1 package Mouse::Meta::Role;
2 use Mouse::Util qw(:meta not_supported english_list); # enables strict and warnings
4 use Mouse::Meta::Module;
5 our @ISA = qw(Mouse::Meta::Module);
7 sub method_metaclass(){ 'Mouse::Meta::Role::Method' } # required for get_method()
14 $args{methods} ||= {};
15 $args{attributes} ||= {};
16 $args{required_methods} ||= [];
19 my $self = bless \%args, ref($class) || $class;
20 if($class ne __PACKAGE__){
21 $self->meta->_initialize_object($self, \%args);
29 return $self->create(undef, @_);
33 return exists $_[0]->{anon_serial_id};
36 sub get_roles { $_[0]->{roles} }
38 sub get_required_method_list{
39 return @{ $_[0]->{required_methods} };
42 sub add_required_methods {
43 my($self, @methods) = @_;
44 my %required = map{ $_ => 1 } @{$self->{required_methods}};
45 push @{$self->{required_methods}}, grep{ !$required{$_}++ && !$self->has_method($_) } @methods;
50 my($self, $name) = @_;
51 return scalar( grep{ $_ eq $name } @{ $self->{required_methods} } ) != 0;
58 $self->{attributes}->{$name} = (@_ == 1) ? $_[0] : { @_ };
61 sub _check_required_methods{
62 my($role, $applicant, $args) = @_;
64 if($args->{_to} eq 'role'){
65 $applicant->add_required_methods($role->get_required_method_list);
67 else{ # to class or instance
68 my $applicant_class_name = $applicant->name;
71 foreach my $method_name(@{$role->{required_methods}}){
72 next if exists $args->{aliased_methods}{$method_name};
73 next if exists $role->{methods}{$method_name};
74 next if $applicant_class_name->can($method_name);
76 push @missing, $method_name;
79 $role->throw_error(sprintf "'%s' requires the method%s %s to be implemented by '%s'",
81 (@missing == 1 ? '' : 's'), # method or methods
82 english_list(map{ sprintf q{'%s'}, $_ } @missing),
83 $applicant_class_name);
91 my($role, $applicant, $args) = @_;
93 my $alias = $args->{-alias};
94 my $excludes = $args->{-excludes};
96 foreach my $method_name($role->get_method_list){
97 next if $method_name eq 'meta';
99 my $code = $role->get_method_body($method_name);
101 if(!exists $excludes->{$method_name}){
102 if(!$applicant->has_method($method_name)){
103 # The third argument $role is used in Role::Composite
104 $applicant->add_method($method_name => $code, $role);
108 if(exists $alias->{$method_name}){
109 my $dstname = $alias->{$method_name};
111 my $dstcode = $applicant->get_method_body($dstname);
113 if(defined($dstcode) && $dstcode != $code){
114 $role->throw_error("Cannot create a method alias if a local method of the same name exists");
117 $applicant->add_method($dstname => $code, $role);
125 sub _apply_attributes{
126 my($role, $applicant, $args) = @_;
128 for my $attr_name ($role->get_attribute_list) {
129 next if $applicant->has_attribute($attr_name);
131 $applicant->add_attribute($attr_name => $role->get_attribute($attr_name));
136 sub _apply_modifiers{
137 my($role, $applicant, $args) = @_;
139 if(my $modifiers = $role->{override_method_modifiers}){
140 foreach my $method_name (keys %{$modifiers}){
141 $applicant->add_override_method_modifier($method_name => $modifiers->{$method_name});
145 for my $modifier_type (qw/before around after/) {
146 my $modifiers = $role->{"${modifier_type}_method_modifiers"}
149 my $add_modifier = "add_${modifier_type}_method_modifier";
151 foreach my $method_name (keys %{$modifiers}){
152 foreach my $code(@{ $modifiers->{$method_name} }){
153 next if $applicant->{"_applied_$modifier_type"}{$method_name, $code}++; # skip applied modifiers
154 $applicant->$add_modifier($method_name => $code);
162 my($role, $applicant, $args) = @_;
164 my $roles = ($args->{_to} eq 'role') ? $applicant->get_roles : $applicant->roles;
166 foreach my $r($role, @{$role->get_roles}){
167 if(!$applicant->does_role($r->name)){
174 # Moose uses Application::ToInstance, Application::ToClass, Application::ToRole
177 my $applicant = shift;
179 my %args = (@_ == 1) ? %{ $_[0] } : @_;
181 if($applicant->isa('Mouse::Meta::Class')){ # Application::ToClass
182 $args{_to} = 'class';
184 elsif($applicant->isa('Mouse::Meta::Role')){ # Application::ToRole
187 else{ # Appplication::ToInstance
188 $args{_to} = 'instance';
190 my $metaclass = $applicant->meta->create_anon_class(
191 superclasses => [ref $applicant],
194 bless $applicant, $metaclass->name; # rebless
196 $applicant = $metaclass;
199 if($args{alias} && !exists $args{-alias}){
200 $args{-alias} = $args{alias};
202 if($args{excludes} && !exists $args{-excludes}){
203 $args{-excludes} = $args{excludes};
206 $args{aliased_methods} = {};
207 if(my $alias = $args{-alias}){
208 @{$args{aliased_methods}}{ values %{$alias} } = ();
211 if(my $excludes = $args{-excludes}){
212 $args{-excludes} = {}; # replace with a hash ref
214 %{$args{-excludes}} = (map{ $_ => undef } @{$excludes});
217 $args{-excludes}{$excludes} = undef;
221 $self->_check_required_methods($applicant, \%args);
222 $self->_apply_attributes($applicant, \%args);
223 $self->_apply_methods($applicant, \%args);
224 $self->_apply_modifiers($applicant, \%args);
225 $self->_append_roles($applicant, \%args);
231 my($role_class, @role_specs) = @_;
233 require 'Mouse/Meta/Role/Composite.pm'; # we don't want to create its namespace
235 my $composite = Mouse::Meta::Role::Composite->create_anon_role();
237 foreach my $role_spec (@role_specs) {
238 my($role_name, $args) = @{$role_spec};
239 $role_name->meta->apply($composite, %{$args});
244 for my $modifier_type (qw/before after around/) {
246 my $modifier = "${modifier_type}_method_modifiers";
247 my $add_method_modifier = sub {
248 my ($self, $method_name, $method) = @_;
250 push @{ $self->{$modifier}->{$method_name} ||= [] }, $method;
253 my $has_method_modifiers = sub{
254 my($self, $method_name) = @_;
255 my $m = $self->{$modifier}->{$method_name};
256 return $m && @{$m} != 0;
258 my $get_method_modifiers = sub {
259 my ($self, $method_name) = @_;
260 return @{ $self->{$modifier}->{$method_name} ||= [] }
264 *{ 'add_' . $modifier_type . '_method_modifier' } = $add_method_modifier;
265 *{ 'has_' . $modifier_type . '_method_modifiers' } = $has_method_modifiers;
266 *{ 'get_' . $modifier_type . '_method_modifiers' } = $get_method_modifiers;
269 sub add_override_method_modifier{
270 my($self, $method_name, $method) = @_;
272 if($self->has_method($method_name)){
273 # This error happens in the override keyword or during role composition,
274 # so I added a message, "A local method of ...", only for compatibility (gfx)
275 $self->throw_error("Cannot add an override of method '$method_name' "
276 . "because there is a local version of '$method_name'"
277 . "(A local method of the same name as been found)");
280 $self->{override_method_modifiers}->{$method_name} = $method;
283 sub has_override_method_modifier {
284 my ($self, $method_name) = @_;
285 return exists $self->{override_method_modifiers}->{$method_name};
288 sub get_override_method_modifier {
289 my ($self, $method_name) = @_;
290 return $self->{override_method_modifiers}->{$method_name};
293 sub get_method_modifier_list {
294 my($self, $modifier_type) = @_;
296 return keys %{ $self->{$modifier_type . '_method_modifiers'} };
299 # This is currently not passing all the Moose tests.
301 my ($self, $role_name) = @_;
304 || $self->throw_error("You must supply a role name to look for");
306 # if we are it,.. then return true
307 return 1 if $role_name eq $self->name;
308 # otherwise.. check our children
309 for my $role (@{ $self->get_roles }) {
310 return 1 if $role->does_role($role_name);
322 Mouse::Meta::Role - The Mouse Role metaclass