2 package Moose::Meta::Class;
10 use Scalar::Util 'weaken', 'blessed';
12 our $VERSION = '0.55_01';
13 $VERSION = eval $VERSION;
14 our $AUTHORITY = 'cpan:STEVAN';
16 use Moose::Meta::Method::Overriden;
17 use Moose::Meta::Method::Augmented;
19 use base 'Class::MOP::Class';
21 __PACKAGE__->meta->add_attribute('roles' => (
26 __PACKAGE__->meta->add_attribute('constructor_class' => (
27 accessor => 'constructor_class',
28 default => sub { 'Moose::Meta::Method::Constructor' }
31 __PACKAGE__->meta->add_attribute('destructor_class' => (
32 accessor => 'destructor_class',
33 default => sub { 'Moose::Meta::Method::Destructor' }
39 return Class::MOP::get_metaclass_by_name($pkg)
40 || $class->SUPER::initialize($pkg,
41 'attribute_metaclass' => 'Moose::Meta::Attribute',
42 'method_metaclass' => 'Moose::Meta::Method',
43 'instance_metaclass' => 'Moose::Meta::Instance',
49 my ($self, $package_name, %options) = @_;
51 (ref $options{roles} eq 'ARRAY')
52 || confess "You must pass an ARRAY ref of roles"
53 if exists $options{roles};
55 my $class = $self->SUPER::create($package_name, %options);
57 if (exists $options{roles}) {
58 Moose::Util::apply_all_roles($class, @{$options{roles}});
66 sub create_anon_class {
67 my ($self, %options) = @_;
69 my $cache_ok = delete $options{cache};
71 # something like Super::Class|Super::Class::2=Role|Role::1
72 my $cache_key = join '=' => (
73 join('|', sort @{$options{superclasses} || []}),
74 join('|', sort @{$options{roles} || []}),
77 if ($cache_ok && defined $ANON_CLASSES{$cache_key}) {
78 return $ANON_CLASSES{$cache_key};
81 my $new_class = $self->SUPER::create_anon_class(%options);
83 $ANON_CLASSES{$cache_key} = $new_class
90 my ($self, $role) = @_;
91 (blessed($role) && $role->isa('Moose::Meta::Role'))
92 || confess "Roles must be instances of Moose::Meta::Role";
93 push @{$self->roles} => $role;
96 sub calculate_all_roles {
99 grep { !$seen{$_->name}++ } map { $_->calculate_all_roles } @{ $self->roles };
103 my ($self, $role_name) = @_;
105 || confess "You must supply a role name to look for";
106 foreach my $class ($self->class_precedence_list) {
107 next unless $class->can('meta') && $class->meta->can('roles');
108 foreach my $role (@{$class->meta->roles}) {
109 return 1 if $role->does_role($role_name);
116 my ($self, $role_name) = @_;
118 || confess "You must supply a role name to look for";
119 foreach my $class ($self->class_precedence_list) {
120 next unless $class->can('meta');
122 # in the pretty rare instance when a Moose metaclass
123 # is itself extended with a role, this check needs to
124 # be done since some items in the class_precedence_list
125 # might in fact be Class::MOP based still.
126 next unless $class->meta->can('roles');
127 foreach my $role (@{$class->meta->roles}) {
128 return 1 if $role->excludes_role($role_name);
136 my $params = @_ == 1 ? $_[0] : {@_};
137 my $self = $class->SUPER::new_object($params);
138 foreach my $attr ($class->compute_all_applicable_attributes()) {
139 # if we have a trigger, then ...
140 if ($attr->can('has_trigger') && $attr->has_trigger) {
141 # make sure we have an init-arg ...
142 if (defined(my $init_arg = $attr->init_arg)) {
143 # now make sure an init-arg was passes ...
144 if (exists $params->{$init_arg}) {
145 # and if get here, fire the trigger
148 # check if there is a coercion
149 ($attr->should_coerce
150 # and if so, we need to grab the
151 # value that is actually been stored
152 ? $attr->get_read_method_ref->($self)
153 # otherwise, just get the value from
154 # the constructor params
155 : $params->{$init_arg}),
165 sub construct_instance {
167 my $params = @_ == 1 ? $_[0] : {@_};
168 my $meta_instance = $class->get_meta_instance;
170 # the code below is almost certainly incorrect
171 # but this is foreign inheritence, so we might
172 # have to kludge it in the end.
173 my $instance = $params->{'__INSTANCE__'} || $meta_instance->create_instance();
174 foreach my $attr ($class->compute_all_applicable_attributes()) {
175 $attr->initialize_instance_slot($meta_instance, $instance, $params);
185 my $current = Class::MOP::check_package_cache_flag($self->name);
187 if (defined $self->{'_package_cache_flag'} && $self->{'_package_cache_flag'} == $current) {
188 return $self->{'methods'};
191 $self->{_package_cache_flag} = $current;
193 my $map = $self->{'methods'};
195 my $class_name = $self->name;
196 my $method_metaclass = $self->method_metaclass;
198 my %all_code = $self->get_all_package_symbols('CODE');
200 foreach my $symbol (keys %all_code) {
201 my $code = $all_code{$symbol};
203 next if exists $map->{$symbol} &&
204 defined $map->{$symbol} &&
205 $map->{$symbol}->body == $code;
207 my ($pkg, $name) = Class::MOP::get_code_info($code);
209 if ($pkg->can('meta')
211 # we don't know what ->meta we are calling
212 # here, so we need to be careful cause it
213 # just might blow up at us, or just complain
214 # loudly (in the case of Curses.pm) so we
215 # just be a little overly cautious here.
217 && eval { no warnings; blessed($pkg->meta) }
218 && $pkg->meta->isa('Moose::Meta::Role')) {
219 #my $role = $pkg->meta->name;
220 #next unless $self->does_role($role);
225 # in 5.10 constant.pm the constants show up
226 # as being in the right package, but in pre-5.10
227 # they show up as constant::__ANON__ so we
228 # make an exception here to be sure that things
229 # work as expected in both.
231 unless ($pkg eq 'constant' && $name eq '__ANON__') {
232 next if ($pkg || '') ne $class_name ||
233 (($name || '') ne '__ANON__' && ($pkg || '') ne $class_name);
238 $map->{$symbol} = $method_metaclass->wrap(
240 package_name => $class_name,
248 ### ---------------------------------------------
252 $self->SUPER::add_attribute(
253 (blessed $_[0] && $_[0]->isa('Class::MOP::Attribute')
255 : $self->_process_attribute(@_))
259 sub add_override_method_modifier {
260 my ($self, $name, $method, $_super_package) = @_;
262 (!$self->has_method($name))
263 || confess "Cannot add an override method if a local method is already present";
265 $self->add_method($name => Moose::Meta::Method::Overriden->new(
268 package => $_super_package, # need this for roles
273 sub add_augment_method_modifier {
274 my ($self, $name, $method) = @_;
275 (!$self->has_method($name))
276 || confess "Cannot add an augment method if a local method is already present";
278 $self->add_method($name => Moose::Meta::Method::Augmented->new(
285 ## Private Utility methods ...
287 sub _find_next_method_by_name_which_is_not_overridden {
288 my ($self, $name) = @_;
289 foreach my $method ($self->find_all_methods_by_name($name)) {
290 return $method->{code}
291 if blessed($method->{code}) && !$method->{code}->isa('Moose::Meta::Method::Overriden');
296 # Right now, this method does not handle the case where two
297 # metaclasses differ only in roles applied against a common parent
298 # class. This can happen fairly easily when ClassA applies metaclass
299 # Role1, and then a subclass, ClassB, applies a metaclass Role2. In
300 # reality, the way to resolve the problem is to apply Role1 to
301 # ClassB's metaclass. However, we cannot currently detect this, and so
302 # we simply fail to fix the incompatibility.
304 # The algorithm for fixing it is not that complicated.
306 # First, we see if the two metaclasses share a common parent (probably
307 # Moose::Meta::Class).
309 # Second, we see if the metaclasses only differ in terms of roles
310 # applied. This second point is where things break down. There is no
311 # easy way to determine if the difference is from roles only. To do
312 # that, we'd need to able to reliably determine the origin of each
313 # method and attribute in each metaclass. If all the unshared methods
314 # & attributes come from roles, and there is no name collision, then
315 # we can apply the missing roles to the child's metaclass.
317 # Tracking the origin of these things will require some fairly
318 # invasive changes to various parts of Moose & Class::MOP.
320 # For now, the workaround is for ClassB to subclass ClassA _and then_
321 # apply metaclass roles to its metaclass.
322 sub _fix_metaclass_incompatability {
323 my ($self, @superclasses) = @_;
325 my $self_meta_name = ref($self);
327 foreach my $super (@superclasses) {
328 # don't bother if it does not have a meta.
329 my $super_meta = Class::MOP::Class->initialize($super) or next;
330 next unless $super_meta->isa("Class::MOP::Class");
332 # get the name, make sure we take
333 # immutable classes into account
335 = $super_meta->is_immutable
336 ? $super_meta->get_mutable_metaclass_name
340 # if our metaclass is compatible
341 $self->isa($super_meta_name)
343 # and our instance metaclass is also compatible then no
345 $self->instance_metaclass->isa( $super_meta->instance_metaclass );
347 if ( $super_meta->isa($self_meta_name) ) {
348 $self->_require_pristine_to_reinitialize;
350 $self = $super_meta->reinitialize(
352 attribute_metaclass => $super_meta->attribute_metaclass,
353 method_metaclass => $super_meta->method_metaclass,
354 instance_metaclass => $super_meta->instance_metaclass,
357 $self->$_( $super_meta->$_ )
358 for qw( constructor_class destructor_class );
360 elsif ( __difference_is_roles_only( $self, $super_meta ) ) {
361 $self->_require_pristine_to_reinitialize;
363 my @roles = map { $_->name } @{$self->meta->roles};
365 $self = $super_meta->reinitialize(
367 attribute_metaclass => $super_meta->attribute_metaclass,
368 method_metaclass => $super_meta->method_metaclass,
369 instance_metaclass => $super_meta->instance_metaclass,
372 $self = Moose::Util::MetaRole::apply_metaclass_roles(
373 for_class => $self->name,
374 metaclass_roles => \@roles,
382 sub _require_pristine_to_reinitialize {
385 return if $self->is_pristine;
387 confess "Not reinitializing metaclass for "
389 . ", it isn't pristine";
392 # This stuff is called as functions because while it operates on
393 # metaclasses, it might get a Class::MOP::Class as opposed to a
394 # Moose::Meta::Class.
395 sub __difference_is_roles_only {
396 my ( $meta1, $meta2 ) = @_;
399 unless $meta1->meta->can('does_role')
400 || $meta2->meta->can('does_role');
404 __methods_excluding_roles( $meta1->meta ),
405 __methods_excluding_roles( $meta2->meta )
410 __attr_excluding_roles( $meta1->meta ),
411 __attr_excluding_roles( $meta2->meta )
417 sub __arrays_differ {
418 my ( $arr1, $arr2 ) = @_;
420 my %arr1_vals = map { $_ => 1 } @{$arr1};
421 delete @arr1_vals{ @{$arr2} };
423 return keys %arr1_vals ? 1 : 0;
426 sub __methods_excluding_roles {
429 my %map = map { $_->name => $_ } $meta->get_all_methods;
433 return values %map unless $meta->can('roles') && $meta->roles;
435 for my $role ( @{$meta->roles} ) {
436 for my $role_meth ( values %{$role->get_method_map} ) {
437 next if $role_meth->name eq 'meta';
439 my $meta_meth = $map{ $role_meth->name };
441 next unless $meta_meth;
442 next unless $meta_meth->body eq $role_meth->body;
444 delete $map{ $role_meth->name };
447 for my $attr ( grep { defined } map { $meta->get_attribute($_) } $role->get_attribute_list ) {
448 delete @map{ map { $_->name } @{$attr->associated_methods} };
452 return [ values %map ];
455 sub __attr_excluding_roles {
458 my %map = map { $_->name => $_ } $meta->get_all_attributes;
460 return values %map unless $meta->can('roles') && $meta->roles;
462 for my $role ( @{$meta->roles} ) {
463 delete @map{ $role->get_attribute_list };
466 return [ values %map ];
470 # this was crap anyway, see
471 # Moose::Util::apply_all_roles
473 sub _apply_all_roles {
474 Carp::croak 'DEPRECATED: use Moose::Util::apply_all_roles($meta, @roles) instead'
477 sub _process_attribute {
478 my ( $self, $name, @args ) = @_;
480 @args = %{$args[0]} if scalar @args == 1 && ref($args[0]) eq 'HASH';
482 if ($name =~ /^\+(.*)/) {
483 return $self->_process_inherited_attribute($1, @args);
486 return $self->_process_new_attribute($name, @args);
490 sub _process_new_attribute {
491 my ( $self, $name, @args ) = @_;
493 $self->attribute_metaclass->interpolate_class_and_new($name, @args);
496 sub _process_inherited_attribute {
497 my ($self, $attr_name, %options) = @_;
498 my $inherited_attr = $self->find_attribute_by_name($attr_name);
499 (defined $inherited_attr)
500 || confess "Could not find an attribute by the name of '$attr_name' to inherit from";
501 if ($inherited_attr->isa('Moose::Meta::Attribute')) {
502 return $inherited_attr->clone_and_inherit_options(%options);
506 # kind of a kludge to handle Class::MOP::Attributes
507 return $inherited_attr->Moose::Meta::Attribute::clone_and_inherit_options(%options);
511 ## -------------------------------------------------
513 use Moose::Meta::Method::Constructor;
514 use Moose::Meta::Method::Destructor;
516 # This could be done by using SUPER and altering ->options
517 # I am keeping it this way to make it more explicit.
518 sub create_immutable_transformer {
520 my $class = Class::MOP::Immutable->new($self, {
521 read_only => [qw/superclasses/],
528 remove_package_symbol
532 class_precedence_list => 'ARRAY',
533 linearized_isa => 'ARRAY', # FIXME perl 5.10 memoizes this on its own, no need?
534 get_all_methods => 'ARRAY',
535 #get_all_attributes => 'ARRAY', # it's an alias, no need, but maybe in the future
536 compute_all_applicable_attributes => 'ARRAY',
537 get_meta_instance => 'SCALAR',
538 get_method_map => 'SCALAR',
539 calculate_all_roles => 'ARRAY',
542 # this is ugly, but so are typeglobs,
543 # so whattayahgonnadoboutit
546 add_package_symbol => sub {
547 my $original = shift;
548 confess "Cannot add package symbols to an immutable metaclass"
549 unless (caller(2))[3] eq 'Class::MOP::Package::get_package_symbol';
550 goto $original->body;
559 $self->SUPER::make_immutable
561 constructor_class => $self->constructor_class,
562 destructor_class => $self->destructor_class,
563 inline_destructor => 1,
565 # no need to do this,
566 # Moose always does it
567 inline_accessors => 0,
580 Moose::Meta::Class - The Moose metaclass
584 This is a subclass of L<Class::MOP::Class> with Moose specific
587 For the most part, the only time you will ever encounter an
588 instance of this class is if you are doing some serious deep
589 introspection. To really understand this class, you need to refer
590 to the L<Class::MOP::Class> documentation.
600 Overrides original to accept a list of roles to apply to
603 my $metaclass = Moose::Meta::Class->create( 'New::Class', roles => [...] );
605 =item B<create_anon_class>
607 Overrides original to support roles and caching.
609 my $metaclass = Moose::Meta::Class->create_anon_class(
610 superclasses => ['Foo'],
611 roles => [qw/Some Roles Go Here/],
615 =item B<make_immutable>
617 Override original to add default options for inlining destructor
618 and altering the Constructor metaclass.
620 =item B<create_immutable_transformer>
622 Override original to lock C<add_role> and memoize C<calculate_all_roles>
626 We override this method to support the C<trigger> attribute option.
628 =item B<construct_instance>
630 This provides some Moose specific extensions to this method, you
631 almost never call this method directly unless you really know what
634 This method makes sure to handle the moose weak-ref, type-constraint
635 and type coercion features.
637 =item B<get_method_map>
639 This accommodates Moose::Meta::Role::Method instances, which are
640 aliased, instead of added, but still need to be counted as valid
643 =item B<add_override_method_modifier ($name, $method)>
645 This will create an C<override> method modifier for you, and install
648 =item B<add_augment_method_modifier ($name, $method)>
650 This will create an C<augment> method modifier for you, and install
653 =item B<calculate_all_roles>
657 This will return an array of C<Moose::Meta::Role> instances which are
658 attached to this class.
660 =item B<add_role ($role)>
662 This takes an instance of C<Moose::Meta::Role> in C<$role>, and adds it
663 to the list of associated roles.
665 =item B<does_role ($role_name)>
667 This will test if this class C<does> a given C<$role_name>. It will
668 not only check it's local roles, but ask them as well in order to
669 cascade down the role hierarchy.
671 =item B<excludes_role ($role_name)>
673 This will test if this class C<excludes> a given C<$role_name>. It will
674 not only check it's local roles, but ask them as well in order to
675 cascade down the role hierarchy.
677 =item B<add_attribute ($attr_name, %params|$params)>
679 This method does the same thing as L<Class::MOP::Class::add_attribute>, but adds
680 support for taking the C<$params> as a HASH ref.
686 All complex software has bugs lurking in it, and this module is no
687 exception. If you find a bug please either email me, or add the bug
692 Stevan Little E<lt>stevan@iinteractive.comE<gt>
694 =head1 COPYRIGHT AND LICENSE
696 Copyright 2006-2008 by Infinity Interactive, Inc.
698 L<http://www.iinteractive.com>
700 This library is free software; you can redistribute it and/or modify
701 it under the same terms as Perl itself.