Commit | Line | Data |
c3398f5b |
1 | #!/usr/bin/env perl |
306290e8 |
2 | package Mouse::Meta::Attribute; |
c3398f5b |
3 | use strict; |
4 | use warnings; |
3b8fe109 |
5 | require overload; |
c3398f5b |
6 | |
7 | use Carp 'confess'; |
45f2e6a7 |
8 | require Mouse::Util; |
c3398f5b |
9 | |
10 | sub new { |
11 | my $class = shift; |
12 | my %args = @_; |
13 | |
2e7e86c6 |
14 | my $name = $args{name}; |
15 | |
16 | $args{init_arg} = $name |
7ee01d77 |
17 | unless exists $args{init_arg}; |
45959ffa |
18 | |
c3398f5b |
19 | $args{is} ||= ''; |
20 | |
21 | bless \%args, $class; |
22 | } |
23 | |
181502b9 |
24 | sub name { $_[0]->{name} } |
25 | sub associated_class { $_[0]->{associated_class} } |
26 | sub _is_metadata { $_[0]->{is} } |
27 | sub is_required { $_[0]->{required} } |
28 | sub default { $_[0]->{default} } |
29 | sub is_lazy { $_[0]->{lazy} } |
30 | sub is_lazy_build { $_[0]->{lazy_build} } |
31 | sub predicate { $_[0]->{predicate} } |
32 | sub clearer { $_[0]->{clearer} } |
33 | sub handles { $_[0]->{handles} } |
34 | sub is_weak_ref { $_[0]->{weak_ref} } |
35 | sub init_arg { $_[0]->{init_arg} } |
36 | sub type_constraint { $_[0]->{type_constraint} } |
37 | sub trigger { $_[0]->{trigger} } |
38 | sub builder { $_[0]->{builder} } |
39 | sub should_auto_deref { $_[0]->{auto_deref} } |
32af3489 |
40 | sub should_coerce { $_[0]->{should_coerce} } |
c3398f5b |
41 | |
ccea8101 |
42 | sub has_default { exists $_[0]->{default} } |
43 | sub has_predicate { exists $_[0]->{predicate} } |
44 | sub has_clearer { exists $_[0]->{clearer} } |
45 | sub has_handles { exists $_[0]->{handles} } |
ccea8101 |
46 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
de9a434a |
47 | sub has_trigger { exists $_[0]->{trigger} } |
48 | sub has_builder { exists $_[0]->{builder} } |
ccea8101 |
49 | |
eec1bb49 |
50 | sub find_type_constraint { $_[0]->{find_type_constraint} } |
51 | sub type_constraint_as_string { |
52 | ref($_[0]->{type_constraint}) eq 'ARRAY' ? join '|', @{ $_[0]->{type_constraint} } : $_[0]->{type_constraint} |
53 | } |
54 | |
1bfebf5f |
55 | sub _create_args { |
56 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
57 | $_[0]->{_create_args} |
58 | } |
59 | |
7f7406a5 |
60 | sub inlined_name { |
61 | my $self = shift; |
62 | my $name = $self->name; |
63 | my $key = "'" . $name . "'"; |
64 | return $key; |
65 | } |
66 | |
c3398f5b |
67 | sub generate_accessor { |
68 | my $attribute = shift; |
69 | |
32af3489 |
70 | my $name = $attribute->name; |
71 | my $default = $attribute->default; |
eec1bb49 |
72 | my $type = $attribute->type_constraint_as_string; |
32af3489 |
73 | my $constraint = $attribute->find_type_constraint; |
74 | my $builder = $attribute->builder; |
75 | my $trigger = $attribute->trigger; |
76 | my $is_weak = $attribute->is_weak_ref; |
77 | my $should_deref = $attribute->should_auto_deref; |
78 | my $should_coerce = $attribute->should_coerce; |
4e757c98 |
79 | |
85ccd3e9 |
80 | my $self = '$_[0]'; |
85ccd3e9 |
81 | my $key = $attribute->inlined_name; |
c3398f5b |
82 | |
85ccd3e9 |
83 | my $accessor = "sub {\n"; |
2434d21b |
84 | if ($attribute->_is_metadata eq 'rw') { |
7de13475 |
85 | $accessor .= 'if (scalar(@_) >= 2) {' . "\n"; |
86 | |
87 | my $value = '$_[1]'; |
a707f587 |
88 | |
a08e715f |
89 | if ($constraint) { |
eec1bb49 |
90 | $accessor .= 'my $val = '; |
32af3489 |
91 | if ($should_coerce) { |
eec1bb49 |
92 | $accessor .= '$attribute->coerce_constraint('.$value.');'; |
93 | } else { |
94 | $accessor .= $value.';'; |
4188b837 |
95 | } |
eec1bb49 |
96 | $accessor .= 'local $_ = $val;'; |
4188b837 |
97 | $accessor .= ' |
ed1eec39 |
98 | unless ($constraint->()) { |
a08e715f |
99 | my $display = defined($_) ? overload::StrVal($_) : "undef"; |
100 | Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display"); |
eec1bb49 |
101 | }' . "\n"; |
102 | $value = '$val'; |
a707f587 |
103 | } |
104 | |
ccd73de7 |
105 | # if there's nothing left to do for the attribute we can return during |
106 | # this setter |
107 | $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref; |
c3398f5b |
108 | |
2b9094e8 |
109 | $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n"; |
110 | |
ccd73de7 |
111 | if ($is_weak) { |
45f2e6a7 |
112 | $accessor .= 'Mouse::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n"; |
c3398f5b |
113 | } |
114 | |
a08e715f |
115 | if ($trigger) { |
85ccd3e9 |
116 | $accessor .= '$trigger->('.$self.', '.$value.', $attribute);' . "\n"; |
c3398f5b |
117 | } |
118 | |
85ccd3e9 |
119 | $accessor .= "}\n"; |
c3398f5b |
120 | } |
121 | else { |
85ccd3e9 |
122 | $accessor .= 'confess "Cannot assign a value to a read-only accessor" if scalar(@_) >= 2;' . "\n"; |
c3398f5b |
123 | } |
124 | |
2434d21b |
125 | if ($attribute->is_lazy) { |
85ccd3e9 |
126 | $accessor .= $self.'->{'.$key.'} = '; |
9367e029 |
127 | |
128 | $accessor .= $attribute->has_builder |
85ccd3e9 |
129 | ? $self.'->$builder' |
130 | : ref($default) eq 'CODE' |
131 | ? '$default->('.$self.')' |
132 | : '$default'; |
133 | $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n"; |
c3398f5b |
134 | } |
135 | |
ccd73de7 |
136 | if ($should_deref) { |
eec1bb49 |
137 | my $type_constraint = $attribute->type_constraint; |
138 | if (!ref($type_constraint) && $type_constraint eq 'ArrayRef') { |
3cf68001 |
139 | $accessor .= 'if (wantarray) { |
85ccd3e9 |
140 | return @{ '.$self.'->{'.$key.'} || [] }; |
7de13475 |
141 | }'; |
3cf68001 |
142 | } |
143 | else { |
144 | $accessor .= 'if (wantarray) { |
85ccd3e9 |
145 | return %{ '.$self.'->{'.$key.'} || {} }; |
7de13475 |
146 | }'; |
3cf68001 |
147 | } |
148 | } |
149 | |
85ccd3e9 |
150 | $accessor .= 'return '.$self.'->{'.$key.'}; |
c3398f5b |
151 | }'; |
152 | |
71b948d1 |
153 | my $sub = eval $accessor; |
154 | confess $@ if $@; |
155 | return $sub; |
c3398f5b |
156 | } |
157 | |
158 | sub generate_predicate { |
159 | my $attribute = shift; |
d10fd510 |
160 | my $key = $attribute->inlined_name; |
c3398f5b |
161 | |
d10fd510 |
162 | my $predicate = 'sub { exists($_[0]->{'.$key.'}) }'; |
c3398f5b |
163 | |
71b948d1 |
164 | my $sub = eval $predicate; |
165 | confess $@ if $@; |
166 | return $sub; |
c3398f5b |
167 | } |
168 | |
169 | sub generate_clearer { |
170 | my $attribute = shift; |
d10fd510 |
171 | my $key = $attribute->inlined_name; |
c3398f5b |
172 | |
d10fd510 |
173 | my $clearer = 'sub { delete($_[0]->{'.$key.'}) }'; |
c3398f5b |
174 | |
71b948d1 |
175 | my $sub = eval $clearer; |
176 | confess $@ if $@; |
177 | return $sub; |
c3398f5b |
178 | } |
179 | |
180 | sub generate_handles { |
181 | my $attribute = shift; |
2434d21b |
182 | my $reader = $attribute->name; |
c3cc3642 |
183 | my %handles = $attribute->_canonicalize_handles($attribute->handles); |
c3398f5b |
184 | |
185 | my %method_map; |
186 | |
c3cc3642 |
187 | for my $local_method (keys %handles) { |
188 | my $remote_method = $handles{$local_method}; |
c3398f5b |
189 | |
190 | my $method = 'sub { |
191 | my $self = shift; |
192 | $self->$reader->$remote_method(@_) |
193 | }'; |
194 | |
195 | $method_map{$local_method} = eval $method; |
71b948d1 |
196 | confess $@ if $@; |
c3398f5b |
197 | } |
198 | |
199 | return \%method_map; |
200 | } |
201 | |
202 | sub create { |
203 | my ($self, $class, $name, %args) = @_; |
204 | |
1bfebf5f |
205 | $args{name} = $name; |
181502b9 |
206 | $args{associated_class} = $class; |
1bfebf5f |
207 | |
93d190e0 |
208 | %args = $self->canonicalize_args($name, %args); |
1bbaa8ed |
209 | $self->validate_args($name, \%args); |
45ea8620 |
210 | |
32af3489 |
211 | $args{should_coerce} = delete $args{coerce} |
4188b837 |
212 | if exists $args{coerce}; |
213 | |
eec1bb49 |
214 | if (exists $args{isa}) { |
215 | my $type_constraint = delete $args{isa}; |
216 | $type_constraint =~ s/\s//g; |
217 | my @type_constraints = split /\|/, $type_constraint; |
218 | |
219 | my $code; |
220 | my $optimized_constraints = Mouse::TypeRegistry->optimized_constraints; |
221 | if (@type_constraints == 1) { |
222 | $code = $optimized_constraints->{$type_constraints[0]} || |
223 | sub { Mouse::Util::blessed($_) && Mouse::Util::blessed($_) eq $type_constraints[0] }; |
224 | $args{type_constraint} = $type_constraints[0]; |
225 | } else { |
226 | my @code_list = map { |
227 | my $type = $_; |
228 | $optimized_constraints->{$type} || |
229 | sub { Mouse::Util::blessed($_) && Mouse::Util::blessed($_) eq $type } |
230 | } @type_constraints; |
231 | $code = sub { |
232 | for my $code (@code_list) { |
233 | return 1 if $code->(); |
234 | } |
235 | return 0; |
236 | }; |
237 | $args{type_constraint} = \@type_constraints; |
238 | } |
239 | $args{find_type_constraint} = $code; |
240 | } |
186657a9 |
241 | |
1bfebf5f |
242 | my $attribute = $self->new(%args); |
1bfebf5f |
243 | |
724c77c0 |
244 | $attribute->_create_args(\%args); |
c3398f5b |
245 | |
724c77c0 |
246 | $class->add_attribute($attribute); |
b2500191 |
247 | |
c3398f5b |
248 | # install an accessor |
2434d21b |
249 | if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') { |
c3398f5b |
250 | my $accessor = $attribute->generate_accessor; |
724c77c0 |
251 | $class->add_method($name => $accessor); |
c3398f5b |
252 | } |
253 | |
c3398f5b |
254 | for my $method (qw/predicate clearer/) { |
2434d21b |
255 | my $predicate = "has_$method"; |
256 | if ($attribute->$predicate) { |
c3398f5b |
257 | my $generator = "generate_$method"; |
258 | my $coderef = $attribute->$generator; |
724c77c0 |
259 | $class->add_method($attribute->$method => $coderef); |
c3398f5b |
260 | } |
261 | } |
262 | |
2434d21b |
263 | if ($attribute->has_handles) { |
c3398f5b |
264 | my $method_map = $attribute->generate_handles; |
265 | for my $method_name (keys %$method_map) { |
724c77c0 |
266 | $class->add_method($method_name => $method_map->{$method_name}); |
c3398f5b |
267 | } |
268 | } |
269 | |
270 | return $attribute; |
271 | } |
272 | |
93d190e0 |
273 | sub canonicalize_args { |
274 | my $self = shift; |
275 | my $name = shift; |
276 | my %args = @_; |
277 | |
278 | if ($args{lazy_build}) { |
279 | $args{lazy} = 1; |
280 | $args{required} = 1; |
281 | $args{builder} = "_build_${name}" |
282 | if !exists($args{builder}); |
283 | if ($name =~ /^_/) { |
284 | $args{clearer} = "_clear${name}" if !exists($args{clearer}); |
285 | $args{predicate} = "_has${name}" if !exists($args{predicate}); |
286 | } |
287 | else { |
288 | $args{clearer} = "clear_${name}" if !exists($args{clearer}); |
289 | $args{predicate} = "has_${name}" if !exists($args{predicate}); |
290 | } |
291 | } |
292 | |
293 | return %args; |
294 | } |
295 | |
8fd9e611 |
296 | sub validate_args { |
297 | my $self = shift; |
298 | my $name = shift; |
1bbaa8ed |
299 | my $args = shift; |
8fd9e611 |
300 | |
93d190e0 |
301 | confess "You can not use lazy_build and default for the same attribute ($name)" |
1bbaa8ed |
302 | if $args->{lazy_build} && exists $args->{default}; |
93d190e0 |
303 | |
8fd9e611 |
304 | confess "You cannot have lazy attribute ($name) without specifying a default value for it" |
1bbaa8ed |
305 | if $args->{lazy} |
306 | && !exists($args->{default}) |
307 | && !exists($args->{builder}); |
8fd9e611 |
308 | |
309 | confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])" |
1bbaa8ed |
310 | if ref($args->{default}) |
311 | && ref($args->{default}) ne 'CODE'; |
8fd9e611 |
312 | |
97661b77 |
313 | confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)" |
1bbaa8ed |
314 | if $args->{auto_deref} && !exists($args->{isa}); |
8fd9e611 |
315 | |
97661b77 |
316 | confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)" |
1bbaa8ed |
317 | if $args->{auto_deref} |
318 | && $args->{isa} ne 'ArrayRef' |
319 | && $args->{isa} ne 'HashRef'; |
8fd9e611 |
320 | |
506db557 |
321 | if ($args->{trigger}) { |
a08e715f |
322 | if (ref($args->{trigger}) eq 'HASH') { |
323 | Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported."; |
844fa049 |
324 | } |
506db557 |
325 | |
844fa049 |
326 | confess "Trigger must be a CODE ref on attribute ($name)" |
a08e715f |
327 | if ref($args->{trigger}) ne 'CODE'; |
506db557 |
328 | } |
6c5498d0 |
329 | |
8fd9e611 |
330 | return 1; |
331 | } |
332 | |
5aa30ced |
333 | sub verify_type_constraint { |
334 | my $self = shift; |
335 | local $_ = shift; |
336 | |
eec1bb49 |
337 | my $type = $self->type_constraint_as_string |
5aa30ced |
338 | or return 1; |
af745d5a |
339 | my $constraint = $self->find_type_constraint; |
5aa30ced |
340 | |
341 | return 1 if $constraint->($_); |
342 | |
343 | my $name = $self->name; |
f3e05dfd |
344 | my $display = defined($_) ? overload::StrVal($_) : 'undef'; |
345 | Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display"); |
5aa30ced |
346 | } |
347 | |
4188b837 |
348 | sub coerce_constraint { |
349 | my($self, $value) = @_; |
350 | my $type = $self->type_constraint |
351 | or return $value; |
eec1bb49 |
352 | return Mouse::TypeRegistry->typecast_constraints($self->associated_class->name, $self->find_type_constraint, $type, $value); |
4188b837 |
353 | } |
354 | |
af745d5a |
355 | sub _canonicalize_handles { |
356 | my $self = shift; |
357 | my $handles = shift; |
358 | |
359 | if (ref($handles) eq 'HASH') { |
360 | return %$handles; |
361 | } |
362 | elsif (ref($handles) eq 'ARRAY') { |
363 | return map { $_ => $_ } @$handles; |
364 | } |
365 | else { |
366 | confess "Unable to canonicalize the 'handles' option with $handles"; |
367 | } |
368 | } |
369 | |
1bfebf5f |
370 | sub clone_parent { |
371 | my $self = shift; |
372 | my $class = shift; |
373 | my $name = shift; |
374 | my %args = ($self->get_parent_args($class, $name), @_); |
375 | |
376 | $self->create($class, $name, %args); |
377 | } |
378 | |
379 | sub get_parent_args { |
380 | my $self = shift; |
381 | my $class = shift; |
382 | my $name = shift; |
383 | |
724c77c0 |
384 | for my $super ($class->linearized_isa) { |
bb733405 |
385 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
386 | or next; |
387 | return %{ $super_attr->_create_args }; |
388 | } |
389 | |
390 | confess "Could not find an attribute by the name of '$name' to inherit from"; |
391 | } |
392 | |
c3398f5b |
393 | 1; |
394 | |
395 | __END__ |
396 | |
397 | =head1 NAME |
398 | |
306290e8 |
399 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
400 | |
401 | =head1 METHODS |
402 | |
306290e8 |
403 | =head2 new %args -> Mouse::Meta::Attribute |
c3398f5b |
404 | |
306290e8 |
405 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
406 | |
306290e8 |
407 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
c3398f5b |
408 | |
409 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
410 | installed. Some error checking is done. |
411 | |
412 | =head2 name -> AttributeName |
413 | |
181502b9 |
414 | =head2 associated_class -> OwnerClass |
c3398f5b |
415 | |
ab27a55e |
416 | =head2 is_required -> Bool |
c3398f5b |
417 | |
ab27a55e |
418 | =head2 default -> Item |
c3398f5b |
419 | |
ab27a55e |
420 | =head2 has_default -> Bool |
421 | |
422 | =head2 is_lazy -> Bool |
423 | |
424 | =head2 predicate -> MethodName | Undef |
425 | |
426 | =head2 has_predicate -> Bool |
427 | |
428 | =head2 clearer -> MethodName | Undef |
429 | |
430 | =head2 has_clearer -> Bool |
c3398f5b |
431 | |
432 | =head2 handles -> { LocalName => RemoteName } |
433 | |
ab27a55e |
434 | =head2 has_handles -> Bool |
435 | |
3645b316 |
436 | =head2 is_weak_ref -> Bool |
c3398f5b |
437 | |
438 | =head2 init_arg -> Str |
439 | |
ab27a55e |
440 | =head2 type_constraint -> Str |
441 | |
442 | =head2 has_type_constraint -> Bool |
443 | |
444 | =head2 trigger => CODE | Undef |
445 | |
446 | =head2 has_trigger -> Bool |
447 | |
448 | =head2 builder => MethodName | Undef |
449 | |
450 | =head2 has_builder -> Bool |
451 | |
93f08899 |
452 | =head2 is_lazy_build => Bool |
453 | |
0fff36e6 |
454 | =head2 should_auto_deref -> Bool |
455 | |
c3398f5b |
456 | Informational methods. |
457 | |
458 | =head2 generate_accessor -> CODE |
459 | |
460 | Creates a new code reference for the attribute's accessor. |
461 | |
462 | =head2 generate_predicate -> CODE |
463 | |
464 | Creates a new code reference for the attribute's predicate. |
465 | |
466 | =head2 generate_clearer -> CODE |
467 | |
468 | Creates a new code reference for the attribute's clearer. |
469 | |
470 | =head2 generate_handles -> { MethodName => CODE } |
471 | |
472 | Creates a new code reference for each of the attribute's handles methods. |
473 | |
fb706f5c |
474 | =head2 find_type_constraint -> CODE |
475 | |
476 | Returns a code reference which can be used to check that a given value passes |
477 | this attribute's type constraint; |
478 | |
479 | =head2 verify_type_constraint Item -> 1 | ERROR |
480 | |
481 | Checks that the given value passes this attribute's type constraint. Returns 1 |
482 | on success, otherwise C<confess>es. |
483 | |
93d190e0 |
484 | =head2 canonicalize_args Name, %args -> %args |
485 | |
486 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
487 | canonicalized into C<lazy>, C<builder>, etc. |
488 | |
1bbaa8ed |
489 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
490 | |
491 | Checks that the arguments to create the attribute (ie those specified by |
492 | C<has>) are valid. |
493 | |
f7b11a21 |
494 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
495 | |
496 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
497 | Accessors and helper methods are installed. Some error checking is done. |
498 | |
499 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
500 | |
501 | Returns the options that the parent class of C<OwnerClass> used for attribute |
502 | C<AttributeName>. |
503 | |
c3398f5b |
504 | =cut |
505 | |