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,
124 my $role = $args{for_class}
126 "Cannot call init_meta without specifying a for_class";
128 my $metaclass = $args{metaclass} || "Moose::Meta::Role";
130 # make a subtype for each Moose class
131 role_type $role unless find_type_constraint($role);
133 # FIXME copy from Moose.pm
135 if ($role->can('meta')) {
136 $meta = $role->meta();
137 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
138 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
141 $meta = $metaclass->initialize($role);
142 $meta->alias_method('meta' => sub { $meta });
156 Moose::Role - The Moose Role
161 use Moose::Role; # automatically turns on strict and warnings
166 my ($self, $other) = @_;
167 !$self->equal($other);
170 # ... then in your classes
173 use Moose; # automatically turns on strict and warnings
178 my ($self, $other) = @_;
179 $self->as_float == $other->as_float;
184 Role support in Moose is pretty solid at this point. However, the best
185 documentation is still the the test suite. It is fairly safe to assume Perl 6
186 style behavior and then either refer to the test suite, or ask questions on
187 #moose if something doesn't quite do what you expect.
189 We are planning writing some more documentation in the near future, but nothing
192 =head1 EXPORTED FUNCTIONS
194 Moose::Role currently supports all of the functions that L<Moose> exports, but
195 differs slightly in how some items are handled (see L<CAVEATS> below for
198 Moose::Role also offers two role-specific keyword exports:
202 =item B<requires (@method_names)>
204 Roles can require that certain methods are implemented by any class which
207 =item B<excludes (@role_names)>
209 Roles can C<exclude> other roles, in effect saying "I can never be combined
210 with these C<@role_names>". This is a feature which should not be used
217 Moose::Role offers a way to remove the keywords it exports, through the
218 C<unimport> method. You simply have to say C<no Moose::Role> at the bottom of
219 your code for this to work.
221 =head2 B<< Moose::Role->init_meta(for_class => $role, metaclass => $metaclass) >>
223 The C<init_meta> method sets up the metaclass object for the role
224 specified by C<for_class>. It also injects a a C<meta> accessor into
225 the role so you can get at this object.
227 The default metaclass is L<Moose::Meta::Role>. You can specify an
228 alternate metaclass with the C<metaclass> parameter.
232 Role support has only a few caveats:
238 Roles cannot use the C<extends> keyword; it will throw an exception for now.
239 The same is true of the C<augment> and C<inner> keywords (not sure those
240 really make sense for roles). All other Moose keywords will be I<deferred>
241 so that they can be applied to the consuming class.
245 Role composition does its best to B<not> be order-sensitive when it comes to
246 conflict resolution and requirements detection. However, it is order-sensitive
247 when it comes to method modifiers. All before/around/after modifiers are
248 included whenever a role is composed into a class, and then applied in the order
249 in which the roles are used. This also means that there is no conflict for
250 before/around/after modifiers.
252 In most cases, this will be a non-issue; however, it is something to keep in
253 mind when using method modifiers in a role. You should never assume any
258 The C<requires> keyword currently only works with actual methods. A method
259 modifier (before/around/after and override) will not count as a fufillment
260 of the requirement, and neither will an autogenerated accessor for an attribute.
262 It is likely that attribute accessors will eventually be allowed to fufill those
263 requirements, or we will introduce a C<requires_attr> keyword of some kind
264 instead. This decision has not yet been finalized.
270 All complex software has bugs lurking in it, and this module is no
271 exception. If you find a bug please either email me, or add the bug
276 Stevan Little E<lt>stevan@iinteractive.comE<gt>
278 Christian Hansen E<lt>chansen@cpan.orgE<gt>
280 =head1 COPYRIGHT AND LICENSE
282 Copyright 2006-2008 by Infinity Interactive, Inc.
284 L<http://www.iinteractive.com>
286 This library is free software; you can redistribute it and/or modify
287 it under the same terms as Perl itself.