Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
c3398f5b |
2 | use strict; |
3 | use warnings; |
4 | |
5 | use Carp 'confess'; |
6c169c50 |
6 | use Scalar::Util (); |
684db121 |
7 | use Mouse::Meta::TypeConstraint; |
c3398f5b |
8 | |
9 | sub new { |
2608b115 |
10 | my ($class, $name, %options) = @_; |
c3398f5b |
11 | |
2608b115 |
12 | $options{name} = $name; |
2e7e86c6 |
13 | |
2608b115 |
14 | $options{init_arg} = $name |
15 | unless exists $options{init_arg}; |
45959ffa |
16 | |
2608b115 |
17 | $options{is} ||= ''; |
c3398f5b |
18 | |
2608b115 |
19 | bless \%options, $class; |
c3398f5b |
20 | } |
21 | |
f6715552 |
22 | sub name { $_[0]->{name} } |
23 | sub associated_class { $_[0]->{associated_class} } |
24 | sub _is_metadata { $_[0]->{is} } |
25 | sub is_required { $_[0]->{required} } |
26 | sub default { $_[0]->{default} } |
27 | sub is_lazy { $_[0]->{lazy} } |
28 | sub is_lazy_build { $_[0]->{lazy_build} } |
29 | sub predicate { $_[0]->{predicate} } |
30 | sub clearer { $_[0]->{clearer} } |
31 | sub handles { $_[0]->{handles} } |
32 | sub is_weak_ref { $_[0]->{weak_ref} } |
33 | sub init_arg { $_[0]->{init_arg} } |
34 | sub type_constraint { $_[0]->{type_constraint} } |
4c03ed87 |
35 | sub find_type_constraint { |
36 | Carp::carp("This method was deprecated"); |
37 | $_[0]->type_constraint(); |
38 | } |
f6715552 |
39 | sub trigger { $_[0]->{trigger} } |
40 | sub builder { $_[0]->{builder} } |
41 | sub should_auto_deref { $_[0]->{auto_deref} } |
42 | sub should_coerce { $_[0]->{should_coerce} } |
c3398f5b |
43 | |
f6715552 |
44 | sub has_default { exists $_[0]->{default} } |
45 | sub has_predicate { exists $_[0]->{predicate} } |
46 | sub has_clearer { exists $_[0]->{clearer} } |
47 | sub has_handles { exists $_[0]->{handles} } |
48 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
49 | sub has_trigger { exists $_[0]->{trigger} } |
50 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
51 | |
1bfebf5f |
52 | sub _create_args { |
53 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
54 | $_[0]->{_create_args} |
55 | } |
56 | |
b5bc67d9 |
57 | sub _inlined_name { |
7f7406a5 |
58 | my $self = shift; |
b5bc67d9 |
59 | return sprintf '"%s"', quotemeta $self->name; |
7f7406a5 |
60 | } |
61 | |
b5bc67d9 |
62 | sub _generate_accessor{ |
9c3c9a02 |
63 | my ($attribute) = @_; |
64 | |
65 | my $name = $attribute->name; |
66 | my $default = $attribute->default; |
67 | my $constraint = $attribute->type_constraint; |
68 | my $builder = $attribute->builder; |
69 | my $trigger = $attribute->trigger; |
70 | my $is_weak = $attribute->is_weak_ref; |
71 | my $should_deref = $attribute->should_auto_deref; |
72 | my $should_coerce = $attribute->should_coerce; |
73 | |
74 | my $compiled_type_constraint = $constraint ? $constraint->{_compiled_type_constraint} : undef; |
75 | |
76 | my $self = '$_[0]'; |
b5bc67d9 |
77 | my $key = $attribute->_inlined_name; |
9c3c9a02 |
78 | |
79 | my $accessor = |
80 | '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" . |
81 | "sub {\n"; |
82 | if ($attribute->_is_metadata eq 'rw') { |
83 | $accessor .= |
84 | '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" . |
85 | 'if (scalar(@_) >= 2) {' . "\n"; |
86 | |
87 | my $value = '$_[1]'; |
88 | |
89 | if ($constraint) { |
90 | if ($should_coerce) { |
91 | $accessor .= |
92 | "\n". |
93 | '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" . |
94 | 'my $val = Mouse::Util::TypeConstraints->typecast_constraints("'.$attribute->associated_class->name.'", $attribute->{type_constraint}, '.$value.');'; |
95 | $value = '$val'; |
96 | } |
97 | if ($compiled_type_constraint) { |
98 | $accessor .= |
99 | "\n". |
100 | '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" . |
101 | 'unless ($compiled_type_constraint->('.$value.')) { |
102 | $attribute->verify_type_constraint_error($name, '.$value.', $attribute->{type_constraint}); |
103 | }' . "\n"; |
104 | } else { |
105 | $accessor .= |
106 | "\n". |
107 | '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" . |
108 | 'unless ($constraint->check('.$value.')) { |
109 | $attribute->verify_type_constraint_error($name, '.$value.', $attribute->{type_constraint}); |
110 | }' . "\n"; |
111 | } |
112 | } |
113 | |
114 | # if there's nothing left to do for the attribute we can return during |
115 | # this setter |
116 | $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref; |
117 | |
118 | $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n"; |
119 | |
120 | if ($is_weak) { |
121 | $accessor .= 'Scalar::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n"; |
122 | } |
123 | |
124 | if ($trigger) { |
125 | $accessor .= '$trigger->('.$self.', '.$value.');' . "\n"; |
126 | } |
127 | |
128 | $accessor .= "}\n"; |
129 | } |
130 | else { |
131 | $accessor .= 'Carp::confess("Cannot assign a value to a read-only accessor") if scalar(@_) >= 2;' . "\n"; |
132 | } |
133 | |
134 | if ($attribute->is_lazy) { |
135 | $accessor .= $self.'->{'.$key.'} = '; |
136 | |
137 | $accessor .= $attribute->has_builder |
138 | ? $self.'->$builder' |
139 | : ref($default) eq 'CODE' |
140 | ? '$default->('.$self.')' |
141 | : '$default'; |
142 | $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n"; |
143 | } |
144 | |
145 | if ($should_deref) { |
146 | if (ref($constraint) && $constraint->name =~ '^ArrayRef\b') { |
147 | $accessor .= 'if (wantarray) { |
148 | return @{ '.$self.'->{'.$key.'} || [] }; |
149 | }'; |
150 | } |
151 | else { |
152 | $accessor .= 'if (wantarray) { |
153 | return %{ '.$self.'->{'.$key.'} || {} }; |
154 | }'; |
155 | } |
156 | } |
157 | |
158 | $accessor .= 'return '.$self.'->{'.$key.'}; |
159 | }'; |
160 | |
161 | my $sub = eval $accessor; |
162 | Carp::confess($@) if $@; |
163 | return $sub; |
164 | } |
165 | |
166 | |
b5bc67d9 |
167 | sub _generate_predicate { |
c3398f5b |
168 | my $attribute = shift; |
b5bc67d9 |
169 | my $key = $attribute->_inlined_name; |
c3398f5b |
170 | |
d10fd510 |
171 | my $predicate = 'sub { exists($_[0]->{'.$key.'}) }'; |
c3398f5b |
172 | |
71b948d1 |
173 | my $sub = eval $predicate; |
174 | confess $@ if $@; |
175 | return $sub; |
c3398f5b |
176 | } |
177 | |
b5bc67d9 |
178 | sub _generate_clearer { |
c3398f5b |
179 | my $attribute = shift; |
b5bc67d9 |
180 | my $key = $attribute->_inlined_name; |
c3398f5b |
181 | |
d10fd510 |
182 | my $clearer = 'sub { delete($_[0]->{'.$key.'}) }'; |
c3398f5b |
183 | |
71b948d1 |
184 | my $sub = eval $clearer; |
185 | confess $@ if $@; |
186 | return $sub; |
c3398f5b |
187 | } |
188 | |
b5bc67d9 |
189 | sub _generate_handles { |
c3398f5b |
190 | my $attribute = shift; |
2434d21b |
191 | my $reader = $attribute->name; |
c3cc3642 |
192 | my %handles = $attribute->_canonicalize_handles($attribute->handles); |
c3398f5b |
193 | |
194 | my %method_map; |
195 | |
c3cc3642 |
196 | for my $local_method (keys %handles) { |
197 | my $remote_method = $handles{$local_method}; |
c3398f5b |
198 | |
199 | my $method = 'sub { |
200 | my $self = shift; |
0ecefe82 |
201 | $self->'.$reader.'->'.$remote_method.'(@_) |
c3398f5b |
202 | }'; |
203 | |
204 | $method_map{$local_method} = eval $method; |
71b948d1 |
205 | confess $@ if $@; |
c3398f5b |
206 | } |
207 | |
208 | return \%method_map; |
209 | } |
210 | |
211 | sub create { |
212 | my ($self, $class, $name, %args) = @_; |
213 | |
1bfebf5f |
214 | $args{name} = $name; |
181502b9 |
215 | $args{associated_class} = $class; |
1bfebf5f |
216 | |
93d190e0 |
217 | %args = $self->canonicalize_args($name, %args); |
1bbaa8ed |
218 | $self->validate_args($name, \%args); |
45ea8620 |
219 | |
32af3489 |
220 | $args{should_coerce} = delete $args{coerce} |
4188b837 |
221 | if exists $args{coerce}; |
222 | |
eec1bb49 |
223 | if (exists $args{isa}) { |
224 | my $type_constraint = delete $args{isa}; |
684db121 |
225 | $args{type_constraint}= Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($type_constraint); |
eec1bb49 |
226 | } |
186657a9 |
227 | |
2608b115 |
228 | my $attribute = $self->new($name, %args); |
1bfebf5f |
229 | |
724c77c0 |
230 | $attribute->_create_args(\%args); |
c3398f5b |
231 | |
724c77c0 |
232 | $class->add_attribute($attribute); |
b2500191 |
233 | |
74be9f76 |
234 | my $associated_methods = 0; |
235 | |
236 | my $is_metadata = $attribute->_is_metadata || ''; |
237 | |
c3398f5b |
238 | # install an accessor |
74be9f76 |
239 | if ($is_metadata eq 'rw' || $is_metadata eq 'ro') { |
b5bc67d9 |
240 | my $code = $attribute->_generate_accessor(); |
ca5a9ec1 |
241 | $class->add_method($name => $code); |
74be9f76 |
242 | $associated_methods++; |
c3398f5b |
243 | } |
244 | |
c3398f5b |
245 | for my $method (qw/predicate clearer/) { |
2434d21b |
246 | my $predicate = "has_$method"; |
247 | if ($attribute->$predicate) { |
b5bc67d9 |
248 | my $generator = "_generate_$method"; |
c3398f5b |
249 | my $coderef = $attribute->$generator; |
724c77c0 |
250 | $class->add_method($attribute->$method => $coderef); |
74be9f76 |
251 | $associated_methods++; |
c3398f5b |
252 | } |
253 | } |
254 | |
2434d21b |
255 | if ($attribute->has_handles) { |
b5bc67d9 |
256 | my $method_map = $attribute->_generate_handles; |
c3398f5b |
257 | for my $method_name (keys %$method_map) { |
724c77c0 |
258 | $class->add_method($method_name => $method_map->{$method_name}); |
74be9f76 |
259 | $associated_methods++; |
c3398f5b |
260 | } |
261 | } |
262 | |
74be9f76 |
263 | if($associated_methods == 0 && $is_metadata ne 'bare'){ |
c8c1aeaf |
264 | Carp::cluck(qq{Attribute ($name) of class }.$class->name.qq{ has no associated methods (did you mean to provide an "is" argument?)}); |
a7d31de0 |
265 | |
74be9f76 |
266 | } |
267 | |
c3398f5b |
268 | return $attribute; |
269 | } |
270 | |
93d190e0 |
271 | sub canonicalize_args { |
272 | my $self = shift; |
273 | my $name = shift; |
274 | my %args = @_; |
275 | |
276 | if ($args{lazy_build}) { |
277 | $args{lazy} = 1; |
278 | $args{required} = 1; |
279 | $args{builder} = "_build_${name}" |
280 | if !exists($args{builder}); |
281 | if ($name =~ /^_/) { |
282 | $args{clearer} = "_clear${name}" if !exists($args{clearer}); |
283 | $args{predicate} = "_has${name}" if !exists($args{predicate}); |
284 | } |
285 | else { |
286 | $args{clearer} = "clear_${name}" if !exists($args{clearer}); |
287 | $args{predicate} = "has_${name}" if !exists($args{predicate}); |
288 | } |
289 | } |
290 | |
291 | return %args; |
292 | } |
293 | |
8fd9e611 |
294 | sub validate_args { |
295 | my $self = shift; |
296 | my $name = shift; |
1bbaa8ed |
297 | my $args = shift; |
8fd9e611 |
298 | |
93d190e0 |
299 | confess "You can not use lazy_build and default for the same attribute ($name)" |
1bbaa8ed |
300 | if $args->{lazy_build} && exists $args->{default}; |
93d190e0 |
301 | |
8fd9e611 |
302 | confess "You cannot have lazy attribute ($name) without specifying a default value for it" |
1bbaa8ed |
303 | if $args->{lazy} |
304 | && !exists($args->{default}) |
305 | && !exists($args->{builder}); |
8fd9e611 |
306 | |
307 | confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])" |
1bbaa8ed |
308 | if ref($args->{default}) |
309 | && ref($args->{default}) ne 'CODE'; |
8fd9e611 |
310 | |
97661b77 |
311 | confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)" |
1bbaa8ed |
312 | if $args->{auto_deref} && !exists($args->{isa}); |
8fd9e611 |
313 | |
97661b77 |
314 | confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)" |
1bbaa8ed |
315 | if $args->{auto_deref} |
a3f4f68e |
316 | && $args->{isa} !~ /^(?:ArrayRef|HashRef)(?:\[.*\])?$/; |
8fd9e611 |
317 | |
506db557 |
318 | if ($args->{trigger}) { |
a08e715f |
319 | if (ref($args->{trigger}) eq 'HASH') { |
320 | Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported."; |
844fa049 |
321 | } |
506db557 |
322 | |
844fa049 |
323 | confess "Trigger must be a CODE ref on attribute ($name)" |
a08e715f |
324 | if ref($args->{trigger}) ne 'CODE'; |
506db557 |
325 | } |
6c5498d0 |
326 | |
8fd9e611 |
327 | return 1; |
328 | } |
329 | |
20e25eb9 |
330 | sub verify_against_type_constraint { |
f55f60dd |
331 | my ($self, $value) = @_; |
332 | my $tc = $self->type_constraint; |
333 | return 1 unless $tc; |
5aa30ced |
334 | |
f55f60dd |
335 | local $_ = $value; |
336 | return 1 if $tc->check($value); |
5aa30ced |
337 | |
f55f60dd |
338 | $self->verify_type_constraint_error($self->name, $value, $tc); |
b3b74cc6 |
339 | } |
5aa30ced |
340 | |
b3b74cc6 |
341 | sub verify_type_constraint_error { |
342 | my($self, $name, $value, $type) = @_; |
29607c02 |
343 | Carp::confess("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
344 | } |
345 | |
8a7f2a8a |
346 | sub coerce_constraint { ## my($self, $value) = @_; |
347 | my $type = $_[0]->{type_constraint} |
348 | or return $_[1]; |
684db121 |
349 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]); |
4188b837 |
350 | } |
351 | |
af745d5a |
352 | sub _canonicalize_handles { |
353 | my $self = shift; |
354 | my $handles = shift; |
355 | |
356 | if (ref($handles) eq 'HASH') { |
357 | return %$handles; |
358 | } |
359 | elsif (ref($handles) eq 'ARRAY') { |
360 | return map { $_ => $_ } @$handles; |
361 | } |
362 | else { |
363 | confess "Unable to canonicalize the 'handles' option with $handles"; |
364 | } |
365 | } |
366 | |
1bfebf5f |
367 | sub clone_parent { |
368 | my $self = shift; |
369 | my $class = shift; |
370 | my $name = shift; |
371 | my %args = ($self->get_parent_args($class, $name), @_); |
372 | |
373 | $self->create($class, $name, %args); |
374 | } |
375 | |
376 | sub get_parent_args { |
377 | my $self = shift; |
378 | my $class = shift; |
379 | my $name = shift; |
380 | |
724c77c0 |
381 | for my $super ($class->linearized_isa) { |
bb733405 |
382 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
383 | or next; |
384 | return %{ $super_attr->_create_args }; |
385 | } |
386 | |
387 | confess "Could not find an attribute by the name of '$name' to inherit from"; |
388 | } |
389 | |
c3398f5b |
390 | 1; |
391 | |
392 | __END__ |
393 | |
394 | =head1 NAME |
395 | |
306290e8 |
396 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
397 | |
398 | =head1 METHODS |
399 | |
306290e8 |
400 | =head2 new %args -> Mouse::Meta::Attribute |
c3398f5b |
401 | |
306290e8 |
402 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
403 | |
306290e8 |
404 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
c3398f5b |
405 | |
406 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
407 | installed. Some error checking is done. |
408 | |
409 | =head2 name -> AttributeName |
410 | |
181502b9 |
411 | =head2 associated_class -> OwnerClass |
c3398f5b |
412 | |
ab27a55e |
413 | =head2 is_required -> Bool |
c3398f5b |
414 | |
ab27a55e |
415 | =head2 default -> Item |
c3398f5b |
416 | |
ab27a55e |
417 | =head2 has_default -> Bool |
418 | |
419 | =head2 is_lazy -> Bool |
420 | |
421 | =head2 predicate -> MethodName | Undef |
422 | |
423 | =head2 has_predicate -> Bool |
424 | |
425 | =head2 clearer -> MethodName | Undef |
426 | |
427 | =head2 has_clearer -> Bool |
c3398f5b |
428 | |
429 | =head2 handles -> { LocalName => RemoteName } |
430 | |
ab27a55e |
431 | =head2 has_handles -> Bool |
432 | |
3645b316 |
433 | =head2 is_weak_ref -> Bool |
c3398f5b |
434 | |
435 | =head2 init_arg -> Str |
436 | |
ab27a55e |
437 | =head2 type_constraint -> Str |
438 | |
439 | =head2 has_type_constraint -> Bool |
440 | |
441 | =head2 trigger => CODE | Undef |
442 | |
443 | =head2 has_trigger -> Bool |
444 | |
445 | =head2 builder => MethodName | Undef |
446 | |
447 | =head2 has_builder -> Bool |
448 | |
93f08899 |
449 | =head2 is_lazy_build => Bool |
450 | |
0fff36e6 |
451 | =head2 should_auto_deref -> Bool |
452 | |
c3398f5b |
453 | Informational methods. |
454 | |
20e25eb9 |
455 | =head2 verify_against_type_constraint Item -> 1 | ERROR |
fb706f5c |
456 | |
457 | Checks that the given value passes this attribute's type constraint. Returns 1 |
458 | on success, otherwise C<confess>es. |
459 | |
93d190e0 |
460 | =head2 canonicalize_args Name, %args -> %args |
461 | |
462 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
463 | canonicalized into C<lazy>, C<builder>, etc. |
464 | |
1bbaa8ed |
465 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
466 | |
467 | Checks that the arguments to create the attribute (ie those specified by |
468 | C<has>) are valid. |
469 | |
f7b11a21 |
470 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
471 | |
472 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
473 | Accessors and helper methods are installed. Some error checking is done. |
474 | |
475 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
476 | |
477 | Returns the options that the parent class of C<OwnerClass> used for attribute |
478 | C<AttributeName>. |
479 | |
c3398f5b |
480 | =cut |
481 | |