2 package Moose::Meta::Role;
8 use Scalar::Util 'blessed';
11 our $VERSION = '0.72';
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 unless ( defined $name && $name ) {
127 Moose->throw_error("You must provide a name for the attribute");
130 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
136 $self->get_attribute_map->{$name} = $attr_desc;
140 # sub _clean_up_required_methods {
142 # foreach my $method ($self->get_required_method_list) {
143 # $self->remove_required_methods($method)
144 # if $self->has_method($method);
148 ## ------------------------------------------------------------------
152 # the before/around/after method modifiers are
153 # stored by name, but there can be many methods
154 # then associated with that name. So again we have
155 # lots of similar functionality, so we can do some
156 # meta-programmin' and save some time.
159 foreach my $modifier_type (qw[ before around after ]) {
161 my $attr_reader = "get_${modifier_type}_method_modifiers_map";
163 # create the attribute ...
164 $META->add_attribute("${modifier_type}_method_modifiers" => (
165 reader => $attr_reader,
166 default => sub { {} }
169 # and some helper methods ...
170 $META->add_method("get_${modifier_type}_method_modifiers" => sub {
171 my ($self, $method_name) = @_;
172 #return () unless exists $self->$attr_reader->{$method_name};
173 @{$self->$attr_reader->{$method_name}};
176 $META->add_method("has_${modifier_type}_method_modifiers" => sub {
177 my ($self, $method_name) = @_;
179 # for now we assume that if it exists,..
180 # it has at least one modifier in it
181 (exists $self->$attr_reader->{$method_name}) ? 1 : 0;
184 $META->add_method("add_${modifier_type}_method_modifier" => sub {
185 my ($self, $method_name, $method) = @_;
187 $self->$attr_reader->{$method_name} = []
188 unless exists $self->$attr_reader->{$method_name};
190 my $modifiers = $self->$attr_reader->{$method_name};
193 # check to see that we aren't adding the
194 # same code twice. We err in favor of the
195 # first on here, this may not be as expected
196 foreach my $modifier (@{$modifiers}) {
197 return if $modifier == $method;
200 push @{$modifiers} => $method;
205 ## ------------------------------------------------------------------
206 ## override method mofidiers
208 $META->add_attribute('override_method_modifiers' => (
209 reader => 'get_override_method_modifiers_map',
210 default => sub { {} }
214 # these are a little different because there
215 # can only be one per name, whereas the other
216 # method modifiers can have multiples.
219 sub add_override_method_modifier {
220 my ($self, $method_name, $method) = @_;
221 (!$self->has_method($method_name))
222 || Moose->throw_error("Cannot add an override of method '$method_name' " .
223 "because there is a local version of '$method_name'");
224 $self->get_override_method_modifiers_map->{$method_name} = $method;
227 sub has_override_method_modifier {
228 my ($self, $method_name) = @_;
230 # for now we assume that if it exists,..
231 # it has at least one modifier in it
232 (exists $self->get_override_method_modifiers_map->{$method_name}) ? 1 : 0;
235 sub get_override_method_modifier {
236 my ($self, $method_name) = @_;
237 $self->get_override_method_modifiers_map->{$method_name};
240 ## general list accessor ...
242 sub get_method_modifier_list {
243 my ($self, $modifier_type) = @_;
244 my $accessor = "get_${modifier_type}_method_modifiers_map";
245 keys %{$self->$accessor};
248 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
249 sub update_package_cache_flag {
251 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
256 ## ------------------------------------------------------------------
259 __PACKAGE__->meta->add_attribute('roles' => (
260 reader => 'get_roles',
261 default => sub { [] }
265 my ($self, $role) = @_;
266 (blessed($role) && $role->isa('Moose::Meta::Role'))
267 || Moose->throw_error("Roles must be instances of Moose::Meta::Role");
268 push @{$self->get_roles} => $role;
269 $self->reset_package_cache_flag;
272 sub calculate_all_roles {
278 $_->calculate_all_roles
279 } @{ $self->get_roles });
283 my ($self, $role_name) = @_;
285 || Moose->throw_error("You must supply a role name to look for");
286 # if we are it,.. then return true
287 return 1 if $role_name eq $self->name;
288 # otherwise.. check our children
289 foreach my $role (@{$self->get_roles}) {
290 return 1 if $role->does_role($role_name);
295 ## ------------------------------------------------------------------
298 sub method_metaclass { 'Moose::Meta::Role::Method' }
303 my $current = Class::MOP::check_package_cache_flag($self->name);
305 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
306 return $self->{'methods'} ||= {};
309 $self->{_package_cache_flag} = $current;
311 my $map = $self->{'methods'} ||= {};
313 my $role_name = $self->name;
314 my $method_metaclass = $self->method_metaclass;
316 my $all_code = $self->get_all_package_symbols('CODE');
318 foreach my $symbol (keys %{ $all_code }) {
319 my $code = $all_code->{$symbol};
321 next if exists $map->{$symbol} &&
322 defined $map->{$symbol} &&
323 $map->{$symbol}->body == $code;
325 my ($pkg, $name) = Class::MOP::get_code_info($code);
327 if ($pkg->can('meta')
329 # we don't know what ->meta we are calling
330 # here, so we need to be careful cause it
331 # just might blow up at us, or just complain
332 # loudly (in the case of Curses.pm) so we
333 # just be a little overly cautious here.
335 && eval { no warnings; blessed($pkg->meta) } # FIXME calls meta
336 && $pkg->meta->isa('Moose::Meta::Role')) {
337 my $role = $pkg->meta->name;
338 next unless $self->does_role($role);
342 # in 5.10 constant.pm the constants show up
343 # as being in the right package, but in pre-5.10
344 # they show up as constant::__ANON__ so we
345 # make an exception here to be sure that things
346 # work as expected in both.
348 unless ($pkg eq 'constant' && $name eq '__ANON__') {
349 next if ($pkg || '') ne $role_name ||
350 (($name || '') ne '__ANON__' && ($pkg || '') ne $role_name);
354 $map->{$symbol} = $method_metaclass->wrap(
356 package_name => $role_name,
365 my ($self, $name) = @_;
366 $self->get_method_map->{$name};
370 my ($self, $name) = @_;
371 exists $self->get_method_map->{$name} ? 1 : 0
374 # FIXME this is copy-pasted from Class::MOP::Class
375 # refactor to inherit from some common base
376 sub wrap_method_body {
377 my ( $self, %args ) = @_;
379 ('CODE' eq ref $args{body})
380 || Moose->throw_error("Your code block must be a CODE reference");
382 $self->method_metaclass->wrap(
383 package_name => $self->name,
389 my ($self, $method_name, $method) = @_;
390 (defined $method_name && $method_name)
391 || Moose->throw_error("You must define a method name");
394 if (blessed($method)) {
395 $body = $method->body;
396 if ($method->package_name ne $self->name) {
397 $method = $method->clone(
398 package_name => $self->name,
400 ) if $method->can('clone');
405 $method = $self->wrap_method_body( body => $body, name => $method_name );
408 $method->attach_to_class($self);
410 $self->get_method_map->{$method_name} = $method;
412 my $full_method_name = ($self->name . '::' . $method_name);
413 $self->add_package_symbol(
414 { sigil => '&', type => 'CODE', name => $method_name },
415 Class::MOP::subname($full_method_name => $body)
418 $self->update_package_cache_flag; # still valid, since we just added the method to the map, and if it was invalid before that then get_method_map updated it
421 sub find_method_by_name { (shift)->get_method(@_) }
423 sub get_method_list {
425 grep { !/^meta$/ } keys %{$self->get_method_map};
431 $self->add_method(@_);
434 ## ------------------------------------------------------------------
436 ## ------------------------------------------------------------------
439 my ($self, $other, @args) = @_;
442 || Moose->throw_error("You must pass in an blessed instance");
444 if ($other->isa('Moose::Meta::Role')) {
445 require Moose::Meta::Role::Application::ToRole;
446 return Moose::Meta::Role::Application::ToRole->new(@args)->apply($self, $other);
448 elsif ($other->isa('Moose::Meta::Class')) {
449 require Moose::Meta::Role::Application::ToClass;
450 return Moose::Meta::Role::Application::ToClass->new(@args)->apply($self, $other);
453 require Moose::Meta::Role::Application::ToInstance;
454 return Moose::Meta::Role::Application::ToInstance->new(@args)->apply($self, $other);
459 my ($class, @role_specs) = @_;
461 require Moose::Meta::Role::Application::RoleSummation;
462 require Moose::Meta::Role::Composite;
464 my (@roles, %role_params);
465 while (@role_specs) {
466 my ($role, $params) = @{ splice @role_specs, 0, 1 };
467 push @roles => $role->meta;
468 next unless defined $params;
469 $role_params{$role} = $params;
472 my $c = Moose::Meta::Role::Composite->new(roles => \@roles);
473 Moose::Meta::Role::Application::RoleSummation->new(
474 role_params => \%role_params
481 my ( $role, $package_name, %options ) = @_;
483 $options{package} = $package_name;
485 (ref $options{attributes} eq 'HASH')
486 || confess "You must pass a HASH ref of attributes"
487 if exists $options{attributes};
489 (ref $options{methods} eq 'HASH')
490 || confess "You must pass a HASH ref of methods"
491 if exists $options{methods};
493 my (%initialize_options) = %options;
494 delete @initialize_options{qw(
502 my $meta = $role->initialize( $package_name => %initialize_options );
504 $meta->_instantiate_module( $options{version}, $options{authority} );
507 $meta->add_method('meta' => sub {
508 $role->initialize(ref($_[0]) || $_[0]);
511 if (exists $options{attributes}) {
512 foreach my $attribute_name (keys %{$options{attributes}}) {
513 my $attr = $options{attributes}->{$attribute_name};
514 $meta->add_attribute($attribute_name => $attr);
518 if (exists $options{methods}) {
519 foreach my $method_name (keys %{$options{methods}}) {
520 $meta->add_method($method_name, $options{methods}->{$method_name});
524 Class::MOP::weaken_metaclass($meta->name)
525 if $meta->is_anon_role;
530 # anonymous roles. most of it is copied straight out of Class::MOP::Class.
531 # an intrepid hacker might find great riches if he unifies this code with that
532 # code in Class::MOP::Module or Class::MOP::Package
535 # this should be sufficient, if you have a
536 # use case where it is not, write a test and
538 my $ANON_ROLE_SERIAL = 0;
541 # we need a sufficiently annoying prefix
542 # this should suffice for now, this is
543 # used in a couple of places below, so
544 # need to put it up here for now.
545 my $ANON_ROLE_PREFIX = 'Moose::Meta::Role::__ANON__::SERIAL::';
549 no warnings 'uninitialized';
550 $self->name =~ /^$ANON_ROLE_PREFIX/;
553 sub create_anon_role {
554 my ($role, %options) = @_;
555 my $package_name = $ANON_ROLE_PREFIX . ++$ANON_ROLE_SERIAL;
556 return $role->create($package_name, %options);
560 # this will only get called for
561 # anon-roles, all other calls
562 # are assumed to occur during
563 # global destruction and so don't
564 # really need to be handled explicitly
568 return if Class::MOP::in_global_destruction(); # it'll happen soon anyway and this just makes things more complicated
570 no warnings 'uninitialized';
571 return unless $self->name =~ /^$ANON_ROLE_PREFIX/;
573 # XXX: is this necessary for us? I don't understand what it's doing
576 # Moose does a weird thing where it replaces the metaclass for
577 # class when fixing metaclass incompatibility. In that case,
578 # we don't want to clean out the namespace now. We can detect
579 # that because Moose will explicitly update the singleton
580 # cache in Class::MOP.
581 #my $current_meta = Class::MOP::get_metaclass_by_name($self->name);
582 #return if $current_meta ne $self;
584 my ($serial_id) = ($self->name =~ /^$ANON_ROLE_PREFIX(\d+)/);
586 foreach my $key (keys %{$ANON_ROLE_PREFIX . $serial_id}) {
587 delete ${$ANON_ROLE_PREFIX . $serial_id}{$key};
589 delete ${'main::' . $ANON_ROLE_PREFIX}{$serial_id . '::'};
593 #####################################################################
595 ## This is Moose::Meta::Role as defined by Moose (plus the use of
596 ## MooseX::AttributeHelpers module). It is here as a reference to
597 ## make it easier to see what is happening above with all the meta
599 #####################################################################
602 # metaclass => 'Collection::Array',
603 # reader => 'get_roles',
604 # isa => 'ArrayRef[Moose::Meta::Roles]',
605 # default => sub { [] },
607 # 'push' => 'add_role',
611 # has 'excluded_roles_map' => (
612 # metaclass => 'Collection::Hash',
613 # reader => 'get_excluded_roles_map',
614 # isa => 'HashRef[Str]',
616 # # Not exactly set, cause it sets multiple
617 # 'set' => 'add_excluded_roles',
618 # 'keys' => 'get_excluded_roles_list',
619 # 'exists' => 'excludes_role',
623 # has 'attribute_map' => (
624 # metaclass => 'Collection::Hash',
625 # reader => 'get_attribute_map',
626 # isa => 'HashRef[Str]',
628 # # 'set' => 'add_attribute' # has some special crap in it
629 # 'get' => 'get_attribute',
630 # 'keys' => 'get_attribute_list',
631 # 'exists' => 'has_attribute',
632 # # Not exactly delete, cause it sets multiple
633 # 'delete' => 'remove_attribute',
637 # has 'required_methods' => (
638 # metaclass => 'Collection::Hash',
639 # reader => 'get_required_methods_map',
640 # isa => 'HashRef[Str]',
642 # # not exactly set, or delete since it works for multiple
643 # 'set' => 'add_required_methods',
644 # 'delete' => 'remove_required_methods',
645 # 'keys' => 'get_required_method_list',
646 # 'exists' => 'requires_method',
650 # # the before, around and after modifiers are
651 # # HASH keyed by method-name, with ARRAY of
652 # # CODE refs to apply in that order
654 # has 'before_method_modifiers' => (
655 # metaclass => 'Collection::Hash',
656 # reader => 'get_before_method_modifiers_map',
657 # isa => 'HashRef[ArrayRef[CodeRef]]',
659 # 'keys' => 'get_before_method_modifiers',
660 # 'exists' => 'has_before_method_modifiers',
661 # # This actually makes sure there is an
662 # # ARRAY at the given key, and pushed onto
663 # # it. It also checks for duplicates as well
664 # # 'add' => 'add_before_method_modifier'
668 # has 'after_method_modifiers' => (
669 # metaclass => 'Collection::Hash',
670 # reader =>'get_after_method_modifiers_map',
671 # isa => 'HashRef[ArrayRef[CodeRef]]',
673 # 'keys' => 'get_after_method_modifiers',
674 # 'exists' => 'has_after_method_modifiers',
675 # # This actually makes sure there is an
676 # # ARRAY at the given key, and pushed onto
677 # # it. It also checks for duplicates as well
678 # # 'add' => 'add_after_method_modifier'
682 # has 'around_method_modifiers' => (
683 # metaclass => 'Collection::Hash',
684 # reader =>'get_around_method_modifiers_map',
685 # isa => 'HashRef[ArrayRef[CodeRef]]',
687 # 'keys' => 'get_around_method_modifiers',
688 # 'exists' => 'has_around_method_modifiers',
689 # # This actually makes sure there is an
690 # # ARRAY at the given key, and pushed onto
691 # # it. It also checks for duplicates as well
692 # # 'add' => 'add_around_method_modifier'
696 # # override is similar to the other modifiers
697 # # except that it is not an ARRAY of code refs
698 # # but instead just a single name->code mapping
700 # has 'override_method_modifiers' => (
701 # metaclass => 'Collection::Hash',
702 # reader =>'get_override_method_modifiers_map',
703 # isa => 'HashRef[CodeRef]',
705 # 'keys' => 'get_override_method_modifier',
706 # 'exists' => 'has_override_method_modifier',
707 # 'add' => 'add_override_method_modifier', # checks for local method ..
711 #####################################################################
722 Moose::Meta::Role - The Moose Role metaclass
726 Please see L<Moose::Role> for more information about roles.
727 For the most part, this has no user-serviceable parts inside
728 this module. It's API is still subject to some change (although
729 probably not that much really).
741 =item B<apply_to_metaclass_instance>
769 =item B<add_excluded_roles>
771 =item B<excludes_role>
773 =item B<get_excluded_roles_list>
775 =item B<get_excluded_roles_map>
777 =item B<calculate_all_roles>
783 =item B<method_metaclass>
785 =item B<find_method_by_name>
793 =item B<wrap_method_body>
795 =item B<alias_method>
797 =item B<get_method_list>
799 =item B<get_method_map>
801 =item B<update_package_cache_flag>
803 =item B<reset_package_cache_flag>
809 =item B<add_attribute>
811 =item B<has_attribute>
813 =item B<get_attribute>
815 =item B<get_attribute_list>
817 =item B<get_attribute_map>
819 =item B<remove_attribute>
825 =item B<add_required_methods>
827 =item B<remove_required_methods>
829 =item B<get_required_method_list>
831 =item B<get_required_methods_map>
833 =item B<requires_method>
839 =item B<add_after_method_modifier>
841 =item B<add_around_method_modifier>
843 =item B<add_before_method_modifier>
845 =item B<add_override_method_modifier>
851 =item B<has_after_method_modifiers>
853 =item B<has_around_method_modifiers>
855 =item B<has_before_method_modifiers>
857 =item B<has_override_method_modifier>
863 =item B<get_after_method_modifiers>
865 =item B<get_around_method_modifiers>
867 =item B<get_before_method_modifiers>
869 =item B<get_method_modifier_list>
875 =item B<get_override_method_modifier>
877 =item B<get_after_method_modifiers_map>
879 =item B<get_around_method_modifiers_map>
881 =item B<get_before_method_modifiers_map>
883 =item B<get_override_method_modifiers_map>
891 =item B<create_anon_role>
893 =item B<is_anon_role>
899 All complex software has bugs lurking in it, and this module is no
900 exception. If you find a bug please either email me, or add the bug
905 Stevan Little E<lt>stevan@iinteractive.comE<gt>
907 =head1 COPYRIGHT AND LICENSE
909 Copyright 2006-2009 by Infinity Interactive, Inc.
911 L<http://www.iinteractive.com>
913 This library is free software; you can redistribute it and/or modify
914 it under the same terms as Perl itself.