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_exporter(
111 qw( with requires excludes has before after around override make_immutable )
114 qw( extends super inner augment ),
116 \&Scalar::Util::blessed,
121 my $caller = Moose::Exporter->get_caller(@_);
123 # this works because both pragmas set $^H (see perldoc perlvar)
124 # which affects the current compilation - i.e. the file who use'd
125 # us - which is why we don't need to do anything special to make
126 # it affect that file rather than this one (which is already compiled)
131 # we should never export to main
132 if ($caller eq 'main') {
133 warn qq{Moose::Role does not export its sugar to the 'main' package.\n};
143 my $caller = Moose::Exporter->get_caller(@_);
145 Moose::Exporter->remove_keywords(
146 source => __PACKAGE__,
157 return $METAS{$role} if exists $METAS{$role};
159 # make a subtype for each Moose class
160 role_type $role unless find_type_constraint($role);
163 if ($role->can('meta')) {
164 $meta = $role->meta();
165 (blessed($meta) && $meta->isa('Moose::Meta::Role'))
166 || confess "You already have a &meta function, but it does not return a Moose::Meta::Role";
169 $meta = Moose::Meta::Role->initialize($role);
170 $meta->alias_method('meta' => sub { $meta });
173 return $METAS{$role} = $meta;
185 Moose::Role - The Moose Role
190 use Moose::Role; # automatically turns on strict and warnings
195 my ($self, $other) = @_;
196 !$self->equal($other);
199 # ... then in your classes
202 use Moose; # automatically turns on strict and warnings
207 my ($self, $other) = @_;
208 $self->as_float == $other->as_float;
213 Role support in Moose is pretty solid at this point. However, the best
214 documentation is still the the test suite. It is fairly safe to assume Perl 6
215 style behavior and then either refer to the test suite, or ask questions on
216 #moose if something doesn't quite do what you expect.
218 We are planning writing some more documentation in the near future, but nothing
221 =head1 EXPORTED FUNCTIONS
223 Moose::Role currently supports all of the functions that L<Moose> exports, but
224 differs slightly in how some items are handled (see L<CAVEATS> below for
227 Moose::Role also offers two role-specific keyword exports:
231 =item B<requires (@method_names)>
233 Roles can require that certain methods are implemented by any class which
236 =item B<excludes (@role_names)>
238 Roles can C<exclude> other roles, in effect saying "I can never be combined
239 with these C<@role_names>". This is a feature which should not be used
246 Moose::Role offers a way to remove the keywords it exports, through the
247 C<unimport> method. You simply have to say C<no Moose::Role> at the bottom of
248 your code for this to work.
252 Role support has only a few caveats:
258 Roles cannot use the C<extends> keyword; it will throw an exception for now.
259 The same is true of the C<augment> and C<inner> keywords (not sure those
260 really make sense for roles). All other Moose keywords will be I<deferred>
261 so that they can be applied to the consuming class.
265 Role composition does its best to B<not> be order-sensitive when it comes to
266 conflict resolution and requirements detection. However, it is order-sensitive
267 when it comes to method modifiers. All before/around/after modifiers are
268 included whenever a role is composed into a class, and then applied in the order
269 in which the roles are used. This also means that there is no conflict for
270 before/around/after modifiers.
272 In most cases, this will be a non-issue; however, it is something to keep in
273 mind when using method modifiers in a role. You should never assume any
278 The C<requires> keyword currently only works with actual methods. A method
279 modifier (before/around/after and override) will not count as a fufillment
280 of the requirement, and neither will an autogenerated accessor for an attribute.
282 It is likely that attribute accessors will eventually be allowed to fufill those
283 requirements, or we will introduce a C<requires_attr> keyword of some kind
284 instead. This decision has not yet been finalized.
290 All complex software has bugs lurking in it, and this module is no
291 exception. If you find a bug please either email me, or add the bug
296 Stevan Little E<lt>stevan@iinteractive.comE<gt>
298 Christian Hansen E<lt>chansen@cpan.orgE<gt>
300 =head1 COPYRIGHT AND LICENSE
302 Copyright 2006-2008 by Infinity Interactive, Inc.
304 L<http://www.iinteractive.com>
306 This library is free software; you can redistribute it and/or modify
307 it under the same terms as Perl itself.