package Mouse::Meta::Role; use Mouse::Util qw(:meta not_supported); # enables strict and warnings use Mouse::Meta::Module; our @ISA = qw(Mouse::Meta::Module); sub method_metaclass; sub _construct_meta { my $class = shift; my %args = @_; $args{methods} = {}; $args{attributes} = {}; $args{required_methods} = []; $args{roles} = []; my $self = bless \%args, ref($class) || $class; if($class ne __PACKAGE__){ $self->meta->_initialize_object($self, \%args); } return $self; } sub create_anon_role{ my $self = shift; return $self->create(undef, @_); } sub is_anon_role; sub get_roles; sub calculate_all_roles { my $self = shift; my %seen; return grep { !$seen{ $_->name }++ } ($self, map { $_->calculate_all_roles } @{ $self->get_roles }); } sub get_required_method_list{ return @{ $_[0]->{required_methods} }; } sub add_required_methods { my($self, @methods) = @_; my %required = map{ $_ => 1 } @{$self->{required_methods}}; push @{$self->{required_methods}}, grep{ !$required{$_}++ && !$self->has_method($_) } @methods; return; } sub requires_method { my($self, $name) = @_; return scalar( grep{ $_ eq $name } @{ $self->{required_methods} } ) != 0; } sub add_attribute { my $self = shift; my $name = shift; $self->{attributes}->{$name} = (@_ == 1) ? $_[0] : { @_ }; return; } sub _check_required_methods{ my($role, $consumer, $args) = @_; if($args->{_to} eq 'role'){ $consumer->add_required_methods($role->get_required_method_list); } else{ # to class or instance my $consumer_class_name = $consumer->name; my @missing; foreach my $method_name(@{$role->{required_methods}}){ next if exists $args->{aliased_methods}{$method_name}; next if exists $role->{methods}{$method_name}; next if $consumer_class_name->can($method_name); push @missing, $method_name; } if(@missing){ $role->throw_error(sprintf "'%s' requires the method%s %s to be implemented by '%s'", $role->name, (@missing == 1 ? '' : 's'), # method or methods Mouse::Util::quoted_english_list(@missing), $consumer_class_name); } } return; } sub _apply_methods{ my($role, $consumer, $args) = @_; my $alias = $args->{-alias}; my $excludes = $args->{-excludes}; foreach my $method_name($role->get_method_list){ next if $method_name eq 'meta'; my $code = $role->get_method_body($method_name); if(!exists $excludes->{$method_name}){ if(!$consumer->has_method($method_name)){ # The third argument $role is used in Role::Composite $consumer->add_method($method_name => $code, $role); } } if(exists $alias->{$method_name}){ my $dstname = $alias->{$method_name}; my $dstcode = $consumer->get_method_body($dstname); if(defined($dstcode) && $dstcode != $code){ $role->throw_error("Cannot create a method alias if a local method of the same name exists"); } else{ $consumer->add_method($dstname => $code, $role); } } } return; } sub _apply_attributes{ my($role, $consumer, $args) = @_; for my $attr_name ($role->get_attribute_list) { next if $consumer->has_attribute($attr_name); $consumer->add_attribute($attr_name => $role->get_attribute($attr_name)); } return; } sub _apply_modifiers{ my($role, $consumer, $args) = @_; if(my $modifiers = $role->{override_method_modifiers}){ foreach my $method_name (keys %{$modifiers}){ $consumer->add_override_method_modifier($method_name => $modifiers->{$method_name}); } } for my $modifier_type (qw/before around after/) { my $modifiers = $role->{"${modifier_type}_method_modifiers"} or next; my $add_modifier = "add_${modifier_type}_method_modifier"; foreach my $method_name (keys %{$modifiers}){ foreach my $code(@{ $modifiers->{$method_name} }){ next if $consumer->{"_applied_$modifier_type"}{$method_name, $code}++; # skip applied modifiers $consumer->$add_modifier($method_name => $code); } } } return; } sub _append_roles{ my($role, $consumer, $args) = @_; my $roles = ($args->{_to} eq 'role') ? $consumer->get_roles : $consumer->roles; foreach my $r($role, @{$role->get_roles}){ if(!$consumer->does_role($r->name)){ push @{$roles}, $r; } } return; } # Moose uses Application::ToInstance, Application::ToClass, Application::ToRole sub apply { my $self = shift; my $consumer = shift; my %args = (@_ == 1) ? %{ $_[0] } : @_; my $instance; if(Mouse::Util::is_a_metaclass($consumer)){ # Application::ToClass $args{_to} = 'class'; } elsif(Mouse::Util::is_a_metarole($consumer)){ # Application::ToRole $args{_to} = 'role'; } else{ # Appplication::ToInstance $args{_to} = 'instance'; $instance = $consumer; $consumer = (Mouse::Util::class_of($instance) || 'Mouse::Meta::Class')->create_anon_class( superclasses => [ref $instance], cache => 1, ); } if($args{alias} && !exists $args{-alias}){ $args{-alias} = $args{alias}; } if($args{excludes} && !exists $args{-excludes}){ $args{-excludes} = $args{excludes}; } $args{aliased_methods} = {}; if(my $alias = $args{-alias}){ @{$args{aliased_methods}}{ values %{$alias} } = (); } if(my $excludes = $args{-excludes}){ $args{-excludes} = {}; # replace with a hash ref if(ref $excludes){ %{$args{-excludes}} = (map{ $_ => undef } @{$excludes}); } else{ $args{-excludes}{$excludes} = undef; } } $self->_check_required_methods($consumer, \%args); $self->_apply_attributes($consumer, \%args); $self->_apply_methods($consumer, \%args); $self->_apply_modifiers($consumer, \%args); $self->_append_roles($consumer, \%args); if(defined $instance){ # Application::ToInstance # rebless instance bless $instance, $consumer->name; $consumer->_initialize_object($instance, $instance); } return; } sub combine { my($role_class, @role_specs) = @_; require 'Mouse/Meta/Role/Composite.pm'; # we don't want to create its namespace my $composite = Mouse::Meta::Role::Composite->create_anon_role(); foreach my $role_spec (@role_specs) { my($role_name, $args) = @{$role_spec}; $role_name->meta->apply($composite, %{$args}); } return $composite; } sub add_before_method_modifier; sub add_around_method_modifier; sub add_after_method_modifier; sub get_before_method_modifiers; sub get_around_method_modifiers; sub get_after_method_modifiers; sub add_override_method_modifier{ my($self, $method_name, $method) = @_; if($self->has_method($method_name)){ # This error happens in the override keyword or during role composition, # so I added a message, "A local method of ...", only for compatibility (gfx) $self->throw_error("Cannot add an override of method '$method_name' " . "because there is a local version of '$method_name'" . "(A local method of the same name as been found)"); } $self->{override_method_modifiers}->{$method_name} = $method; } sub get_override_method_modifier { my ($self, $method_name) = @_; return $self->{override_method_modifiers}->{$method_name}; } sub does_role { my ($self, $role_name) = @_; (defined $role_name) || $self->throw_error("You must supply a role name to look for"); # if we are it,.. then return true return 1 if $role_name eq $self->name; # otherwise.. check our children for my $role (@{ $self->get_roles }) { return 1 if $role->does_role($role_name); } return 0; } 1; __END__ =head1 NAME Mouse::Meta::Role - The Mouse Role metaclass =head1 VERSION This document describes Mouse version 0.50_03 =head1 SEE ALSO L =cut