Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
bc69ee88 |
2 | use Mouse::Util qw(:meta); # enables strict and warnings |
c3398f5b |
3 | |
2efc0af1 |
4 | use Carp (); |
2efc0af1 |
5 | |
684db121 |
6 | use Mouse::Meta::TypeConstraint; |
90fe520e |
7 | use Mouse::Meta::Method::Accessor; |
c3398f5b |
8 | |
4ab51fb0 |
9 | |
87ca293b |
10 | sub _process_options{ |
11 | my($class, $name, $args) = @_; |
c3398f5b |
12 | |
04493075 |
13 | |
14 | # XXX: for backward compatibility (with method modifiers) |
15 | if($class->can('canonicalize_args') != \&canonicalize_args){ |
16 | %{$args} = $class->canonicalize_args($name, %{$args}); |
17 | } |
18 | |
2efc0af1 |
19 | # taken from Class::MOP::Attribute::new |
20 | |
21 | defined($name) |
22 | or $class->throw_error('You must provide a name for the attribute'); |
2e7e86c6 |
23 | |
1b9e472d |
24 | if(!exists $args->{init_arg}){ |
25 | $args->{init_arg} = $name; |
2efc0af1 |
26 | } |
27 | |
28 | # 'required' requires eigher 'init_arg', 'builder', or 'default' |
1b9e472d |
29 | my $can_be_required = defined( $args->{init_arg} ); |
2efc0af1 |
30 | |
1b9e472d |
31 | if(exists $args->{builder}){ |
c6d8f5ca |
32 | # XXX: |
33 | # Moose refuses a CODE ref builder, but Mouse doesn't for backward compatibility |
34 | # This feature will be changed in a future. (gfx) |
121acb8a |
35 | $class->throw_error('builder must be a defined scalar value which is a method name') |
c6d8f5ca |
36 | #if ref $args->{builder} || !defined $args->{builder}; |
37 | if !defined $args->{builder}; |
2efc0af1 |
38 | |
39 | $can_be_required++; |
40 | } |
1b9e472d |
41 | elsif(exists $args->{default}){ |
42 | if(ref $args->{default} && ref($args->{default}) ne 'CODE'){ |
2efc0af1 |
43 | $class->throw_error("References are not allowed as default values, you must " |
44 | . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); |
45 | } |
46 | $can_be_required++; |
47 | } |
48 | |
1b9e472d |
49 | if( $args->{required} && !$can_be_required ) { |
121acb8a |
50 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); |
2efc0af1 |
51 | } |
52 | |
1b9e472d |
53 | # taken from Mouse::Meta::Attribute->new and _process_args-> |
2efc0af1 |
54 | |
1b9e472d |
55 | if(exists $args->{is}){ |
56 | my $is = $args->{is}; |
2efc0af1 |
57 | |
58 | if($is eq 'ro'){ |
1b9e472d |
59 | $args->{reader} ||= $name; |
2efc0af1 |
60 | } |
61 | elsif($is eq 'rw'){ |
1b9e472d |
62 | if(exists $args->{writer}){ |
63 | $args->{reader} ||= $name; |
2efc0af1 |
64 | } |
65 | else{ |
1b9e472d |
66 | $args->{accessor} ||= $name; |
2efc0af1 |
67 | } |
68 | } |
69 | elsif($is eq 'bare'){ |
70 | # do nothing, but don't complain (later) about missing methods |
71 | } |
72 | else{ |
73 | $is = 'undef' if !defined $is; |
74 | $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); |
75 | } |
76 | } |
77 | |
78 | my $tc; |
1b9e472d |
79 | if(exists $args->{isa}){ |
80 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa}); |
2efc0af1 |
81 | } |
1b9e472d |
82 | elsif(exists $args->{does}){ |
9f74c401 |
83 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
84 | } |
1b9e472d |
85 | $tc = $args->{type_constraint}; |
2efc0af1 |
86 | |
1b9e472d |
87 | if($args->{coerce}){ |
2efc0af1 |
88 | defined($tc) |
89 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
90 | |
1b9e472d |
91 | $args->{weak_ref} |
121acb8a |
92 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
93 | } |
94 | |
1b9e472d |
95 | if ($args->{lazy_build}) { |
96 | exists($args->{default}) |
121acb8a |
97 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
98 | |
1b9e472d |
99 | $args->{lazy} = 1; |
100 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
101 | if ($name =~ /^_/) { |
1b9e472d |
102 | $args->{clearer} ||= "_clear${name}"; |
103 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
104 | } |
105 | else { |
1b9e472d |
106 | $args->{clearer} ||= "clear_${name}"; |
107 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
108 | } |
2efc0af1 |
109 | } |
110 | |
1b9e472d |
111 | if ($args->{auto_deref}) { |
121acb8a |
112 | defined($tc) |
113 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
114 | |
121acb8a |
115 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
116 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
117 | } |
118 | |
1b9e472d |
119 | if (exists $args->{trigger}) { |
120 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
121 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
122 | } |
45959ffa |
123 | |
1b9e472d |
124 | if ($args->{lazy}) { |
125 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
126 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
127 | } |
90fe520e |
128 | |
87ca293b |
129 | return; |
130 | } |
131 | |
132 | sub new { |
133 | my $class = shift; |
134 | my $name = shift; |
135 | |
136 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
137 | |
138 | $class->_process_options($name, \%args); |
139 | |
140 | $args{name} = $name; |
141 | |
926290ac |
142 | my $self = bless \%args, $class; |
2efc0af1 |
143 | |
1b9e472d |
144 | # extra attributes |
145 | if($class ne __PACKAGE__){ |
926290ac |
146 | $class->meta->_initialize_object($self, \%args); |
90fe520e |
147 | } |
c3398f5b |
148 | |
2efc0af1 |
149 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
150 | # my @bad = ...; |
2efc0af1 |
151 | # if(@bad){ |
152 | # @bad = sort @bad; |
153 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
154 | # } |
155 | |
926290ac |
156 | return $self; |
c3398f5b |
157 | } |
158 | |
90fe520e |
159 | # readers |
160 | |
f6715552 |
161 | sub name { $_[0]->{name} } |
162 | sub associated_class { $_[0]->{associated_class} } |
90fe520e |
163 | |
164 | sub accessor { $_[0]->{accessor} } |
165 | sub reader { $_[0]->{reader} } |
166 | sub writer { $_[0]->{writer} } |
167 | sub predicate { $_[0]->{predicate} } |
168 | sub clearer { $_[0]->{clearer} } |
169 | sub handles { $_[0]->{handles} } |
170 | |
f6715552 |
171 | sub _is_metadata { $_[0]->{is} } |
172 | sub is_required { $_[0]->{required} } |
173 | sub default { $_[0]->{default} } |
174 | sub is_lazy { $_[0]->{lazy} } |
175 | sub is_lazy_build { $_[0]->{lazy_build} } |
f6715552 |
176 | sub is_weak_ref { $_[0]->{weak_ref} } |
177 | sub init_arg { $_[0]->{init_arg} } |
178 | sub type_constraint { $_[0]->{type_constraint} } |
2efc0af1 |
179 | |
f6715552 |
180 | sub trigger { $_[0]->{trigger} } |
181 | sub builder { $_[0]->{builder} } |
182 | sub should_auto_deref { $_[0]->{auto_deref} } |
2efc0af1 |
183 | sub should_coerce { $_[0]->{coerce} } |
c3398f5b |
184 | |
90fe520e |
185 | # predicates |
186 | |
187 | sub has_accessor { exists $_[0]->{accessor} } |
188 | sub has_reader { exists $_[0]->{reader} } |
189 | sub has_writer { exists $_[0]->{writer} } |
f6715552 |
190 | sub has_predicate { exists $_[0]->{predicate} } |
191 | sub has_clearer { exists $_[0]->{clearer} } |
192 | sub has_handles { exists $_[0]->{handles} } |
90fe520e |
193 | |
194 | sub has_default { exists $_[0]->{default} } |
f6715552 |
195 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
196 | sub has_trigger { exists $_[0]->{trigger} } |
197 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
198 | |
1b9e472d |
199 | sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} } |
200 | sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} } |
201 | |
df77fd72 |
202 | sub _create_args { # DEPRECATED |
1bfebf5f |
203 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
204 | $_[0]->{_create_args} |
205 | } |
206 | |
87ca293b |
207 | sub interpolate_class{ |
8cf51b82 |
208 | my($class, $args) = @_; |
c3398f5b |
209 | |
1b9e472d |
210 | if(my $metaclass = delete $args->{metaclass}){ |
211 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
212 | } |
1bfebf5f |
213 | |
87ca293b |
214 | my @traits; |
1b9e472d |
215 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
216 | |
341a3046 |
217 | local $@; |
218 | eval{ |
219 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
220 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
221 | |
341a3046 |
222 | next if $class->does($trait); |
74be9f76 |
223 | |
341a3046 |
224 | push @traits, $trait; |
1b9e472d |
225 | |
341a3046 |
226 | # are there options? |
227 | push @traits, $traits_ref->[++$i] |
228 | if ref($traits_ref->[$i+1]); |
229 | } |
230 | }; |
231 | warn "Fatal error in traits: $@" if _MOUSE_VERBOSE; |
c3398f5b |
232 | |
1b9e472d |
233 | if (@traits) { |
234 | $class = Mouse::Meta::Class->create_anon_class( |
235 | superclasses => [ $class ], |
236 | roles => \@traits, |
237 | cache => 1, |
238 | )->name; |
1b9e472d |
239 | } |
74be9f76 |
240 | } |
241 | |
87ca293b |
242 | return( $class, @traits ); |
1b9e472d |
243 | } |
244 | |
df77fd72 |
245 | sub canonicalize_args{ # DEPRECATED |
1b9e472d |
246 | my ($self, $name, %args) = @_; |
247 | |
248 | Carp::cluck("$self->canonicalize_args has been deprecated." |
04493075 |
249 | . "Use \$self->_process_options instead.") |
250 | if _MOUSE_VERBOSE; |
1b9e472d |
251 | |
252 | return %args; |
253 | } |
254 | |
ce5920b7 |
255 | sub create { # DEPRECATED |
1b9e472d |
256 | my ($self, $class, $name, %args) = @_; |
257 | |
258 | Carp::cluck("$self->create has been deprecated." |
04493075 |
259 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
260 | if _MOUSE_VERBOSE; |
1b9e472d |
261 | |
262 | # noop |
263 | return $self; |
c3398f5b |
264 | } |
265 | |
ffbbf459 |
266 | sub _coerce_and_verify { |
267 | my($self, $value, $instance) = @_; |
268 | |
269 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
270 | return $value if !defined $type_constraint; |
ffbbf459 |
271 | |
272 | if ($self->should_coerce && $type_constraint->has_coercion) { |
273 | $value = $type_constraint->coerce($value); |
274 | } |
275 | |
ffbbf459 |
276 | $self->verify_against_type_constraint($value); |
277 | |
278 | return $value; |
279 | } |
280 | |
20e25eb9 |
281 | sub verify_against_type_constraint { |
f55f60dd |
282 | my ($self, $value) = @_; |
5aa30ced |
283 | |
ffbbf459 |
284 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
285 | return 1 if !$type_constraint; |
ffbbf459 |
286 | return 1 if $type_constraint->check($value); |
5aa30ced |
287 | |
ffbbf459 |
288 | $self->verify_type_constraint_error($self->name, $value, $type_constraint); |
b3b74cc6 |
289 | } |
5aa30ced |
290 | |
b3b74cc6 |
291 | sub verify_type_constraint_error { |
292 | my($self, $name, $value, $type) = @_; |
4331a3f9 |
293 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " |
294 | . $type->get_message($value)); |
5aa30ced |
295 | } |
296 | |
df77fd72 |
297 | sub coerce_constraint { # DEPRECATED |
8a7f2a8a |
298 | my $type = $_[0]->{type_constraint} |
299 | or return $_[1]; |
e763d56e |
300 | |
301 | Carp::cluck("coerce_constraint() has been deprecated, which was an internal utility anyway"); |
302 | |
7ca5c5fb |
303 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); |
4188b837 |
304 | } |
305 | |
1b9e472d |
306 | sub clone_and_inherit_options{ |
8cf51b82 |
307 | my($self, %args) = @_; |
308 | |
309 | my($attribute_class, @traits) = ref($self)->interpolate_class(\%args); |
1b9e472d |
310 | |
8cf51b82 |
311 | $args{traits} = \@traits if @traits; |
312 | return $attribute_class->new($self->name, %{$self}, %args); |
1b9e472d |
313 | } |
314 | |
df77fd72 |
315 | sub clone_parent { # DEPRECATED |
1bfebf5f |
316 | my $self = shift; |
317 | my $class = shift; |
318 | my $name = shift; |
319 | my %args = ($self->get_parent_args($class, $name), @_); |
320 | |
1b9e472d |
321 | Carp::cluck("$self->clone_parent has been deprecated." |
04493075 |
322 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
323 | if _MOUSE_VERBOSE; |
1b9e472d |
324 | |
7ca5c5fb |
325 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
326 | } |
327 | |
df77fd72 |
328 | sub get_parent_args { # DEPRECATED |
1bfebf5f |
329 | my $self = shift; |
330 | my $class = shift; |
331 | my $name = shift; |
332 | |
724c77c0 |
333 | for my $super ($class->linearized_isa) { |
bb733405 |
334 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
335 | or next; |
336 | return %{ $super_attr->_create_args }; |
337 | } |
338 | |
fce211ae |
339 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
340 | } |
341 | |
2a464664 |
342 | |
0126c27c |
343 | sub get_read_method { |
df77fd72 |
344 | $_[0]->{reader} || $_[0]->{accessor} |
345 | } |
0126c27c |
346 | sub get_write_method { |
df77fd72 |
347 | $_[0]->{writer} || $_[0]->{accessor} |
348 | } |
2a464664 |
349 | |
350 | sub get_read_method_ref{ |
351 | my($self) = @_; |
352 | |
353 | $self->{_read_method_ref} ||= do{ |
354 | my $metaclass = $self->associated_class |
355 | or $self->throw_error('No asocciated class for ' . $self->name); |
356 | |
357 | my $reader = $self->{reader} || $self->{accessor}; |
358 | if($reader){ |
359 | $metaclass->name->can($reader); |
360 | } |
361 | else{ |
4ab51fb0 |
362 | $self->accessor_metaclass->_generate_reader($self, $metaclass); |
2a464664 |
363 | } |
364 | }; |
365 | } |
366 | |
367 | sub get_write_method_ref{ |
368 | my($self) = @_; |
369 | |
370 | $self->{_write_method_ref} ||= do{ |
371 | my $metaclass = $self->associated_class |
372 | or $self->throw_error('No asocciated class for ' . $self->name); |
373 | |
374 | my $reader = $self->{writer} || $self->{accessor}; |
375 | if($reader){ |
376 | $metaclass->name->can($reader); |
377 | } |
378 | else{ |
4ab51fb0 |
379 | $self->accessor_metaclass->_generate_writer($self, $metaclass); |
2a464664 |
380 | } |
381 | }; |
382 | } |
383 | |
4ab51fb0 |
384 | sub _canonicalize_handles { |
385 | my($self, $handles) = @_; |
386 | |
387 | if (ref($handles) eq 'HASH') { |
388 | return %$handles; |
389 | } |
390 | elsif (ref($handles) eq 'ARRAY') { |
391 | return map { $_ => $_ } @$handles; |
392 | } |
9ae9702e |
393 | elsif (ref($handles) eq 'Regexp') { |
394 | my $class_or_role = ($self->{isa} || $self->{does}) |
395 | || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); |
396 | |
397 | my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify |
398 | return map { $_ => $_ } |
399 | grep { $_ ne 'meta' && !Mouse::Object->can($_) && $_ =~ $handles } |
400 | $meta->isa('Mouse::Meta::Class') ? $meta->get_all_method_names : $meta->get_method_list; |
401 | } |
4ab51fb0 |
402 | else { |
403 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
404 | } |
405 | } |
406 | |
407 | |
04493075 |
408 | sub associate_method{ |
409 | my ($attribute, $method) = @_; |
410 | $attribute->{associated_methods}++; |
411 | return; |
412 | } |
413 | |
4ab51fb0 |
414 | sub accessor_metaclass(){ 'Mouse::Meta::Method::Accessor' } |
415 | |
1b9e472d |
416 | sub install_accessors{ |
417 | my($attribute) = @_; |
418 | |
4ab51fb0 |
419 | my $metaclass = $attribute->{associated_class}; |
420 | my $accessor_class = $attribute->accessor_metaclass; |
1b9e472d |
421 | |
4ab51fb0 |
422 | foreach my $type(qw(accessor reader writer predicate clearer)){ |
1b9e472d |
423 | if(exists $attribute->{$type}){ |
4ab51fb0 |
424 | my $generator = '_generate_' . $type; |
425 | my $code = $accessor_class->$generator($attribute, $metaclass); |
426 | $metaclass->add_method($attribute->{$type} => $code); |
427 | $attribute->associate_method($code); |
428 | } |
429 | } |
7ca5c5fb |
430 | |
4ab51fb0 |
431 | # install delegation |
432 | if(exists $attribute->{handles}){ |
433 | my %handles = $attribute->_canonicalize_handles($attribute->{handles}); |
434 | my $reader = $attribute->get_read_method_ref; |
7ca5c5fb |
435 | |
4ab51fb0 |
436 | while(my($handle_name, $method_to_call) = each %handles){ |
437 | my $code = $accessor_class->_generate_delegation($attribute, $metaclass, |
438 | $reader, $handle_name, $method_to_call); |
439 | |
440 | $metaclass->add_method($handle_name => $code); |
441 | $attribute->associate_method($code); |
1b9e472d |
442 | } |
443 | } |
444 | |
4ab51fb0 |
445 | |
1b9e472d |
446 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
447 | # backword compatibility |
1b9e472d |
448 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
449 | } |
450 | |
451 | return; |
452 | } |
453 | |
fce211ae |
454 | sub throw_error{ |
455 | my $self = shift; |
456 | |
457 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
458 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
459 | } |
460 | |
c3398f5b |
461 | 1; |
462 | |
463 | __END__ |
464 | |
465 | =head1 NAME |
466 | |
bedd575c |
467 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
468 | |
a25ca8d6 |
469 | =head1 VERSION |
470 | |
9b9e4b65 |
471 | This document describes Mouse version 0.39 |
a25ca8d6 |
472 | |
c3398f5b |
473 | =head1 METHODS |
474 | |
1820fffe |
475 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
476 | |
306290e8 |
477 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
478 | |
1820fffe |
479 | It adds the following options to the constructor: |
c3398f5b |
480 | |
1820fffe |
481 | =over 4 |
c3398f5b |
482 | |
612d3e1a |
483 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
484 | |
1820fffe |
485 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
486 | C<accessor> names. If the attribute is read-only ('ro') then it will |
487 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
488 | |
1820fffe |
489 | If it is read-write ('rw') then it will have an C<accessor> method |
490 | with the same name. If you provide an explicit C<writer> for a |
491 | read-write attribute, then you will have a C<reader> with the same |
492 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
493 | |
1820fffe |
494 | Use 'bare' when you are deliberately not installing any methods |
495 | (accessor, reader, etc.) associated with this attribute; otherwise, |
496 | Moose will issue a deprecation warning when this attribute is added to a |
497 | metaclass. |
c3398f5b |
498 | |
612d3e1a |
499 | =item C<< isa => Type >> |
ab27a55e |
500 | |
1820fffe |
501 | This option accepts a type. The type can be a string, which should be |
502 | a type name. If the type name is unknown, it is assumed to be a class |
503 | name. |
ab27a55e |
504 | |
1820fffe |
505 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
506 | |
1820fffe |
507 | If you I<also> provide a C<does> option, then your C<isa> option must |
508 | be a class name, and that class must do the role specified with |
509 | C<does>. |
ab27a55e |
510 | |
612d3e1a |
511 | =item C<< does => Role >> |
ab27a55e |
512 | |
1820fffe |
513 | This is short-hand for saying that the attribute's type must be an |
514 | object which does the named role. |
c3398f5b |
515 | |
1820fffe |
516 | B<This option is not yet supported.> |
c3398f5b |
517 | |
612d3e1a |
518 | =item C<< coerce => Bool >> |
ab27a55e |
519 | |
1820fffe |
520 | This option is only valid for objects with a type constraint |
521 | (C<isa>). If this is true, then coercions will be applied whenever |
522 | this attribute is set. |
c3398f5b |
523 | |
1820fffe |
524 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
525 | |
612d3e1a |
526 | =item C<< trigger => CodeRef >> |
ab27a55e |
527 | |
1820fffe |
528 | This option accepts a subroutine reference, which will be called after |
529 | the attribute is set. |
ab27a55e |
530 | |
612d3e1a |
531 | =item C<< required => Bool >> |
ab27a55e |
532 | |
1820fffe |
533 | An attribute which is required must be provided to the constructor. An |
534 | attribute which is required can also have a C<default> or C<builder>, |
535 | which will satisfy its required-ness. |
ab27a55e |
536 | |
1820fffe |
537 | A required attribute must have a C<default>, C<builder> or a |
538 | non-C<undef> C<init_arg> |
ab27a55e |
539 | |
612d3e1a |
540 | =item C<< lazy => Bool >> |
ab27a55e |
541 | |
1820fffe |
542 | A lazy attribute must have a C<default> or C<builder>. When an |
543 | attribute is lazy, the default value will not be calculated until the |
544 | attribute is read. |
93f08899 |
545 | |
612d3e1a |
546 | =item C<< weak_ref => Bool >> |
0fff36e6 |
547 | |
1820fffe |
548 | If this is true, the attribute's value will be stored as a weak |
549 | reference. |
c3398f5b |
550 | |
612d3e1a |
551 | =item C<< auto_deref => Bool >> |
fb706f5c |
552 | |
1820fffe |
553 | If this is true, then the reader will dereference the value when it is |
554 | called. The attribute must have a type constraint which defines the |
555 | attribute as an array or hash reference. |
556 | |
612d3e1a |
557 | =item C<< lazy_build => Bool >> |
1820fffe |
558 | |
559 | Setting this to true makes the attribute lazy and provides a number of |
560 | default methods. |
fb706f5c |
561 | |
1820fffe |
562 | has 'size' => ( |
563 | is => 'ro', |
564 | lazy_build => 1, |
565 | ); |
93d190e0 |
566 | |
1820fffe |
567 | is equivalent to this: |
93d190e0 |
568 | |
1820fffe |
569 | has 'size' => ( |
570 | is => 'ro', |
571 | lazy => 1, |
572 | builder => '_build_size', |
573 | clearer => 'clear_size', |
574 | predicate => 'has_size', |
575 | ); |
93d190e0 |
576 | |
1820fffe |
577 | =back |
578 | |
31c5194b |
579 | =head2 C<< associate_method(Method) >> |
580 | |
581 | Associates a method with the attribute. Typically, this is called internally |
582 | when an attribute generates its accessors. |
583 | |
584 | Currently the argument I<Method> is ignored in Mouse. |
585 | |
1820fffe |
586 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
587 | |
588 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
589 | on success, otherwise C<confess>es. |
93d190e0 |
590 | |
1820fffe |
591 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
592 | |
612d3e1a |
593 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
594 | Accessors and helper methods are installed. Some error checking is done. |
595 | |
9ae9702e |
596 | =head2 C<< get_read_method_ref >> |
597 | |
598 | =head2 C<< get_write_method_ref >> |
599 | |
600 | Returns the subroutine reference of a method suitable for reading or |
601 | writing the attribute's value in the associated class. These methods |
602 | always return a subroutine reference, regardless of whether or not the |
df77fd72 |
603 | attribute is read- or write-only. |
604 | |
1820fffe |
605 | =head1 SEE ALSO |
f7b11a21 |
606 | |
1820fffe |
607 | L<Moose::Meta::Attribute> |
f7b11a21 |
608 | |
31c5194b |
609 | L<Class::MOP::Attribute> |
610 | |
c3398f5b |
611 | =cut |
612 | |