2 package Moose::Meta::Role;
8 use Scalar::Util 'blessed';
10 our $VERSION = '0.57';
11 $VERSION = eval $VERSION;
12 our $AUTHORITY = 'cpan:STEVAN';
14 use Moose::Meta::Class;
15 use Moose::Meta::Role::Method;
16 use Moose::Meta::Role::Method::Required;
18 use base 'Class::MOP::Module';
20 ## ------------------------------------------------------------------
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
30 ## ------------------------------------------------------------------
32 my $META = __PACKAGE__->meta;
34 ## ------------------------------------------------------------------
38 # since roles are lazy, we hold all the attributes
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
42 # using a little of that meta-programmin' magic
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
47 # very compact solution to this normally verbose
53 name => 'excluded_roles_map',
54 attr_reader => 'get_excluded_roles_map' ,
56 add => 'add_excluded_roles',
57 get_list => 'get_excluded_roles_list',
58 existence => 'excludes_role',
62 name => 'required_methods',
63 attr_reader => 'get_required_methods_map',
65 add => 'add_required_methods',
66 remove => 'remove_required_methods',
67 get_list => 'get_required_method_list',
68 existence => 'requires_method',
72 name => 'attribute_map',
73 attr_reader => 'get_attribute_map',
75 get => 'get_attribute',
76 get_list => 'get_attribute_list',
77 existence => 'has_attribute',
78 remove => 'remove_attribute',
83 my $attr_reader = $action->{attr_reader};
84 my $methods = $action->{methods};
86 # create the attribute
87 $META->add_attribute($action->{name} => (
88 reader => $attr_reader,
92 # create some helper methods
93 $META->add_method($methods->{add} => sub {
94 my ($self, @values) = @_;
95 $self->$attr_reader->{$_} = undef foreach @values;
96 }) if exists $methods->{add};
98 $META->add_method($methods->{get_list} => sub {
100 keys %{$self->$attr_reader};
101 }) if exists $methods->{get_list};
103 $META->add_method($methods->{get} => sub {
104 my ($self, $name) = @_;
105 $self->$attr_reader->{$name}
106 }) if exists $methods->{get};
108 $META->add_method($methods->{existence} => sub {
109 my ($self, $name) = @_;
110 exists $self->$attr_reader->{$name} ? 1 : 0;
111 }) if exists $methods->{existence};
113 $META->add_method($methods->{remove} => sub {
114 my ($self, @values) = @_;
115 delete $self->$attr_reader->{$_} foreach @values;
116 }) if exists $methods->{remove};
119 ## some things don't always fit, so they go here ...
125 if (scalar @_ == 1 && ref($_[0]) eq 'HASH') {
131 $self->get_attribute_map->{$name} = $attr_desc;
135 # sub _clean_up_required_methods {
137 # foreach my $method ($self->get_required_method_list) {
138 # $self->remove_required_methods($method)
139 # if $self->has_method($method);
143 ## ------------------------------------------------------------------
147 # the before/around/after method modifiers are
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.
154 foreach my $modifier_type (qw[ before around after ]) {
156 my $attr_reader = "get_${modifier_type}_method_modifiers_map";
158 # create the attribute ...
159 $META->add_attribute("${modifier_type}_method_modifiers" => (
160 reader => $attr_reader,
161 default => sub { {} }
164 # and some helper methods ...
165 $META->add_method("get_${modifier_type}_method_modifiers" => sub {
166 my ($self, $method_name) = @_;
167 #return () unless exists $self->$attr_reader->{$method_name};
168 @{$self->$attr_reader->{$method_name}};
171 $META->add_method("has_${modifier_type}_method_modifiers" => sub {
172 my ($self, $method_name) = @_;
174 # for now we assume that if it exists,..
175 # it has at least one modifier in it
176 (exists $self->$attr_reader->{$method_name}) ? 1 : 0;
179 $META->add_method("add_${modifier_type}_method_modifier" => sub {
180 my ($self, $method_name, $method) = @_;
182 $self->$attr_reader->{$method_name} = []
183 unless exists $self->$attr_reader->{$method_name};
185 my $modifiers = $self->$attr_reader->{$method_name};
188 # check to see that we aren't adding the
189 # same code twice. We err in favor of the
190 # first on here, this may not be as expected
191 foreach my $modifier (@{$modifiers}) {
192 return if $modifier == $method;
195 push @{$modifiers} => $method;
200 ## ------------------------------------------------------------------
201 ## override method mofidiers
203 $META->add_attribute('override_method_modifiers' => (
204 reader => 'get_override_method_modifiers_map',
205 default => sub { {} }
209 # these are a little different because there
210 # can only be one per name, whereas the other
211 # method modifiers can have multiples.
214 sub add_override_method_modifier {
215 my ($self, $method_name, $method) = @_;
216 (!$self->has_method($method_name))
217 || Moose->throw_error("Cannot add an override of method '$method_name' " .
218 "because there is a local version of '$method_name'");
219 $self->get_override_method_modifiers_map->{$method_name} = $method;
222 sub has_override_method_modifier {
223 my ($self, $method_name) = @_;
225 # for now we assume that if it exists,..
226 # it has at least one modifier in it
227 (exists $self->get_override_method_modifiers_map->{$method_name}) ? 1 : 0;
230 sub get_override_method_modifier {
231 my ($self, $method_name) = @_;
232 $self->get_override_method_modifiers_map->{$method_name};
235 ## general list accessor ...
237 sub get_method_modifier_list {
238 my ($self, $modifier_type) = @_;
239 my $accessor = "get_${modifier_type}_method_modifiers_map";
240 keys %{$self->$accessor};
243 sub reset_package_cache_flag { (shift)->{'_package_cache_flag'} = undef }
244 sub update_package_cache_flag {
246 $self->{'_package_cache_flag'} = Class::MOP::check_package_cache_flag($self->name);
251 ## ------------------------------------------------------------------
254 __PACKAGE__->meta->add_attribute('roles' => (
255 reader => 'get_roles',
256 default => sub { [] }
260 my ($self, $role) = @_;
261 (blessed($role) && $role->isa('Moose::Meta::Role'))
262 || Moose->throw_error("Roles must be instances of Moose::Meta::Role");
263 push @{$self->get_roles} => $role;
264 $self->reset_package_cache_flag;
267 sub calculate_all_roles {
273 $_->calculate_all_roles
274 } @{ $self->get_roles });
278 my ($self, $role_name) = @_;
280 || Moose->throw_error("You must supply a role name to look for");
281 # if we are it,.. then return true
282 return 1 if $role_name eq $self->name;
283 # otherwise.. check our children
284 foreach my $role (@{$self->get_roles}) {
285 return 1 if $role->does_role($role_name);
290 ## ------------------------------------------------------------------
293 sub method_metaclass { 'Moose::Meta::Role::Method' }
298 my $current = Class::MOP::check_package_cache_flag($self->name);
300 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
301 return $self->{'methods'} ||= {};
304 $self->{_package_cache_flag} = $current;
306 my $map = $self->{'methods'} ||= {};
308 my $role_name = $self->name;
309 my $method_metaclass = $self->method_metaclass;
311 my %all_code = $self->get_all_package_symbols('CODE');
313 foreach my $symbol (keys %all_code) {
314 my $code = $all_code{$symbol};
316 next if exists $map->{$symbol} &&
317 defined $map->{$symbol} &&
318 $map->{$symbol}->body == $code;
320 my ($pkg, $name) = Class::MOP::get_code_info($code);
322 if ($pkg->can('meta')
324 # we don't know what ->meta we are calling
325 # here, so we need to be careful cause it
326 # just might blow up at us, or just complain
327 # loudly (in the case of Curses.pm) so we
328 # just be a little overly cautious here.
330 && eval { no warnings; blessed($pkg->meta) } # FIXME calls meta
331 && $pkg->meta->isa('Moose::Meta::Role')) {
332 my $role = $pkg->meta->name;
333 next unless $self->does_role($role);
337 # in 5.10 constant.pm the constants show up
338 # as being in the right package, but in pre-5.10
339 # they show up as constant::__ANON__ so we
340 # make an exception here to be sure that things
341 # work as expected in both.
343 unless ($pkg eq 'constant' && $name eq '__ANON__') {
344 next if ($pkg || '') ne $role_name ||
345 (($name || '') ne '__ANON__' && ($pkg || '') ne $role_name);
349 $map->{$symbol} = $method_metaclass->wrap(
351 package_name => $role_name,
360 my ($self, $name) = @_;
361 $self->get_method_map->{$name};
365 my ($self, $name) = @_;
366 exists $self->get_method_map->{$name} ? 1 : 0
369 # FIXME this is copypasated from Class::MOP::Class
370 # refactor to inherit from some common base
371 sub wrap_method_body {
372 my ( $self, %args ) = @_;
374 my $body = delete $args{body}; # delete is for compat
376 ('CODE' eq ref($body))
377 || Moose->throw_error("Your code block must be a CODE reference");
379 $self->method_metaclass->wrap( $body => (
380 package_name => $self->name,
386 my ($self, $method_name, $method) = @_;
387 (defined $method_name && $method_name)
388 || Moose->throw_error("You must define a method name");
391 if (blessed($method)) {
392 $body = $method->body;
393 if ($method->package_name ne $self->name &&
394 $method->name ne $method_name) {
395 warn "Hello there, got something for you."
396 . " Method says " . $method->package_name . " " . $method->name
397 . " Class says " . $self->name . " " . $method_name;
398 $method = $method->clone(
399 package_name => $self->name,
401 ) if $method->can('clone');
406 $method = $self->wrap_method_body( body => $body, name => $method_name );
409 $method->attach_to_class($self);
411 $self->get_method_map->{$method_name} = $method;
413 my $full_method_name = ($self->name . '::' . $method_name);
414 $self->add_package_symbol(
415 { sigil => '&', type => 'CODE', name => $method_name },
416 Class::MOP::subname($full_method_name => $body)
419 $self->update_package_cache_flag; # still valid, since we just added the method to the map, and if it was invalid before that then get_method_map updated it
422 sub find_method_by_name { (shift)->get_method(@_) }
424 sub get_method_list {
426 grep { !/^meta$/ } keys %{$self->get_method_map};
430 my ($self, $method_name, $method) = @_;
431 (defined $method_name && $method_name)
432 || Moose->throw_error("You must define a method name");
434 my $body = (blessed($method) ? $method->body : $method);
435 ('CODE' eq ref($body))
436 || Moose->throw_error("Your code block must be a CODE reference");
438 $self->add_package_symbol(
439 { sigil => '&', type => 'CODE', name => $method_name },
444 ## ------------------------------------------------------------------
446 ## ------------------------------------------------------------------
449 my ($self, $other, @args) = @_;
452 || Moose->throw_error("You must pass in an blessed instance");
454 if ($other->isa('Moose::Meta::Role')) {
455 require Moose::Meta::Role::Application::ToRole;
456 return Moose::Meta::Role::Application::ToRole->new(@args)->apply($self, $other);
458 elsif ($other->isa('Moose::Meta::Class')) {
459 require Moose::Meta::Role::Application::ToClass;
460 return Moose::Meta::Role::Application::ToClass->new(@args)->apply($self, $other);
463 require Moose::Meta::Role::Application::ToInstance;
464 return Moose::Meta::Role::Application::ToInstance->new(@args)->apply($self, $other);
469 my ($class, @role_specs) = @_;
471 require Moose::Meta::Role::Application::RoleSummation;
472 require Moose::Meta::Role::Composite;
474 my (@roles, %role_params);
475 while (@role_specs) {
476 my ($role, $params) = @{ splice @role_specs, 0, 1 };
477 push @roles => $role->meta;
478 next unless defined $params;
479 $role_params{$role} = $params;
482 my $c = Moose::Meta::Role::Composite->new(roles => \@roles);
483 Moose::Meta::Role::Application::RoleSummation->new(
484 role_params => \%role_params
490 #####################################################################
492 ## This is Moose::Meta::Role as defined by Moose (plus the use of
493 ## MooseX::AttributeHelpers module). It is here as a reference to
494 ## make it easier to see what is happening above with all the meta
496 #####################################################################
499 # metaclass => 'Collection::Array',
500 # reader => 'get_roles',
501 # isa => 'ArrayRef[Moose::Meta::Roles]',
502 # default => sub { [] },
504 # 'push' => 'add_role',
508 # has 'excluded_roles_map' => (
509 # metaclass => 'Collection::Hash',
510 # reader => 'get_excluded_roles_map',
511 # isa => 'HashRef[Str]',
513 # # Not exactly set, cause it sets multiple
514 # 'set' => 'add_excluded_roles',
515 # 'keys' => 'get_excluded_roles_list',
516 # 'exists' => 'excludes_role',
520 # has 'attribute_map' => (
521 # metaclass => 'Collection::Hash',
522 # reader => 'get_attribute_map',
523 # isa => 'HashRef[Str]',
525 # # 'set' => 'add_attribute' # has some special crap in it
526 # 'get' => 'get_attribute',
527 # 'keys' => 'get_attribute_list',
528 # 'exists' => 'has_attribute',
529 # # Not exactly delete, cause it sets multiple
530 # 'delete' => 'remove_attribute',
534 # has 'required_methods' => (
535 # metaclass => 'Collection::Hash',
536 # reader => 'get_required_methods_map',
537 # isa => 'HashRef[Str]',
539 # # not exactly set, or delete since it works for multiple
540 # 'set' => 'add_required_methods',
541 # 'delete' => 'remove_required_methods',
542 # 'keys' => 'get_required_method_list',
543 # 'exists' => 'requires_method',
547 # # the before, around and after modifiers are
548 # # HASH keyed by method-name, with ARRAY of
549 # # CODE refs to apply in that order
551 # has 'before_method_modifiers' => (
552 # metaclass => 'Collection::Hash',
553 # reader => 'get_before_method_modifiers_map',
554 # isa => 'HashRef[ArrayRef[CodeRef]]',
556 # 'keys' => 'get_before_method_modifiers',
557 # 'exists' => 'has_before_method_modifiers',
558 # # This actually makes sure there is an
559 # # ARRAY at the given key, and pushed onto
560 # # it. It also checks for duplicates as well
561 # # 'add' => 'add_before_method_modifier'
565 # has 'after_method_modifiers' => (
566 # metaclass => 'Collection::Hash',
567 # reader =>'get_after_method_modifiers_map',
568 # isa => 'HashRef[ArrayRef[CodeRef]]',
570 # 'keys' => 'get_after_method_modifiers',
571 # 'exists' => 'has_after_method_modifiers',
572 # # This actually makes sure there is an
573 # # ARRAY at the given key, and pushed onto
574 # # it. It also checks for duplicates as well
575 # # 'add' => 'add_after_method_modifier'
579 # has 'around_method_modifiers' => (
580 # metaclass => 'Collection::Hash',
581 # reader =>'get_around_method_modifiers_map',
582 # isa => 'HashRef[ArrayRef[CodeRef]]',
584 # 'keys' => 'get_around_method_modifiers',
585 # 'exists' => 'has_around_method_modifiers',
586 # # This actually makes sure there is an
587 # # ARRAY at the given key, and pushed onto
588 # # it. It also checks for duplicates as well
589 # # 'add' => 'add_around_method_modifier'
593 # # override is similar to the other modifiers
594 # # except that it is not an ARRAY of code refs
595 # # but instead just a single name->code mapping
597 # has 'override_method_modifiers' => (
598 # metaclass => 'Collection::Hash',
599 # reader =>'get_override_method_modifiers_map',
600 # isa => 'HashRef[CodeRef]',
602 # 'keys' => 'get_override_method_modifier',
603 # 'exists' => 'has_override_method_modifier',
604 # 'add' => 'add_override_method_modifier', # checks for local method ..
608 #####################################################################
619 Moose::Meta::Role - The Moose Role metaclass
623 Please see L<Moose::Role> for more information about roles.
624 For the most part, this has no user-serviceable parts inside
625 this module. It's API is still subject to some change (although
626 probably not that much really).
638 =item B<apply_to_metaclass_instance>
666 =item B<add_excluded_roles>
668 =item B<excludes_role>
670 =item B<get_excluded_roles_list>
672 =item B<get_excluded_roles_map>
674 =item B<calculate_all_roles>
680 =item B<method_metaclass>
682 =item B<find_method_by_name>
690 =item B<wrap_method_body>
692 =item B<alias_method>
694 =item B<get_method_list>
696 =item B<get_method_map>
698 =item B<update_package_cache_flag>
700 =item B<reset_package_cache_flag>
706 =item B<add_attribute>
708 =item B<has_attribute>
710 =item B<get_attribute>
712 =item B<get_attribute_list>
714 =item B<get_attribute_map>
716 =item B<remove_attribute>
722 =item B<add_required_methods>
724 =item B<remove_required_methods>
726 =item B<get_required_method_list>
728 =item B<get_required_methods_map>
730 =item B<requires_method>
736 =item B<add_after_method_modifier>
738 =item B<add_around_method_modifier>
740 =item B<add_before_method_modifier>
742 =item B<add_override_method_modifier>
748 =item B<has_after_method_modifiers>
750 =item B<has_around_method_modifiers>
752 =item B<has_before_method_modifiers>
754 =item B<has_override_method_modifier>
760 =item B<get_after_method_modifiers>
762 =item B<get_around_method_modifiers>
764 =item B<get_before_method_modifiers>
766 =item B<get_method_modifier_list>
772 =item B<get_override_method_modifier>
774 =item B<get_after_method_modifiers_map>
776 =item B<get_around_method_modifiers_map>
778 =item B<get_before_method_modifiers_map>
780 =item B<get_override_method_modifiers_map>
786 All complex software has bugs lurking in it, and this module is no
787 exception. If you find a bug please either email me, or add the bug
792 Stevan Little E<lt>stevan@iinteractive.comE<gt>
794 =head1 COPYRIGHT AND LICENSE
796 Copyright 2006-2008 by Infinity Interactive, Inc.
798 L<http://www.iinteractive.com>
800 This library is free software; you can redistribute it and/or modify
801 it under the same terms as Perl itself.