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( shift->meta(), @_ );
31 my $meta = shift->meta();
32 croak "Must specify at least one method" unless @_;
33 $meta->add_required_methods(@_);
37 my $meta = shift->meta();
38 croak "Must specify at least one role" unless @_;
39 $meta->add_excluded_roles(@_);
43 my $meta = shift->meta();
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 = shift->meta();
56 croak "Moose::Role do not currently support "
58 . " references for before method modifiers"
60 $meta->add_before_method_modifier( $_, $code );
65 my $meta = shift->meta();
69 croak "Moose::Role do not currently support "
71 . " references for after method modifiers"
73 $meta->add_after_method_modifier( $_, $code );
78 my $meta = shift->meta();
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 = shift->meta();
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->build_import_methods(
111 qw( with requires excludes has before after around override make_immutable )
114 qw( extends super inner augment ),
116 \&Scalar::Util::blessed,
118 also => sub { init_meta(shift) },
127 return $METAS{$role} if exists $METAS{$role};
129 # make a subtype for each Moose class
130 role_type $role unless find_type_constraint($role);
133 if ($role->can('meta')) {
134 $meta = $role->meta();
135 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
136 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
139 $meta = Moose::Meta::Role->initialize($role);
140 $meta->alias_method('meta' => sub { $meta });
143 return $METAS{$role} = $meta;
155 Moose::Role - The Moose Role
160 use Moose::Role; # automatically turns on strict and warnings
165 my ($self, $other) = @_;
166 !$self->equal($other);
169 # ... then in your classes
172 use Moose; # automatically turns on strict and warnings
177 my ($self, $other) = @_;
178 $self->as_float == $other->as_float;
183 Role support in Moose is pretty solid at this point. However, the best
184 documentation is still the the test suite. It is fairly safe to assume Perl 6
185 style behavior and then either refer to the test suite, or ask questions on
186 #moose if something doesn't quite do what you expect.
188 We are planning writing some more documentation in the near future, but nothing
191 =head1 EXPORTED FUNCTIONS
193 Moose::Role currently supports all of the functions that L<Moose> exports, but
194 differs slightly in how some items are handled (see L<CAVEATS> below for
197 Moose::Role also offers two role-specific keyword exports:
201 =item B<requires (@method_names)>
203 Roles can require that certain methods are implemented by any class which
206 =item B<excludes (@role_names)>
208 Roles can C<exclude> other roles, in effect saying "I can never be combined
209 with these C<@role_names>". This is a feature which should not be used
216 Moose::Role offers a way to remove the keywords it exports, through the
217 C<unimport> method. You simply have to say C<no Moose::Role> at the bottom of
218 your code for this to work.
222 Role support has only a few caveats:
228 Roles cannot use the C<extends> keyword; it will throw an exception for now.
229 The same is true of the C<augment> and C<inner> keywords (not sure those
230 really make sense for roles). All other Moose keywords will be I<deferred>
231 so that they can be applied to the consuming class.
235 Role composition does its best to B<not> be order-sensitive when it comes to
236 conflict resolution and requirements detection. However, it is order-sensitive
237 when it comes to method modifiers. All before/around/after modifiers are
238 included whenever a role is composed into a class, and then applied in the order
239 in which the roles are used. This also means that there is no conflict for
240 before/around/after modifiers.
242 In most cases, this will be a non-issue; however, it is something to keep in
243 mind when using method modifiers in a role. You should never assume any
248 The C<requires> keyword currently only works with actual methods. A method
249 modifier (before/around/after and override) will not count as a fufillment
250 of the requirement, and neither will an autogenerated accessor for an attribute.
252 It is likely that attribute accessors will eventually be allowed to fufill those
253 requirements, or we will introduce a C<requires_attr> keyword of some kind
254 instead. This decision has not yet been finalized.
260 All complex software has bugs lurking in it, and this module is no
261 exception. If you find a bug please either email me, or add the bug
266 Stevan Little E<lt>stevan@iinteractive.comE<gt>
268 Christian Hansen E<lt>chansen@cpan.orgE<gt>
270 =head1 COPYRIGHT AND LICENSE
272 Copyright 2006-2008 by Infinity Interactive, Inc.
274 L<http://www.iinteractive.com>
276 This library is free software; you can redistribute it and/or modify
277 it under the same terms as Perl itself.