package Moose::Meta::Class; use strict; use warnings; use Class::MOP; use Carp qw( confess ); use Data::OptList; use List::Util qw( first ); use List::MoreUtils qw( any all uniq first_index ); use Scalar::Util 'weaken', 'blessed'; our $VERSION = '1.24'; $VERSION = eval $VERSION; our $AUTHORITY = 'cpan:STEVAN'; use Moose::Meta::Method::Overridden; use Moose::Meta::Method::Augmented; use Moose::Error::Default; use Moose::Meta::Class::Immutable::Trait; use Moose::Meta::Method::Constructor; use Moose::Meta::Method::Destructor; use Moose::Meta::Method::Meta; use Moose::Util; use Class::MOP::MiniTrait; use base 'Class::MOP::Class'; Class::MOP::MiniTrait::apply(__PACKAGE__, 'Moose::Meta::Object::Trait'); __PACKAGE__->meta->add_attribute('roles' => ( reader => 'roles', default => sub { [] } )); __PACKAGE__->meta->add_attribute('role_applications' => ( reader => '_get_role_applications', default => sub { [] } )); __PACKAGE__->meta->add_attribute( Class::MOP::Attribute->new('immutable_trait' => ( accessor => "immutable_trait", default => 'Moose::Meta::Class::Immutable::Trait', )) ); __PACKAGE__->meta->add_attribute('constructor_class' => ( accessor => 'constructor_class', default => 'Moose::Meta::Method::Constructor', )); __PACKAGE__->meta->add_attribute('destructor_class' => ( accessor => 'destructor_class', default => 'Moose::Meta::Method::Destructor', )); __PACKAGE__->meta->add_attribute('error_class' => ( accessor => 'error_class', default => 'Moose::Error::Default', )); sub initialize { my $class = shift; my $pkg = shift; return Class::MOP::get_metaclass_by_name($pkg) || $class->SUPER::initialize($pkg, 'attribute_metaclass' => 'Moose::Meta::Attribute', 'method_metaclass' => 'Moose::Meta::Method', 'instance_metaclass' => 'Moose::Meta::Instance', @_ ); } sub create { my ($class, $package_name, %options) = @_; (ref $options{roles} eq 'ARRAY') || $class->throw_error("You must pass an ARRAY ref of roles", data => $options{roles}) if exists $options{roles}; my $roles = delete $options{roles}; my $new_meta = $class->SUPER::create($package_name, %options); if ($roles) { Moose::Util::apply_all_roles( $new_meta, @$roles ); } return $new_meta; } my %ANON_CLASSES; sub create_anon_class { my ($self, %options) = @_; my $cache_ok = delete $options{cache}; my $cache_key = _anon_cache_key( $options{superclasses}, $options{roles} ); if ($cache_ok && defined $ANON_CLASSES{$cache_key}) { return $ANON_CLASSES{$cache_key}; } $options{weaken} = !$cache_ok unless exists $options{weaken}; my $new_class = $self->SUPER::create_anon_class(%options); if ($cache_ok) { $ANON_CLASSES{$cache_key} = $new_class; weaken($ANON_CLASSES{$cache_key}); } return $new_class; } sub _meta_method_class { 'Moose::Meta::Method::Meta' } sub _anon_cache_key { # Makes something like Super::Class|Super::Class::2=Role|Role::1 return join '=' => ( join( '|', @{ $_[0] || [] } ), join( '|', sort @{ $_[1] || [] } ), ); } sub reinitialize { my $self = shift; my $pkg = shift; my $meta = blessed $pkg ? $pkg : Class::MOP::class_of($pkg); my $cache_key; my %existing_classes; if ($meta) { %existing_classes = map { $_ => $meta->$_() } qw( attribute_metaclass method_metaclass wrapped_method_metaclass instance_metaclass constructor_class destructor_class error_class ); $cache_key = _anon_cache_key( [ $meta->superclasses ], [ map { $_->name } @{ $meta->roles } ], ) if $meta->is_anon_class; } my $new_meta = $self->SUPER::reinitialize( $pkg, %existing_classes, @_, ); return $new_meta unless defined $cache_key; my $new_cache_key = _anon_cache_key( [ $meta->superclasses ], [ map { $_->name } @{ $meta->roles } ], ); delete $ANON_CLASSES{$cache_key}; $ANON_CLASSES{$new_cache_key} = $new_meta; weaken($ANON_CLASSES{$new_cache_key}); return $new_meta; } sub add_role { my ($self, $role) = @_; (blessed($role) && $role->isa('Moose::Meta::Role')) || $self->throw_error("Roles must be instances of Moose::Meta::Role", data => $role); push @{$self->roles} => $role; } sub role_applications { my ($self) = @_; return @{$self->_get_role_applications}; } sub add_role_application { my ($self, $application) = @_; (blessed($application) && $application->isa('Moose::Meta::Role::Application::ToClass')) || $self->throw_error("Role applications must be instances of Moose::Meta::Role::Application::ToClass", data => $application); push @{$self->_get_role_applications} => $application; } sub calculate_all_roles { my $self = shift; my %seen; grep { !$seen{$_->name}++ } map { $_->calculate_all_roles } @{ $self->roles }; } sub calculate_all_roles_with_inheritance { my $self = shift; my %seen; grep { !$seen{$_->name}++ } map { Class::MOP::class_of($_)->can('calculate_all_roles') ? Class::MOP::class_of($_)->calculate_all_roles : () } $self->linearized_isa; } sub does_role { my ($self, $role_name) = @_; (defined $role_name) || $self->throw_error("You must supply a role name to look for"); foreach my $class ($self->class_precedence_list) { my $meta = Class::MOP::class_of($class); # when a Moose metaclass is itself extended with a role, # this check needs to be done since some items in the # class_precedence_list might in fact be Class::MOP # based still. next unless $meta && $meta->can('roles'); foreach my $role (@{$meta->roles}) { return 1 if $role->does_role($role_name); } } return 0; } sub excludes_role { my ($self, $role_name) = @_; (defined $role_name) || $self->throw_error("You must supply a role name to look for"); foreach my $class ($self->class_precedence_list) { my $meta = Class::MOP::class_of($class); # when a Moose metaclass is itself extended with a role, # this check needs to be done since some items in the # class_precedence_list might in fact be Class::MOP # based still. next unless $meta && $meta->can('roles'); foreach my $role (@{$meta->roles}) { return 1 if $role->excludes_role($role_name); } } return 0; } sub new_object { my $self = shift; my $params = @_ == 1 ? $_[0] : {@_}; my $object = $self->SUPER::new_object($params); foreach my $attr ( $self->get_all_attributes() ) { next unless $attr->can('has_trigger') && $attr->has_trigger; my $init_arg = $attr->init_arg; next unless defined $init_arg; next unless exists $params->{$init_arg}; $attr->trigger->( $object, ( $attr->should_coerce ? $attr->get_read_method_ref->($object) : $params->{$init_arg} ), ); } $object->BUILDALL($params) if $object->can('BUILDALL'); return $object; } sub superclasses { my $self = shift; my $supers = Data::OptList::mkopt(\@_); foreach my $super (@{ $supers }) { my ($name, $opts) = @{ $super }; Class::MOP::load_class($name, $opts); my $meta = Class::MOP::class_of($name); $self->throw_error("You cannot inherit from a Moose Role ($name)") if $meta && $meta->isa('Moose::Meta::Role') } return $self->SUPER::superclasses(map { $_->[0] } @{ $supers }); } ### --------------------------------------------- sub add_attribute { my $self = shift; my $attr = (blessed $_[0] && $_[0]->isa('Class::MOP::Attribute') ? $_[0] : $self->_process_attribute(@_)); $self->SUPER::add_attribute($attr); # it may be a Class::MOP::Attribute, theoretically, which doesn't have # 'bare' and doesn't implement this method if ($attr->can('_check_associated_methods')) { $attr->_check_associated_methods; } return $attr; } sub add_override_method_modifier { my ($self, $name, $method, $_super_package) = @_; (!$self->has_method($name)) || $self->throw_error("Cannot add an override method if a local method is already present"); $self->add_method($name => Moose::Meta::Method::Overridden->new( method => $method, class => $self, package => $_super_package, # need this for roles name => $name, )); } sub add_augment_method_modifier { my ($self, $name, $method) = @_; (!$self->has_method($name)) || $self->throw_error("Cannot add an augment method if a local method is already present"); $self->add_method($name => Moose::Meta::Method::Augmented->new( method => $method, class => $self, name => $name, )); } ## Private Utility methods ... sub _find_next_method_by_name_which_is_not_overridden { my ($self, $name) = @_; foreach my $method ($self->find_all_methods_by_name($name)) { return $method->{code} if blessed($method->{code}) && !$method->{code}->isa('Moose::Meta::Method::Overridden'); } return undef; } ## Metaclass compatibility sub _base_metaclasses { my $self = shift; my %metaclasses = $self->SUPER::_base_metaclasses; for my $class (keys %metaclasses) { $metaclasses{$class} =~ s/^Class::MOP/Moose::Meta/; } return ( %metaclasses, error_class => 'Moose::Error::Default', ); } sub _fix_class_metaclass_incompatibility { my $self = shift; my ($super_meta) = @_; $self->SUPER::_fix_class_metaclass_incompatibility(@_); if ($self->_class_metaclass_can_be_made_compatible($super_meta)) { ($self->is_pristine) || confess "Can't fix metaclass incompatibility for " . $self->name . " because it is not pristine."; my $super_meta_name = $super_meta->_real_ref_name; my $class_meta_subclass_meta_name = Moose::Util::_reconcile_roles_for_metaclass(blessed($self), $super_meta_name); my $new_self = $class_meta_subclass_meta_name->reinitialize( $self->name, ); $self->_replace_self( $new_self, $class_meta_subclass_meta_name ); } } sub _fix_single_metaclass_incompatibility { my $self = shift; my ($metaclass_type, $super_meta) = @_; $self->SUPER::_fix_single_metaclass_incompatibility(@_); if ($self->_single_metaclass_can_be_made_compatible($super_meta, $metaclass_type)) { ($self->is_pristine) || confess "Can't fix metaclass incompatibility for " . $self->name . " because it is not pristine."; my $super_meta_name = $super_meta->_real_ref_name; my $class_specific_meta_subclass_meta_name = Moose::Util::_reconcile_roles_for_metaclass($self->$metaclass_type, $super_meta->$metaclass_type); my $new_self = $super_meta->reinitialize( $self->name, $metaclass_type => $class_specific_meta_subclass_meta_name, ); $self->_replace_self( $new_self, $super_meta_name ); } } sub _replace_self { my $self = shift; my ( $new_self, $new_class) = @_; %$self = %$new_self; bless $self, $new_class; # We need to replace the cached metaclass instance or else when it goes # out of scope Class::MOP::Class destroy's the namespace for the # metaclass's class, causing much havoc. my $weaken = Class::MOP::metaclass_is_weak( $self->name ); Class::MOP::store_metaclass_by_name( $self->name, $self ); Class::MOP::weaken_metaclass( $self->name ) if $weaken; } sub _process_attribute { my ( $self, $name, @args ) = @_; @args = %{$args[0]} if scalar @args == 1 && ref($args[0]) eq 'HASH'; if (($name || '') =~ /^\+(.*)/) { return $self->_process_inherited_attribute($1, @args); } else { return $self->_process_new_attribute($name, @args); } } sub _process_new_attribute { my ( $self, $name, @args ) = @_; $self->attribute_metaclass->interpolate_class_and_new($name, @args); } sub _process_inherited_attribute { my ($self, $attr_name, %options) = @_; my $inherited_attr = $self->find_attribute_by_name($attr_name); (defined $inherited_attr) || $self->throw_error("Could not find an attribute by the name of '$attr_name' to inherit from in ${\$self->name}", data => $attr_name); if ($inherited_attr->isa('Moose::Meta::Attribute')) { return $inherited_attr->clone_and_inherit_options(%options); } else { # NOTE: # kind of a kludge to handle Class::MOP::Attributes return $inherited_attr->Moose::Meta::Attribute::clone_and_inherit_options(%options); } } # reinitialization support sub _restore_metaobjects_from { my $self = shift; my ($old_meta) = @_; $self->SUPER::_restore_metaobjects_from($old_meta); for my $role ( @{ $old_meta->roles } ) { $self->add_role($role); } for my $application ( @{ $old_meta->_get_role_applications } ) { $application->class($self); $self->add_role_application ($application); } } ## Immutability sub _immutable_options { my ( $self, @args ) = @_; $self->SUPER::_immutable_options( inline_destructor => 1, # Moose always does this when an attribute is created inline_accessors => 0, @args, ); } ## ------------------------------------------------- our $error_level; sub throw_error { my ( $self, @args ) = @_; local $error_level = ($error_level || 0) + 1; $self->raise_error($self->create_error(@args)); } sub raise_error { my ( $self, @args ) = @_; die @args; } sub create_error { my ( $self, @args ) = @_; require Carp::Heavy; local $error_level = ($error_level || 0 ) + 1; if ( @args % 2 == 1 ) { unshift @args, "message"; } my %args = ( metaclass => $self, last_error => $@, @args ); $args{depth} += $error_level; my $class = ref $self ? $self->error_class : "Moose::Error::Default"; Class::MOP::load_class($class); $class->new( Carp::caller_info($args{depth}), %args ); } 1; __END__ =pod =head1 NAME Moose::Meta::Class - The Moose metaclass =head1 DESCRIPTION This class is a subclass of L<Class::MOP::Class> that provides additional Moose-specific functionality. To really understand this class, you will need to start with the L<Class::MOP::Class> documentation. This class can be understood as a set of additional features on top of the basic feature provided by that parent class. =head1 INHERITANCE C<Moose::Meta::Class> is a subclass of L<Class::MOP::Class>. =head1 METHODS =over 4 =item B<< Moose::Meta::Class->initialize($package_name, %options) >> This overrides the parent's method in order to provide its own defaults for the C<attribute_metaclass>, C<instance_metaclass>, and C<method_metaclass> options. These all default to the appropriate Moose class. =item B<< Moose::Meta::Class->create($package_name, %options) >> This overrides the parent's method in order to accept a C<roles> option. This should be an array reference containing roles that the class does, each optionally followed by a hashref of options (C<-excludes> and C<-alias>). my $metaclass = Moose::Meta::Class->create( 'New::Class', roles => [...] ); =item B<< Moose::Meta::Class->create_anon_class >> This overrides the parent's method to accept a C<roles> option, just as C<create> does. It also accepts a C<cache> option. If this is true, then the anonymous class will be cached based on its superclasses and roles. If an existing anonymous class in the cache has the same superclasses and roles, it will be reused. my $metaclass = Moose::Meta::Class->create_anon_class( superclasses => ['Foo'], roles => [qw/Some Roles Go Here/], cache => 1, ); Each entry in both the C<superclasses> and the C<roles> option can be followed by a hash reference with arguments. The C<superclasses> option can be supplied with a L<-version|Class::MOP/Class Loading Options> option that ensures the loaded superclass satisfies the required version. The C<role> option also takes the C<-version> as an argument, but the option hash reference can also contain any other role relevant values like exclusions or parameterized role arguments. =item B<< $metaclass->make_immutable(%options) >> This overrides the parent's method to add a few options. Specifically, it uses the Moose-specific constructor and destructor classes, and enables inlining the destructor. Since Moose always inlines attributes, it sets the C<inline_accessors> option to false. =item B<< $metaclass->new_object(%params) >> This overrides the parent's method in order to add support for attribute triggers. =item B<< $metaclass->superclasses(@superclasses) >> This is the accessor allowing you to read or change the parents of the class. Each superclass can be followed by a hash reference containing a L<-version|Class::MOP/Class Loading Options> value. If the version requirement is not satisfied an error will be thrown. =item B<< $metaclass->add_override_method_modifier($name, $sub) >> This adds an C<override> method modifier to the package. =item B<< $metaclass->add_augment_method_modifier($name, $sub) >> This adds an C<augment> method modifier to the package. =item B<< $metaclass->calculate_all_roles >> This will return a unique array of C<Moose::Meta::Role> instances which are attached to this class. =item B<< $metaclass->calculate_all_roles_with_inheritance >> This will return a unique array of C<Moose::Meta::Role> instances which are attached to this class, and each of this class's ancestors. =item B<< $metaclass->add_role($role) >> This takes a L<Moose::Meta::Role> object, and adds it to the class's list of roles. This I<does not> actually apply the role to the class. =item B<< $metaclass->role_applications >> Returns a list of L<Moose::Meta::Role::Application::ToClass> objects, which contain the arguments to role application. =item B<< $metaclass->add_role_application($application) >> This takes a L<Moose::Meta::Role::Application::ToClass> object, and adds it to the class's list of role applications. This I<does not> actually apply any role to the class; it is only for tracking role applications. =item B<< $metaclass->does_role($role) >> This returns a boolean indicating whether or not the class does the specified role. The role provided can be either a role name or a L<Moose::Meta::Role> object. This tests both the class and its parents. =item B<< $metaclass->excludes_role($role_name) >> A class excludes a role if it has already composed a role which excludes the named role. This tests both the class and its parents. =item B<< $metaclass->add_attribute($attr_name, %params|$params) >> This overrides the parent's method in order to allow the parameters to be provided as a hash reference. =item B<< $metaclass->constructor_class($class_name) >> =item B<< $metaclass->destructor_class($class_name) >> These are the names of classes used when making a class immutable. These default to L<Moose::Meta::Method::Constructor> and L<Moose::Meta::Method::Destructor> respectively. These accessors are read-write, so you can use them to change the class name. =item B<< $metaclass->error_class($class_name) >> The name of the class used to throw errors. This defaults to L<Moose::Error::Default>, which generates an error with a stacktrace just like C<Carp::confess>. =item B<< $metaclass->throw_error($message, %extra) >> Throws the error created by C<create_error> using C<raise_error> =back =head1 BUGS See L<Moose/BUGS> for details on reporting bugs. =head1 AUTHOR Stevan Little E<lt>stevan@iinteractive.comE<gt> =head1 COPYRIGHT AND LICENSE Copyright 2006-2010 by Infinity Interactive, Inc. L<http://www.iinteractive.com> This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =cut