X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMoose%2FRole.pm;h=48e40b7be34f3530aa30a82a8be3d27923c8086a;hb=7e39015e28d0e9810c4dd819fa2be402c05af74a;hp=9671f3a2701e95195c5b28de001a1c5777879591;hpb=7eaef7ad987c89e849c8d55fe718c5db617b55df;p=gitmo%2FMoose.git diff --git a/lib/Moose/Role.pm b/lib/Moose/Role.pm index 9671f3a..48e40b7 100644 --- a/lib/Moose/Role.pm +++ b/lib/Moose/Role.pm @@ -1,237 +1,300 @@ - package Moose::Role; - use strict; use warnings; -use Scalar::Util (); -use Carp 'confess'; -use Sub::Name 'subname'; +use Scalar::Util 'blessed'; +use Carp 'croak'; +use Class::Load 'is_class_loaded'; use Sub::Exporter; -our $VERSION = '0.03'; +use Moose (); +use Moose::Util (); +use Moose::Exporter; use Moose::Meta::Role; use Moose::Util::TypeConstraints; -{ - my ( $CALLER, %METAS ); - - sub _find_meta { - my $role = $CALLER; - - return $METAS{$role} if exists $METAS{$role}; - - # make a subtype for each Moose class - subtype $role - => as 'Role' - => where { $_->does($role) } - unless find_type_constraint($role); - - my $meta; - if ($role->can('meta')) { - $meta = $role->meta(); - (blessed($meta) && $meta->isa('Moose::Meta::Role')) - || confess "Whoops, not møøsey enough"; - } - else { - $meta = Moose::Meta::Role->new(role_name => $role); - $meta->_role_meta->add_method('meta' => sub { $meta }) - } - - return $METAS{$role} = $meta; +sub extends { + croak "Roles do not support 'extends' (you can use 'with' to specialize a role)"; +} + +sub with { + Moose::Util::apply_all_roles( shift, @_ ); +} + +sub requires { + my $meta = shift; + croak "Must specify at least one method" unless @_; + $meta->add_required_methods(@_); +} + +sub excludes { + my $meta = shift; + croak "Must specify at least one role" unless @_; + $meta->add_excluded_roles(@_); +} + +sub has { + my $meta = shift; + my $name = shift; + croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1; + my %options = ( definition_context => Moose::Util::_caller_info(), @_ ); + my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; + $meta->add_attribute( $_, %options ) for @$attrs; +} + +sub _add_method_modifier { + my $type = shift; + my $meta = shift; + + if ( ref($_[0]) eq 'Regexp' ) { + croak "Roles do not currently support regex " + . " references for $type method modifiers"; } - - - my %exports = ( - extends => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::extends' => sub { - confess "Moose::Role does not currently support 'extends'" - }; - }, - with => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::with' => sub { - my ($role) = @_; - Moose::_load_all_classes($role); - $role->meta->apply($meta); - }; - }, - requires => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::requires' => sub { - $meta->add_required_methods(@_); - }; - }, - has => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::has' => sub { - my ($name, %options) = @_; - $meta->add_attribute($name, %options) - }; - }, - before => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::before' => sub { - my $code = pop @_; - $meta->add_before_method_modifier($_, $code) for @_; - }; - }, - after => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::after' => sub { - my $code = pop @_; - $meta->add_after_method_modifier($_, $code) for @_; - }; - }, - around => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::around' => sub { - my $code = pop @_; - $meta->add_around_method_modifier($_, $code) for @_; - }; - }, - super => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::super' => sub {}; - }, - override => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::override' => sub { - my ($name, $code) = @_; - $meta->add_override_method_modifier($name, $code); - }; - }, - inner => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::inner' => sub { - confess "Moose::Role does not currently support 'inner'"; - }; - }, - augment => sub { - my $meta = _find_meta(); - return subname 'Moose::Role::augment' => sub { - confess "Moose::Role does not currently support 'augment'"; - }; - }, - confess => sub { - return \&Carp::confess; - }, - blessed => sub { - return \&Scalar::Util::blessed; - } - ); - - my $exporter = Sub::Exporter::build_exporter({ - exports => \%exports, - groups => { - default => [':all'] - } - }); - - sub import { - $CALLER = caller(); - # we should never export to main - return if $CALLER eq 'main'; + Moose::Util::add_method_modifier($meta, $type, \@_); +} + +sub before { _add_method_modifier('before', @_) } + +sub after { _add_method_modifier('after', @_) } + +sub around { _add_method_modifier('around', @_) } + +# see Moose.pm for discussion +sub super { + return unless $Moose::SUPER_BODY; + $Moose::SUPER_BODY->(@Moose::SUPER_ARGS); +} + +sub override { + my $meta = shift; + my ( $name, $code ) = @_; + $meta->add_override_method_modifier( $name, $code ); +} + +sub inner { + croak "Roles cannot support 'inner'"; +} + +sub augment { + croak "Roles cannot support 'augment'"; +} + +Moose::Exporter->setup_import_methods( + with_meta => [ + qw( with requires excludes has before after around override ) + ], + as_is => [ + qw( extends super inner augment ), + \&Carp::confess, + \&Scalar::Util::blessed, + ], +); + +sub init_meta { + shift; + my %args = @_; + + my $role = $args{for_class}; + + unless ($role) { + require Moose; + Moose->throw_error("Cannot call init_meta without specifying a for_class"); + } + + my $metaclass = $args{metaclass} || "Moose::Meta::Role"; + my $meta_name = exists $args{meta_name} ? $args{meta_name} : 'meta'; + + Moose->throw_error("The Metaclass $metaclass must be loaded. (Perhaps you forgot to 'use $metaclass'?)") + unless is_class_loaded($metaclass); - goto $exporter; - }; + Moose->throw_error("The Metaclass $metaclass must be a subclass of Moose::Meta::Role.") + unless $metaclass->isa('Moose::Meta::Role'); + # make a subtype for each Moose role + role_type $role unless find_type_constraint($role); + + my $meta; + if ( $meta = Class::MOP::get_metaclass_by_name($role) ) { + unless ( $meta->isa("Moose::Meta::Role") ) { + my $error_message = "$role already has a metaclass, but it does not inherit $metaclass ($meta)."; + if ( $meta->isa('Moose::Meta::Class') ) { + Moose->throw_error($error_message . ' You cannot make the same thing a role and a class. Remove either Moose or Moose::Role.'); + } else { + Moose->throw_error($error_message); + } + } + } + else { + $meta = $metaclass->initialize($role); + } + + if (defined $meta_name) { + # also check for inherited non moose 'meta' method? + my $existing = $meta->get_method($meta_name); + if ($existing && !$existing->isa('Class::MOP::Method::Meta')) { + Carp::cluck "Moose::Role is overwriting an existing method named " + . "$meta_name in role $role with a method " + . "which returns the class's metaclass. If this is " + . "actually what you want, you should remove the " + . "existing method, otherwise, you should rename or " + . "disable this generated method using the " + . "'-meta_name' option to 'use Moose::Role'."; + } + $meta->_add_meta_method($meta_name); + } + + return $meta; } 1; +# ABSTRACT: The Moose Role + __END__ =pod -=head1 NAME - -Moose::Role - The Moose Role - =head1 SYNOPSIS package Eq; - use strict; - use warnings; - use Moose::Role; - + use Moose::Role; # automatically turns on strict and warnings + requires 'equal'; - - sub no_equal { + + sub no_equal { my ($self, $other) = @_; !$self->equal($other); } - + # ... then in your classes - + package Currency; - use strict; - use warnings; - use Moose; - + use Moose; # automatically turns on strict and warnings + with 'Eq'; - + sub equal { my ($self, $other) = @_; $self->as_float == $other->as_float; } + # ... and also + + package Comparator; + use Moose; + + has compare_to => ( + is => 'ro', + does => 'Eq', + handles => 'Eq', + ); + + # ... which allows + + my $currency1 = Currency->new(...); + my $currency2 = Currency->new(...); + Comparator->new(compare_to => $currency1)->equal($currency2); + =head1 DESCRIPTION -This is currently a very early release of Perl 6 style Roles for -Moose, it is still incomplete, but getting much closer. If you are -interested in helping move this feature along, please come to -#moose on irc.perl.org and we can talk. +The concept of roles is documented in L. This document +serves as API documentation. -=head1 CAVEATS +=head1 EXPORTED FUNCTIONS -Currently, the role support has a few of caveats. They are as follows: +Moose::Role currently supports all of the functions that L exports, but +differs slightly in how some items are handled (see L below for +details). + +Moose::Role also offers two role-specific keyword exports: =over 4 -=item * +=item B -At this time classes I correctly consume more than one role. The -role composition process, and it's conflict detection has not been added -yet. While this should be considered a major feature, it can easily be -worked around, and in many cases, is not needed at all. - -A class can actually consume multiple roles, they are just applied one -after another in the order you ask for them. This is incorrect behavior, -the roles should be merged first, and conflicts determined, etc. However, -if your roles do not have any conflicts, then things will work just -fine. This actually tends to be quite sufficient for basic roles. +Roles can require that certain methods are implemented by any class which +C the role. -=item * +Note that attribute accessors also count as methods for the purposes +of satisfying the requirements of a role. -Roles cannot use the C keyword, it will throw an exception for now. -The same is true of the C and C keywords (not sure those -really make sense for roles). All other Moose keywords will be I -so that they can be applied to the consuming class. +=item B + +Roles can C other roles, in effect saying "I can never be combined +with these C<@role_names>". This is a feature which should not be used +lightly. =back -=head1 BUGS +=head2 B -All complex software has bugs lurking in it, and this module is no -exception. If you find a bug please either email me, or add the bug -to cpan-RT. +Moose::Role offers a way to remove the keywords it exports, through the +C method. You simply have to say C at the bottom of +your code for this to work. -=head1 AUTHOR +=head1 METACLASS -Stevan Little Estevan@iinteractive.comE +When you use Moose::Role, you can specify traits which will be applied to your +role metaclass: -=head1 COPYRIGHT AND LICENSE + use Moose::Role -traits => 'My::Trait'; -Copyright 2006 by Infinity Interactive, Inc. +This is very similar to the attribute traits feature. When you do +this, your class's C object will have the specified traits +applied to it. See L for more +details. -L +=head1 APPLYING ROLES + +In addition to being applied to a class using the 'with' syntax (see +L) and using the L 'apply_all_roles' +method, roles may also be applied to an instance of a class using +L 'apply_all_roles' or the role's metaclass: + + MyApp::Test::SomeRole->meta->apply( $instance ); + +Doing this creates a new, mutable, anonymous subclass, applies the role to that, +and reblesses. In a debugger, for example, you will see class names of the +form C< Moose::Meta::Class::__ANON__::SERIAL::6 >, which means that doing a +'ref' on your instance may not return what you expect. See L for +'DOES'. + +Additional params may be added to the new instance by providing +'rebless_params'. See L. + +=head1 CAVEATS + +Role support has only a few caveats: + +=over 4 + +=item * + +Roles cannot use the C keyword; it will throw an exception for now. +The same is true of the C and C keywords (not sure those +really make sense for roles). All other Moose keywords will be I +so that they can be applied to the consuming class. + +=item * + +Role composition does its best to B be order-sensitive when it comes to +conflict resolution and requirements detection. However, it is order-sensitive +when it comes to method modifiers. All before/around/after modifiers are +included whenever a role is composed into a class, and then applied in the order +in which the roles are used. This also means that there is no conflict for +before/around/after modifiers. + +In most cases, this will be a non-issue; however, it is something to keep in +mind when using method modifiers in a role. You should never assume any +ordering. + +=back + +=head1 BUGS -This library is free software; you can redistribute it and/or modify -it under the same terms as Perl itself. +See L for details on reporting bugs. -=cut \ No newline at end of file +=cut