2 package Moose::Meta::Role;
8 use Scalar::Util 'blessed';
11 our $VERSION = '0.61';
12 $VERSION = eval $VERSION;
13 our $AUTHORITY = 'cpan:STEVAN';
15 use Moose::Meta::Class;
16 use Moose::Meta::Role::Method;
17 use Moose::Meta::Role::Method::Required;
19 use base 'Class::MOP::Module';
21 ## ------------------------------------------------------------------
23 ## I normally don't do this, but I am doing
24 ## a whole bunch of meta-programmin in this
25 ## module, so it just makes sense. For a clearer
26 ## picture of what is going on in the next
27 ## several lines of code, look at the really
28 ## big comment at the end of this file (right
31 ## ------------------------------------------------------------------
33 my $META = __PACKAGE__->meta;
35 ## ------------------------------------------------------------------
39 # since roles are lazy, we hold all the attributes
40 # of the individual role in 'statis' until which
41 # time when it is applied to a class. This means
42 # keeping a lot of things in hash maps, so we are
43 # using a little of that meta-programmin' magic
44 # here an saving lots of extra typin. And since
45 # many of these attributes above require similar
46 # functionality to support them, so we again use
47 # the wonders of meta-programmin' to deliver a
48 # very compact solution to this normally verbose
54 name => 'excluded_roles_map',
55 attr_reader => 'get_excluded_roles_map' ,
57 add => 'add_excluded_roles',
58 get_list => 'get_excluded_roles_list',
59 existence => 'excludes_role',
63 name => 'required_methods',
64 attr_reader => 'get_required_methods_map',
66 add => 'add_required_methods',
67 remove => 'remove_required_methods',
68 get_list => 'get_required_method_list',
69 existence => 'requires_method',
73 name => 'attribute_map',
74 attr_reader => 'get_attribute_map',
76 get => 'get_attribute',
77 get_list => 'get_attribute_list',
78 existence => 'has_attribute',
79 remove => 'remove_attribute',
84 my $attr_reader = $action->{attr_reader};
85 my $methods = $action->{methods};
87 # create the attribute
88 $META->add_attribute($action->{name} => (
89 reader => $attr_reader,
93 # create some helper methods
94 $META->add_method($methods->{add} => sub {
95 my ($self, @values) = @_;
96 $self->$attr_reader->{$_} = undef foreach @values;
97 }) if exists $methods->{add};
99 $META->add_method($methods->{get_list} => sub {
101 keys %{$self->$attr_reader};
102 }) if exists $methods->{get_list};
104 $META->add_method($methods->{get} => sub {
105 my ($self, $name) = @_;
106 $self->$attr_reader->{$name}
107 }) if exists $methods->{get};
109 $META->add_method($methods->{existence} => sub {
110 my ($self, $name) = @_;
111 exists $self->$attr_reader->{$name} ? 1 : 0;
112 }) if exists $methods->{existence};
114 $META->add_method($methods->{remove} => sub {
115 my ($self, @values) = @_;
116 delete $self->$attr_reader->{$_} foreach @values;
117 }) if exists $methods->{remove};
120 ## some things don't always fit, so they go here ...
125 (defined $name && $name)
126 || Moose->throw_error("You must provide a name for the attribute");
128 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
134 $self->get_attribute_map->{$name} = $attr_desc;
138 # sub _clean_up_required_methods {
140 # foreach my $method ($self->get_required_method_list) {
141 # $self->remove_required_methods($method)
142 # if $self->has_method($method);
146 ## ------------------------------------------------------------------
150 # the before/around/after method modifiers are
151 # stored by name, but there can be many methods
152 # then associated with that name. So again we have
153 # lots of similar functionality, so we can do some
154 # meta-programmin' and save some time.
157 foreach my $modifier_type (qw[ before around after ]) {
159 my $attr_reader = "get_${modifier_type}_method_modifiers_map";
161 # create the attribute ...
162 $META->add_attribute("${modifier_type}_method_modifiers" => (
163 reader => $attr_reader,
164 default => sub { {} }
167 # and some helper methods ...
168 $META->add_method("get_${modifier_type}_method_modifiers" => sub {
169 my ($self, $method_name) = @_;
170 #return () unless exists $self->$attr_reader->{$method_name};
171 @{$self->$attr_reader->{$method_name}};
174 $META->add_method("has_${modifier_type}_method_modifiers" => sub {
175 my ($self, $method_name) = @_;
177 # for now we assume that if it exists,..
178 # it has at least one modifier in it
179 (exists $self->$attr_reader->{$method_name}) ? 1 : 0;
182 $META->add_method("add_${modifier_type}_method_modifier" => sub {
183 my ($self, $method_name, $method) = @_;
185 $self->$attr_reader->{$method_name} = []
186 unless exists $self->$attr_reader->{$method_name};
188 my $modifiers = $self->$attr_reader->{$method_name};
191 # check to see that we aren't adding the
192 # same code twice. We err in favor of the
193 # first on here, this may not be as expected
194 foreach my $modifier (@{$modifiers}) {
195 return if $modifier == $method;
198 push @{$modifiers} => $method;
203 ## ------------------------------------------------------------------
204 ## override method mofidiers
206 $META->add_attribute('override_method_modifiers' => (
207 reader => 'get_override_method_modifiers_map',
208 default => sub { {} }
212 # these are a little different because there
213 # can only be one per name, whereas the other
214 # method modifiers can have multiples.
217 sub add_override_method_modifier {
218 my ($self, $method_name, $method) = @_;
219 (!$self->has_method($method_name))
220 || Moose->throw_error("Cannot add an override of method '$method_name' " .
221 "because there is a local version of '$method_name'");
222 $self->get_override_method_modifiers_map->{$method_name} = $method;
225 sub has_override_method_modifier {
226 my ($self, $method_name) = @_;
228 # for now we assume that if it exists,..
229 # it has at least one modifier in it
230 (exists $self->get_override_method_modifiers_map->{$method_name}) ? 1 : 0;
233 sub get_override_method_modifier {
234 my ($self, $method_name) = @_;
235 $self->get_override_method_modifiers_map->{$method_name};
238 ## general list accessor ...
240 sub get_method_modifier_list {
241 my ($self, $modifier_type) = @_;
242 my $accessor = "get_${modifier_type}_method_modifiers_map";
243 keys %{$self->$accessor};
246 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
247 sub update_package_cache_flag {
249 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
254 ## ------------------------------------------------------------------
257 __PACKAGE__->meta->add_attribute('roles' => (
258 reader => 'get_roles',
259 default => sub { [] }
263 my ($self, $role) = @_;
264 (blessed($role) && $role->isa('Moose::Meta::Role'))
265 || Moose->throw_error("Roles must be instances of Moose::Meta::Role");
266 push @{$self->get_roles} => $role;
267 $self->reset_package_cache_flag;
270 sub calculate_all_roles {
276 $_->calculate_all_roles
277 } @{ $self->get_roles });
281 my ($self, $role_name) = @_;
283 || Moose->throw_error("You must supply a role name to look for");
284 # if we are it,.. then return true
285 return 1 if $role_name eq $self->name;
286 # otherwise.. check our children
287 foreach my $role (@{$self->get_roles}) {
288 return 1 if $role->does_role($role_name);
293 ## ------------------------------------------------------------------
296 sub method_metaclass { 'Moose::Meta::Role::Method' }
301 my $current = Class::MOP::check_package_cache_flag($self->name);
303 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
304 return $self->{'methods'} ||= {};
307 $self->{_package_cache_flag} = $current;
309 my $map = $self->{'methods'} ||= {};
311 my $role_name = $self->name;
312 my $method_metaclass = $self->method_metaclass;
314 my %all_code = $self->get_all_package_symbols('CODE');
316 foreach my $symbol (keys %all_code) {
317 my $code = $all_code{$symbol};
319 next if exists $map->{$symbol} &&
320 defined $map->{$symbol} &&
321 $map->{$symbol}->body == $code;
323 my ($pkg, $name) = Class::MOP::get_code_info($code);
325 if ($pkg->can('meta')
327 # we don't know what ->meta we are calling
328 # here, so we need to be careful cause it
329 # just might blow up at us, or just complain
330 # loudly (in the case of Curses.pm) so we
331 # just be a little overly cautious here.
333 && eval { no warnings; blessed($pkg->meta) } # FIXME calls meta
334 && $pkg->meta->isa('Moose::Meta::Role')) {
335 my $role = $pkg->meta->name;
336 next unless $self->does_role($role);
340 # in 5.10 constant.pm the constants show up
341 # as being in the right package, but in pre-5.10
342 # they show up as constant::__ANON__ so we
343 # make an exception here to be sure that things
344 # work as expected in both.
346 unless ($pkg eq 'constant' && $name eq '__ANON__') {
347 next if ($pkg || '') ne $role_name ||
348 (($name || '') ne '__ANON__' && ($pkg || '') ne $role_name);
352 $map->{$symbol} = $method_metaclass->wrap(
354 package_name => $role_name,
363 my ($self, $name) = @_;
364 $self->get_method_map->{$name};
368 my ($self, $name) = @_;
369 exists $self->get_method_map->{$name} ? 1 : 0
372 # FIXME this is copy-pasted from Class::MOP::Class
373 # refactor to inherit from some common base
374 sub wrap_method_body {
375 my ( $self, %args ) = @_;
377 ('CODE' eq ref $args{body})
378 || Moose->throw_error("Your code block must be a CODE reference");
380 $self->method_metaclass->wrap(
381 package_name => $self->name,
387 my ($self, $method_name, $method) = @_;
388 (defined $method_name && $method_name)
389 || Moose->throw_error("You must define a method name");
392 if (blessed($method)) {
393 $body = $method->body;
394 if ($method->package_name ne $self->name) {
395 $method = $method->clone(
396 package_name => $self->name,
398 ) if $method->can('clone');
403 $method = $self->wrap_method_body( body => $body, name => $method_name );
406 $method->attach_to_class($self);
408 $self->get_method_map->{$method_name} = $method;
410 my $full_method_name = ($self->name . '::' . $method_name);
411 $self->add_package_symbol(
412 { sigil => '&', type => 'CODE', name => $method_name },
413 Class::MOP::subname($full_method_name => $body)
416 $self->update_package_cache_flag; # still valid, since we just added the method to the map, and if it was invalid before that then get_method_map updated it
419 sub find_method_by_name { (shift)->get_method(@_) }
421 sub get_method_list {
423 grep { !/^meta$/ } keys %{$self->get_method_map};
429 $self->add_method(@_);
432 ## ------------------------------------------------------------------
434 ## ------------------------------------------------------------------
437 my ($self, $other, @args) = @_;
440 || Moose->throw_error("You must pass in an blessed instance");
442 if ($other->isa('Moose::Meta::Role')) {
443 require Moose::Meta::Role::Application::ToRole;
444 return Moose::Meta::Role::Application::ToRole->new(@args)->apply($self, $other);
446 elsif ($other->isa('Moose::Meta::Class')) {
447 require Moose::Meta::Role::Application::ToClass;
448 return Moose::Meta::Role::Application::ToClass->new(@args)->apply($self, $other);
451 require Moose::Meta::Role::Application::ToInstance;
452 return Moose::Meta::Role::Application::ToInstance->new(@args)->apply($self, $other);
457 my ($class, @role_specs) = @_;
459 require Moose::Meta::Role::Application::RoleSummation;
460 require Moose::Meta::Role::Composite;
462 my (@roles, %role_params);
463 while (@role_specs) {
464 my ($role, $params) = @{ splice @role_specs, 0, 1 };
465 push @roles => $role->meta;
466 next unless defined $params;
467 $role_params{$role} = $params;
470 my $c = Moose::Meta::Role::Composite->new(roles => \@roles);
471 Moose::Meta::Role::Application::RoleSummation->new(
472 role_params => \%role_params
479 my ( $role, $package_name, %options ) = @_;
481 $options{package} = $package_name;
483 (ref $options{attributes} eq 'HASH')
484 || confess "You must pass a HASH ref of attributes"
485 if exists $options{attributes};
487 (ref $options{methods} eq 'HASH')
488 || confess "You must pass a HASH ref of methods"
489 if exists $options{methods};
491 $role->SUPER::create(%options);
493 my (%initialize_options) = %options;
494 delete @initialize_options{qw(
502 my $meta = $role->initialize( $package_name => %initialize_options );
505 $meta->add_method('meta' => sub {
506 $role->initialize(ref($_[0]) || $_[0]);
509 if (exists $options{attributes}) {
510 foreach my $attribute_name (keys %{$options{attributes}}) {
511 my $attr = $options{attributes}->{$attribute_name};
512 $meta->add_attribute($attribute_name => $attr);
516 if (exists $options{methods}) {
517 foreach my $method_name (keys %{$options{methods}}) {
518 $meta->add_method($method_name, $options{methods}->{$method_name});
522 Class::MOP::weaken_metaclass($meta->name)
523 if $meta->is_anon_role;
528 # anonymous roles. most of it is copied straight out of Class::MOP::Class.
529 # an intrepid hacker might find great riches if he unifies this code with that
530 # code in Class::MOP::Module or Class::MOP::Package
533 # this should be sufficient, if you have a
534 # use case where it is not, write a test and
536 my $ANON_ROLE_SERIAL = 0;
539 # we need a sufficiently annoying prefix
540 # this should suffice for now, this is
541 # used in a couple of places below, so
542 # need to put it up here for now.
543 my $ANON_ROLE_PREFIX = 'Moose::Meta::Role::__ANON__::SERIAL::';
547 no warnings 'uninitialized';
548 $self->name =~ /^$ANON_ROLE_PREFIX/;
551 sub create_anon_role {
552 my ($role, %options) = @_;
553 my $package_name = $ANON_ROLE_PREFIX . ++$ANON_ROLE_SERIAL;
554 return $role->create($package_name, %options);
558 # this will only get called for
559 # anon-roles, all other calls
560 # are assumed to occur during
561 # global destruction and so don't
562 # really need to be handled explicitly
566 return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
568 no warnings 'uninitialized';
569 return unless $self->name =~ /^$ANON_ROLE_PREFIX/;
571 # XXX: is this necessary for us? I don't understand what it's doing
574 # Moose does a weird thing where it replaces the metaclass for
575 # class when fixing metaclass incompatibility. In that case,
576 # we don't want to clean out the namespace now. We can detect
577 # that because Moose will explicitly update the singleton
578 # cache in Class::MOP.
579 #my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
580 #return if $current_meta ne $self;
582 my ($serial_id) = ($self->name =~ /^$ANON_ROLE_PREFIX(\d+)/);
584 foreach my $key (keys %{$ANON_ROLE_PREFIX . $serial_id}) {
585 delete ${$ANON_ROLE_PREFIX . $serial_id}{$key};
587 delete ${'main::' . $ANON_ROLE_PREFIX}{$serial_id . '::'};
591 #####################################################################
593 ## This is Moose::Meta::Role as defined by Moose (plus the use of
594 ## MooseX::AttributeHelpers module). It is here as a reference to
595 ## make it easier to see what is happening above with all the meta
597 #####################################################################
600 # metaclass => 'Collection::Array',
601 # reader => 'get_roles',
602 # isa => 'ArrayRef[Moose::Meta::Roles]',
603 # default => sub { [] },
605 # 'push' => 'add_role',
609 # has 'excluded_roles_map' => (
610 # metaclass => 'Collection::Hash',
611 # reader => 'get_excluded_roles_map',
612 # isa => 'HashRef[Str]',
614 # # Not exactly set, cause it sets multiple
615 # 'set' => 'add_excluded_roles',
616 # 'keys' => 'get_excluded_roles_list',
617 # 'exists' => 'excludes_role',
621 # has 'attribute_map' => (
622 # metaclass => 'Collection::Hash',
623 # reader => 'get_attribute_map',
624 # isa => 'HashRef[Str]',
626 # # 'set' => 'add_attribute' # has some special crap in it
627 # 'get' => 'get_attribute',
628 # 'keys' => 'get_attribute_list',
629 # 'exists' => 'has_attribute',
630 # # Not exactly delete, cause it sets multiple
631 # 'delete' => 'remove_attribute',
635 # has 'required_methods' => (
636 # metaclass => 'Collection::Hash',
637 # reader => 'get_required_methods_map',
638 # isa => 'HashRef[Str]',
640 # # not exactly set, or delete since it works for multiple
641 # 'set' => 'add_required_methods',
642 # 'delete' => 'remove_required_methods',
643 # 'keys' => 'get_required_method_list',
644 # 'exists' => 'requires_method',
648 # # the before, around and after modifiers are
649 # # HASH keyed by method-name, with ARRAY of
650 # # CODE refs to apply in that order
652 # has 'before_method_modifiers' => (
653 # metaclass => 'Collection::Hash',
654 # reader => 'get_before_method_modifiers_map',
655 # isa => 'HashRef[ArrayRef[CodeRef]]',
657 # 'keys' => 'get_before_method_modifiers',
658 # 'exists' => 'has_before_method_modifiers',
659 # # This actually makes sure there is an
660 # # ARRAY at the given key, and pushed onto
661 # # it. It also checks for duplicates as well
662 # # 'add' => 'add_before_method_modifier'
666 # has 'after_method_modifiers' => (
667 # metaclass => 'Collection::Hash',
668 # reader =>'get_after_method_modifiers_map',
669 # isa => 'HashRef[ArrayRef[CodeRef]]',
671 # 'keys' => 'get_after_method_modifiers',
672 # 'exists' => 'has_after_method_modifiers',
673 # # This actually makes sure there is an
674 # # ARRAY at the given key, and pushed onto
675 # # it. It also checks for duplicates as well
676 # # 'add' => 'add_after_method_modifier'
680 # has 'around_method_modifiers' => (
681 # metaclass => 'Collection::Hash',
682 # reader =>'get_around_method_modifiers_map',
683 # isa => 'HashRef[ArrayRef[CodeRef]]',
685 # 'keys' => 'get_around_method_modifiers',
686 # 'exists' => 'has_around_method_modifiers',
687 # # This actually makes sure there is an
688 # # ARRAY at the given key, and pushed onto
689 # # it. It also checks for duplicates as well
690 # # 'add' => 'add_around_method_modifier'
694 # # override is similar to the other modifiers
695 # # except that it is not an ARRAY of code refs
696 # # but instead just a single name->code mapping
698 # has 'override_method_modifiers' => (
699 # metaclass => 'Collection::Hash',
700 # reader =>'get_override_method_modifiers_map',
701 # isa => 'HashRef[CodeRef]',
703 # 'keys' => 'get_override_method_modifier',
704 # 'exists' => 'has_override_method_modifier',
705 # 'add' => 'add_override_method_modifier', # checks for local method ..
709 #####################################################################
720 Moose::Meta::Role - The Moose Role metaclass
724 Please see L<Moose::Role> for more information about roles.
725 For the most part, this has no user-serviceable parts inside
726 this module. It's API is still subject to some change (although
727 probably not that much really).
739 =item B<apply_to_metaclass_instance>
767 =item B<add_excluded_roles>
769 =item B<excludes_role>
771 =item B<get_excluded_roles_list>
773 =item B<get_excluded_roles_map>
775 =item B<calculate_all_roles>
781 =item B<method_metaclass>
783 =item B<find_method_by_name>
791 =item B<wrap_method_body>
793 =item B<alias_method>
795 =item B<get_method_list>
797 =item B<get_method_map>
799 =item B<update_package_cache_flag>
801 =item B<reset_package_cache_flag>
807 =item B<add_attribute>
809 =item B<has_attribute>
811 =item B<get_attribute>
813 =item B<get_attribute_list>
815 =item B<get_attribute_map>
817 =item B<remove_attribute>
823 =item B<add_required_methods>
825 =item B<remove_required_methods>
827 =item B<get_required_method_list>
829 =item B<get_required_methods_map>
831 =item B<requires_method>
837 =item B<add_after_method_modifier>
839 =item B<add_around_method_modifier>
841 =item B<add_before_method_modifier>
843 =item B<add_override_method_modifier>
849 =item B<has_after_method_modifiers>
851 =item B<has_around_method_modifiers>
853 =item B<has_before_method_modifiers>
855 =item B<has_override_method_modifier>
861 =item B<get_after_method_modifiers>
863 =item B<get_around_method_modifiers>
865 =item B<get_before_method_modifiers>
867 =item B<get_method_modifier_list>
873 =item B<get_override_method_modifier>
875 =item B<get_after_method_modifiers_map>
877 =item B<get_around_method_modifiers_map>
879 =item B<get_before_method_modifiers_map>
881 =item B<get_override_method_modifiers_map>
889 =item B<create_anon_role>
891 =item B<is_anon_role>
897 All complex software has bugs lurking in it, and this module is no
898 exception. If you find a bug please either email me, or add the bug
903 Stevan Little E<lt>stevan@iinteractive.comE<gt>
905 =head1 COPYRIGHT AND LICENSE
907 Copyright 2006-2008 by Infinity Interactive, Inc.
909 L<http://www.iinteractive.com>
911 This library is free software; you can redistribute it and/or modify
912 it under the same terms as Perl itself.