Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
c3398f5b |
2 | use strict; |
3 | use warnings; |
4 | |
2efc0af1 |
5 | use Carp (); |
2efc0af1 |
6 | |
53875581 |
7 | use Mouse::Util qw(:meta); |
6d28c5cf |
8 | |
684db121 |
9 | use Mouse::Meta::TypeConstraint; |
90fe520e |
10 | use Mouse::Meta::Method::Accessor; |
c3398f5b |
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}){ |
4a29b63e |
85 | # TODO |
86 | # $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
87 | } |
1b9e472d |
88 | $tc = $args->{type_constraint}; |
2efc0af1 |
89 | |
1b9e472d |
90 | if($args->{coerce}){ |
2efc0af1 |
91 | defined($tc) |
92 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
93 | |
1b9e472d |
94 | $args->{weak_ref} |
121acb8a |
95 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
96 | } |
97 | |
1b9e472d |
98 | if ($args->{lazy_build}) { |
99 | exists($args->{default}) |
121acb8a |
100 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
101 | |
1b9e472d |
102 | $args->{lazy} = 1; |
103 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
104 | if ($name =~ /^_/) { |
1b9e472d |
105 | $args->{clearer} ||= "_clear${name}"; |
106 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
107 | } |
108 | else { |
1b9e472d |
109 | $args->{clearer} ||= "clear_${name}"; |
110 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
111 | } |
2efc0af1 |
112 | } |
113 | |
1b9e472d |
114 | if ($args->{auto_deref}) { |
121acb8a |
115 | defined($tc) |
116 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
117 | |
121acb8a |
118 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
119 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
120 | } |
121 | |
1b9e472d |
122 | if (exists $args->{trigger}) { |
123 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
124 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
125 | } |
45959ffa |
126 | |
1b9e472d |
127 | if ($args->{lazy}) { |
128 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
129 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
130 | } |
90fe520e |
131 | |
87ca293b |
132 | return; |
133 | } |
134 | |
135 | sub new { |
136 | my $class = shift; |
137 | my $name = shift; |
138 | |
139 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
140 | |
141 | $class->_process_options($name, \%args); |
142 | |
143 | $args{name} = $name; |
144 | |
145 | my $instance = bless \%args, $class; |
2efc0af1 |
146 | |
1b9e472d |
147 | # extra attributes |
148 | if($class ne __PACKAGE__){ |
87ca293b |
149 | $class->meta->_initialize_instance($instance,\%args); |
90fe520e |
150 | } |
c3398f5b |
151 | |
2efc0af1 |
152 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
153 | # my @bad = ...; |
2efc0af1 |
154 | # if(@bad){ |
155 | # @bad = sort @bad; |
156 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
157 | # } |
158 | |
06f35b36 |
159 | return $instance; |
c3398f5b |
160 | } |
161 | |
90fe520e |
162 | # readers |
163 | |
f6715552 |
164 | sub name { $_[0]->{name} } |
165 | sub associated_class { $_[0]->{associated_class} } |
90fe520e |
166 | |
167 | sub accessor { $_[0]->{accessor} } |
168 | sub reader { $_[0]->{reader} } |
169 | sub writer { $_[0]->{writer} } |
170 | sub predicate { $_[0]->{predicate} } |
171 | sub clearer { $_[0]->{clearer} } |
172 | sub handles { $_[0]->{handles} } |
173 | |
f6715552 |
174 | sub _is_metadata { $_[0]->{is} } |
175 | sub is_required { $_[0]->{required} } |
176 | sub default { $_[0]->{default} } |
177 | sub is_lazy { $_[0]->{lazy} } |
178 | sub is_lazy_build { $_[0]->{lazy_build} } |
f6715552 |
179 | sub is_weak_ref { $_[0]->{weak_ref} } |
180 | sub init_arg { $_[0]->{init_arg} } |
181 | sub type_constraint { $_[0]->{type_constraint} } |
2efc0af1 |
182 | |
f6715552 |
183 | sub trigger { $_[0]->{trigger} } |
184 | sub builder { $_[0]->{builder} } |
185 | sub should_auto_deref { $_[0]->{auto_deref} } |
2efc0af1 |
186 | sub should_coerce { $_[0]->{coerce} } |
c3398f5b |
187 | |
1b9e472d |
188 | sub get_read_method { $_[0]->{reader} || $_[0]->{accessor} } |
189 | sub get_write_method { $_[0]->{writer} || $_[0]->{accessor} } |
190 | |
90fe520e |
191 | # predicates |
192 | |
193 | sub has_accessor { exists $_[0]->{accessor} } |
194 | sub has_reader { exists $_[0]->{reader} } |
195 | sub has_writer { exists $_[0]->{writer} } |
f6715552 |
196 | sub has_predicate { exists $_[0]->{predicate} } |
197 | sub has_clearer { exists $_[0]->{clearer} } |
198 | sub has_handles { exists $_[0]->{handles} } |
90fe520e |
199 | |
200 | sub has_default { exists $_[0]->{default} } |
f6715552 |
201 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
202 | sub has_trigger { exists $_[0]->{trigger} } |
203 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
204 | |
1b9e472d |
205 | sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} } |
206 | sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} } |
207 | |
1bfebf5f |
208 | sub _create_args { |
209 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
210 | $_[0]->{_create_args} |
211 | } |
212 | |
87ca293b |
213 | sub interpolate_class{ |
1b9e472d |
214 | my($class, $name, $args) = @_; |
c3398f5b |
215 | |
1b9e472d |
216 | if(my $metaclass = delete $args->{metaclass}){ |
217 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
218 | } |
1bfebf5f |
219 | |
87ca293b |
220 | my @traits; |
1b9e472d |
221 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
222 | |
1b9e472d |
223 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
224 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
225 | |
1b9e472d |
226 | next if $class->does($trait); |
74be9f76 |
227 | |
1b9e472d |
228 | push @traits, $trait; |
229 | |
230 | # are there options? |
231 | push @traits, $traits_ref->[++$i] |
232 | if ref($traits_ref->[$i+1]); |
c3398f5b |
233 | } |
c3398f5b |
234 | |
1b9e472d |
235 | if (@traits) { |
236 | $class = Mouse::Meta::Class->create_anon_class( |
237 | superclasses => [ $class ], |
238 | roles => \@traits, |
239 | cache => 1, |
240 | )->name; |
1b9e472d |
241 | } |
74be9f76 |
242 | } |
243 | |
87ca293b |
244 | return( $class, @traits ); |
1b9e472d |
245 | } |
246 | |
247 | sub canonicalize_args{ |
248 | my ($self, $name, %args) = @_; |
249 | |
250 | Carp::cluck("$self->canonicalize_args has been deprecated." |
04493075 |
251 | . "Use \$self->_process_options instead.") |
252 | if _MOUSE_VERBOSE; |
1b9e472d |
253 | |
254 | return %args; |
255 | } |
256 | |
257 | sub create { |
258 | my ($self, $class, $name, %args) = @_; |
259 | |
260 | Carp::cluck("$self->create has been deprecated." |
04493075 |
261 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
262 | if _MOUSE_VERBOSE; |
1b9e472d |
263 | |
264 | # noop |
265 | return $self; |
c3398f5b |
266 | } |
267 | |
ffbbf459 |
268 | sub _coerce_and_verify { |
269 | my($self, $value, $instance) = @_; |
270 | |
271 | my $type_constraint = $self->{type_constraint}; |
272 | |
273 | return $value if !$type_constraint; |
274 | |
275 | if ($self->should_coerce && $type_constraint->has_coercion) { |
276 | $value = $type_constraint->coerce($value); |
277 | } |
278 | |
279 | return $value if $type_constraint->check($value); |
280 | |
281 | $self->verify_against_type_constraint($value); |
282 | |
283 | return $value; |
284 | } |
285 | |
20e25eb9 |
286 | sub verify_against_type_constraint { |
f55f60dd |
287 | my ($self, $value) = @_; |
5aa30ced |
288 | |
ffbbf459 |
289 | my $type_constraint = $self->{type_constraint}; |
290 | return 1 if !$type_constraint;; |
291 | return 1 if $type_constraint->check($value); |
5aa30ced |
292 | |
ffbbf459 |
293 | $self->verify_type_constraint_error($self->name, $value, $type_constraint); |
b3b74cc6 |
294 | } |
5aa30ced |
295 | |
b3b74cc6 |
296 | sub verify_type_constraint_error { |
297 | my($self, $name, $value, $type) = @_; |
fce211ae |
298 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
299 | } |
300 | |
8a7f2a8a |
301 | sub coerce_constraint { ## my($self, $value) = @_; |
302 | my $type = $_[0]->{type_constraint} |
303 | or return $_[1]; |
e763d56e |
304 | |
305 | Carp::cluck("coerce_constraint() has been deprecated, which was an internal utility anyway"); |
306 | |
7ca5c5fb |
307 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); |
4188b837 |
308 | } |
309 | |
af745d5a |
310 | sub _canonicalize_handles { |
311 | my $self = shift; |
312 | my $handles = shift; |
313 | |
314 | if (ref($handles) eq 'HASH') { |
315 | return %$handles; |
316 | } |
317 | elsif (ref($handles) eq 'ARRAY') { |
318 | return map { $_ => $_ } @$handles; |
319 | } |
320 | else { |
fce211ae |
321 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
af745d5a |
322 | } |
323 | } |
324 | |
1b9e472d |
325 | sub clone_and_inherit_options{ |
326 | my $self = shift; |
327 | my $name = shift; |
328 | |
7ca5c5fb |
329 | return ref($self)->new($name, %{$self}, (@_ == 1) ? %{$_[0]} : @_); |
1b9e472d |
330 | } |
331 | |
1bfebf5f |
332 | sub clone_parent { |
333 | my $self = shift; |
334 | my $class = shift; |
335 | my $name = shift; |
336 | my %args = ($self->get_parent_args($class, $name), @_); |
337 | |
1b9e472d |
338 | Carp::cluck("$self->clone_parent has been deprecated." |
04493075 |
339 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
340 | if _MOUSE_VERBOSE; |
1b9e472d |
341 | |
7ca5c5fb |
342 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
343 | } |
344 | |
345 | sub get_parent_args { |
346 | my $self = shift; |
347 | my $class = shift; |
348 | my $name = shift; |
349 | |
724c77c0 |
350 | for my $super ($class->linearized_isa) { |
bb733405 |
351 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
352 | or next; |
353 | return %{ $super_attr->_create_args }; |
354 | } |
355 | |
fce211ae |
356 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
357 | } |
358 | |
04493075 |
359 | sub associate_method{ |
360 | my ($attribute, $method) = @_; |
361 | $attribute->{associated_methods}++; |
362 | return; |
363 | } |
364 | |
1b9e472d |
365 | sub install_accessors{ |
366 | my($attribute) = @_; |
367 | |
368 | my $metaclass = $attribute->{associated_class}; |
1b9e472d |
369 | |
370 | foreach my $type(qw(accessor reader writer predicate clearer handles)){ |
371 | if(exists $attribute->{$type}){ |
372 | my $installer = '_install_' . $type; |
7ca5c5fb |
373 | |
374 | Mouse::Meta::Method::Accessor->$installer($attribute, $attribute->{$type}, $metaclass); |
375 | |
1b9e472d |
376 | $attribute->{associated_methods}++; |
377 | } |
378 | } |
379 | |
380 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
381 | # backword compatibility |
1b9e472d |
382 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
383 | } |
384 | |
385 | return; |
386 | } |
387 | |
fce211ae |
388 | sub throw_error{ |
389 | my $self = shift; |
390 | |
391 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
392 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
393 | } |
394 | |
c3398f5b |
395 | 1; |
396 | |
397 | __END__ |
398 | |
399 | =head1 NAME |
400 | |
bedd575c |
401 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
402 | |
403 | =head1 METHODS |
404 | |
1820fffe |
405 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
406 | |
306290e8 |
407 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
408 | |
1820fffe |
409 | It adds the following options to the constructor: |
c3398f5b |
410 | |
1820fffe |
411 | =over 4 |
c3398f5b |
412 | |
612d3e1a |
413 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
414 | |
1820fffe |
415 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
416 | C<accessor> names. If the attribute is read-only ('ro') then it will |
417 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
418 | |
1820fffe |
419 | If it is read-write ('rw') then it will have an C<accessor> method |
420 | with the same name. If you provide an explicit C<writer> for a |
421 | read-write attribute, then you will have a C<reader> with the same |
422 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
423 | |
1820fffe |
424 | Use 'bare' when you are deliberately not installing any methods |
425 | (accessor, reader, etc.) associated with this attribute; otherwise, |
426 | Moose will issue a deprecation warning when this attribute is added to a |
427 | metaclass. |
c3398f5b |
428 | |
612d3e1a |
429 | =item C<< isa => Type >> |
ab27a55e |
430 | |
1820fffe |
431 | This option accepts a type. The type can be a string, which should be |
432 | a type name. If the type name is unknown, it is assumed to be a class |
433 | name. |
ab27a55e |
434 | |
1820fffe |
435 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
436 | |
1820fffe |
437 | If you I<also> provide a C<does> option, then your C<isa> option must |
438 | be a class name, and that class must do the role specified with |
439 | C<does>. |
ab27a55e |
440 | |
612d3e1a |
441 | =item C<< does => Role >> |
ab27a55e |
442 | |
1820fffe |
443 | This is short-hand for saying that the attribute's type must be an |
444 | object which does the named role. |
c3398f5b |
445 | |
1820fffe |
446 | B<This option is not yet supported.> |
c3398f5b |
447 | |
612d3e1a |
448 | =item C<< coerce => Bool >> |
ab27a55e |
449 | |
1820fffe |
450 | This option is only valid for objects with a type constraint |
451 | (C<isa>). If this is true, then coercions will be applied whenever |
452 | this attribute is set. |
c3398f5b |
453 | |
1820fffe |
454 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
455 | |
612d3e1a |
456 | =item C<< trigger => CodeRef >> |
ab27a55e |
457 | |
1820fffe |
458 | This option accepts a subroutine reference, which will be called after |
459 | the attribute is set. |
ab27a55e |
460 | |
612d3e1a |
461 | =item C<< required => Bool >> |
ab27a55e |
462 | |
1820fffe |
463 | An attribute which is required must be provided to the constructor. An |
464 | attribute which is required can also have a C<default> or C<builder>, |
465 | which will satisfy its required-ness. |
ab27a55e |
466 | |
1820fffe |
467 | A required attribute must have a C<default>, C<builder> or a |
468 | non-C<undef> C<init_arg> |
ab27a55e |
469 | |
612d3e1a |
470 | =item C<< lazy => Bool >> |
ab27a55e |
471 | |
1820fffe |
472 | A lazy attribute must have a C<default> or C<builder>. When an |
473 | attribute is lazy, the default value will not be calculated until the |
474 | attribute is read. |
93f08899 |
475 | |
612d3e1a |
476 | =item C<< weak_ref => Bool >> |
0fff36e6 |
477 | |
1820fffe |
478 | If this is true, the attribute's value will be stored as a weak |
479 | reference. |
c3398f5b |
480 | |
612d3e1a |
481 | =item C<< auto_deref => Bool >> |
fb706f5c |
482 | |
1820fffe |
483 | If this is true, then the reader will dereference the value when it is |
484 | called. The attribute must have a type constraint which defines the |
485 | attribute as an array or hash reference. |
486 | |
612d3e1a |
487 | =item C<< lazy_build => Bool >> |
1820fffe |
488 | |
489 | Setting this to true makes the attribute lazy and provides a number of |
490 | default methods. |
fb706f5c |
491 | |
1820fffe |
492 | has 'size' => ( |
493 | is => 'ro', |
494 | lazy_build => 1, |
495 | ); |
93d190e0 |
496 | |
1820fffe |
497 | is equivalent to this: |
93d190e0 |
498 | |
1820fffe |
499 | has 'size' => ( |
500 | is => 'ro', |
501 | lazy => 1, |
502 | builder => '_build_size', |
503 | clearer => 'clear_size', |
504 | predicate => 'has_size', |
505 | ); |
93d190e0 |
506 | |
1820fffe |
507 | =back |
508 | |
31c5194b |
509 | =head2 C<< associate_method(Method) >> |
510 | |
511 | Associates a method with the attribute. Typically, this is called internally |
512 | when an attribute generates its accessors. |
513 | |
514 | Currently the argument I<Method> is ignored in Mouse. |
515 | |
1820fffe |
516 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
517 | |
518 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
519 | on success, otherwise C<confess>es. |
93d190e0 |
520 | |
1820fffe |
521 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
522 | |
612d3e1a |
523 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
524 | Accessors and helper methods are installed. Some error checking is done. |
525 | |
1820fffe |
526 | =head1 SEE ALSO |
f7b11a21 |
527 | |
1820fffe |
528 | L<Moose::Meta::Attribute> |
f7b11a21 |
529 | |
31c5194b |
530 | L<Class::MOP::Attribute> |
531 | |
c3398f5b |
532 | =cut |
533 | |