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 | |
4ab51fb0 |
11 | |
87ca293b |
12 | sub _process_options{ |
13 | my($class, $name, $args) = @_; |
c3398f5b |
14 | |
04493075 |
15 | |
16 | # XXX: for backward compatibility (with method modifiers) |
17 | if($class->can('canonicalize_args') != \&canonicalize_args){ |
18 | %{$args} = $class->canonicalize_args($name, %{$args}); |
19 | } |
20 | |
2efc0af1 |
21 | # taken from Class::MOP::Attribute::new |
22 | |
23 | defined($name) |
24 | or $class->throw_error('You must provide a name for the attribute'); |
2e7e86c6 |
25 | |
1b9e472d |
26 | if(!exists $args->{init_arg}){ |
27 | $args->{init_arg} = $name; |
2efc0af1 |
28 | } |
29 | |
30 | # 'required' requires eigher 'init_arg', 'builder', or 'default' |
1b9e472d |
31 | my $can_be_required = defined( $args->{init_arg} ); |
2efc0af1 |
32 | |
1b9e472d |
33 | if(exists $args->{builder}){ |
c6d8f5ca |
34 | # XXX: |
35 | # Moose refuses a CODE ref builder, but Mouse doesn't for backward compatibility |
36 | # This feature will be changed in a future. (gfx) |
121acb8a |
37 | $class->throw_error('builder must be a defined scalar value which is a method name') |
c6d8f5ca |
38 | #if ref $args->{builder} || !defined $args->{builder}; |
39 | if !defined $args->{builder}; |
2efc0af1 |
40 | |
41 | $can_be_required++; |
42 | } |
1b9e472d |
43 | elsif(exists $args->{default}){ |
44 | if(ref $args->{default} && ref($args->{default}) ne 'CODE'){ |
2efc0af1 |
45 | $class->throw_error("References are not allowed as default values, you must " |
46 | . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); |
47 | } |
48 | $can_be_required++; |
49 | } |
50 | |
1b9e472d |
51 | if( $args->{required} && !$can_be_required ) { |
121acb8a |
52 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); |
2efc0af1 |
53 | } |
54 | |
1b9e472d |
55 | # taken from Mouse::Meta::Attribute->new and _process_args-> |
2efc0af1 |
56 | |
1b9e472d |
57 | if(exists $args->{is}){ |
58 | my $is = $args->{is}; |
2efc0af1 |
59 | |
60 | if($is eq 'ro'){ |
1b9e472d |
61 | $args->{reader} ||= $name; |
2efc0af1 |
62 | } |
63 | elsif($is eq 'rw'){ |
1b9e472d |
64 | if(exists $args->{writer}){ |
65 | $args->{reader} ||= $name; |
2efc0af1 |
66 | } |
67 | else{ |
1b9e472d |
68 | $args->{accessor} ||= $name; |
2efc0af1 |
69 | } |
70 | } |
71 | elsif($is eq 'bare'){ |
72 | # do nothing, but don't complain (later) about missing methods |
73 | } |
74 | else{ |
75 | $is = 'undef' if !defined $is; |
76 | $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); |
77 | } |
78 | } |
79 | |
80 | my $tc; |
1b9e472d |
81 | if(exists $args->{isa}){ |
82 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa}); |
2efc0af1 |
83 | } |
1b9e472d |
84 | elsif(exists $args->{does}){ |
9f74c401 |
85 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
86 | } |
1b9e472d |
87 | $tc = $args->{type_constraint}; |
2efc0af1 |
88 | |
1b9e472d |
89 | if($args->{coerce}){ |
2efc0af1 |
90 | defined($tc) |
91 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
92 | |
1b9e472d |
93 | $args->{weak_ref} |
121acb8a |
94 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
95 | } |
96 | |
1b9e472d |
97 | if ($args->{lazy_build}) { |
98 | exists($args->{default}) |
121acb8a |
99 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
100 | |
1b9e472d |
101 | $args->{lazy} = 1; |
102 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
103 | if ($name =~ /^_/) { |
1b9e472d |
104 | $args->{clearer} ||= "_clear${name}"; |
105 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
106 | } |
107 | else { |
1b9e472d |
108 | $args->{clearer} ||= "clear_${name}"; |
109 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
110 | } |
2efc0af1 |
111 | } |
112 | |
1b9e472d |
113 | if ($args->{auto_deref}) { |
121acb8a |
114 | defined($tc) |
115 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
116 | |
121acb8a |
117 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
118 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
119 | } |
120 | |
1b9e472d |
121 | if (exists $args->{trigger}) { |
122 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
123 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
124 | } |
45959ffa |
125 | |
1b9e472d |
126 | if ($args->{lazy}) { |
127 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
128 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
129 | } |
90fe520e |
130 | |
87ca293b |
131 | return; |
132 | } |
133 | |
134 | sub new { |
135 | my $class = shift; |
136 | my $name = shift; |
137 | |
138 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
139 | |
140 | $class->_process_options($name, \%args); |
141 | |
142 | $args{name} = $name; |
143 | |
926290ac |
144 | my $self = bless \%args, $class; |
2efc0af1 |
145 | |
1b9e472d |
146 | # extra attributes |
147 | if($class ne __PACKAGE__){ |
926290ac |
148 | $class->meta->_initialize_object($self, \%args); |
90fe520e |
149 | } |
c3398f5b |
150 | |
2efc0af1 |
151 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
152 | # my @bad = ...; |
2efc0af1 |
153 | # if(@bad){ |
154 | # @bad = sort @bad; |
155 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
156 | # } |
157 | |
926290ac |
158 | return $self; |
c3398f5b |
159 | } |
160 | |
43165725 |
161 | sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } |
162 | sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } |
1b9e472d |
163 | |
df77fd72 |
164 | sub _create_args { # DEPRECATED |
1bfebf5f |
165 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
166 | $_[0]->{_create_args} |
167 | } |
168 | |
87ca293b |
169 | sub interpolate_class{ |
8cf51b82 |
170 | my($class, $args) = @_; |
c3398f5b |
171 | |
1b9e472d |
172 | if(my $metaclass = delete $args->{metaclass}){ |
173 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
174 | } |
1bfebf5f |
175 | |
87ca293b |
176 | my @traits; |
1b9e472d |
177 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
178 | |
f3f04eed |
179 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
180 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
181 | |
f3f04eed |
182 | next if $class->does($trait); |
74be9f76 |
183 | |
f3f04eed |
184 | push @traits, $trait; |
1b9e472d |
185 | |
f3f04eed |
186 | # are there options? |
187 | push @traits, $traits_ref->[++$i] |
188 | if ref($traits_ref->[$i+1]); |
189 | } |
c3398f5b |
190 | |
1b9e472d |
191 | if (@traits) { |
192 | $class = Mouse::Meta::Class->create_anon_class( |
193 | superclasses => [ $class ], |
194 | roles => \@traits, |
195 | cache => 1, |
196 | )->name; |
1b9e472d |
197 | } |
74be9f76 |
198 | } |
199 | |
87ca293b |
200 | return( $class, @traits ); |
1b9e472d |
201 | } |
202 | |
df77fd72 |
203 | sub canonicalize_args{ # DEPRECATED |
1b9e472d |
204 | my ($self, $name, %args) = @_; |
205 | |
206 | Carp::cluck("$self->canonicalize_args has been deprecated." |
04493075 |
207 | . "Use \$self->_process_options instead.") |
8aba926d |
208 | if Mouse::Util::_MOUSE_VERBOSE; |
1b9e472d |
209 | |
210 | return %args; |
211 | } |
212 | |
ce5920b7 |
213 | sub create { # DEPRECATED |
1b9e472d |
214 | my ($self, $class, $name, %args) = @_; |
215 | |
216 | Carp::cluck("$self->create has been deprecated." |
04493075 |
217 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
8aba926d |
218 | if Mouse::Util::_MOUSE_VERBOSE; |
1b9e472d |
219 | |
220 | # noop |
221 | return $self; |
c3398f5b |
222 | } |
223 | |
ffbbf459 |
224 | sub _coerce_and_verify { |
225 | my($self, $value, $instance) = @_; |
226 | |
227 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
228 | return $value if !defined $type_constraint; |
ffbbf459 |
229 | |
230 | if ($self->should_coerce && $type_constraint->has_coercion) { |
231 | $value = $type_constraint->coerce($value); |
232 | } |
233 | |
ffbbf459 |
234 | $self->verify_against_type_constraint($value); |
235 | |
236 | return $value; |
237 | } |
238 | |
20e25eb9 |
239 | sub verify_against_type_constraint { |
f55f60dd |
240 | my ($self, $value) = @_; |
5aa30ced |
241 | |
ffbbf459 |
242 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
243 | return 1 if !$type_constraint; |
ffbbf459 |
244 | return 1 if $type_constraint->check($value); |
5aa30ced |
245 | |
ffbbf459 |
246 | $self->verify_type_constraint_error($self->name, $value, $type_constraint); |
b3b74cc6 |
247 | } |
5aa30ced |
248 | |
b3b74cc6 |
249 | sub verify_type_constraint_error { |
250 | my($self, $name, $value, $type) = @_; |
4331a3f9 |
251 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " |
252 | . $type->get_message($value)); |
5aa30ced |
253 | } |
254 | |
df77fd72 |
255 | sub coerce_constraint { # DEPRECATED |
8a7f2a8a |
256 | my $type = $_[0]->{type_constraint} |
257 | or return $_[1]; |
e763d56e |
258 | |
259 | Carp::cluck("coerce_constraint() has been deprecated, which was an internal utility anyway"); |
260 | |
7ca5c5fb |
261 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); |
4188b837 |
262 | } |
263 | |
1b9e472d |
264 | sub clone_and_inherit_options{ |
8cf51b82 |
265 | my($self, %args) = @_; |
266 | |
267 | my($attribute_class, @traits) = ref($self)->interpolate_class(\%args); |
1b9e472d |
268 | |
8cf51b82 |
269 | $args{traits} = \@traits if @traits; |
4f41d79b |
270 | # do not inherit the 'handles' attribute |
271 | foreach my $name(keys %{$self}){ |
272 | if(!exists $args{$name} && $name ne 'handles'){ |
273 | $args{$name} = $self->{$name}; |
274 | } |
275 | } |
276 | return $attribute_class->new($self->name, %args); |
1b9e472d |
277 | } |
278 | |
df77fd72 |
279 | sub clone_parent { # DEPRECATED |
1bfebf5f |
280 | my $self = shift; |
281 | my $class = shift; |
282 | my $name = shift; |
283 | my %args = ($self->get_parent_args($class, $name), @_); |
284 | |
1b9e472d |
285 | Carp::cluck("$self->clone_parent has been deprecated." |
04493075 |
286 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
8aba926d |
287 | if Mouse::Util::_MOUSE_VERBOSE; |
1b9e472d |
288 | |
7ca5c5fb |
289 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
290 | } |
291 | |
df77fd72 |
292 | sub get_parent_args { # DEPRECATED |
1bfebf5f |
293 | my $self = shift; |
294 | my $class = shift; |
295 | my $name = shift; |
296 | |
724c77c0 |
297 | for my $super ($class->linearized_isa) { |
bb733405 |
298 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
299 | or next; |
300 | return %{ $super_attr->_create_args }; |
301 | } |
302 | |
fce211ae |
303 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
304 | } |
305 | |
2a464664 |
306 | |
0126c27c |
307 | sub get_read_method { |
43165725 |
308 | $_[0]->reader || $_[0]->accessor |
df77fd72 |
309 | } |
0126c27c |
310 | sub get_write_method { |
43165725 |
311 | $_[0]->writer || $_[0]->accessor |
df77fd72 |
312 | } |
2a464664 |
313 | |
314 | sub get_read_method_ref{ |
315 | my($self) = @_; |
316 | |
317 | $self->{_read_method_ref} ||= do{ |
318 | my $metaclass = $self->associated_class |
319 | or $self->throw_error('No asocciated class for ' . $self->name); |
320 | |
321 | my $reader = $self->{reader} || $self->{accessor}; |
322 | if($reader){ |
323 | $metaclass->name->can($reader); |
324 | } |
325 | else{ |
4ab51fb0 |
326 | $self->accessor_metaclass->_generate_reader($self, $metaclass); |
2a464664 |
327 | } |
328 | }; |
329 | } |
330 | |
331 | sub get_write_method_ref{ |
332 | my($self) = @_; |
333 | |
334 | $self->{_write_method_ref} ||= do{ |
335 | my $metaclass = $self->associated_class |
336 | or $self->throw_error('No asocciated class for ' . $self->name); |
337 | |
338 | my $reader = $self->{writer} || $self->{accessor}; |
339 | if($reader){ |
340 | $metaclass->name->can($reader); |
341 | } |
342 | else{ |
4ab51fb0 |
343 | $self->accessor_metaclass->_generate_writer($self, $metaclass); |
2a464664 |
344 | } |
345 | }; |
346 | } |
347 | |
4ab51fb0 |
348 | sub _canonicalize_handles { |
349 | my($self, $handles) = @_; |
350 | |
351 | if (ref($handles) eq 'HASH') { |
352 | return %$handles; |
353 | } |
354 | elsif (ref($handles) eq 'ARRAY') { |
355 | return map { $_ => $_ } @$handles; |
356 | } |
9ae9702e |
357 | elsif (ref($handles) eq 'Regexp') { |
358 | my $class_or_role = ($self->{isa} || $self->{does}) |
359 | || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); |
360 | |
361 | my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify |
362 | return map { $_ => $_ } |
007481ba |
363 | grep { !Mouse::Object->can($_) && $_ =~ $handles } |
f48920c1 |
364 | Mouse::Util::is_a_metarole($meta) |
745220df |
365 | ? $meta->get_method_list |
366 | : $meta->get_all_method_names; |
9ae9702e |
367 | } |
4ab51fb0 |
368 | else { |
369 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
370 | } |
371 | } |
372 | |
04493075 |
373 | sub associate_method{ |
e5e22afd |
374 | my ($attribute, $method_name) = @_; |
04493075 |
375 | $attribute->{associated_methods}++; |
376 | return; |
377 | } |
378 | |
d7d8d49b |
379 | |
380 | sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' } |
381 | |
1b9e472d |
382 | sub install_accessors{ |
383 | my($attribute) = @_; |
384 | |
93540011 |
385 | my $metaclass = $attribute->associated_class; |
4ab51fb0 |
386 | my $accessor_class = $attribute->accessor_metaclass; |
1b9e472d |
387 | |
4ab51fb0 |
388 | foreach my $type(qw(accessor reader writer predicate clearer)){ |
1b9e472d |
389 | if(exists $attribute->{$type}){ |
4ab51fb0 |
390 | my $generator = '_generate_' . $type; |
391 | my $code = $accessor_class->$generator($attribute, $metaclass); |
392 | $metaclass->add_method($attribute->{$type} => $code); |
e5e22afd |
393 | $attribute->associate_method($attribute->{$type}); |
4ab51fb0 |
394 | } |
395 | } |
7ca5c5fb |
396 | |
4ab51fb0 |
397 | # install delegation |
398 | if(exists $attribute->{handles}){ |
d7d8d49b |
399 | my $delegation_class = $attribute->delegation_metaclass; |
4ab51fb0 |
400 | my %handles = $attribute->_canonicalize_handles($attribute->{handles}); |
401 | my $reader = $attribute->get_read_method_ref; |
7ca5c5fb |
402 | |
4ab51fb0 |
403 | while(my($handle_name, $method_to_call) = each %handles){ |
d7d8d49b |
404 | my $code = $delegation_class->_generate_delegation($attribute, $metaclass, |
4ab51fb0 |
405 | $reader, $handle_name, $method_to_call); |
406 | |
407 | $metaclass->add_method($handle_name => $code); |
e5e22afd |
408 | $attribute->associate_method($handle_name); |
1b9e472d |
409 | } |
410 | } |
411 | |
4ab51fb0 |
412 | |
1b9e472d |
413 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
414 | # backword compatibility |
1b9e472d |
415 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
416 | } |
417 | |
418 | return; |
419 | } |
420 | |
fce211ae |
421 | sub throw_error{ |
422 | my $self = shift; |
423 | |
424 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
425 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
426 | } |
427 | |
c3398f5b |
428 | 1; |
429 | |
430 | __END__ |
431 | |
432 | =head1 NAME |
433 | |
bedd575c |
434 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
435 | |
a25ca8d6 |
436 | =head1 VERSION |
437 | |
506fb74d |
438 | This document describes Mouse version 0.40_09 |
a25ca8d6 |
439 | |
c3398f5b |
440 | =head1 METHODS |
441 | |
1820fffe |
442 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
443 | |
306290e8 |
444 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
445 | |
1820fffe |
446 | It adds the following options to the constructor: |
c3398f5b |
447 | |
1820fffe |
448 | =over 4 |
c3398f5b |
449 | |
612d3e1a |
450 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
451 | |
1820fffe |
452 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
453 | C<accessor> names. If the attribute is read-only ('ro') then it will |
454 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
455 | |
1820fffe |
456 | If it is read-write ('rw') then it will have an C<accessor> method |
457 | with the same name. If you provide an explicit C<writer> for a |
458 | read-write attribute, then you will have a C<reader> with the same |
459 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
460 | |
1820fffe |
461 | Use 'bare' when you are deliberately not installing any methods |
462 | (accessor, reader, etc.) associated with this attribute; otherwise, |
463 | Moose will issue a deprecation warning when this attribute is added to a |
464 | metaclass. |
c3398f5b |
465 | |
612d3e1a |
466 | =item C<< isa => Type >> |
ab27a55e |
467 | |
1820fffe |
468 | This option accepts a type. The type can be a string, which should be |
469 | a type name. If the type name is unknown, it is assumed to be a class |
470 | name. |
ab27a55e |
471 | |
1820fffe |
472 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
473 | |
1820fffe |
474 | If you I<also> provide a C<does> option, then your C<isa> option must |
475 | be a class name, and that class must do the role specified with |
476 | C<does>. |
ab27a55e |
477 | |
612d3e1a |
478 | =item C<< does => Role >> |
ab27a55e |
479 | |
1820fffe |
480 | This is short-hand for saying that the attribute's type must be an |
481 | object which does the named role. |
c3398f5b |
482 | |
1820fffe |
483 | B<This option is not yet supported.> |
c3398f5b |
484 | |
612d3e1a |
485 | =item C<< coerce => Bool >> |
ab27a55e |
486 | |
1820fffe |
487 | This option is only valid for objects with a type constraint |
488 | (C<isa>). If this is true, then coercions will be applied whenever |
489 | this attribute is set. |
c3398f5b |
490 | |
1820fffe |
491 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
492 | |
612d3e1a |
493 | =item C<< trigger => CodeRef >> |
ab27a55e |
494 | |
1820fffe |
495 | This option accepts a subroutine reference, which will be called after |
496 | the attribute is set. |
ab27a55e |
497 | |
612d3e1a |
498 | =item C<< required => Bool >> |
ab27a55e |
499 | |
1820fffe |
500 | An attribute which is required must be provided to the constructor. An |
501 | attribute which is required can also have a C<default> or C<builder>, |
502 | which will satisfy its required-ness. |
ab27a55e |
503 | |
1820fffe |
504 | A required attribute must have a C<default>, C<builder> or a |
505 | non-C<undef> C<init_arg> |
ab27a55e |
506 | |
612d3e1a |
507 | =item C<< lazy => Bool >> |
ab27a55e |
508 | |
1820fffe |
509 | A lazy attribute must have a C<default> or C<builder>. When an |
510 | attribute is lazy, the default value will not be calculated until the |
511 | attribute is read. |
93f08899 |
512 | |
612d3e1a |
513 | =item C<< weak_ref => Bool >> |
0fff36e6 |
514 | |
1820fffe |
515 | If this is true, the attribute's value will be stored as a weak |
516 | reference. |
c3398f5b |
517 | |
612d3e1a |
518 | =item C<< auto_deref => Bool >> |
fb706f5c |
519 | |
1820fffe |
520 | If this is true, then the reader will dereference the value when it is |
521 | called. The attribute must have a type constraint which defines the |
522 | attribute as an array or hash reference. |
523 | |
612d3e1a |
524 | =item C<< lazy_build => Bool >> |
1820fffe |
525 | |
526 | Setting this to true makes the attribute lazy and provides a number of |
527 | default methods. |
fb706f5c |
528 | |
1820fffe |
529 | has 'size' => ( |
530 | is => 'ro', |
531 | lazy_build => 1, |
532 | ); |
93d190e0 |
533 | |
1820fffe |
534 | is equivalent to this: |
93d190e0 |
535 | |
1820fffe |
536 | has 'size' => ( |
537 | is => 'ro', |
538 | lazy => 1, |
539 | builder => '_build_size', |
540 | clearer => 'clear_size', |
541 | predicate => 'has_size', |
542 | ); |
93d190e0 |
543 | |
1820fffe |
544 | =back |
545 | |
e5e22afd |
546 | =head2 C<< associate_method(MethodName) >> |
31c5194b |
547 | |
548 | Associates a method with the attribute. Typically, this is called internally |
549 | when an attribute generates its accessors. |
550 | |
e5e22afd |
551 | Currently the argument I<MethodName> is ignored in Mouse. |
31c5194b |
552 | |
1820fffe |
553 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
554 | |
555 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
556 | on success, otherwise C<confess>es. |
93d190e0 |
557 | |
1820fffe |
558 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
559 | |
612d3e1a |
560 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
561 | Accessors and helper methods are installed. Some error checking is done. |
562 | |
9ae9702e |
563 | =head2 C<< get_read_method_ref >> |
564 | |
565 | =head2 C<< get_write_method_ref >> |
566 | |
567 | Returns the subroutine reference of a method suitable for reading or |
568 | writing the attribute's value in the associated class. These methods |
569 | always return a subroutine reference, regardless of whether or not the |
df77fd72 |
570 | attribute is read- or write-only. |
571 | |
1820fffe |
572 | =head1 SEE ALSO |
f7b11a21 |
573 | |
1820fffe |
574 | L<Moose::Meta::Attribute> |
f7b11a21 |
575 | |
31c5194b |
576 | L<Class::MOP::Attribute> |
577 | |
c3398f5b |
578 | =cut |
579 | |