Commit | Line | Data |
e185c027 |
1 | |
2 | package Moose::Role; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
e65dccbc |
7 | use Scalar::Util 'blessed'; |
cc5e6b6f |
8 | use Carp 'confess', 'croak'; |
e185c027 |
9 | |
c4538447 |
10 | use Data::OptList; |
2d562421 |
11 | use Sub::Exporter; |
12 | |
a94188ac |
13 | our $VERSION = '0.56'; |
d44714be |
14 | our $AUTHORITY = 'cpan:STEVAN'; |
e185c027 |
15 | |
d7d8a8c7 |
16 | use Moose (); |
17 | use Moose::Util (); |
e65dccbc |
18 | |
e185c027 |
19 | use Moose::Meta::Role; |
7eaef7ad |
20 | use Moose::Util::TypeConstraints; |
e185c027 |
21 | |
2d562421 |
22 | { |
5bd4db9b |
23 | my %METAS; |
2d562421 |
24 | |
5bd4db9b |
25 | sub init_meta { |
26 | my $role = shift; |
2d562421 |
27 | |
7eaef7ad |
28 | return $METAS{$role} if exists $METAS{$role}; |
fb1e11d5 |
29 | |
7eaef7ad |
30 | # make a subtype for each Moose class |
e324865b |
31 | role_type $role unless find_type_constraint($role); |
2d562421 |
32 | |
fb1e11d5 |
33 | my $meta; |
34 | if ($role->can('meta')) { |
35 | $meta = $role->meta(); |
36 | (blessed($meta) && $meta->isa('Moose::Meta::Role')) |
68efb014 |
37 | || confess "You already have a &meta function, but it does not return a Moose::Meta::Role"; |
fb1e11d5 |
38 | } |
39 | else { |
40 | $meta = Moose::Meta::Role->initialize($role); |
41 | $meta->alias_method('meta' => sub { $meta }); |
42 | } |
2d562421 |
43 | |
7eaef7ad |
44 | return $METAS{$role} = $meta; |
2d562421 |
45 | } |
5bd4db9b |
46 | } |
fb1e11d5 |
47 | |
5bd4db9b |
48 | sub extends { |
49 | croak "Roles do not currently support 'extends'"; |
50 | } |
fb1e11d5 |
51 | |
5bd4db9b |
52 | sub with { |
53 | Moose::Util::apply_all_roles( shift->meta(), @_ ); |
54 | } |
2d562421 |
55 | |
5bd4db9b |
56 | sub requires { |
57 | my $meta = shift->meta(); |
58 | croak "Must specify at least one method" unless @_; |
59 | $meta->add_required_methods(@_); |
60 | } |
fb1e11d5 |
61 | |
5bd4db9b |
62 | sub excludes { |
63 | my $meta = shift->meta(); |
64 | croak "Must specify at least one role" unless @_; |
65 | $meta->add_excluded_roles(@_); |
66 | } |
fc9a40d7 |
67 | |
5bd4db9b |
68 | sub has { |
69 | my $meta = shift->meta(); |
70 | my $name = shift; |
71 | croak 'Usage: has \'name\' => ( key => value, ... )' if @_ == 1; |
72 | my %options = @_; |
73 | my $attrs = ( ref($name) eq 'ARRAY' ) ? $name : [ ($name) ]; |
74 | $meta->add_attribute( $_, %options ) for @$attrs; |
75 | } |
fb1e11d5 |
76 | |
5bd4db9b |
77 | sub before { |
78 | my $meta = shift->meta(); |
79 | my $code = pop @_; |
2d562421 |
80 | |
5bd4db9b |
81 | for (@_) { |
82 | croak "Moose::Role do not currently support " |
83 | . ref($_) |
84 | . " references for before method modifiers" |
85 | if ref $_; |
86 | $meta->add_before_method_modifier( $_, $code ); |
87 | } |
88 | } |
89 | |
90 | sub after { |
91 | my $meta = shift->meta(); |
92 | |
93 | my $code = pop @_; |
94 | for (@_) { |
95 | croak "Moose::Role do not currently support " |
96 | . ref($_) |
97 | . " references for after method modifiers" |
98 | if ref $_; |
99 | $meta->add_after_method_modifier( $_, $code ); |
100 | } |
101 | } |
2d562421 |
102 | |
5bd4db9b |
103 | sub around { |
104 | my $meta = shift->meta(); |
105 | my $code = pop @_; |
106 | for (@_) { |
107 | croak "Moose::Role do not currently support " |
108 | . ref($_) |
109 | . " references for around method modifiers" |
110 | if ref $_; |
111 | $meta->add_around_method_modifier( $_, $code ); |
112 | } |
113 | } |
2d562421 |
114 | |
5bd4db9b |
115 | # see Moose.pm for discussion |
116 | sub super { |
117 | return unless $Moose::SUPER_BODY; |
118 | $Moose::SUPER_BODY->(@Moose::SUPER_ARGS); |
119 | } |
d31f9614 |
120 | |
5bd4db9b |
121 | sub override { |
122 | my $meta = shift->meta(); |
123 | my ( $name, $code ) = @_; |
124 | $meta->add_override_method_modifier( $name, $code ); |
125 | } |
d31f9614 |
126 | |
5bd4db9b |
127 | sub inner { |
128 | croak "Moose::Role cannot support 'inner'"; |
129 | } |
d31f9614 |
130 | |
5bd4db9b |
131 | sub augment { |
132 | croak "Moose::Role cannot support 'augment'"; |
133 | } |
d31f9614 |
134 | |
5bd4db9b |
135 | my $exporter = Moose::Exporter->build_exporter( |
136 | with_caller => [ |
137 | qw( with requires excludes has before after around override make_immutable ) |
138 | ], |
139 | as_is => [ |
140 | qw( extends super inner augment ), |
141 | \&Carp::confess, |
142 | \&Scalar::Util::blessed, |
143 | ], |
144 | ); |
145 | |
146 | sub import { |
147 | my $caller = Moose::Exporter->get_caller(@_); |
148 | |
149 | # this works because both pragmas set $^H (see perldoc perlvar) |
150 | # which affects the current compilation - i.e. the file who use'd |
151 | # us - which is why we don't need to do anything special to make |
152 | # it affect that file rather than this one (which is already compiled) |
153 | |
154 | strict->import; |
155 | warnings->import; |
156 | |
157 | # we should never export to main |
158 | if ($caller eq 'main') { |
159 | warn qq{Moose::Role does not export its sugar to the 'main' package.\n}; |
160 | return; |
d31f9614 |
161 | } |
5bd4db9b |
162 | |
163 | init_meta($caller); |
164 | |
165 | goto $exporter; |
166 | } |
167 | |
168 | sub unimport { |
169 | my $caller = Moose::Exporter->get_caller(@_); |
170 | |
171 | Moose::Exporter->remove_keywords( |
172 | source => __PACKAGE__, |
173 | from => $caller, |
174 | ); |
e185c027 |
175 | } |
176 | |
177 | 1; |
178 | |
179 | __END__ |
180 | |
181 | =pod |
182 | |
183 | =head1 NAME |
184 | |
185 | Moose::Role - The Moose Role |
186 | |
76d37e5a |
187 | =head1 SYNOPSIS |
188 | |
189 | package Eq; |
85424612 |
190 | use Moose::Role; # automatically turns on strict and warnings |
fb1e11d5 |
191 | |
e46edf94 |
192 | requires 'equal'; |
fb1e11d5 |
193 | |
194 | sub no_equal { |
76d37e5a |
195 | my ($self, $other) = @_; |
196 | !$self->equal($other); |
197 | } |
fb1e11d5 |
198 | |
76d37e5a |
199 | # ... then in your classes |
fb1e11d5 |
200 | |
76d37e5a |
201 | package Currency; |
85424612 |
202 | use Moose; # automatically turns on strict and warnings |
fb1e11d5 |
203 | |
76d37e5a |
204 | with 'Eq'; |
fb1e11d5 |
205 | |
76d37e5a |
206 | sub equal { |
207 | my ($self, $other) = @_; |
bdabd620 |
208 | $self->as_float == $other->as_float; |
76d37e5a |
209 | } |
210 | |
e185c027 |
211 | =head1 DESCRIPTION |
212 | |
85424612 |
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. |
d44714be |
217 | |
85424612 |
218 | We are planning writing some more documentation in the near future, but nothing |
219 | is ready yet, sorry. |
76d37e5a |
220 | |
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221 | =head1 EXPORTED FUNCTIONS |
222 | |
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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 |
225 | details). |
76d37e5a |
226 | |
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227 | Moose::Role also offers two role-specific keyword exports: |
e185c027 |
228 | |
229 | =over 4 |
230 | |
2c0cbef7 |
231 | =item B<requires (@method_names)> |
76d37e5a |
232 | |
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233 | Roles can require that certain methods are implemented by any class which |
85424612 |
234 | C<does> the role. |
9e93dd19 |
235 | |
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236 | =item B<excludes (@role_names)> |
237 | |
9e93dd19 |
238 | Roles can C<exclude> other roles, in effect saying "I can never be combined |
fb1e11d5 |
239 | with these C<@role_names>". This is a feature which should not be used |
85424612 |
240 | lightly. |
9e93dd19 |
241 | |
2c0cbef7 |
242 | =back |
243 | |
d31f9614 |
244 | =head2 B<unimport> |
245 | |
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. |
249 | |
2c0cbef7 |
250 | =head1 CAVEATS |
251 | |
85424612 |
252 | Role support has only a few caveats: |
2c0cbef7 |
253 | |
254 | =over 4 |
76d37e5a |
255 | |
76d37e5a |
256 | =item * |
257 | |
fb1e11d5 |
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> |
85424612 |
261 | so that they can be applied to the consuming class. |
76d37e5a |
262 | |
fb1e11d5 |
263 | =item * |
2c0cbef7 |
264 | |
85424612 |
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. |
2c0cbef7 |
271 | |
85424612 |
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 |
2c0cbef7 |
274 | ordering. |
275 | |
276 | =item * |
277 | |
fb1e11d5 |
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 |
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280 | of the requirement, and neither will an autogenerated accessor for an attribute. |
281 | |
85424612 |
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. |
2c0cbef7 |
285 | |
e185c027 |
286 | =back |
287 | |
288 | =head1 BUGS |
289 | |
fb1e11d5 |
290 | All complex software has bugs lurking in it, and this module is no |
e185c027 |
291 | exception. If you find a bug please either email me, or add the bug |
292 | to cpan-RT. |
293 | |
294 | =head1 AUTHOR |
295 | |
296 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
297 | |
db1ab48d |
298 | Christian Hansen E<lt>chansen@cpan.orgE<gt> |
98aae381 |
299 | |
e185c027 |
300 | =head1 COPYRIGHT AND LICENSE |
301 | |
778db3ac |
302 | Copyright 2006-2008 by Infinity Interactive, Inc. |
e185c027 |
303 | |
304 | L<http://www.iinteractive.com> |
305 | |
306 | This library is free software; you can redistribute it and/or modify |
fb1e11d5 |
307 | it under the same terms as Perl itself. |
e185c027 |
308 | |
68117c45 |
309 | =cut |