Commit | Line | Data |
c3398f5b |
1 | #!/usr/bin/env perl |
306290e8 |
2 | package Mouse::Meta::Attribute; |
c3398f5b |
3 | use strict; |
4 | use warnings; |
5 | |
6 | use Carp 'confess'; |
626cd940 |
7 | use Mouse::Util qw/blessed weaken/; |
c3398f5b |
8 | |
9 | sub new { |
10 | my $class = shift; |
11 | my %args = @_; |
12 | |
2e7e86c6 |
13 | my $name = $args{name}; |
14 | |
15 | $args{init_arg} = $name |
7ee01d77 |
16 | unless exists $args{init_arg}; |
45959ffa |
17 | |
c3398f5b |
18 | $args{is} ||= ''; |
19 | |
20 | bless \%args, $class; |
21 | } |
22 | |
181502b9 |
23 | sub name { $_[0]->{name} } |
24 | sub associated_class { $_[0]->{associated_class} } |
25 | sub _is_metadata { $_[0]->{is} } |
26 | sub is_required { $_[0]->{required} } |
27 | sub default { $_[0]->{default} } |
28 | sub is_lazy { $_[0]->{lazy} } |
29 | sub is_lazy_build { $_[0]->{lazy_build} } |
30 | sub predicate { $_[0]->{predicate} } |
31 | sub clearer { $_[0]->{clearer} } |
32 | sub handles { $_[0]->{handles} } |
33 | sub is_weak_ref { $_[0]->{weak_ref} } |
34 | sub init_arg { $_[0]->{init_arg} } |
35 | sub type_constraint { $_[0]->{type_constraint} } |
36 | sub trigger { $_[0]->{trigger} } |
37 | sub builder { $_[0]->{builder} } |
38 | sub should_auto_deref { $_[0]->{auto_deref} } |
c3398f5b |
39 | |
ccea8101 |
40 | sub has_default { exists $_[0]->{default} } |
41 | sub has_predicate { exists $_[0]->{predicate} } |
42 | sub has_clearer { exists $_[0]->{clearer} } |
43 | sub has_handles { exists $_[0]->{handles} } |
ccea8101 |
44 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
de9a434a |
45 | sub has_trigger { exists $_[0]->{trigger} } |
46 | sub has_builder { exists $_[0]->{builder} } |
ccea8101 |
47 | |
1bfebf5f |
48 | sub _create_args { |
49 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
50 | $_[0]->{_create_args} |
51 | } |
52 | |
c3398f5b |
53 | sub generate_accessor { |
54 | my $attribute = shift; |
55 | |
2434d21b |
56 | my $name = $attribute->name; |
f3c1ccc8 |
57 | my $key = $name; |
2434d21b |
58 | my $default = $attribute->default; |
2434d21b |
59 | my $type = $attribute->type_constraint; |
5aa30ced |
60 | my $constraint = $attribute->find_type_constraint; |
9367e029 |
61 | my $builder = $attribute->builder; |
a08e715f |
62 | my $trigger = $attribute->trigger; |
4e757c98 |
63 | |
c3398f5b |
64 | my $accessor = 'sub { |
65 | my $self = shift;'; |
66 | |
2434d21b |
67 | if ($attribute->_is_metadata eq 'rw') { |
c3398f5b |
68 | $accessor .= 'if (@_) { |
ed1eec39 |
69 | '; |
a707f587 |
70 | |
a08e715f |
71 | if ($constraint) { |
ed1eec39 |
72 | $accessor .= 'local $_ = $_[0]; |
73 | unless ($constraint->()) { |
a08e715f |
74 | my $display = defined($_) ? overload::StrVal($_) : "undef"; |
75 | Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display"); |
76 | }' |
a707f587 |
77 | } |
78 | |
ed1eec39 |
79 | $accessor .= '$self->{$key} = $_[0];'; |
c3398f5b |
80 | |
a08e715f |
81 | if ($attribute->is_weak_ref) { |
626cd940 |
82 | $accessor .= 'weaken($self->{$key}) if ref($self->{$key});'; |
c3398f5b |
83 | } |
84 | |
a08e715f |
85 | if ($trigger) { |
ed1eec39 |
86 | $accessor .= '$trigger->($self, $_[0], $attribute);'; |
c3398f5b |
87 | } |
88 | |
89 | $accessor .= '}'; |
90 | } |
91 | else { |
636c002e |
92 | $accessor .= 'confess "Cannot assign a value to a read-only accessor" if @_;'; |
c3398f5b |
93 | } |
94 | |
2434d21b |
95 | if ($attribute->is_lazy) { |
c3398f5b |
96 | $accessor .= '$self->{$key} = '; |
9367e029 |
97 | |
98 | $accessor .= $attribute->has_builder |
99 | ? '$self->$builder' |
100 | : ref($default) eq 'CODE' |
101 | ? '$default->($self)' |
102 | : '$default'; |
103 | |
c3398f5b |
104 | $accessor .= ' if !exists($self->{$key});'; |
105 | } |
106 | |
3cf68001 |
107 | if ($attribute->should_auto_deref) { |
108 | if ($attribute->type_constraint eq 'ArrayRef') { |
109 | $accessor .= 'if (wantarray) { |
110 | return @{ $self->{$key} || [] }; |
111 | }'; |
112 | } |
113 | else { |
114 | $accessor .= 'if (wantarray) { |
115 | return %{ $self->{$key} || {} }; |
116 | }'; |
117 | } |
118 | } |
119 | |
120 | $accessor .= 'return $self->{$key}; |
c3398f5b |
121 | }'; |
122 | |
71b948d1 |
123 | my $sub = eval $accessor; |
124 | confess $@ if $@; |
125 | return $sub; |
c3398f5b |
126 | } |
127 | |
128 | sub generate_predicate { |
129 | my $attribute = shift; |
f3c1ccc8 |
130 | my $key = $attribute->name; |
c3398f5b |
131 | |
132 | my $predicate = 'sub { exists($_[0]->{$key}) }'; |
133 | |
71b948d1 |
134 | my $sub = eval $predicate; |
135 | confess $@ if $@; |
136 | return $sub; |
c3398f5b |
137 | } |
138 | |
139 | sub generate_clearer { |
140 | my $attribute = shift; |
f3c1ccc8 |
141 | my $key = $attribute->name; |
c3398f5b |
142 | |
71b948d1 |
143 | my $clearer = 'sub { delete($_[0]->{$key}) }'; |
c3398f5b |
144 | |
71b948d1 |
145 | my $sub = eval $clearer; |
146 | confess $@ if $@; |
147 | return $sub; |
c3398f5b |
148 | } |
149 | |
150 | sub generate_handles { |
151 | my $attribute = shift; |
2434d21b |
152 | my $reader = $attribute->name; |
c3cc3642 |
153 | my %handles = $attribute->_canonicalize_handles($attribute->handles); |
c3398f5b |
154 | |
155 | my %method_map; |
156 | |
c3cc3642 |
157 | for my $local_method (keys %handles) { |
158 | my $remote_method = $handles{$local_method}; |
c3398f5b |
159 | |
160 | my $method = 'sub { |
161 | my $self = shift; |
162 | $self->$reader->$remote_method(@_) |
163 | }'; |
164 | |
165 | $method_map{$local_method} = eval $method; |
71b948d1 |
166 | confess $@ if $@; |
c3398f5b |
167 | } |
168 | |
169 | return \%method_map; |
170 | } |
171 | |
172 | sub create { |
173 | my ($self, $class, $name, %args) = @_; |
174 | |
1bfebf5f |
175 | $args{name} = $name; |
181502b9 |
176 | $args{associated_class} = $class; |
1bfebf5f |
177 | |
93d190e0 |
178 | %args = $self->canonicalize_args($name, %args); |
1bbaa8ed |
179 | $self->validate_args($name, \%args); |
45ea8620 |
180 | |
c021207d |
181 | $args{type_constraint} = delete $args{isa} |
182 | if exists $args{isa}; |
186657a9 |
183 | |
1bfebf5f |
184 | my $attribute = $self->new(%args); |
1bfebf5f |
185 | |
724c77c0 |
186 | $attribute->_create_args(\%args); |
c3398f5b |
187 | |
724c77c0 |
188 | $class->add_attribute($attribute); |
b2500191 |
189 | |
c3398f5b |
190 | # install an accessor |
2434d21b |
191 | if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') { |
c3398f5b |
192 | my $accessor = $attribute->generate_accessor; |
724c77c0 |
193 | $class->add_method($name => $accessor); |
c3398f5b |
194 | } |
195 | |
c3398f5b |
196 | for my $method (qw/predicate clearer/) { |
2434d21b |
197 | my $predicate = "has_$method"; |
198 | if ($attribute->$predicate) { |
c3398f5b |
199 | my $generator = "generate_$method"; |
200 | my $coderef = $attribute->$generator; |
724c77c0 |
201 | $class->add_method($attribute->$method => $coderef); |
c3398f5b |
202 | } |
203 | } |
204 | |
2434d21b |
205 | if ($attribute->has_handles) { |
c3398f5b |
206 | my $method_map = $attribute->generate_handles; |
207 | for my $method_name (keys %$method_map) { |
724c77c0 |
208 | $class->add_method($method_name => $method_map->{$method_name}); |
c3398f5b |
209 | } |
210 | } |
211 | |
212 | return $attribute; |
213 | } |
214 | |
93d190e0 |
215 | sub canonicalize_args { |
216 | my $self = shift; |
217 | my $name = shift; |
218 | my %args = @_; |
219 | |
220 | if ($args{lazy_build}) { |
221 | $args{lazy} = 1; |
222 | $args{required} = 1; |
223 | $args{builder} = "_build_${name}" |
224 | if !exists($args{builder}); |
225 | if ($name =~ /^_/) { |
226 | $args{clearer} = "_clear${name}" if !exists($args{clearer}); |
227 | $args{predicate} = "_has${name}" if !exists($args{predicate}); |
228 | } |
229 | else { |
230 | $args{clearer} = "clear_${name}" if !exists($args{clearer}); |
231 | $args{predicate} = "has_${name}" if !exists($args{predicate}); |
232 | } |
233 | } |
234 | |
235 | return %args; |
236 | } |
237 | |
8fd9e611 |
238 | sub validate_args { |
239 | my $self = shift; |
240 | my $name = shift; |
1bbaa8ed |
241 | my $args = shift; |
8fd9e611 |
242 | |
93d190e0 |
243 | confess "You can not use lazy_build and default for the same attribute ($name)" |
1bbaa8ed |
244 | if $args->{lazy_build} && exists $args->{default}; |
93d190e0 |
245 | |
8fd9e611 |
246 | confess "You cannot have lazy attribute ($name) without specifying a default value for it" |
1bbaa8ed |
247 | if $args->{lazy} |
248 | && !exists($args->{default}) |
249 | && !exists($args->{builder}); |
8fd9e611 |
250 | |
251 | confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])" |
1bbaa8ed |
252 | if ref($args->{default}) |
253 | && ref($args->{default}) ne 'CODE'; |
8fd9e611 |
254 | |
97661b77 |
255 | confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)" |
1bbaa8ed |
256 | if $args->{auto_deref} && !exists($args->{isa}); |
8fd9e611 |
257 | |
97661b77 |
258 | confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)" |
1bbaa8ed |
259 | if $args->{auto_deref} |
260 | && $args->{isa} ne 'ArrayRef' |
261 | && $args->{isa} ne 'HashRef'; |
8fd9e611 |
262 | |
506db557 |
263 | if ($args->{trigger}) { |
a08e715f |
264 | if (ref($args->{trigger}) eq 'HASH') { |
265 | Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported."; |
844fa049 |
266 | } |
506db557 |
267 | |
844fa049 |
268 | confess "Trigger must be a CODE ref on attribute ($name)" |
a08e715f |
269 | if ref($args->{trigger}) ne 'CODE'; |
506db557 |
270 | } |
6c5498d0 |
271 | |
8fd9e611 |
272 | return 1; |
273 | } |
274 | |
5aa30ced |
275 | sub find_type_constraint { |
276 | my $self = shift; |
277 | my $type = $self->type_constraint; |
278 | |
279 | return unless $type; |
280 | |
281 | my $checker = Mouse::TypeRegistry->optimized_constraints->{$type}; |
282 | return $checker if $checker; |
283 | |
3301fa54 |
284 | return sub { blessed($_) && blessed($_) eq $type }; |
5aa30ced |
285 | } |
286 | |
287 | sub verify_type_constraint { |
288 | my $self = shift; |
289 | local $_ = shift; |
290 | |
291 | my $type = $self->type_constraint |
292 | or return 1; |
af745d5a |
293 | my $constraint = $self->find_type_constraint; |
5aa30ced |
294 | |
295 | return 1 if $constraint->($_); |
296 | |
297 | my $name = $self->name; |
f3e05dfd |
298 | my $display = defined($_) ? overload::StrVal($_) : 'undef'; |
299 | Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display"); |
5aa30ced |
300 | } |
301 | |
af745d5a |
302 | sub _canonicalize_handles { |
303 | my $self = shift; |
304 | my $handles = shift; |
305 | |
306 | if (ref($handles) eq 'HASH') { |
307 | return %$handles; |
308 | } |
309 | elsif (ref($handles) eq 'ARRAY') { |
310 | return map { $_ => $_ } @$handles; |
311 | } |
312 | else { |
313 | confess "Unable to canonicalize the 'handles' option with $handles"; |
314 | } |
315 | } |
316 | |
1bfebf5f |
317 | sub clone_parent { |
318 | my $self = shift; |
319 | my $class = shift; |
320 | my $name = shift; |
321 | my %args = ($self->get_parent_args($class, $name), @_); |
322 | |
323 | $self->create($class, $name, %args); |
324 | } |
325 | |
326 | sub get_parent_args { |
327 | my $self = shift; |
328 | my $class = shift; |
329 | my $name = shift; |
330 | |
724c77c0 |
331 | for my $super ($class->linearized_isa) { |
bb733405 |
332 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
333 | or next; |
334 | return %{ $super_attr->_create_args }; |
335 | } |
336 | |
337 | confess "Could not find an attribute by the name of '$name' to inherit from"; |
338 | } |
339 | |
c3398f5b |
340 | 1; |
341 | |
342 | __END__ |
343 | |
344 | =head1 NAME |
345 | |
306290e8 |
346 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
347 | |
348 | =head1 METHODS |
349 | |
306290e8 |
350 | =head2 new %args -> Mouse::Meta::Attribute |
c3398f5b |
351 | |
306290e8 |
352 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
353 | |
306290e8 |
354 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
c3398f5b |
355 | |
356 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
357 | installed. Some error checking is done. |
358 | |
359 | =head2 name -> AttributeName |
360 | |
181502b9 |
361 | =head2 associated_class -> OwnerClass |
c3398f5b |
362 | |
ab27a55e |
363 | =head2 is_required -> Bool |
c3398f5b |
364 | |
ab27a55e |
365 | =head2 default -> Item |
c3398f5b |
366 | |
ab27a55e |
367 | =head2 has_default -> Bool |
368 | |
369 | =head2 is_lazy -> Bool |
370 | |
371 | =head2 predicate -> MethodName | Undef |
372 | |
373 | =head2 has_predicate -> Bool |
374 | |
375 | =head2 clearer -> MethodName | Undef |
376 | |
377 | =head2 has_clearer -> Bool |
c3398f5b |
378 | |
379 | =head2 handles -> { LocalName => RemoteName } |
380 | |
ab27a55e |
381 | =head2 has_handles -> Bool |
382 | |
3645b316 |
383 | =head2 is_weak_ref -> Bool |
c3398f5b |
384 | |
385 | =head2 init_arg -> Str |
386 | |
ab27a55e |
387 | =head2 type_constraint -> Str |
388 | |
389 | =head2 has_type_constraint -> Bool |
390 | |
391 | =head2 trigger => CODE | Undef |
392 | |
393 | =head2 has_trigger -> Bool |
394 | |
395 | =head2 builder => MethodName | Undef |
396 | |
397 | =head2 has_builder -> Bool |
398 | |
93f08899 |
399 | =head2 is_lazy_build => Bool |
400 | |
0fff36e6 |
401 | =head2 should_auto_deref -> Bool |
402 | |
c3398f5b |
403 | Informational methods. |
404 | |
405 | =head2 generate_accessor -> CODE |
406 | |
407 | Creates a new code reference for the attribute's accessor. |
408 | |
409 | =head2 generate_predicate -> CODE |
410 | |
411 | Creates a new code reference for the attribute's predicate. |
412 | |
413 | =head2 generate_clearer -> CODE |
414 | |
415 | Creates a new code reference for the attribute's clearer. |
416 | |
417 | =head2 generate_handles -> { MethodName => CODE } |
418 | |
419 | Creates a new code reference for each of the attribute's handles methods. |
420 | |
fb706f5c |
421 | =head2 find_type_constraint -> CODE |
422 | |
423 | Returns a code reference which can be used to check that a given value passes |
424 | this attribute's type constraint; |
425 | |
426 | =head2 verify_type_constraint Item -> 1 | ERROR |
427 | |
428 | Checks that the given value passes this attribute's type constraint. Returns 1 |
429 | on success, otherwise C<confess>es. |
430 | |
93d190e0 |
431 | =head2 canonicalize_args Name, %args -> %args |
432 | |
433 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
434 | canonicalized into C<lazy>, C<builder>, etc. |
435 | |
1bbaa8ed |
436 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
437 | |
438 | Checks that the arguments to create the attribute (ie those specified by |
439 | C<has>) are valid. |
440 | |
f7b11a21 |
441 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
442 | |
443 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
444 | Accessors and helper methods are installed. Some error checking is done. |
445 | |
446 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
447 | |
448 | Returns the options that the parent class of C<OwnerClass> used for attribute |
449 | C<AttributeName>. |
450 | |
c3398f5b |
451 | =cut |
452 | |