Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
c3398f5b |
2 | use strict; |
3 | use warnings; |
3b8fe109 |
4 | require overload; |
c3398f5b |
5 | |
6 | use Carp 'confess'; |
6c169c50 |
7 | use Scalar::Util (); |
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} } |
35 | sub trigger { $_[0]->{trigger} } |
36 | sub builder { $_[0]->{builder} } |
37 | sub should_auto_deref { $_[0]->{auto_deref} } |
38 | sub should_coerce { $_[0]->{should_coerce} } |
39 | sub find_type_constraint { $_[0]->{find_type_constraint} } |
c3398f5b |
40 | |
f6715552 |
41 | sub has_default { exists $_[0]->{default} } |
42 | sub has_predicate { exists $_[0]->{predicate} } |
43 | sub has_clearer { exists $_[0]->{clearer} } |
44 | sub has_handles { exists $_[0]->{handles} } |
45 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
46 | sub has_trigger { exists $_[0]->{trigger} } |
47 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
48 | |
1bfebf5f |
49 | sub _create_args { |
50 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
51 | $_[0]->{_create_args} |
52 | } |
53 | |
7f7406a5 |
54 | sub inlined_name { |
55 | my $self = shift; |
56 | my $name = $self->name; |
57 | my $key = "'" . $name . "'"; |
58 | return $key; |
59 | } |
60 | |
c3398f5b |
61 | sub generate_accessor { |
62 | my $attribute = shift; |
63 | |
32af3489 |
64 | my $name = $attribute->name; |
65 | my $default = $attribute->default; |
32af3489 |
66 | my $constraint = $attribute->find_type_constraint; |
67 | my $builder = $attribute->builder; |
68 | my $trigger = $attribute->trigger; |
69 | my $is_weak = $attribute->is_weak_ref; |
70 | my $should_deref = $attribute->should_auto_deref; |
71 | my $should_coerce = $attribute->should_coerce; |
4e757c98 |
72 | |
85ccd3e9 |
73 | my $self = '$_[0]'; |
85ccd3e9 |
74 | my $key = $attribute->inlined_name; |
c3398f5b |
75 | |
85ccd3e9 |
76 | my $accessor = "sub {\n"; |
2434d21b |
77 | if ($attribute->_is_metadata eq 'rw') { |
7de13475 |
78 | $accessor .= 'if (scalar(@_) >= 2) {' . "\n"; |
79 | |
80 | my $value = '$_[1]'; |
a707f587 |
81 | |
a08e715f |
82 | if ($constraint) { |
eec1bb49 |
83 | $accessor .= 'my $val = '; |
32af3489 |
84 | if ($should_coerce) { |
3b46bd49 |
85 | $accessor .= 'Mouse::Util::TypeConstraints->typecast_constraints("'.$attribute->associated_class->name.'", $attribute->{find_type_constraint}, $attribute->{type_constraint}, '.$value.');'; |
eec1bb49 |
86 | } else { |
87 | $accessor .= $value.';'; |
4188b837 |
88 | } |
eec1bb49 |
89 | $accessor .= 'local $_ = $val;'; |
4188b837 |
90 | $accessor .= ' |
ed1eec39 |
91 | unless ($constraint->()) { |
b3b74cc6 |
92 | $attribute->verify_type_constraint_error($name, $_, $attribute->type_constraint); |
93 | }' . "\n"; |
eec1bb49 |
94 | $value = '$val'; |
a707f587 |
95 | } |
96 | |
ccd73de7 |
97 | # if there's nothing left to do for the attribute we can return during |
98 | # this setter |
99 | $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref; |
c3398f5b |
100 | |
2b9094e8 |
101 | $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n"; |
102 | |
ccd73de7 |
103 | if ($is_weak) { |
6c169c50 |
104 | $accessor .= 'Scalar::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n"; |
c3398f5b |
105 | } |
106 | |
a08e715f |
107 | if ($trigger) { |
85ccd3e9 |
108 | $accessor .= '$trigger->('.$self.', '.$value.', $attribute);' . "\n"; |
c3398f5b |
109 | } |
110 | |
85ccd3e9 |
111 | $accessor .= "}\n"; |
c3398f5b |
112 | } |
113 | else { |
85ccd3e9 |
114 | $accessor .= 'confess "Cannot assign a value to a read-only accessor" if scalar(@_) >= 2;' . "\n"; |
c3398f5b |
115 | } |
116 | |
2434d21b |
117 | if ($attribute->is_lazy) { |
85ccd3e9 |
118 | $accessor .= $self.'->{'.$key.'} = '; |
9367e029 |
119 | |
120 | $accessor .= $attribute->has_builder |
85ccd3e9 |
121 | ? $self.'->$builder' |
122 | : ref($default) eq 'CODE' |
123 | ? '$default->('.$self.')' |
124 | : '$default'; |
125 | $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n"; |
c3398f5b |
126 | } |
127 | |
ccd73de7 |
128 | if ($should_deref) { |
eec1bb49 |
129 | my $type_constraint = $attribute->type_constraint; |
130 | if (!ref($type_constraint) && $type_constraint eq 'ArrayRef') { |
3cf68001 |
131 | $accessor .= 'if (wantarray) { |
85ccd3e9 |
132 | return @{ '.$self.'->{'.$key.'} || [] }; |
7de13475 |
133 | }'; |
3cf68001 |
134 | } |
135 | else { |
136 | $accessor .= 'if (wantarray) { |
85ccd3e9 |
137 | return %{ '.$self.'->{'.$key.'} || {} }; |
7de13475 |
138 | }'; |
3cf68001 |
139 | } |
140 | } |
141 | |
85ccd3e9 |
142 | $accessor .= 'return '.$self.'->{'.$key.'}; |
c3398f5b |
143 | }'; |
144 | |
71b948d1 |
145 | my $sub = eval $accessor; |
146 | confess $@ if $@; |
147 | return $sub; |
c3398f5b |
148 | } |
149 | |
150 | sub generate_predicate { |
151 | my $attribute = shift; |
d10fd510 |
152 | my $key = $attribute->inlined_name; |
c3398f5b |
153 | |
d10fd510 |
154 | my $predicate = 'sub { exists($_[0]->{'.$key.'}) }'; |
c3398f5b |
155 | |
71b948d1 |
156 | my $sub = eval $predicate; |
157 | confess $@ if $@; |
158 | return $sub; |
c3398f5b |
159 | } |
160 | |
161 | sub generate_clearer { |
162 | my $attribute = shift; |
d10fd510 |
163 | my $key = $attribute->inlined_name; |
c3398f5b |
164 | |
d10fd510 |
165 | my $clearer = 'sub { delete($_[0]->{'.$key.'}) }'; |
c3398f5b |
166 | |
71b948d1 |
167 | my $sub = eval $clearer; |
168 | confess $@ if $@; |
169 | return $sub; |
c3398f5b |
170 | } |
171 | |
172 | sub generate_handles { |
173 | my $attribute = shift; |
2434d21b |
174 | my $reader = $attribute->name; |
c3cc3642 |
175 | my %handles = $attribute->_canonicalize_handles($attribute->handles); |
c3398f5b |
176 | |
177 | my %method_map; |
178 | |
c3cc3642 |
179 | for my $local_method (keys %handles) { |
180 | my $remote_method = $handles{$local_method}; |
c3398f5b |
181 | |
182 | my $method = 'sub { |
183 | my $self = shift; |
0ecefe82 |
184 | $self->'.$reader.'->'.$remote_method.'(@_) |
c3398f5b |
185 | }'; |
186 | |
187 | $method_map{$local_method} = eval $method; |
71b948d1 |
188 | confess $@ if $@; |
c3398f5b |
189 | } |
190 | |
191 | return \%method_map; |
192 | } |
193 | |
194 | sub create { |
195 | my ($self, $class, $name, %args) = @_; |
196 | |
1bfebf5f |
197 | $args{name} = $name; |
181502b9 |
198 | $args{associated_class} = $class; |
1bfebf5f |
199 | |
93d190e0 |
200 | %args = $self->canonicalize_args($name, %args); |
1bbaa8ed |
201 | $self->validate_args($name, \%args); |
45ea8620 |
202 | |
32af3489 |
203 | $args{should_coerce} = delete $args{coerce} |
4188b837 |
204 | if exists $args{coerce}; |
205 | |
eec1bb49 |
206 | if (exists $args{isa}) { |
207 | my $type_constraint = delete $args{isa}; |
208 | $type_constraint =~ s/\s//g; |
209 | my @type_constraints = split /\|/, $type_constraint; |
210 | |
211 | my $code; |
3b46bd49 |
212 | my $optimized_constraints = Mouse::Util::TypeConstraints->optimized_constraints; |
eec1bb49 |
213 | if (@type_constraints == 1) { |
214 | $code = $optimized_constraints->{$type_constraints[0]} || |
4a957f05 |
215 | sub { Scalar::Util::blessed($_) && $_->isa($type_constraints[0]) }; |
eec1bb49 |
216 | $args{type_constraint} = $type_constraints[0]; |
217 | } else { |
218 | my @code_list = map { |
219 | my $type = $_; |
220 | $optimized_constraints->{$type} || |
4a957f05 |
221 | sub { Scalar::Util::blessed($_) && $_->isa($type) } |
eec1bb49 |
222 | } @type_constraints; |
223 | $code = sub { |
224 | for my $code (@code_list) { |
225 | return 1 if $code->(); |
226 | } |
227 | return 0; |
228 | }; |
229 | $args{type_constraint} = \@type_constraints; |
230 | } |
231 | $args{find_type_constraint} = $code; |
232 | } |
186657a9 |
233 | |
2608b115 |
234 | my $attribute = $self->new($name, %args); |
1bfebf5f |
235 | |
724c77c0 |
236 | $attribute->_create_args(\%args); |
c3398f5b |
237 | |
724c77c0 |
238 | $class->add_attribute($attribute); |
b2500191 |
239 | |
c3398f5b |
240 | # install an accessor |
2434d21b |
241 | if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') { |
c3398f5b |
242 | my $accessor = $attribute->generate_accessor; |
724c77c0 |
243 | $class->add_method($name => $accessor); |
c3398f5b |
244 | } |
245 | |
c3398f5b |
246 | for my $method (qw/predicate clearer/) { |
2434d21b |
247 | my $predicate = "has_$method"; |
248 | if ($attribute->$predicate) { |
c3398f5b |
249 | my $generator = "generate_$method"; |
250 | my $coderef = $attribute->$generator; |
724c77c0 |
251 | $class->add_method($attribute->$method => $coderef); |
c3398f5b |
252 | } |
253 | } |
254 | |
2434d21b |
255 | if ($attribute->has_handles) { |
c3398f5b |
256 | my $method_map = $attribute->generate_handles; |
257 | for my $method_name (keys %$method_map) { |
724c77c0 |
258 | $class->add_method($method_name => $method_map->{$method_name}); |
c3398f5b |
259 | } |
260 | } |
261 | |
262 | return $attribute; |
263 | } |
264 | |
93d190e0 |
265 | sub canonicalize_args { |
266 | my $self = shift; |
267 | my $name = shift; |
268 | my %args = @_; |
269 | |
270 | if ($args{lazy_build}) { |
271 | $args{lazy} = 1; |
272 | $args{required} = 1; |
273 | $args{builder} = "_build_${name}" |
274 | if !exists($args{builder}); |
275 | if ($name =~ /^_/) { |
276 | $args{clearer} = "_clear${name}" if !exists($args{clearer}); |
277 | $args{predicate} = "_has${name}" if !exists($args{predicate}); |
278 | } |
279 | else { |
280 | $args{clearer} = "clear_${name}" if !exists($args{clearer}); |
281 | $args{predicate} = "has_${name}" if !exists($args{predicate}); |
282 | } |
283 | } |
284 | |
285 | return %args; |
286 | } |
287 | |
8fd9e611 |
288 | sub validate_args { |
289 | my $self = shift; |
290 | my $name = shift; |
1bbaa8ed |
291 | my $args = shift; |
8fd9e611 |
292 | |
93d190e0 |
293 | confess "You can not use lazy_build and default for the same attribute ($name)" |
1bbaa8ed |
294 | if $args->{lazy_build} && exists $args->{default}; |
93d190e0 |
295 | |
8fd9e611 |
296 | confess "You cannot have lazy attribute ($name) without specifying a default value for it" |
1bbaa8ed |
297 | if $args->{lazy} |
298 | && !exists($args->{default}) |
299 | && !exists($args->{builder}); |
8fd9e611 |
300 | |
301 | confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])" |
1bbaa8ed |
302 | if ref($args->{default}) |
303 | && ref($args->{default}) ne 'CODE'; |
8fd9e611 |
304 | |
97661b77 |
305 | confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)" |
1bbaa8ed |
306 | if $args->{auto_deref} && !exists($args->{isa}); |
8fd9e611 |
307 | |
97661b77 |
308 | confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)" |
1bbaa8ed |
309 | if $args->{auto_deref} |
310 | && $args->{isa} ne 'ArrayRef' |
311 | && $args->{isa} ne 'HashRef'; |
8fd9e611 |
312 | |
506db557 |
313 | if ($args->{trigger}) { |
a08e715f |
314 | if (ref($args->{trigger}) eq 'HASH') { |
315 | Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported."; |
844fa049 |
316 | } |
506db557 |
317 | |
844fa049 |
318 | confess "Trigger must be a CODE ref on attribute ($name)" |
a08e715f |
319 | if ref($args->{trigger}) ne 'CODE'; |
506db557 |
320 | } |
6c5498d0 |
321 | |
8fd9e611 |
322 | return 1; |
323 | } |
324 | |
20e25eb9 |
325 | sub verify_against_type_constraint { |
8a7f2a8a |
326 | return 1 unless $_[0]->{type_constraint}; |
5aa30ced |
327 | |
8a7f2a8a |
328 | local $_ = $_[1]; |
329 | return 1 if $_[0]->{find_type_constraint}->($_); |
5aa30ced |
330 | |
8a7f2a8a |
331 | my $self = shift; |
b3b74cc6 |
332 | $self->verify_type_constraint_error($self->name, $_, $self->type_constraint); |
333 | } |
5aa30ced |
334 | |
b3b74cc6 |
335 | sub verify_type_constraint_error { |
336 | my($self, $name, $value, $type) = @_; |
337 | $type = ref($type) eq 'ARRAY' ? join '|', @{ $type } : $type; |
f3e05dfd |
338 | my $display = defined($_) ? overload::StrVal($_) : 'undef'; |
339 | Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display"); |
5aa30ced |
340 | } |
341 | |
8a7f2a8a |
342 | sub coerce_constraint { ## my($self, $value) = @_; |
343 | my $type = $_[0]->{type_constraint} |
344 | or return $_[1]; |
3b46bd49 |
345 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->find_type_constraint, $type, $_[1]); |
4188b837 |
346 | } |
347 | |
af745d5a |
348 | sub _canonicalize_handles { |
349 | my $self = shift; |
350 | my $handles = shift; |
351 | |
352 | if (ref($handles) eq 'HASH') { |
353 | return %$handles; |
354 | } |
355 | elsif (ref($handles) eq 'ARRAY') { |
356 | return map { $_ => $_ } @$handles; |
357 | } |
358 | else { |
359 | confess "Unable to canonicalize the 'handles' option with $handles"; |
360 | } |
361 | } |
362 | |
1bfebf5f |
363 | sub clone_parent { |
364 | my $self = shift; |
365 | my $class = shift; |
366 | my $name = shift; |
367 | my %args = ($self->get_parent_args($class, $name), @_); |
368 | |
369 | $self->create($class, $name, %args); |
370 | } |
371 | |
372 | sub get_parent_args { |
373 | my $self = shift; |
374 | my $class = shift; |
375 | my $name = shift; |
376 | |
724c77c0 |
377 | for my $super ($class->linearized_isa) { |
bb733405 |
378 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
379 | or next; |
380 | return %{ $super_attr->_create_args }; |
381 | } |
382 | |
383 | confess "Could not find an attribute by the name of '$name' to inherit from"; |
384 | } |
385 | |
c3398f5b |
386 | 1; |
387 | |
388 | __END__ |
389 | |
390 | =head1 NAME |
391 | |
306290e8 |
392 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
393 | |
394 | =head1 METHODS |
395 | |
306290e8 |
396 | =head2 new %args -> Mouse::Meta::Attribute |
c3398f5b |
397 | |
306290e8 |
398 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
399 | |
306290e8 |
400 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
c3398f5b |
401 | |
402 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
403 | installed. Some error checking is done. |
404 | |
405 | =head2 name -> AttributeName |
406 | |
181502b9 |
407 | =head2 associated_class -> OwnerClass |
c3398f5b |
408 | |
ab27a55e |
409 | =head2 is_required -> Bool |
c3398f5b |
410 | |
ab27a55e |
411 | =head2 default -> Item |
c3398f5b |
412 | |
ab27a55e |
413 | =head2 has_default -> Bool |
414 | |
415 | =head2 is_lazy -> Bool |
416 | |
417 | =head2 predicate -> MethodName | Undef |
418 | |
419 | =head2 has_predicate -> Bool |
420 | |
421 | =head2 clearer -> MethodName | Undef |
422 | |
423 | =head2 has_clearer -> Bool |
c3398f5b |
424 | |
425 | =head2 handles -> { LocalName => RemoteName } |
426 | |
ab27a55e |
427 | =head2 has_handles -> Bool |
428 | |
3645b316 |
429 | =head2 is_weak_ref -> Bool |
c3398f5b |
430 | |
431 | =head2 init_arg -> Str |
432 | |
ab27a55e |
433 | =head2 type_constraint -> Str |
434 | |
435 | =head2 has_type_constraint -> Bool |
436 | |
437 | =head2 trigger => CODE | Undef |
438 | |
439 | =head2 has_trigger -> Bool |
440 | |
441 | =head2 builder => MethodName | Undef |
442 | |
443 | =head2 has_builder -> Bool |
444 | |
93f08899 |
445 | =head2 is_lazy_build => Bool |
446 | |
0fff36e6 |
447 | =head2 should_auto_deref -> Bool |
448 | |
c3398f5b |
449 | Informational methods. |
450 | |
451 | =head2 generate_accessor -> CODE |
452 | |
453 | Creates a new code reference for the attribute's accessor. |
454 | |
455 | =head2 generate_predicate -> CODE |
456 | |
457 | Creates a new code reference for the attribute's predicate. |
458 | |
459 | =head2 generate_clearer -> CODE |
460 | |
461 | Creates a new code reference for the attribute's clearer. |
462 | |
463 | =head2 generate_handles -> { MethodName => CODE } |
464 | |
465 | Creates a new code reference for each of the attribute's handles methods. |
466 | |
fb706f5c |
467 | =head2 find_type_constraint -> CODE |
468 | |
469 | Returns a code reference which can be used to check that a given value passes |
470 | this attribute's type constraint; |
471 | |
20e25eb9 |
472 | =head2 verify_against_type_constraint Item -> 1 | ERROR |
fb706f5c |
473 | |
474 | Checks that the given value passes this attribute's type constraint. Returns 1 |
475 | on success, otherwise C<confess>es. |
476 | |
93d190e0 |
477 | =head2 canonicalize_args Name, %args -> %args |
478 | |
479 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
480 | canonicalized into C<lazy>, C<builder>, etc. |
481 | |
1bbaa8ed |
482 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
483 | |
484 | Checks that the arguments to create the attribute (ie those specified by |
485 | C<has>) are valid. |
486 | |
f7b11a21 |
487 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
488 | |
489 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
490 | Accessors and helper methods are installed. Some error checking is done. |
491 | |
492 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
493 | |
494 | Returns the options that the parent class of C<OwnerClass> used for attribute |
495 | C<AttributeName>. |
496 | |
c3398f5b |
497 | =cut |
498 | |