Commit | Line | Data |
e185c027 |
1 | |
2 | package Moose::Role; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
e65dccbc |
7 | use Scalar::Util 'blessed'; |
e185c027 |
8 | use Carp 'confess'; |
9 | use Sub::Name 'subname'; |
10 | |
c4538447 |
11 | use Data::OptList; |
2d562421 |
12 | use Sub::Exporter; |
13 | |
238b424d |
14 | our $VERSION = '0.08'; |
d44714be |
15 | our $AUTHORITY = 'cpan:STEVAN'; |
e185c027 |
16 | |
d7d8a8c7 |
17 | use Moose (); |
18 | use Moose::Util (); |
e65dccbc |
19 | |
e185c027 |
20 | use Moose::Meta::Role; |
7eaef7ad |
21 | use Moose::Util::TypeConstraints; |
e185c027 |
22 | |
2d562421 |
23 | { |
24 | my ( $CALLER, %METAS ); |
25 | |
26 | sub _find_meta { |
7eaef7ad |
27 | my $role = $CALLER; |
2d562421 |
28 | |
7eaef7ad |
29 | return $METAS{$role} if exists $METAS{$role}; |
fb1e11d5 |
30 | |
7eaef7ad |
31 | # make a subtype for each Moose class |
32 | subtype $role |
33 | => as 'Role' |
238b424d |
34 | => where { Moose::Util::does_role($_, $role) } |
35 | => optimize_as { blessed($_[0]) && Moose::Util::does_role($_[0], $role) } |
fb1e11d5 |
36 | unless find_type_constraint($role); |
2d562421 |
37 | |
fb1e11d5 |
38 | my $meta; |
39 | if ($role->can('meta')) { |
40 | $meta = $role->meta(); |
41 | (blessed($meta) && $meta->isa('Moose::Meta::Role')) |
68efb014 |
42 | || confess "You already have a &meta function, but it does not return a Moose::Meta::Role"; |
fb1e11d5 |
43 | } |
44 | else { |
45 | $meta = Moose::Meta::Role->initialize($role); |
46 | $meta->alias_method('meta' => sub { $meta }); |
47 | } |
2d562421 |
48 | |
7eaef7ad |
49 | return $METAS{$role} = $meta; |
2d562421 |
50 | } |
fb1e11d5 |
51 | |
52 | |
53 | my %exports = ( |
2d562421 |
54 | extends => sub { |
55 | my $meta = _find_meta(); |
fb1e11d5 |
56 | return subname 'Moose::Role::extends' => sub { |
2d562421 |
57 | confess "Moose::Role does not currently support 'extends'" |
fb1e11d5 |
58 | }; |
59 | }, |
60 | with => sub { |
61 | my $meta = _find_meta(); |
62 | return subname 'Moose::Role::with' => sub (@) { |
d7d8a8c7 |
63 | Moose::Util::apply_all_roles($meta, @_) |
2d562421 |
64 | }; |
fb1e11d5 |
65 | }, |
2d562421 |
66 | requires => sub { |
67 | my $meta = _find_meta(); |
fb1e11d5 |
68 | return subname 'Moose::Role::requires' => sub (@) { |
68117c45 |
69 | confess "Must specify at least one method" unless @_; |
2d562421 |
70 | $meta->add_required_methods(@_); |
fb1e11d5 |
71 | }; |
72 | }, |
d79e62fd |
73 | excludes => sub { |
74 | my $meta = _find_meta(); |
fb1e11d5 |
75 | return subname 'Moose::Role::excludes' => sub (@) { |
68117c45 |
76 | confess "Must specify at least one role" unless @_; |
d79e62fd |
77 | $meta->add_excluded_roles(@_); |
fb1e11d5 |
78 | }; |
79 | }, |
2d562421 |
80 | has => sub { |
81 | my $meta = _find_meta(); |
fb1e11d5 |
82 | return subname 'Moose::Role::has' => sub ($;%) { |
83 | my ($name, %options) = @_; |
84 | $meta->add_attribute($name, %options) |
85 | }; |
86 | }, |
2d562421 |
87 | before => sub { |
88 | my $meta = _find_meta(); |
fb1e11d5 |
89 | return subname 'Moose::Role::before' => sub (@&) { |
0558683c |
90 | my $code = pop @_; |
91 | $meta->add_before_method_modifier($_, $code) for @_; |
fb1e11d5 |
92 | }; |
93 | }, |
2d562421 |
94 | after => sub { |
95 | my $meta = _find_meta(); |
fb1e11d5 |
96 | return subname 'Moose::Role::after' => sub (@&) { |
97 | my $code = pop @_; |
98 | $meta->add_after_method_modifier($_, $code) for @_; |
99 | }; |
100 | }, |
2d562421 |
101 | around => sub { |
102 | my $meta = _find_meta(); |
fb1e11d5 |
103 | return subname 'Moose::Role::around' => sub (@&) { |
104 | my $code = pop @_; |
105 | $meta->add_around_method_modifier($_, $code) for @_; |
106 | }; |
107 | }, |
108 | super => sub { |
52c7c330 |
109 | { |
110 | no strict 'refs'; |
111 | $Moose::SUPER_SLOT{$CALLER} = \*{"${CALLER}::super"}; |
112 | } |
2d562421 |
113 | my $meta = _find_meta(); |
0558683c |
114 | return subname 'Moose::Role::super' => sub {}; |
2d562421 |
115 | }, |
116 | override => sub { |
117 | my $meta = _find_meta(); |
2c0cbef7 |
118 | return subname 'Moose::Role::override' => sub ($&) { |
0558683c |
119 | my ($name, $code) = @_; |
120 | $meta->add_override_method_modifier($name, $code); |
fb1e11d5 |
121 | }; |
122 | }, |
2d562421 |
123 | inner => sub { |
124 | my $meta = _find_meta(); |
125 | return subname 'Moose::Role::inner' => sub { |
0558683c |
126 | confess "Moose::Role cannot support 'inner'"; |
fb1e11d5 |
127 | }; |
128 | }, |
2d562421 |
129 | augment => sub { |
130 | my $meta = _find_meta(); |
131 | return subname 'Moose::Role::augment' => sub { |
06b30515 |
132 | confess "Moose::Role cannot support 'augment'"; |
fb1e11d5 |
133 | }; |
134 | }, |
2d562421 |
135 | confess => sub { |
136 | return \&Carp::confess; |
137 | }, |
138 | blessed => sub { |
139 | return \&Scalar::Util::blessed; |
fb1e11d5 |
140 | } |
141 | ); |
2d562421 |
142 | |
fb1e11d5 |
143 | my $exporter = Sub::Exporter::build_exporter({ |
2d562421 |
144 | exports => \%exports, |
145 | groups => { |
146 | default => [':all'] |
147 | } |
148 | }); |
fb1e11d5 |
149 | |
2d562421 |
150 | sub import { |
fc9a40d7 |
151 | $CALLER = |
152 | ref $_[1] && defined $_[1]->{into} ? $_[1]->{into} |
153 | : ref $_[1] |
154 | && defined $_[1]->{into_level} ? caller( $_[1]->{into_level} ) |
155 | : caller(); |
156 | |
86dd5d11 |
157 | # this works because both pragmas set $^H (see perldoc perlvar) |
158 | # which affects the current compilation - i.e. the file who use'd |
159 | # us - which is why we don't need to do anything special to make |
160 | # it affect that file rather than this one (which is already compiled) |
fb1e11d5 |
161 | |
c235cd98 |
162 | strict->import; |
fb1e11d5 |
163 | warnings->import; |
2d562421 |
164 | |
165 | # we should never export to main |
166 | return if $CALLER eq 'main'; |
167 | |
168 | goto $exporter; |
169 | }; |
170 | |
e185c027 |
171 | } |
172 | |
173 | 1; |
174 | |
175 | __END__ |
176 | |
177 | =pod |
178 | |
179 | =head1 NAME |
180 | |
181 | Moose::Role - The Moose Role |
182 | |
76d37e5a |
183 | =head1 SYNOPSIS |
184 | |
185 | package Eq; |
85424612 |
186 | use Moose::Role; # automatically turns on strict and warnings |
fb1e11d5 |
187 | |
e46edf94 |
188 | requires 'equal'; |
fb1e11d5 |
189 | |
190 | sub no_equal { |
76d37e5a |
191 | my ($self, $other) = @_; |
192 | !$self->equal($other); |
193 | } |
fb1e11d5 |
194 | |
76d37e5a |
195 | # ... then in your classes |
fb1e11d5 |
196 | |
76d37e5a |
197 | package Currency; |
85424612 |
198 | use Moose; # automatically turns on strict and warnings |
fb1e11d5 |
199 | |
76d37e5a |
200 | with 'Eq'; |
fb1e11d5 |
201 | |
76d37e5a |
202 | sub equal { |
203 | my ($self, $other) = @_; |
bdabd620 |
204 | $self->as_float == $other->as_float; |
76d37e5a |
205 | } |
206 | |
e185c027 |
207 | =head1 DESCRIPTION |
208 | |
85424612 |
209 | Role support in Moose is pretty solid at this point. However, the best |
210 | documentation is still the the test suite. It is fairly safe to assume Perl 6 |
211 | style behavior and then either refer to the test suite, or ask questions on |
212 | #moose if something doesn't quite do what you expect. |
d44714be |
213 | |
85424612 |
214 | We are planning writing some more documentation in the near future, but nothing |
215 | is ready yet, sorry. |
76d37e5a |
216 | |
2c0cbef7 |
217 | =head1 EXPORTED FUNCTIONS |
218 | |
85424612 |
219 | Moose::Role currently supports all of the functions that L<Moose> exports, but |
220 | differs slightly in how some items are handled (see L<CAVEATS> below for |
221 | details). |
76d37e5a |
222 | |
85424612 |
223 | Moose::Role also offers two role-specific keyword exports: |
e185c027 |
224 | |
225 | =over 4 |
226 | |
2c0cbef7 |
227 | =item B<requires (@method_names)> |
76d37e5a |
228 | |
fb1e11d5 |
229 | Roles can require that certain methods are implemented by any class which |
85424612 |
230 | C<does> the role. |
9e93dd19 |
231 | |
2c0cbef7 |
232 | =item B<excludes (@role_names)> |
233 | |
9e93dd19 |
234 | Roles can C<exclude> other roles, in effect saying "I can never be combined |
fb1e11d5 |
235 | with these C<@role_names>". This is a feature which should not be used |
85424612 |
236 | lightly. |
9e93dd19 |
237 | |
2c0cbef7 |
238 | =back |
239 | |
240 | =head1 CAVEATS |
241 | |
85424612 |
242 | Role support has only a few caveats: |
2c0cbef7 |
243 | |
244 | =over 4 |
76d37e5a |
245 | |
76d37e5a |
246 | =item * |
247 | |
fb1e11d5 |
248 | Roles cannot use the C<extends> keyword; it will throw an exception for now. |
249 | The same is true of the C<augment> and C<inner> keywords (not sure those |
250 | really make sense for roles). All other Moose keywords will be I<deferred> |
85424612 |
251 | so that they can be applied to the consuming class. |
76d37e5a |
252 | |
fb1e11d5 |
253 | =item * |
2c0cbef7 |
254 | |
85424612 |
255 | Role composition does its best to B<not> be order-sensitive when it comes to |
256 | conflict resolution and requirements detection. However, it is order-sensitive |
257 | when it comes to method modifiers. All before/around/after modifiers are |
258 | included whenever a role is composed into a class, and then applied in the order |
259 | in which the roles are used. This also means that there is no conflict for |
260 | before/around/after modifiers. |
2c0cbef7 |
261 | |
85424612 |
262 | In most cases, this will be a non-issue; however, it is something to keep in |
263 | mind when using method modifiers in a role. You should never assume any |
2c0cbef7 |
264 | ordering. |
265 | |
266 | =item * |
267 | |
fb1e11d5 |
268 | The C<requires> keyword currently only works with actual methods. A method |
269 | modifier (before/around/after and override) will not count as a fufillment |
2c0cbef7 |
270 | of the requirement, and neither will an autogenerated accessor for an attribute. |
271 | |
85424612 |
272 | It is likely that attribute accessors will eventually be allowed to fufill those |
273 | requirements, or we will introduce a C<requires_attr> keyword of some kind |
274 | instead. This decision has not yet been finalized. |
2c0cbef7 |
275 | |
e185c027 |
276 | =back |
277 | |
278 | =head1 BUGS |
279 | |
fb1e11d5 |
280 | All complex software has bugs lurking in it, and this module is no |
e185c027 |
281 | exception. If you find a bug please either email me, or add the bug |
282 | to cpan-RT. |
283 | |
284 | =head1 AUTHOR |
285 | |
286 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
287 | |
db1ab48d |
288 | Christian Hansen E<lt>chansen@cpan.orgE<gt> |
98aae381 |
289 | |
e185c027 |
290 | =head1 COPYRIGHT AND LICENSE |
291 | |
778db3ac |
292 | Copyright 2006-2008 by Infinity Interactive, Inc. |
e185c027 |
293 | |
294 | L<http://www.iinteractive.com> |
295 | |
296 | This library is free software; you can redistribute it and/or modify |
fb1e11d5 |
297 | it under the same terms as Perl itself. |
e185c027 |
298 | |
68117c45 |
299 | =cut |