 }
379}
380
381sub _apply_methods {
382 my ($self, $other) = @_;
bdabd620 383 foreach my $method_name ($self->get_method_list) {
db1ab48d 384 # it if it has one already
d30bc041 385 if ($other->has_method($method_name) &&
386 # and if they are not the same thing ...
387 $other->get_method($method_name) != $self->get_method($method_name)) {
db1ab48d 388 # see if we are composing into a role
389 if ($other->isa('Moose::Meta::Role')) {
390 # method conflicts between roles result
391 # in the method becoming a requirement
392 $other->add_required_methods($method_name);
393 # NOTE:
394 # we have to remove the method from our
395 # role, if this is being called from combine()
396 # which means the meta is an anon class
397 # this *may* cause problems later, but it
398 # is probably fairly safe to assume that
399 # anon classes will only be used internally
400 # or by people who know what they are doing
401 $other->_role_meta->remove_method($method_name)
402 if $other->_role_meta->name =~ /__ANON__/;
403 }
404 else {
405 next;
406 }
407 }
408 else {
409 # add it, although it could be overriden
410 $other->alias_method(
411 $method_name,
412 $self->get_method($method_name)
413 );
414 }
a2eec5e7 415 }
416}
417
418sub _apply_override_method_modifiers {
419 my ($self, $other) = @_;
bdabd620 420 foreach my $method_name ($self->get_method_modifier_list('override')) {
d05cd563 421 # it if it has one already then ...
422 if ($other->has_method($method_name)) {
423 # if it is being composed into another role
424 # we have a conflict here, because you cannot
425 # combine an overriden method with a locally
426 # defined one
427 if ($other->isa('Moose::Meta::Role')) {
428 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
429 "during composition (A local method of the same name as been found). This " .
430 "is fatal error.";
431 }
432 else {
433 # if it is a class, then we
434 # just ignore this here ...
435 next;
436 }
437 }
438 else {
439 # if no local method is found, then we
440 # must check if we are a role or class
441 if ($other->isa('Moose::Meta::Role')) {
442 # if we are a role, we need to make sure
443 # we dont have a conflict with the role
444 # we are composing into
d30bc041 445 if ($other->has_override_method_modifier($method_name) &&
446 $other->get_override_method_modifier($method_name) != $self->get_override_method_modifier($method_name)) {
d05cd563 447 confess "Role '" . $self->name . "' has encountered an 'override' method conflict " .
448 "during composition (Two 'override' methods of the same name encountered). " .
449 "This is fatal error.";
450 }
d30bc041 451 else {
452 # if there is no conflict,
453 # just add it to the role
d05cd563 454 $other->add_override_method_modifier(
d30bc041 455 $method_name,
456 $self->get_override_method_modifier($method_name)
d05cd563 457 );
458 }
459 }
460 else {
d30bc041 461 # if this is not a role, then we need to
462 # find the original package of the method
463 # so that we can tell the class were to
464 # find the right super() method
465 my $method = $self->get_override_method_modifier($method_name);
466 my $package = svref_2object($method)->GV->STASH->NAME;
d05cd563 467 # if it is a class, we just add it
d30bc041 468 $other->add_override_method_modifier($method_name, $method, $package);
d05cd563 469 }
470 }
bdabd620 471 }
a2eec5e7 472}
473
474sub _apply_method_modifiers {
475 my ($self, $modifier_type, $other) = @_;
476 my $add = "add_${modifier_type}_method_modifier";
477 my $get = "get_${modifier_type}_method_modifiers";
478 foreach my $method_name ($self->get_method_modifier_list($modifier_type)) {
479 $other->$add(
bdabd620 480 $method_name,
481 $_
a2eec5e7 482 ) foreach $self->$get($method_name);
bdabd620 483 }
a2eec5e7 484}
485
486sub _apply_before_method_modifiers { (shift)->_apply_method_modifiers('before' => @_) }
487sub _apply_around_method_modifiers { (shift)->_apply_method_modifiers('around' => @_) }
488sub _apply_after_method_modifiers { (shift)->_apply_method_modifiers('after' => @_) }
489
490sub apply {
491 my ($self, $other) = @_;
bdabd620 492
a2eec5e7 493 $self->_check_excluded_roles($other);
494 $self->_check_required_methods($other);
495
496 $self->_apply_attributes($other);
497 $self->_apply_methods($other);
498
499 $self->_apply_override_method_modifiers($other);
500 $self->_apply_before_method_modifiers($other);
501 $self->_apply_around_method_modifiers($other);
502 $self->_apply_after_method_modifiers($other);
bdabd620 503
bdabd620 504 $other->add_role($self);
505}
506
db1ab48d 507sub combine {
508 my ($class, @roles) = @_;
509
510 my $combined = $class->new(
511 ':role_meta' => Moose::Meta::Class->create_anon_class()
512 );
513
514 foreach my $role (@roles) {
515 $role->apply($combined);
516 }
517
d05cd563 518 $combined->_clean_up_required_methods;
db1ab48d 519
520 return $combined;
521}
522
a7d0cd00 523package Moose::Meta::Role::Method;
524
525use strict;
526use warnings;
527
528our $VERSION = '0.01';
529
530use base 'Class::MOP::Method';
e185c027 531
5321;
533
534__END__
535
536=pod
537
538=head1 NAME
539
540Moose::Meta::Role - The Moose Role metaclass
541
542=head1 DESCRIPTION
543
79592a54 544Moose's Roles are being actively developed, please see L<Moose::Role>
02a0fb52 545for more information. For the most part, this has no user-serviceable
546parts inside. It's API is still subject to some change (although
547probably not that much really).
79592a54 548
e185c027 549=head1 METHODS
550
551=over 4
552
553=item B<meta>
554
555=item B<new>
556
78cd1d3b 557=item B<apply>
558
db1ab48d 559=item B<combine>
560
e185c027 561=back
562
563=over 4
564
565=item B<name>
566
567=item B<version>
568
569=item B<role_meta>
570
571=back
572
573=over 4
574
80572233 575=item B<get_roles>
576
577=item B<add_role>
578
579=item B<does_role>
580
581=back
582
583=over 4
584
d79e62fd 585=item B<add_excluded_roles>
586
587=item B<excludes_role>
588
589=item B<get_excluded_roles_list>
590
591=item B<get_excluded_roles_map>
592
593=back
594
595=over 4
596
e185c027 597=item B<get_method>
598
599=item B<has_method>
600
bdabd620 601=item B<alias_method>
602
e185c027 603=item B<get_method_list>
604
605=back
606
607=over 4
608
609=item B<add_attribute>
610
611=item B<has_attribute>
612
613=item B<get_attribute>
614
615=item B<get_attribute_list>
616
617=item B<get_attribute_map>
618
619=item B<remove_attribute>
620
621=back
622
623=over 4
624
1331430a 625=item B<add_required_methods>
626
38f1204c 627=item B<remove_required_methods>
628
1331430a 629=item B<get_required_method_list>
630
631=item B<get_required_methods_map>
632
633=item B<requires_method>
634
635=back
636
637=over 4
638
80572233 639=item B<add_after_method_modifier>
640
641=item B<add_around_method_modifier>
642
643=item B<add_before_method_modifier>
644
645=item B<add_override_method_modifier>
646
647=over 4
648
649=back
650
651=item B<has_after_method_modifiers>
652
653=item B<has_around_method_modifiers>
654
655=item B<has_before_method_modifiers>
656
657=item B<has_override_method_modifier>
658
659=over 4
660
661=back
662
663=item B<get_after_method_modifiers>
e185c027 664
80572233 665=item B<get_around_method_modifiers>
e185c027 666
80572233 667=item B<get_before_method_modifiers>
e185c027 668
669=item B<get_method_modifier_list>
670
80572233 671=over 4
672
673=back
674
675=item B<get_override_method_modifier>
676
677=item B<get_after_method_modifiers_map>
678
679=item B<get_around_method_modifiers_map>
680
681=item B<get_before_method_modifiers_map>
e185c027 682
80572233 683=item B<get_override_method_modifiers_map>
e185c027 684
685=back
686
687=head1 BUGS
688
689All complex software has bugs lurking in it, and this module is no
690exception. If you find a bug please either email me, or add the bug
691to cpan-RT.
692
693=head1 AUTHOR
694
695Stevan Little E<lt>stevan@iinteractive.comE<gt>
696
697=head1 COPYRIGHT AND LICENSE
698
699Copyright 2006 by Infinity Interactive, Inc.
700
701L<http://www.iinteractive.com>
702
703This library is free software; you can redistribute it and/or modify
704it under the same terms as Perl itself.
705
706=cut