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 { |
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 | |
f6715552 |
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} } |
39 | sub should_coerce { $_[0]->{should_coerce} } |
40 | sub find_type_constraint { $_[0]->{find_type_constraint} } |
c3398f5b |
41 | |
f6715552 |
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} } |
46 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
47 | sub has_trigger { exists $_[0]->{trigger} } |
48 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
49 | |
1bfebf5f |
50 | sub _create_args { |
51 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
52 | $_[0]->{_create_args} |
53 | } |
54 | |
7f7406a5 |
55 | sub inlined_name { |
56 | my $self = shift; |
57 | my $name = $self->name; |
58 | my $key = "'" . $name . "'"; |
59 | return $key; |
60 | } |
61 | |
c3398f5b |
62 | sub generate_accessor { |
63 | my $attribute = shift; |
64 | |
32af3489 |
65 | my $name = $attribute->name; |
66 | my $default = $attribute->default; |
32af3489 |
67 | my $constraint = $attribute->find_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; |
4e757c98 |
73 | |
85ccd3e9 |
74 | my $self = '$_[0]'; |
85ccd3e9 |
75 | my $key = $attribute->inlined_name; |
c3398f5b |
76 | |
85ccd3e9 |
77 | my $accessor = "sub {\n"; |
2434d21b |
78 | if ($attribute->_is_metadata eq 'rw') { |
7de13475 |
79 | $accessor .= 'if (scalar(@_) >= 2) {' . "\n"; |
80 | |
81 | my $value = '$_[1]'; |
a707f587 |
82 | |
a08e715f |
83 | if ($constraint) { |
eec1bb49 |
84 | $accessor .= 'my $val = '; |
32af3489 |
85 | if ($should_coerce) { |
3b46bd49 |
86 | $accessor .= 'Mouse::Util::TypeConstraints->typecast_constraints("'.$attribute->associated_class->name.'", $attribute->{find_type_constraint}, $attribute->{type_constraint}, '.$value.');'; |
eec1bb49 |
87 | } else { |
88 | $accessor .= $value.';'; |
4188b837 |
89 | } |
eec1bb49 |
90 | $accessor .= 'local $_ = $val;'; |
4188b837 |
91 | $accessor .= ' |
ed1eec39 |
92 | unless ($constraint->()) { |
b3b74cc6 |
93 | $attribute->verify_type_constraint_error($name, $_, $attribute->type_constraint); |
94 | }' . "\n"; |
eec1bb49 |
95 | $value = '$val'; |
a707f587 |
96 | } |
97 | |
ccd73de7 |
98 | # if there's nothing left to do for the attribute we can return during |
99 | # this setter |
100 | $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref; |
c3398f5b |
101 | |
2b9094e8 |
102 | $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n"; |
103 | |
ccd73de7 |
104 | if ($is_weak) { |
6c169c50 |
105 | $accessor .= 'Scalar::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n"; |
c3398f5b |
106 | } |
107 | |
a08e715f |
108 | if ($trigger) { |
85ccd3e9 |
109 | $accessor .= '$trigger->('.$self.', '.$value.', $attribute);' . "\n"; |
c3398f5b |
110 | } |
111 | |
85ccd3e9 |
112 | $accessor .= "}\n"; |
c3398f5b |
113 | } |
114 | else { |
85ccd3e9 |
115 | $accessor .= 'confess "Cannot assign a value to a read-only accessor" if scalar(@_) >= 2;' . "\n"; |
c3398f5b |
116 | } |
117 | |
2434d21b |
118 | if ($attribute->is_lazy) { |
85ccd3e9 |
119 | $accessor .= $self.'->{'.$key.'} = '; |
9367e029 |
120 | |
121 | $accessor .= $attribute->has_builder |
85ccd3e9 |
122 | ? $self.'->$builder' |
123 | : ref($default) eq 'CODE' |
124 | ? '$default->('.$self.')' |
125 | : '$default'; |
126 | $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n"; |
c3398f5b |
127 | } |
128 | |
ccd73de7 |
129 | if ($should_deref) { |
eec1bb49 |
130 | my $type_constraint = $attribute->type_constraint; |
131 | if (!ref($type_constraint) && $type_constraint eq 'ArrayRef') { |
3cf68001 |
132 | $accessor .= 'if (wantarray) { |
85ccd3e9 |
133 | return @{ '.$self.'->{'.$key.'} || [] }; |
7de13475 |
134 | }'; |
3cf68001 |
135 | } |
136 | else { |
137 | $accessor .= 'if (wantarray) { |
85ccd3e9 |
138 | return %{ '.$self.'->{'.$key.'} || {} }; |
7de13475 |
139 | }'; |
3cf68001 |
140 | } |
141 | } |
142 | |
85ccd3e9 |
143 | $accessor .= 'return '.$self.'->{'.$key.'}; |
c3398f5b |
144 | }'; |
145 | |
71b948d1 |
146 | my $sub = eval $accessor; |
147 | confess $@ if $@; |
148 | return $sub; |
c3398f5b |
149 | } |
150 | |
151 | sub generate_predicate { |
152 | my $attribute = shift; |
d10fd510 |
153 | my $key = $attribute->inlined_name; |
c3398f5b |
154 | |
d10fd510 |
155 | my $predicate = 'sub { exists($_[0]->{'.$key.'}) }'; |
c3398f5b |
156 | |
71b948d1 |
157 | my $sub = eval $predicate; |
158 | confess $@ if $@; |
159 | return $sub; |
c3398f5b |
160 | } |
161 | |
162 | sub generate_clearer { |
163 | my $attribute = shift; |
d10fd510 |
164 | my $key = $attribute->inlined_name; |
c3398f5b |
165 | |
d10fd510 |
166 | my $clearer = 'sub { delete($_[0]->{'.$key.'}) }'; |
c3398f5b |
167 | |
71b948d1 |
168 | my $sub = eval $clearer; |
169 | confess $@ if $@; |
170 | return $sub; |
c3398f5b |
171 | } |
172 | |
173 | sub generate_handles { |
174 | my $attribute = shift; |
2434d21b |
175 | my $reader = $attribute->name; |
c3cc3642 |
176 | my %handles = $attribute->_canonicalize_handles($attribute->handles); |
c3398f5b |
177 | |
178 | my %method_map; |
179 | |
c3cc3642 |
180 | for my $local_method (keys %handles) { |
181 | my $remote_method = $handles{$local_method}; |
c3398f5b |
182 | |
183 | my $method = 'sub { |
184 | my $self = shift; |
0ecefe82 |
185 | $self->'.$reader.'->'.$remote_method.'(@_) |
c3398f5b |
186 | }'; |
187 | |
188 | $method_map{$local_method} = eval $method; |
71b948d1 |
189 | confess $@ if $@; |
c3398f5b |
190 | } |
191 | |
192 | return \%method_map; |
193 | } |
194 | |
195 | sub create { |
196 | my ($self, $class, $name, %args) = @_; |
197 | |
1bfebf5f |
198 | $args{name} = $name; |
181502b9 |
199 | $args{associated_class} = $class; |
1bfebf5f |
200 | |
93d190e0 |
201 | %args = $self->canonicalize_args($name, %args); |
1bbaa8ed |
202 | $self->validate_args($name, \%args); |
45ea8620 |
203 | |
32af3489 |
204 | $args{should_coerce} = delete $args{coerce} |
4188b837 |
205 | if exists $args{coerce}; |
206 | |
eec1bb49 |
207 | if (exists $args{isa}) { |
208 | my $type_constraint = delete $args{isa}; |
209 | $type_constraint =~ s/\s//g; |
210 | my @type_constraints = split /\|/, $type_constraint; |
211 | |
212 | my $code; |
3b46bd49 |
213 | my $optimized_constraints = Mouse::Util::TypeConstraints->optimized_constraints; |
eec1bb49 |
214 | if (@type_constraints == 1) { |
215 | $code = $optimized_constraints->{$type_constraints[0]} || |
4a957f05 |
216 | sub { Scalar::Util::blessed($_) && $_->isa($type_constraints[0]) }; |
eec1bb49 |
217 | $args{type_constraint} = $type_constraints[0]; |
218 | } else { |
219 | my @code_list = map { |
220 | my $type = $_; |
221 | $optimized_constraints->{$type} || |
4a957f05 |
222 | sub { Scalar::Util::blessed($_) && $_->isa($type) } |
eec1bb49 |
223 | } @type_constraints; |
224 | $code = sub { |
225 | for my $code (@code_list) { |
226 | return 1 if $code->(); |
227 | } |
228 | return 0; |
229 | }; |
230 | $args{type_constraint} = \@type_constraints; |
231 | } |
232 | $args{find_type_constraint} = $code; |
233 | } |
186657a9 |
234 | |
1bfebf5f |
235 | my $attribute = $self->new(%args); |
1bfebf5f |
236 | |
724c77c0 |
237 | $attribute->_create_args(\%args); |
c3398f5b |
238 | |
724c77c0 |
239 | $class->add_attribute($attribute); |
b2500191 |
240 | |
c3398f5b |
241 | # install an accessor |
2434d21b |
242 | if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') { |
c3398f5b |
243 | my $accessor = $attribute->generate_accessor; |
724c77c0 |
244 | $class->add_method($name => $accessor); |
c3398f5b |
245 | } |
246 | |
c3398f5b |
247 | for my $method (qw/predicate clearer/) { |
2434d21b |
248 | my $predicate = "has_$method"; |
249 | if ($attribute->$predicate) { |
c3398f5b |
250 | my $generator = "generate_$method"; |
251 | my $coderef = $attribute->$generator; |
724c77c0 |
252 | $class->add_method($attribute->$method => $coderef); |
c3398f5b |
253 | } |
254 | } |
255 | |
2434d21b |
256 | if ($attribute->has_handles) { |
c3398f5b |
257 | my $method_map = $attribute->generate_handles; |
258 | for my $method_name (keys %$method_map) { |
724c77c0 |
259 | $class->add_method($method_name => $method_map->{$method_name}); |
c3398f5b |
260 | } |
261 | } |
262 | |
263 | return $attribute; |
264 | } |
265 | |
93d190e0 |
266 | sub canonicalize_args { |
267 | my $self = shift; |
268 | my $name = shift; |
269 | my %args = @_; |
270 | |
271 | if ($args{lazy_build}) { |
272 | $args{lazy} = 1; |
273 | $args{required} = 1; |
274 | $args{builder} = "_build_${name}" |
275 | if !exists($args{builder}); |
276 | if ($name =~ /^_/) { |
277 | $args{clearer} = "_clear${name}" if !exists($args{clearer}); |
278 | $args{predicate} = "_has${name}" if !exists($args{predicate}); |
279 | } |
280 | else { |
281 | $args{clearer} = "clear_${name}" if !exists($args{clearer}); |
282 | $args{predicate} = "has_${name}" if !exists($args{predicate}); |
283 | } |
284 | } |
285 | |
286 | return %args; |
287 | } |
288 | |
8fd9e611 |
289 | sub validate_args { |
290 | my $self = shift; |
291 | my $name = shift; |
1bbaa8ed |
292 | my $args = shift; |
8fd9e611 |
293 | |
93d190e0 |
294 | confess "You can not use lazy_build and default for the same attribute ($name)" |
1bbaa8ed |
295 | if $args->{lazy_build} && exists $args->{default}; |
93d190e0 |
296 | |
8fd9e611 |
297 | confess "You cannot have lazy attribute ($name) without specifying a default value for it" |
1bbaa8ed |
298 | if $args->{lazy} |
299 | && !exists($args->{default}) |
300 | && !exists($args->{builder}); |
8fd9e611 |
301 | |
302 | confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])" |
1bbaa8ed |
303 | if ref($args->{default}) |
304 | && ref($args->{default}) ne 'CODE'; |
8fd9e611 |
305 | |
97661b77 |
306 | confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)" |
1bbaa8ed |
307 | if $args->{auto_deref} && !exists($args->{isa}); |
8fd9e611 |
308 | |
97661b77 |
309 | confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)" |
1bbaa8ed |
310 | if $args->{auto_deref} |
311 | && $args->{isa} ne 'ArrayRef' |
312 | && $args->{isa} ne 'HashRef'; |
8fd9e611 |
313 | |
506db557 |
314 | if ($args->{trigger}) { |
a08e715f |
315 | if (ref($args->{trigger}) eq 'HASH') { |
316 | Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported."; |
844fa049 |
317 | } |
506db557 |
318 | |
844fa049 |
319 | confess "Trigger must be a CODE ref on attribute ($name)" |
a08e715f |
320 | if ref($args->{trigger}) ne 'CODE'; |
506db557 |
321 | } |
6c5498d0 |
322 | |
8fd9e611 |
323 | return 1; |
324 | } |
325 | |
20e25eb9 |
326 | sub verify_against_type_constraint { |
8a7f2a8a |
327 | return 1 unless $_[0]->{type_constraint}; |
5aa30ced |
328 | |
8a7f2a8a |
329 | local $_ = $_[1]; |
330 | return 1 if $_[0]->{find_type_constraint}->($_); |
5aa30ced |
331 | |
8a7f2a8a |
332 | my $self = shift; |
b3b74cc6 |
333 | $self->verify_type_constraint_error($self->name, $_, $self->type_constraint); |
334 | } |
5aa30ced |
335 | |
b3b74cc6 |
336 | sub verify_type_constraint_error { |
337 | my($self, $name, $value, $type) = @_; |
338 | $type = ref($type) eq 'ARRAY' ? join '|', @{ $type } : $type; |
f3e05dfd |
339 | my $display = defined($_) ? overload::StrVal($_) : 'undef'; |
340 | Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display"); |
5aa30ced |
341 | } |
342 | |
8a7f2a8a |
343 | sub coerce_constraint { ## my($self, $value) = @_; |
344 | my $type = $_[0]->{type_constraint} |
345 | or return $_[1]; |
3b46bd49 |
346 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->find_type_constraint, $type, $_[1]); |
4188b837 |
347 | } |
348 | |
af745d5a |
349 | sub _canonicalize_handles { |
350 | my $self = shift; |
351 | my $handles = shift; |
352 | |
353 | if (ref($handles) eq 'HASH') { |
354 | return %$handles; |
355 | } |
356 | elsif (ref($handles) eq 'ARRAY') { |
357 | return map { $_ => $_ } @$handles; |
358 | } |
359 | else { |
360 | confess "Unable to canonicalize the 'handles' option with $handles"; |
361 | } |
362 | } |
363 | |
1bfebf5f |
364 | sub clone_parent { |
365 | my $self = shift; |
366 | my $class = shift; |
367 | my $name = shift; |
368 | my %args = ($self->get_parent_args($class, $name), @_); |
369 | |
370 | $self->create($class, $name, %args); |
371 | } |
372 | |
373 | sub get_parent_args { |
374 | my $self = shift; |
375 | my $class = shift; |
376 | my $name = shift; |
377 | |
724c77c0 |
378 | for my $super ($class->linearized_isa) { |
bb733405 |
379 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
380 | or next; |
381 | return %{ $super_attr->_create_args }; |
382 | } |
383 | |
384 | confess "Could not find an attribute by the name of '$name' to inherit from"; |
385 | } |
386 | |
c3398f5b |
387 | 1; |
388 | |
389 | __END__ |
390 | |
391 | =head1 NAME |
392 | |
306290e8 |
393 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
394 | |
395 | =head1 METHODS |
396 | |
306290e8 |
397 | =head2 new %args -> Mouse::Meta::Attribute |
c3398f5b |
398 | |
306290e8 |
399 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
400 | |
306290e8 |
401 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
c3398f5b |
402 | |
403 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
404 | installed. Some error checking is done. |
405 | |
406 | =head2 name -> AttributeName |
407 | |
181502b9 |
408 | =head2 associated_class -> OwnerClass |
c3398f5b |
409 | |
ab27a55e |
410 | =head2 is_required -> Bool |
c3398f5b |
411 | |
ab27a55e |
412 | =head2 default -> Item |
c3398f5b |
413 | |
ab27a55e |
414 | =head2 has_default -> Bool |
415 | |
416 | =head2 is_lazy -> Bool |
417 | |
418 | =head2 predicate -> MethodName | Undef |
419 | |
420 | =head2 has_predicate -> Bool |
421 | |
422 | =head2 clearer -> MethodName | Undef |
423 | |
424 | =head2 has_clearer -> Bool |
c3398f5b |
425 | |
426 | =head2 handles -> { LocalName => RemoteName } |
427 | |
ab27a55e |
428 | =head2 has_handles -> Bool |
429 | |
3645b316 |
430 | =head2 is_weak_ref -> Bool |
c3398f5b |
431 | |
432 | =head2 init_arg -> Str |
433 | |
ab27a55e |
434 | =head2 type_constraint -> Str |
435 | |
436 | =head2 has_type_constraint -> Bool |
437 | |
438 | =head2 trigger => CODE | Undef |
439 | |
440 | =head2 has_trigger -> Bool |
441 | |
442 | =head2 builder => MethodName | Undef |
443 | |
444 | =head2 has_builder -> Bool |
445 | |
93f08899 |
446 | =head2 is_lazy_build => Bool |
447 | |
0fff36e6 |
448 | =head2 should_auto_deref -> Bool |
449 | |
c3398f5b |
450 | Informational methods. |
451 | |
452 | =head2 generate_accessor -> CODE |
453 | |
454 | Creates a new code reference for the attribute's accessor. |
455 | |
456 | =head2 generate_predicate -> CODE |
457 | |
458 | Creates a new code reference for the attribute's predicate. |
459 | |
460 | =head2 generate_clearer -> CODE |
461 | |
462 | Creates a new code reference for the attribute's clearer. |
463 | |
464 | =head2 generate_handles -> { MethodName => CODE } |
465 | |
466 | Creates a new code reference for each of the attribute's handles methods. |
467 | |
fb706f5c |
468 | =head2 find_type_constraint -> CODE |
469 | |
470 | Returns a code reference which can be used to check that a given value passes |
471 | this attribute's type constraint; |
472 | |
20e25eb9 |
473 | =head2 verify_against_type_constraint Item -> 1 | ERROR |
fb706f5c |
474 | |
475 | Checks that the given value passes this attribute's type constraint. Returns 1 |
476 | on success, otherwise C<confess>es. |
477 | |
93d190e0 |
478 | =head2 canonicalize_args Name, %args -> %args |
479 | |
480 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
481 | canonicalized into C<lazy>, C<builder>, etc. |
482 | |
1bbaa8ed |
483 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
484 | |
485 | Checks that the arguments to create the attribute (ie those specified by |
486 | C<has>) are valid. |
487 | |
f7b11a21 |
488 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
489 | |
490 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
491 | Accessors and helper methods are installed. Some error checking is done. |
492 | |
493 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
494 | |
495 | Returns the options that the parent class of C<OwnerClass> used for attribute |
496 | C<AttributeName>. |
497 | |
c3398f5b |
498 | =cut |
499 | |