7 use Scalar::Util 'blessed';
8 use Carp 'confess', 'croak';
13 our $VERSION = '0.56';
14 our $AUTHORITY = 'cpan:STEVAN';
19 use Moose::Meta::Role;
20 use Moose::Util::TypeConstraints;
23 croak "Roles do not currently support 'extends'";
27 Moose::Util::apply_all_roles( Moose::Meta::Role->initialize(shift), @_ );
31 my $meta = Moose::Meta::Role->initialize(shift);
32 croak "Must specify at least one method" unless @_;
33 $meta->add_required_methods(@_);
37 my $meta = Moose::Meta::Role->initialize(shift);
38 croak "Must specify at least one role" unless @_;
39 $meta->add_excluded_roles(@_);
43 my $meta = Moose::Meta::Role->initialize(shift);
45 croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1;
47 my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ];
48 $meta->add_attribute( $_, %options ) for @$attrs;
52 my $meta = Moose::Meta::Role->initialize(shift);
56 croak "Moose::Role do not currently support "
58 . " references for before method modifiers"
60 $meta->add_before_method_modifier( $_, $code );
65 my $meta = Moose::Meta::Role->initialize(shift);
69 croak "Moose::Role do not currently support "
71 . " references for after method modifiers"
73 $meta->add_after_method_modifier( $_, $code );
78 my $meta = Moose::Meta::Role->initialize(shift);
81 croak "Moose::Role do not currently support "
83 . " references for around method modifiers"
85 $meta->add_around_method_modifier( $_, $code );
89 # see Moose.pm for discussion
91 return unless $Moose::SUPER_BODY;
92 $Moose::SUPER_BODY->(@Moose::SUPER_ARGS);
96 my $meta = Moose::Meta::Role->initialize(shift);
97 my ( $name, $code ) = @_;
98 $meta->add_override_method_modifier( $name, $code );
102 croak "Moose::Role cannot support 'inner'";
106 croak "Moose::Role cannot support 'augment'";
109 my $exporter = Moose::Exporter->setup_import_methods(
111 qw( with requires excludes has before after around override make_immutable )
114 qw( extends super inner augment ),
116 \&Scalar::Util::blessed,
127 my $role = $args{for_class}
129 "Cannot call init_meta without specifying a for_class";
131 return $METAS{$role} if exists $METAS{$role};
133 # make a subtype for each Moose class
134 role_type $role unless find_type_constraint($role);
137 if ($role->can('meta')) {
138 $meta = $role->meta();
139 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
140 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
143 $meta = Moose::Meta::Role->initialize($role);
144 $meta->alias_method('meta' => sub { $meta });
147 return $METAS{$role} = $meta;
159 Moose::Role - The Moose Role
164 use Moose::Role; # automatically turns on strict and warnings
169 my ($self, $other) = @_;
170 !$self->equal($other);
173 # ... then in your classes
176 use Moose; # automatically turns on strict and warnings
181 my ($self, $other) = @_;
182 $self->as_float == $other->as_float;
187 Role support in Moose is pretty solid at this point. However, the best
188 documentation is still the the test suite. It is fairly safe to assume Perl 6
189 style behavior and then either refer to the test suite, or ask questions on
190 #moose if something doesn't quite do what you expect.
192 We are planning writing some more documentation in the near future, but nothing
195 =head1 EXPORTED FUNCTIONS
197 Moose::Role currently supports all of the functions that L<Moose> exports, but
198 differs slightly in how some items are handled (see L<CAVEATS> below for
201 Moose::Role also offers two role-specific keyword exports:
205 =item B<requires (@method_names)>
207 Roles can require that certain methods are implemented by any class which
210 =item B<excludes (@role_names)>
212 Roles can C<exclude> other roles, in effect saying "I can never be combined
213 with these C<@role_names>". This is a feature which should not be used
220 Moose::Role offers a way to remove the keywords it exports, through the
221 C<unimport> method. You simply have to say C<no Moose::Role> at the bottom of
222 your code for this to work.
224 =head2 B<< Moose::Role->init_meta(for_class => $role, metaclass => $metaclass) >>
226 The C<init_meta> method sets up the metaclass object for the role
227 specified by C<for_class>. It also injects a a C<meta> accessor into
228 the role so you can get at this object.
230 The default metaclass is L<Moose::Meta::Role>. You can specify an
231 alternate metaclass with the C<metaclass> parameter.
235 Role support has only a few caveats:
241 Roles cannot use the C<extends> keyword; it will throw an exception for now.
242 The same is true of the C<augment> and C<inner> keywords (not sure those
243 really make sense for roles). All other Moose keywords will be I<deferred>
244 so that they can be applied to the consuming class.
248 Role composition does its best to B<not> be order-sensitive when it comes to
249 conflict resolution and requirements detection. However, it is order-sensitive
250 when it comes to method modifiers. All before/around/after modifiers are
251 included whenever a role is composed into a class, and then applied in the order
252 in which the roles are used. This also means that there is no conflict for
253 before/around/after modifiers.
255 In most cases, this will be a non-issue; however, it is something to keep in
256 mind when using method modifiers in a role. You should never assume any
261 The C<requires> keyword currently only works with actual methods. A method
262 modifier (before/around/after and override) will not count as a fufillment
263 of the requirement, and neither will an autogenerated accessor for an attribute.
265 It is likely that attribute accessors will eventually be allowed to fufill those
266 requirements, or we will introduce a C<requires_attr> keyword of some kind
267 instead. This decision has not yet been finalized.
273 All complex software has bugs lurking in it, and this module is no
274 exception. If you find a bug please either email me, or add the bug
279 Stevan Little E<lt>stevan@iinteractive.comE<gt>
281 Christian Hansen E<lt>chansen@cpan.orgE<gt>
283 =head1 COPYRIGHT AND LICENSE
285 Copyright 2006-2008 by Infinity Interactive, Inc.
287 L<http://www.iinteractive.com>
289 This library is free software; you can redistribute it and/or modify
290 it under the same terms as Perl itself.