fixing bug, thanks to Sartak
[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';
21f1e231 9use Scalar::Util 'blessed';
bdabd620 10
21f1e231 11our $VERSION = '0.15';
d44714be 12our $AUTHORITY = 'cpan:STEVAN';
e185c027 13
8ee73eeb 14use Moose::Meta::Class;
39b3bc94 15use Moose::Meta::Role::Method;
d67145ed 16use Moose::Meta::Role::Method::Required;
8ee73eeb 17
68efb014 18use base 'Class::MOP::Module';
80572233 19
fb1e11d5 20## ------------------------------------------------------------------
21## NOTE:
22## I normally don't do this, but I am doing
23## a whole bunch of meta-programmin in this
24## module, so it just makes sense. For a clearer
25## picture of what is going on in the next
26## several lines of code, look at the really
27## big comment at the end of this file (right
28## before the POD).
29## - SL
30## ------------------------------------------------------------------
80572233 31
21716c07 32my $META = __PACKAGE__->meta;
33
34## ------------------------------------------------------------------
35## attributes ...
e185c027 36
21716c07 37# NOTE:
38# since roles are lazy, we hold all the attributes
fb1e11d5 39# of the individual role in 'statis' until which
40# time when it is applied to a class. This means
41# keeping a lot of things in hash maps, so we are
21716c07 42# using a little of that meta-programmin' magic
fb1e11d5 43# here an saving lots of extra typin. And since
44# many of these attributes above require similar
45# functionality to support them, so we again use
46# the wonders of meta-programmin' to deliver a
21716c07 47# very compact solution to this normally verbose
48# problem.
49# - SL
50
51foreach my $action (
fb1e11d5 52 {
53 name => 'excluded_roles_map',
54 attr_reader => 'get_excluded_roles_map' ,
21716c07 55 methods => {
fb1e11d5 56 add => 'add_excluded_roles',
57 get_list => 'get_excluded_roles_list',
58 existence => 'excludes_role',
21716c07 59 }
60 },
fb1e11d5 61 {
62 name => 'required_methods',
21716c07 63 attr_reader => 'get_required_methods_map',
64 methods => {
fb1e11d5 65 add => 'add_required_methods',
21716c07 66 remove => 'remove_required_methods',
67 get_list => 'get_required_method_list',
68 existence => 'requires_method',
69 }
709c321c 70 },
21716c07 71 {
fb1e11d5 72 name => 'attribute_map',
21716c07 73 attr_reader => 'get_attribute_map',
74 methods => {
75 get => 'get_attribute',
76 get_list => 'get_attribute_list',
77 existence => 'has_attribute',
78 remove => 'remove_attribute',
79 }
80 }
81) {
fb1e11d5 82
21716c07 83 my $attr_reader = $action->{attr_reader};
84 my $methods = $action->{methods};
fb1e11d5 85
86 # create the attribute
87 $META->add_attribute($action->{name} => (
88 reader => $attr_reader,
89 default => sub { {} }
90 ));
91
92 # create some helper methods
21716c07 93 $META->add_method($methods->{add} => sub {
94 my ($self, @values) = @_;
fb1e11d5 95 $self->$attr_reader->{$_} = undef foreach @values;
21716c07 96 }) if exists $methods->{add};
fb1e11d5 97
21716c07 98 $META->add_method($methods->{get_list} => sub {
99 my ($self) = @_;
fb1e11d5 100 keys %{$self->$attr_reader};
101 }) if exists $methods->{get_list};
102
21716c07 103 $META->add_method($methods->{get} => sub {
104 my ($self, $name) = @_;
fb1e11d5 105 $self->$attr_reader->{$name}
106 }) if exists $methods->{get};
107
21716c07 108 $META->add_method($methods->{existence} => sub {
109 my ($self, $name) = @_;
fb1e11d5 110 exists $self->$attr_reader->{$name} ? 1 : 0;
111 }) if exists $methods->{existence};
112
21716c07 113 $META->add_method($methods->{remove} => sub {
114 my ($self, @values) = @_;
115 delete $self->$attr_reader->{$_} foreach @values;
fb1e11d5 116 }) if exists $methods->{remove};
21716c07 117}
d79e62fd 118
21716c07 119## some things don't always fit, so they go here ...
80572233 120
21716c07 121sub add_attribute {
122 my $self = shift;
123 my $name = shift;
124 my $attr_desc;
125 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
126 $attr_desc = $_[0];
127 }
128 else {
129 $attr_desc = { @_ };
130 }
131 $self->get_attribute_map->{$name} = $attr_desc;
132}
e185c027 133
bca01282 134# DEPRECATED
135# sub _clean_up_required_methods {
136# my $self = shift;
137# foreach my $method ($self->get_required_method_list) {
138# $self->remove_required_methods($method)
139# if $self->has_method($method);
140# }
141# }
1331430a 142
21716c07 143## ------------------------------------------------------------------
144## method modifiers
145
21716c07 146# NOTE:
fb1e11d5 147# the before/around/after method modifiers are
21716c07 148# stored by name, but there can be many methods
149# then associated with that name. So again we have
150# lots of similar functionality, so we can do some
151# meta-programmin' and save some time.
152# - SL
153
154foreach my $modifier_type (qw[ before around after ]) {
fb1e11d5 155
156 my $attr_reader = "get_${modifier_type}_method_modifiers_map";
21716c07 157
fb1e11d5 158 # create the attribute ...
159 $META->add_attribute("${modifier_type}_method_modifiers" => (
160 reader => $attr_reader,
161 default => sub { {} }
162 ));
163
164 # and some helper methods ...
21716c07 165 $META->add_method("get_${modifier_type}_method_modifiers" => sub {
166 my ($self, $method_name) = @_;
fb1e11d5 167 #return () unless exists $self->$attr_reader->{$method_name};
21716c07 168 @{$self->$attr_reader->{$method_name}};
169 });
fb1e11d5 170
21716c07 171 $META->add_method("has_${modifier_type}_method_modifiers" => sub {
172 my ($self, $method_name) = @_;
173 # NOTE:
fb1e11d5 174 # for now we assume that if it exists,..
21716c07 175 # it has at least one modifier in it
176 (exists $self->$attr_reader->{$method_name}) ? 1 : 0;
fb1e11d5 177 });
178
21716c07 179 $META->add_method("add_${modifier_type}_method_modifier" => sub {
180 my ($self, $method_name, $method) = @_;
fb1e11d5 181
182 $self->$attr_reader->{$method_name} = []
21716c07 183 unless exists $self->$attr_reader->{$method_name};
fb1e11d5 184
21716c07 185 my $modifiers = $self->$attr_reader->{$method_name};
fb1e11d5 186
21716c07 187 # NOTE:
fb1e11d5 188 # check to see that we aren't adding the
189 # same code twice. We err in favor of the
21716c07 190 # first on here, this may not be as expected
191 foreach my $modifier (@{$modifiers}) {
192 return if $modifier == $method;
193 }
fb1e11d5 194
21716c07 195 push @{$modifiers} => $method;
196 });
fb1e11d5 197
21716c07 198}
1331430a 199
21716c07 200## ------------------------------------------------------------------
201## override method mofidiers
0558683c 202
fb1e11d5 203$META->add_attribute('override_method_modifiers' => (
204 reader => 'get_override_method_modifiers_map',
205 default => sub { {} }
206));
207
21716c07 208# NOTE:
fb1e11d5 209# these are a little different because there
21716c07 210# can only be one per name, whereas the other
211# method modifiers can have multiples.
212# - SL
0558683c 213
21716c07 214sub add_override_method_modifier {
215 my ($self, $method_name, $method) = @_;
216 (!$self->has_method($method_name))
fb1e11d5 217 || confess "Cannot add an override of method '$method_name' " .
21716c07 218 "because there is a local version of '$method_name'";
fb1e11d5 219 $self->get_override_method_modifiers_map->{$method_name} = $method;
21716c07 220}
0558683c 221
21716c07 222sub has_override_method_modifier {
223 my ($self, $method_name) = @_;
224 # NOTE:
fb1e11d5 225 # for now we assume that if it exists,..
21716c07 226 # it has at least one modifier in it
fb1e11d5 227 (exists $self->get_override_method_modifiers_map->{$method_name}) ? 1 : 0;
21716c07 228}
0558683c 229
21716c07 230sub get_override_method_modifier {
231 my ($self, $method_name) = @_;
fb1e11d5 232 $self->get_override_method_modifiers_map->{$method_name};
21716c07 233}
0558683c 234
21716c07 235## general list accessor ...
80572233 236
21716c07 237sub get_method_modifier_list {
238 my ($self, $modifier_type) = @_;
fb1e11d5 239 my $accessor = "get_${modifier_type}_method_modifiers_map";
21716c07 240 keys %{$self->$accessor};
241}
e185c027 242
21716c07 243## ------------------------------------------------------------------
80572233 244## subroles
245
21716c07 246__PACKAGE__->meta->add_attribute('roles' => (
247 reader => 'get_roles',
248 default => sub { [] }
249));
250
80572233 251sub add_role {
252 my ($self, $role) = @_;
253 (blessed($role) && $role->isa('Moose::Meta::Role'))
254 || confess "Roles must be instances of Moose::Meta::Role";
255 push @{$self->get_roles} => $role;
256}
257
b8aeb4dc 258sub calculate_all_roles {
259 my $self = shift;
260 my %seen;
fb1e11d5 261 grep {
262 !$seen{$_->name}++
263 } ($self, map {
264 $_->calculate_all_roles
265 } @{ $self->get_roles });
b8aeb4dc 266}
267
80572233 268sub does_role {
269 my ($self, $role_name) = @_;
270 (defined $role_name)
271 || confess "You must supply a role name to look for";
bdabd620 272 # if we are it,.. then return true
273 return 1 if $role_name eq $self->name;
274 # otherwise.. check our children
80572233 275 foreach my $role (@{$self->get_roles}) {
bdabd620 276 return 1 if $role->does_role($role_name);
80572233 277 }
278 return 0;
279}
280
21716c07 281## ------------------------------------------------------------------
fb1e11d5 282## methods
1331430a 283
21716c07 284sub method_metaclass { 'Moose::Meta::Role::Method' }
80572233 285
fb1e11d5 286sub get_method_map {
093b12c2 287 my $self = shift;
fb1e11d5 288 my $map = {};
289
290 my $role_name = $self->name;
291 my $method_metaclass = $self->method_metaclass;
292
0addec44 293 my %all_code = $self->get_all_package_symbols('CODE');
fb1e11d5 294
0addec44 295 foreach my $symbol (keys %all_code) {
296 my $code = $all_code{$symbol};
fb1e11d5 297
298 my ($pkg, $name) = Class::MOP::get_code_info($code);
299
300 if ($pkg->can('meta')
301 # NOTE:
302 # we don't know what ->meta we are calling
303 # here, so we need to be careful cause it
304 # just might blow up at us, or just complain
305 # loudly (in the case of Curses.pm) so we
306 # just be a little overly cautious here.
307 # - SL
308 && eval { no warnings; blessed($pkg->meta) }
309 && $pkg->meta->isa('Moose::Meta::Role')) {
310 my $role = $pkg->meta->name;
311 next unless $self->does_role($role);
312 }
313 else {
2887c827 314 # NOTE:
315 # in 5.10 constant.pm the constants show up
316 # as being in the right package, but in pre-5.10
317 # they show up as constant::__ANON__ so we
318 # make an exception here to be sure that things
319 # work as expected in both.
320 # - SL
321 unless ($pkg eq 'constant' && $name eq '__ANON__') {
322 next if ($pkg || '') ne $role_name ||
323 (($name || '') ne '__ANON__' && ($pkg || '') ne $role_name);
324 }
fb1e11d5 325 }
c4538447 326
1b2aea39 327 $map->{$symbol} = $method_metaclass->wrap(
328 $code,
329 package_name => $role_name,
330 name => $name
331 );
fb1e11d5 332 }
333
334 return $map;
093b12c2 335}
336
fb1e11d5 337sub get_method {
338 my ($self, $name) = @_;
c4538447 339 $self->get_method_map->{$name};
fb1e11d5 340}
40e89659 341
fb1e11d5 342sub has_method {
343 my ($self, $name) = @_;
344 exists $self->get_method_map->{$name} ? 1 : 0
e185c027 345}
346
1db8ecc7 347sub find_method_by_name { (shift)->get_method(@_) }
093b12c2 348
fb1e11d5 349sub get_method_list {
350 my $self = shift;
351 grep { !/^meta$/ } keys %{$self->get_method_map};
352}
353
354sub alias_method {
355 my ($self, $method_name, $method) = @_;
356 (defined $method_name && $method_name)
357 || confess "You must define a method name";
358
359 my $body = (blessed($method) ? $method->body : $method);
21f1e231 360 ('CODE' eq ref($body))
fb1e11d5 361 || confess "Your code block must be a CODE reference";
362
363 $self->add_package_symbol("&${method_name}" => $body);
364}
365
21716c07 366## ------------------------------------------------------------------
fb1e11d5 367## role construction
21716c07 368## ------------------------------------------------------------------
e185c027 369
21716c07 370sub apply {
bca01282 371 my ($self, $other, @args) = @_;
372
373 (blessed($other))
374 || confess "You must pass in an blessed instance";
375
1c9db35c 376 if ($other->isa('Moose::Meta::Role')) {
377 require Moose::Meta::Role::Application::ToRole;
709c321c 378 return Moose::Meta::Role::Application::ToRole->new(@args)->apply($self, $other);
1c9db35c 379 }
380 elsif ($other->isa('Moose::Meta::Class')) {
381 require Moose::Meta::Role::Application::ToClass;
709c321c 382 return Moose::Meta::Role::Application::ToClass->new(@args)->apply($self, $other);
1c9db35c 383 }
384 else {
385 require Moose::Meta::Role::Application::ToInstance;
709c321c 386 return Moose::Meta::Role::Application::ToInstance->new(@args)->apply($self, $other);
1c9db35c 387 }
0558683c 388}
389
21716c07 390sub combine {
a4e516f6 391 my ($class, @role_specs) = @_;
21716c07 392
fb1e11d5 393 require Moose::Meta::Role::Application::RoleSummation;
a4e516f6 394 require Moose::Meta::Role::Composite;
395
28412c0b 396 my (@roles, %role_params);
397 while (@role_specs) {
398 my ($role, $params) = @{ splice @role_specs, 0, 1 };
399 push @roles => $role->meta;
400 next unless defined $params;
401 $role_params{$role} = $params;
402 }
21716c07 403
fb1e11d5 404 my $c = Moose::Meta::Role::Composite->new(roles => \@roles);
a4e516f6 405 Moose::Meta::Role::Application::RoleSummation->new(
28412c0b 406 role_params => \%role_params
a4e516f6 407 )->apply($c);
28412c0b 408
fb1e11d5 409 return $c;
0558683c 410}
411
fb1e11d5 412#####################################################################
413## NOTE:
414## This is Moose::Meta::Role as defined by Moose (plus the use of
415## MooseX::AttributeHelpers module). It is here as a reference to
416## make it easier to see what is happening above with all the meta
417## programming. - SL
418#####################################################################
419#
420# has 'roles' => (
421# metaclass => 'Collection::Array',
422# reader => 'get_roles',
423# isa => 'ArrayRef[Moose::Meta::Roles]',
424# default => sub { [] },
425# provides => {
426# 'push' => 'add_role',
427# }
428# );
429#
430# has 'excluded_roles_map' => (
431# metaclass => 'Collection::Hash',
432# reader => 'get_excluded_roles_map',
433# isa => 'HashRef[Str]',
434# provides => {
435# # Not exactly set, cause it sets multiple
436# 'set' => 'add_excluded_roles',
437# 'keys' => 'get_excluded_roles_list',
438# 'exists' => 'excludes_role',
439# }
440# );
441#
442# has 'attribute_map' => (
443# metaclass => 'Collection::Hash',
444# reader => 'get_attribute_map',
445# isa => 'HashRef[Str]',
446# provides => {
447# # 'set' => 'add_attribute' # has some special crap in it
448# 'get' => 'get_attribute',
449# 'keys' => 'get_attribute_list',
450# 'exists' => 'has_attribute',
451# # Not exactly delete, cause it sets multiple
452# 'delete' => 'remove_attribute',
453# }
454# );
455#
456# has 'required_methods' => (
457# metaclass => 'Collection::Hash',
458# reader => 'get_required_methods_map',
459# isa => 'HashRef[Str]',
460# provides => {
461# # not exactly set, or delete since it works for multiple
462# 'set' => 'add_required_methods',
463# 'delete' => 'remove_required_methods',
464# 'keys' => 'get_required_method_list',
465# 'exists' => 'requires_method',
466# }
467# );
468#
469# # the before, around and after modifiers are
470# # HASH keyed by method-name, with ARRAY of
471# # CODE refs to apply in that order
472#
473# has 'before_method_modifiers' => (
474# metaclass => 'Collection::Hash',
475# reader => 'get_before_method_modifiers_map',
476# isa => 'HashRef[ArrayRef[CodeRef]]',
477# provides => {
478# 'keys' => 'get_before_method_modifiers',
479# 'exists' => 'has_before_method_modifiers',
480# # This actually makes sure there is an
481# # ARRAY at the given key, and pushed onto
482# # it. It also checks for duplicates as well
483# # 'add' => 'add_before_method_modifier'
484# }
485# );
486#
487# has 'after_method_modifiers' => (
488# metaclass => 'Collection::Hash',
489# reader =>'get_after_method_modifiers_map',
490# isa => 'HashRef[ArrayRef[CodeRef]]',
491# provides => {
492# 'keys' => 'get_after_method_modifiers',
493# 'exists' => 'has_after_method_modifiers',
494# # This actually makes sure there is an
495# # ARRAY at the given key, and pushed onto
496# # it. It also checks for duplicates as well
497# # 'add' => 'add_after_method_modifier'
498# }
499# );
500#
501# has 'around_method_modifiers' => (
502# metaclass => 'Collection::Hash',
503# reader =>'get_around_method_modifiers_map',
504# isa => 'HashRef[ArrayRef[CodeRef]]',
505# provides => {
506# 'keys' => 'get_around_method_modifiers',
507# 'exists' => 'has_around_method_modifiers',
508# # This actually makes sure there is an
509# # ARRAY at the given key, and pushed onto
510# # it. It also checks for duplicates as well
511# # 'add' => 'add_around_method_modifier'
512# }
513# );
514#
515# # override is similar to the other modifiers
516# # except that it is not an ARRAY of code refs
517# # but instead just a single name->code mapping
518#
519# has 'override_method_modifiers' => (
520# metaclass => 'Collection::Hash',
521# reader =>'get_override_method_modifiers_map',
522# isa => 'HashRef[CodeRef]',
523# provides => {
524# 'keys' => 'get_override_method_modifier',
525# 'exists' => 'has_override_method_modifier',
526# 'add' => 'add_override_method_modifier', # checks for local method ..
527# }
528# );
529#
530#####################################################################
531
532
e185c027 5331;
534
535__END__
536
537=pod
538
539=head1 NAME
540
541Moose::Meta::Role - The Moose Role metaclass
542
543=head1 DESCRIPTION
544
fb1e11d5 545Please see L<Moose::Role> for more information about roles.
d44714be 546For the most part, this has no user-serviceable parts inside
fb1e11d5 547this module. It's API is still subject to some change (although
02a0fb52 548probably not that much really).
79592a54 549
e185c027 550=head1 METHODS
551
552=over 4
553
554=item B<meta>
555
556=item B<new>
557
78cd1d3b 558=item B<apply>
559
db1ab48d 560=item B<combine>
561
e185c027 562=back
563
564=over 4
565
566=item B<name>
567
568=item B<version>
569
570=item B<role_meta>
571
572=back
573
574=over 4
575
80572233 576=item B<get_roles>
577
578=item B<add_role>
579
580=item B<does_role>
581
582=back
583
584=over 4
585
d79e62fd 586=item B<add_excluded_roles>
587
588=item B<excludes_role>
589
590=item B<get_excluded_roles_list>
591
592=item B<get_excluded_roles_map>
593
2b14ac61 594=item B<calculate_all_roles>
595
d79e62fd 596=back
597
598=over 4
599
68efb014 600=item B<method_metaclass>
601
be4427d0 602=item B<find_method_by_name>
603
e185c027 604=item B<get_method>
605
606=item B<has_method>
607
bdabd620 608=item B<alias_method>
609
e185c027 610=item B<get_method_list>
611
093b12c2 612=item B<get_method_map>
613
638853cb 614=item B<update_package_cache_flag>
615
53dd42d8 616=item B<reset_package_cache_flag>
617
e185c027 618=back
619
620=over 4
621
622=item B<add_attribute>
623
624=item B<has_attribute>
625
626=item B<get_attribute>
627
628=item B<get_attribute_list>
629
630=item B<get_attribute_map>
631
632=item B<remove_attribute>
633
634=back
635
636=over 4
637
1331430a 638=item B<add_required_methods>
639
38f1204c 640=item B<remove_required_methods>
641
1331430a 642=item B<get_required_method_list>
643
644=item B<get_required_methods_map>
645
646=item B<requires_method>
647
648=back
649
0558683c 650=over 4
651
652=item B<add_after_method_modifier>
653
654=item B<add_around_method_modifier>
655
656=item B<add_before_method_modifier>
657
658=item B<add_override_method_modifier>
659
660=over 4
661
662=back
663
664=item B<has_after_method_modifiers>
665
666=item B<has_around_method_modifiers>
667
668=item B<has_before_method_modifiers>
669
670=item B<has_override_method_modifier>
671
672=over 4
673
674=back
675
676=item B<get_after_method_modifiers>
677
678=item B<get_around_method_modifiers>
679
680=item B<get_before_method_modifiers>
681
682=item B<get_method_modifier_list>
683
684=over 4
685
686=back
687
688=item B<get_override_method_modifier>
689
690=item B<get_after_method_modifiers_map>
691
692=item B<get_around_method_modifiers_map>
693
694=item B<get_before_method_modifiers_map>
695
696=item B<get_override_method_modifiers_map>
697
698=back
699
e185c027 700=head1 BUGS
701
fb1e11d5 702All complex software has bugs lurking in it, and this module is no
e185c027 703exception. If you find a bug please either email me, or add the bug
704to cpan-RT.
705
706=head1 AUTHOR
707
708Stevan Little E<lt>stevan@iinteractive.comE<gt>
709
710=head1 COPYRIGHT AND LICENSE
711
778db3ac 712Copyright 2006-2008 by Infinity Interactive, Inc.
e185c027 713
714L<http://www.iinteractive.com>
715
716This library is free software; you can redistribute it and/or modify
fb1e11d5 717it under the same terms as Perl itself.
e185c027 718
b8aeb4dc 719=cut