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; |
d7d8d49b |
7 | |
8 | #use Mouse::Meta::Method::Accessor; |
9 | use Mouse::Meta::Method::Delegation; |
c3398f5b |
10 | |
87ca293b |
11 | sub _process_options{ |
12 | my($class, $name, $args) = @_; |
c3398f5b |
13 | |
04493075 |
14 | # XXX: for backward compatibility (with method modifiers) |
15 | if($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 | |
43165725 |
159 | sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } |
160 | sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } |
1b9e472d |
161 | |
df77fd72 |
162 | sub _create_args { # DEPRECATED |
1bfebf5f |
163 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
164 | $_[0]->{_create_args} |
165 | } |
166 | |
87ca293b |
167 | sub interpolate_class{ |
8cf51b82 |
168 | my($class, $args) = @_; |
c3398f5b |
169 | |
1b9e472d |
170 | if(my $metaclass = delete $args->{metaclass}){ |
171 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
172 | } |
1bfebf5f |
173 | |
87ca293b |
174 | my @traits; |
1b9e472d |
175 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
176 | |
f3f04eed |
177 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
178 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
179 | |
f3f04eed |
180 | next if $class->does($trait); |
74be9f76 |
181 | |
f3f04eed |
182 | push @traits, $trait; |
1b9e472d |
183 | |
f3f04eed |
184 | # are there options? |
185 | push @traits, $traits_ref->[++$i] |
186 | if ref($traits_ref->[$i+1]); |
187 | } |
c3398f5b |
188 | |
1b9e472d |
189 | if (@traits) { |
190 | $class = Mouse::Meta::Class->create_anon_class( |
191 | superclasses => [ $class ], |
192 | roles => \@traits, |
193 | cache => 1, |
194 | )->name; |
1b9e472d |
195 | } |
74be9f76 |
196 | } |
197 | |
87ca293b |
198 | return( $class, @traits ); |
1b9e472d |
199 | } |
200 | |
df77fd72 |
201 | sub canonicalize_args{ # DEPRECATED |
1b9e472d |
202 | my ($self, $name, %args) = @_; |
203 | |
204 | Carp::cluck("$self->canonicalize_args has been deprecated." |
04493075 |
205 | . "Use \$self->_process_options instead.") |
8aba926d |
206 | if Mouse::Util::_MOUSE_VERBOSE; |
1b9e472d |
207 | |
208 | return %args; |
209 | } |
210 | |
ce5920b7 |
211 | sub create { # DEPRECATED |
1b9e472d |
212 | my ($self, $class, $name, %args) = @_; |
213 | |
214 | Carp::cluck("$self->create has been deprecated." |
04493075 |
215 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
8aba926d |
216 | if Mouse::Util::_MOUSE_VERBOSE; |
1b9e472d |
217 | |
218 | # noop |
219 | return $self; |
c3398f5b |
220 | } |
221 | |
ffbbf459 |
222 | sub _coerce_and_verify { |
223 | my($self, $value, $instance) = @_; |
224 | |
225 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
226 | return $value if !defined $type_constraint; |
ffbbf459 |
227 | |
228 | if ($self->should_coerce && $type_constraint->has_coercion) { |
229 | $value = $type_constraint->coerce($value); |
230 | } |
231 | |
ffbbf459 |
232 | $self->verify_against_type_constraint($value); |
233 | |
234 | return $value; |
235 | } |
236 | |
20e25eb9 |
237 | sub verify_against_type_constraint { |
f55f60dd |
238 | my ($self, $value) = @_; |
5aa30ced |
239 | |
ffbbf459 |
240 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
241 | return 1 if !$type_constraint; |
ffbbf459 |
242 | return 1 if $type_constraint->check($value); |
5aa30ced |
243 | |
ffbbf459 |
244 | $self->verify_type_constraint_error($self->name, $value, $type_constraint); |
b3b74cc6 |
245 | } |
5aa30ced |
246 | |
b3b74cc6 |
247 | sub verify_type_constraint_error { |
248 | my($self, $name, $value, $type) = @_; |
4331a3f9 |
249 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " |
250 | . $type->get_message($value)); |
5aa30ced |
251 | } |
252 | |
df77fd72 |
253 | sub coerce_constraint { # DEPRECATED |
8a7f2a8a |
254 | my $type = $_[0]->{type_constraint} |
255 | or return $_[1]; |
e763d56e |
256 | |
257 | Carp::cluck("coerce_constraint() has been deprecated, which was an internal utility anyway"); |
258 | |
7ca5c5fb |
259 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); |
4188b837 |
260 | } |
261 | |
1b9e472d |
262 | sub clone_and_inherit_options{ |
8cf51b82 |
263 | my($self, %args) = @_; |
264 | |
265 | my($attribute_class, @traits) = ref($self)->interpolate_class(\%args); |
1b9e472d |
266 | |
8cf51b82 |
267 | $args{traits} = \@traits if @traits; |
4f41d79b |
268 | # do not inherit the 'handles' attribute |
269 | foreach my $name(keys %{$self}){ |
270 | if(!exists $args{$name} && $name ne 'handles'){ |
271 | $args{$name} = $self->{$name}; |
272 | } |
273 | } |
274 | return $attribute_class->new($self->name, %args); |
1b9e472d |
275 | } |
276 | |
df77fd72 |
277 | sub clone_parent { # DEPRECATED |
1bfebf5f |
278 | my $self = shift; |
279 | my $class = shift; |
280 | my $name = shift; |
281 | my %args = ($self->get_parent_args($class, $name), @_); |
282 | |
1b9e472d |
283 | Carp::cluck("$self->clone_parent has been deprecated." |
04493075 |
284 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
8aba926d |
285 | if Mouse::Util::_MOUSE_VERBOSE; |
1b9e472d |
286 | |
7ca5c5fb |
287 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
288 | } |
289 | |
df77fd72 |
290 | sub get_parent_args { # DEPRECATED |
1bfebf5f |
291 | my $self = shift; |
292 | my $class = shift; |
293 | my $name = shift; |
294 | |
724c77c0 |
295 | for my $super ($class->linearized_isa) { |
bb733405 |
296 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
297 | or next; |
298 | return %{ $super_attr->_create_args }; |
299 | } |
300 | |
fce211ae |
301 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
302 | } |
303 | |
2a464664 |
304 | |
0126c27c |
305 | sub get_read_method { |
751de1a1 |
306 | return $_[0]->reader || $_[0]->accessor |
df77fd72 |
307 | } |
0126c27c |
308 | sub get_write_method { |
751de1a1 |
309 | return $_[0]->writer || $_[0]->accessor |
310 | } |
311 | |
312 | sub _get_accessor_method_ref { |
313 | my($self, $type, $generator) = @_; |
314 | |
315 | my $metaclass = $self->associated_class |
316 | || $self->throw_error('No asocciated class for ' . $self->name); |
317 | |
318 | my $accessor = $self->$type(); |
319 | if($accessor){ |
320 | return $metaclass->get_method_body($accessor); |
321 | } |
322 | else{ |
323 | return $self->accessor_metaclass->$generator($self, $metaclass); |
324 | } |
df77fd72 |
325 | } |
2a464664 |
326 | |
327 | sub get_read_method_ref{ |
328 | my($self) = @_; |
329 | |
751de1a1 |
330 | return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader'); |
2a464664 |
331 | } |
332 | |
333 | sub get_write_method_ref{ |
334 | my($self) = @_; |
335 | |
751de1a1 |
336 | return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer'); |
337 | } |
2a464664 |
338 | |
751de1a1 |
339 | sub set_value { |
340 | my($self, $object, $value) = @_; |
341 | return $self->get_write_method_ref()->($object, $value); |
342 | } |
343 | |
344 | sub get_value { |
345 | my($self, $object) = @_; |
346 | return $self->get_read_method_ref()->($object); |
2a464664 |
347 | } |
348 | |
751de1a1 |
349 | sub has_value { |
350 | my($self, $object) = @_; |
351 | my $predicate_ref = $self->{_predicate_ref} |
352 | ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate'); |
353 | |
354 | return $predicate_ref->($object); |
355 | } |
356 | |
357 | sub clear_value { |
358 | my($self, $object) = @_; |
359 | my $predicate_ref = $self->{_crealer_ref} |
360 | ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer'); |
361 | |
362 | return $predicate_ref->($object); |
363 | } |
364 | |
365 | |
4ab51fb0 |
366 | sub _canonicalize_handles { |
367 | my($self, $handles) = @_; |
368 | |
369 | if (ref($handles) eq 'HASH') { |
370 | return %$handles; |
371 | } |
372 | elsif (ref($handles) eq 'ARRAY') { |
373 | return map { $_ => $_ } @$handles; |
374 | } |
9ae9702e |
375 | elsif (ref($handles) eq 'Regexp') { |
376 | my $class_or_role = ($self->{isa} || $self->{does}) |
377 | || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); |
378 | |
379 | my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify |
380 | return map { $_ => $_ } |
007481ba |
381 | grep { !Mouse::Object->can($_) && $_ =~ $handles } |
f48920c1 |
382 | Mouse::Util::is_a_metarole($meta) |
745220df |
383 | ? $meta->get_method_list |
384 | : $meta->get_all_method_names; |
9ae9702e |
385 | } |
4ab51fb0 |
386 | else { |
387 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
388 | } |
389 | } |
390 | |
04493075 |
391 | sub associate_method{ |
e5e22afd |
392 | my ($attribute, $method_name) = @_; |
04493075 |
393 | $attribute->{associated_methods}++; |
394 | return; |
395 | } |
396 | |
d7d8d49b |
397 | sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' } |
398 | |
1b9e472d |
399 | sub install_accessors{ |
400 | my($attribute) = @_; |
401 | |
93540011 |
402 | my $metaclass = $attribute->associated_class; |
4ab51fb0 |
403 | my $accessor_class = $attribute->accessor_metaclass; |
1b9e472d |
404 | |
4ab51fb0 |
405 | foreach my $type(qw(accessor reader writer predicate clearer)){ |
1b9e472d |
406 | if(exists $attribute->{$type}){ |
4ab51fb0 |
407 | my $generator = '_generate_' . $type; |
408 | my $code = $accessor_class->$generator($attribute, $metaclass); |
409 | $metaclass->add_method($attribute->{$type} => $code); |
e5e22afd |
410 | $attribute->associate_method($attribute->{$type}); |
4ab51fb0 |
411 | } |
412 | } |
7ca5c5fb |
413 | |
4ab51fb0 |
414 | # install delegation |
415 | if(exists $attribute->{handles}){ |
d7d8d49b |
416 | my $delegation_class = $attribute->delegation_metaclass; |
4ab51fb0 |
417 | my %handles = $attribute->_canonicalize_handles($attribute->{handles}); |
418 | my $reader = $attribute->get_read_method_ref; |
7ca5c5fb |
419 | |
4ab51fb0 |
420 | while(my($handle_name, $method_to_call) = each %handles){ |
d7d8d49b |
421 | my $code = $delegation_class->_generate_delegation($attribute, $metaclass, |
4ab51fb0 |
422 | $reader, $handle_name, $method_to_call); |
423 | |
424 | $metaclass->add_method($handle_name => $code); |
e5e22afd |
425 | $attribute->associate_method($handle_name); |
1b9e472d |
426 | } |
427 | } |
428 | |
429 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
430 | # backword compatibility |
1b9e472d |
431 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
432 | } |
433 | |
434 | return; |
435 | } |
436 | |
fce211ae |
437 | sub throw_error{ |
438 | my $self = shift; |
439 | |
440 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
441 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
442 | } |
443 | |
c3398f5b |
444 | 1; |
c3398f5b |
445 | __END__ |
446 | |
447 | =head1 NAME |
448 | |
bedd575c |
449 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
450 | |
a25ca8d6 |
451 | =head1 VERSION |
452 | |
a4cbb3cb |
453 | This document describes Mouse version 0.44 |
a25ca8d6 |
454 | |
c3398f5b |
455 | =head1 METHODS |
456 | |
1820fffe |
457 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
458 | |
306290e8 |
459 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
460 | |
1820fffe |
461 | It adds the following options to the constructor: |
c3398f5b |
462 | |
1820fffe |
463 | =over 4 |
c3398f5b |
464 | |
612d3e1a |
465 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
466 | |
1820fffe |
467 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
468 | C<accessor> names. If the attribute is read-only ('ro') then it will |
469 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
470 | |
1820fffe |
471 | If it is read-write ('rw') then it will have an C<accessor> method |
472 | with the same name. If you provide an explicit C<writer> for a |
473 | read-write attribute, then you will have a C<reader> with the same |
474 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
475 | |
1820fffe |
476 | Use 'bare' when you are deliberately not installing any methods |
477 | (accessor, reader, etc.) associated with this attribute; otherwise, |
478 | Moose will issue a deprecation warning when this attribute is added to a |
479 | metaclass. |
c3398f5b |
480 | |
612d3e1a |
481 | =item C<< isa => Type >> |
ab27a55e |
482 | |
1820fffe |
483 | This option accepts a type. The type can be a string, which should be |
484 | a type name. If the type name is unknown, it is assumed to be a class |
485 | name. |
ab27a55e |
486 | |
1820fffe |
487 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
488 | |
1820fffe |
489 | If you I<also> provide a C<does> option, then your C<isa> option must |
490 | be a class name, and that class must do the role specified with |
491 | C<does>. |
ab27a55e |
492 | |
612d3e1a |
493 | =item C<< does => Role >> |
ab27a55e |
494 | |
1820fffe |
495 | This is short-hand for saying that the attribute's type must be an |
496 | object which does the named role. |
c3398f5b |
497 | |
1820fffe |
498 | B<This option is not yet supported.> |
c3398f5b |
499 | |
612d3e1a |
500 | =item C<< coerce => Bool >> |
ab27a55e |
501 | |
1820fffe |
502 | This option is only valid for objects with a type constraint |
503 | (C<isa>). If this is true, then coercions will be applied whenever |
504 | this attribute is set. |
c3398f5b |
505 | |
1820fffe |
506 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
507 | |
612d3e1a |
508 | =item C<< trigger => CodeRef >> |
ab27a55e |
509 | |
1820fffe |
510 | This option accepts a subroutine reference, which will be called after |
511 | the attribute is set. |
ab27a55e |
512 | |
612d3e1a |
513 | =item C<< required => Bool >> |
ab27a55e |
514 | |
1820fffe |
515 | An attribute which is required must be provided to the constructor. An |
516 | attribute which is required can also have a C<default> or C<builder>, |
517 | which will satisfy its required-ness. |
ab27a55e |
518 | |
1820fffe |
519 | A required attribute must have a C<default>, C<builder> or a |
520 | non-C<undef> C<init_arg> |
ab27a55e |
521 | |
612d3e1a |
522 | =item C<< lazy => Bool >> |
ab27a55e |
523 | |
1820fffe |
524 | A lazy attribute must have a C<default> or C<builder>. When an |
525 | attribute is lazy, the default value will not be calculated until the |
526 | attribute is read. |
93f08899 |
527 | |
612d3e1a |
528 | =item C<< weak_ref => Bool >> |
0fff36e6 |
529 | |
1820fffe |
530 | If this is true, the attribute's value will be stored as a weak |
531 | reference. |
c3398f5b |
532 | |
612d3e1a |
533 | =item C<< auto_deref => Bool >> |
fb706f5c |
534 | |
1820fffe |
535 | If this is true, then the reader will dereference the value when it is |
536 | called. The attribute must have a type constraint which defines the |
537 | attribute as an array or hash reference. |
538 | |
612d3e1a |
539 | =item C<< lazy_build => Bool >> |
1820fffe |
540 | |
541 | Setting this to true makes the attribute lazy and provides a number of |
542 | default methods. |
fb706f5c |
543 | |
1820fffe |
544 | has 'size' => ( |
545 | is => 'ro', |
546 | lazy_build => 1, |
547 | ); |
93d190e0 |
548 | |
1820fffe |
549 | is equivalent to this: |
93d190e0 |
550 | |
1820fffe |
551 | has 'size' => ( |
552 | is => 'ro', |
553 | lazy => 1, |
554 | builder => '_build_size', |
555 | clearer => 'clear_size', |
556 | predicate => 'has_size', |
557 | ); |
93d190e0 |
558 | |
1820fffe |
559 | =back |
560 | |
e5e22afd |
561 | =head2 C<< associate_method(MethodName) >> |
31c5194b |
562 | |
563 | Associates a method with the attribute. Typically, this is called internally |
564 | when an attribute generates its accessors. |
565 | |
e5e22afd |
566 | Currently the argument I<MethodName> is ignored in Mouse. |
31c5194b |
567 | |
1820fffe |
568 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
569 | |
570 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
571 | on success, otherwise C<confess>es. |
93d190e0 |
572 | |
1820fffe |
573 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
574 | |
612d3e1a |
575 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
576 | Accessors and helper methods are installed. Some error checking is done. |
577 | |
9ae9702e |
578 | =head2 C<< get_read_method_ref >> |
579 | |
580 | =head2 C<< get_write_method_ref >> |
581 | |
582 | Returns the subroutine reference of a method suitable for reading or |
583 | writing the attribute's value in the associated class. These methods |
584 | always return a subroutine reference, regardless of whether or not the |
df77fd72 |
585 | attribute is read- or write-only. |
586 | |
1820fffe |
587 | =head1 SEE ALSO |
f7b11a21 |
588 | |
1820fffe |
589 | L<Moose::Meta::Attribute> |
f7b11a21 |
590 | |
31c5194b |
591 | L<Class::MOP::Attribute> |
592 | |
c3398f5b |
593 | =cut |
594 | |