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}){ |
121acb8a |
34 | $class->throw_error('builder must be a defined scalar value which is a method name') |
1b9e472d |
35 | if ref $args->{builder} || !(defined $args->{builder}); |
2efc0af1 |
36 | |
37 | $can_be_required++; |
38 | } |
1b9e472d |
39 | elsif(exists $args->{default}){ |
40 | if(ref $args->{default} && ref($args->{default}) ne 'CODE'){ |
2efc0af1 |
41 | $class->throw_error("References are not allowed as default values, you must " |
42 | . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); |
43 | } |
44 | $can_be_required++; |
45 | } |
46 | |
1b9e472d |
47 | if( $args->{required} && !$can_be_required ) { |
121acb8a |
48 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); |
2efc0af1 |
49 | } |
50 | |
1b9e472d |
51 | # taken from Mouse::Meta::Attribute->new and _process_args-> |
2efc0af1 |
52 | |
1b9e472d |
53 | if(exists $args->{is}){ |
54 | my $is = $args->{is}; |
2efc0af1 |
55 | |
56 | if($is eq 'ro'){ |
1b9e472d |
57 | $args->{reader} ||= $name; |
2efc0af1 |
58 | } |
59 | elsif($is eq 'rw'){ |
1b9e472d |
60 | if(exists $args->{writer}){ |
61 | $args->{reader} ||= $name; |
2efc0af1 |
62 | } |
63 | else{ |
1b9e472d |
64 | $args->{accessor} ||= $name; |
2efc0af1 |
65 | } |
66 | } |
67 | elsif($is eq 'bare'){ |
68 | # do nothing, but don't complain (later) about missing methods |
69 | } |
70 | else{ |
71 | $is = 'undef' if !defined $is; |
72 | $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); |
73 | } |
74 | } |
75 | |
76 | my $tc; |
1b9e472d |
77 | if(exists $args->{isa}){ |
78 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa}); |
2efc0af1 |
79 | } |
1b9e472d |
80 | elsif(exists $args->{does}){ |
4a29b63e |
81 | # TODO |
82 | # $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
83 | } |
1b9e472d |
84 | $tc = $args->{type_constraint}; |
2efc0af1 |
85 | |
1b9e472d |
86 | if($args->{coerce}){ |
2efc0af1 |
87 | defined($tc) |
88 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
89 | |
1b9e472d |
90 | $args->{weak_ref} |
121acb8a |
91 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
92 | } |
93 | |
1b9e472d |
94 | if ($args->{lazy_build}) { |
95 | exists($args->{default}) |
121acb8a |
96 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
97 | |
1b9e472d |
98 | $args->{lazy} = 1; |
99 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
100 | if ($name =~ /^_/) { |
1b9e472d |
101 | $args->{clearer} ||= "_clear${name}"; |
102 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
103 | } |
104 | else { |
1b9e472d |
105 | $args->{clearer} ||= "clear_${name}"; |
106 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
107 | } |
2efc0af1 |
108 | } |
109 | |
1b9e472d |
110 | if ($args->{auto_deref}) { |
121acb8a |
111 | defined($tc) |
112 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
113 | |
121acb8a |
114 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
115 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
116 | } |
117 | |
1b9e472d |
118 | if (exists $args->{trigger}) { |
119 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
120 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
121 | } |
45959ffa |
122 | |
1b9e472d |
123 | if ($args->{lazy}) { |
124 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
125 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
126 | } |
90fe520e |
127 | |
87ca293b |
128 | return; |
129 | } |
130 | |
131 | sub new { |
132 | my $class = shift; |
133 | my $name = shift; |
134 | |
135 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
136 | |
137 | $class->_process_options($name, \%args); |
138 | |
139 | $args{name} = $name; |
140 | |
141 | my $instance = bless \%args, $class; |
2efc0af1 |
142 | |
1b9e472d |
143 | # extra attributes |
144 | if($class ne __PACKAGE__){ |
87ca293b |
145 | $class->meta->_initialize_instance($instance,\%args); |
90fe520e |
146 | } |
c3398f5b |
147 | |
2efc0af1 |
148 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
149 | # my @bad = ...; |
2efc0af1 |
150 | # if(@bad){ |
151 | # @bad = sort @bad; |
152 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
153 | # } |
154 | |
1b9e472d |
155 | return $instance |
c3398f5b |
156 | } |
157 | |
90fe520e |
158 | # readers |
159 | |
f6715552 |
160 | sub name { $_[0]->{name} } |
161 | sub associated_class { $_[0]->{associated_class} } |
90fe520e |
162 | |
163 | sub accessor { $_[0]->{accessor} } |
164 | sub reader { $_[0]->{reader} } |
165 | sub writer { $_[0]->{writer} } |
166 | sub predicate { $_[0]->{predicate} } |
167 | sub clearer { $_[0]->{clearer} } |
168 | sub handles { $_[0]->{handles} } |
169 | |
f6715552 |
170 | sub _is_metadata { $_[0]->{is} } |
171 | sub is_required { $_[0]->{required} } |
172 | sub default { $_[0]->{default} } |
173 | sub is_lazy { $_[0]->{lazy} } |
174 | sub is_lazy_build { $_[0]->{lazy_build} } |
f6715552 |
175 | sub is_weak_ref { $_[0]->{weak_ref} } |
176 | sub init_arg { $_[0]->{init_arg} } |
177 | sub type_constraint { $_[0]->{type_constraint} } |
2efc0af1 |
178 | |
f6715552 |
179 | sub trigger { $_[0]->{trigger} } |
180 | sub builder { $_[0]->{builder} } |
181 | sub should_auto_deref { $_[0]->{auto_deref} } |
2efc0af1 |
182 | sub should_coerce { $_[0]->{coerce} } |
c3398f5b |
183 | |
1b9e472d |
184 | sub get_read_method { $_[0]->{reader} || $_[0]->{accessor} } |
185 | sub get_write_method { $_[0]->{writer} || $_[0]->{accessor} } |
186 | |
90fe520e |
187 | # predicates |
188 | |
189 | sub has_accessor { exists $_[0]->{accessor} } |
190 | sub has_reader { exists $_[0]->{reader} } |
191 | sub has_writer { exists $_[0]->{writer} } |
f6715552 |
192 | sub has_predicate { exists $_[0]->{predicate} } |
193 | sub has_clearer { exists $_[0]->{clearer} } |
194 | sub has_handles { exists $_[0]->{handles} } |
90fe520e |
195 | |
196 | sub has_default { exists $_[0]->{default} } |
f6715552 |
197 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
198 | sub has_trigger { exists $_[0]->{trigger} } |
199 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
200 | |
1b9e472d |
201 | sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} } |
202 | sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} } |
203 | |
1bfebf5f |
204 | sub _create_args { |
205 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
206 | $_[0]->{_create_args} |
207 | } |
208 | |
87ca293b |
209 | sub interpolate_class{ |
1b9e472d |
210 | my($class, $name, $args) = @_; |
c3398f5b |
211 | |
1b9e472d |
212 | if(my $metaclass = delete $args->{metaclass}){ |
213 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
214 | } |
1bfebf5f |
215 | |
87ca293b |
216 | my @traits; |
1b9e472d |
217 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
218 | |
1b9e472d |
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 | |
1b9e472d |
222 | next if $class->does($trait); |
74be9f76 |
223 | |
1b9e472d |
224 | push @traits, $trait; |
225 | |
226 | # are there options? |
227 | push @traits, $traits_ref->[++$i] |
228 | if ref($traits_ref->[$i+1]); |
c3398f5b |
229 | } |
c3398f5b |
230 | |
1b9e472d |
231 | if (@traits) { |
232 | $class = Mouse::Meta::Class->create_anon_class( |
233 | superclasses => [ $class ], |
234 | roles => \@traits, |
235 | cache => 1, |
236 | )->name; |
1b9e472d |
237 | } |
74be9f76 |
238 | } |
239 | |
87ca293b |
240 | return( $class, @traits ); |
1b9e472d |
241 | } |
242 | |
243 | sub canonicalize_args{ |
244 | my ($self, $name, %args) = @_; |
245 | |
246 | Carp::cluck("$self->canonicalize_args has been deprecated." |
04493075 |
247 | . "Use \$self->_process_options instead.") |
248 | if _MOUSE_VERBOSE; |
1b9e472d |
249 | |
250 | return %args; |
251 | } |
252 | |
253 | sub create { |
254 | my ($self, $class, $name, %args) = @_; |
255 | |
256 | Carp::cluck("$self->create has been deprecated." |
04493075 |
257 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
258 | if _MOUSE_VERBOSE; |
1b9e472d |
259 | |
260 | # noop |
261 | return $self; |
c3398f5b |
262 | } |
263 | |
20e25eb9 |
264 | sub verify_against_type_constraint { |
f55f60dd |
265 | my ($self, $value) = @_; |
266 | my $tc = $self->type_constraint; |
267 | return 1 unless $tc; |
5aa30ced |
268 | |
f55f60dd |
269 | local $_ = $value; |
270 | return 1 if $tc->check($value); |
5aa30ced |
271 | |
f55f60dd |
272 | $self->verify_type_constraint_error($self->name, $value, $tc); |
b3b74cc6 |
273 | } |
5aa30ced |
274 | |
b3b74cc6 |
275 | sub verify_type_constraint_error { |
276 | my($self, $name, $value, $type) = @_; |
fce211ae |
277 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
278 | } |
279 | |
8a7f2a8a |
280 | sub coerce_constraint { ## my($self, $value) = @_; |
281 | my $type = $_[0]->{type_constraint} |
282 | or return $_[1]; |
7ca5c5fb |
283 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); |
4188b837 |
284 | } |
285 | |
af745d5a |
286 | sub _canonicalize_handles { |
287 | my $self = shift; |
288 | my $handles = shift; |
289 | |
290 | if (ref($handles) eq 'HASH') { |
291 | return %$handles; |
292 | } |
293 | elsif (ref($handles) eq 'ARRAY') { |
294 | return map { $_ => $_ } @$handles; |
295 | } |
296 | else { |
fce211ae |
297 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
af745d5a |
298 | } |
299 | } |
300 | |
1b9e472d |
301 | sub clone_and_inherit_options{ |
302 | my $self = shift; |
303 | my $name = shift; |
304 | |
7ca5c5fb |
305 | return ref($self)->new($name, %{$self}, (@_ == 1) ? %{$_[0]} : @_); |
1b9e472d |
306 | } |
307 | |
1bfebf5f |
308 | sub clone_parent { |
309 | my $self = shift; |
310 | my $class = shift; |
311 | my $name = shift; |
312 | my %args = ($self->get_parent_args($class, $name), @_); |
313 | |
1b9e472d |
314 | Carp::cluck("$self->clone_parent has been deprecated." |
04493075 |
315 | . "Use \$meta->add_attribute and \$attr->install_accessors instead.") |
316 | if _MOUSE_VERBOSE; |
1b9e472d |
317 | |
7ca5c5fb |
318 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
319 | } |
320 | |
321 | sub get_parent_args { |
322 | my $self = shift; |
323 | my $class = shift; |
324 | my $name = shift; |
325 | |
724c77c0 |
326 | for my $super ($class->linearized_isa) { |
bb733405 |
327 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
328 | or next; |
329 | return %{ $super_attr->_create_args }; |
330 | } |
331 | |
fce211ae |
332 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
333 | } |
334 | |
04493075 |
335 | sub associate_method{ |
336 | my ($attribute, $method) = @_; |
337 | $attribute->{associated_methods}++; |
338 | return; |
339 | } |
340 | |
1b9e472d |
341 | sub install_accessors{ |
342 | my($attribute) = @_; |
343 | |
344 | my $metaclass = $attribute->{associated_class}; |
1b9e472d |
345 | |
346 | foreach my $type(qw(accessor reader writer predicate clearer handles)){ |
347 | if(exists $attribute->{$type}){ |
348 | my $installer = '_install_' . $type; |
7ca5c5fb |
349 | |
350 | Mouse::Meta::Method::Accessor->$installer($attribute, $attribute->{$type}, $metaclass); |
351 | |
1b9e472d |
352 | $attribute->{associated_methods}++; |
353 | } |
354 | } |
355 | |
356 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
357 | # backword compatibility |
1b9e472d |
358 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
359 | } |
360 | |
361 | return; |
362 | } |
363 | |
fce211ae |
364 | sub throw_error{ |
365 | my $self = shift; |
366 | |
367 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
368 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
369 | } |
370 | |
c3398f5b |
371 | 1; |
372 | |
373 | __END__ |
374 | |
375 | =head1 NAME |
376 | |
306290e8 |
377 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
378 | |
379 | =head1 METHODS |
380 | |
1820fffe |
381 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
382 | |
306290e8 |
383 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
384 | |
1820fffe |
385 | It adds the following options to the constructor: |
c3398f5b |
386 | |
1820fffe |
387 | =over 4 |
c3398f5b |
388 | |
612d3e1a |
389 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
390 | |
1820fffe |
391 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
392 | C<accessor> names. If the attribute is read-only ('ro') then it will |
393 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
394 | |
1820fffe |
395 | If it is read-write ('rw') then it will have an C<accessor> method |
396 | with the same name. If you provide an explicit C<writer> for a |
397 | read-write attribute, then you will have a C<reader> with the same |
398 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
399 | |
1820fffe |
400 | Use 'bare' when you are deliberately not installing any methods |
401 | (accessor, reader, etc.) associated with this attribute; otherwise, |
402 | Moose will issue a deprecation warning when this attribute is added to a |
403 | metaclass. |
c3398f5b |
404 | |
612d3e1a |
405 | =item C<< isa => Type >> |
ab27a55e |
406 | |
1820fffe |
407 | This option accepts a type. The type can be a string, which should be |
408 | a type name. If the type name is unknown, it is assumed to be a class |
409 | name. |
ab27a55e |
410 | |
1820fffe |
411 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
412 | |
1820fffe |
413 | If you I<also> provide a C<does> option, then your C<isa> option must |
414 | be a class name, and that class must do the role specified with |
415 | C<does>. |
ab27a55e |
416 | |
612d3e1a |
417 | =item C<< does => Role >> |
ab27a55e |
418 | |
1820fffe |
419 | This is short-hand for saying that the attribute's type must be an |
420 | object which does the named role. |
c3398f5b |
421 | |
1820fffe |
422 | B<This option is not yet supported.> |
c3398f5b |
423 | |
612d3e1a |
424 | =item C<< coerce => Bool >> |
ab27a55e |
425 | |
1820fffe |
426 | This option is only valid for objects with a type constraint |
427 | (C<isa>). If this is true, then coercions will be applied whenever |
428 | this attribute is set. |
c3398f5b |
429 | |
1820fffe |
430 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
431 | |
612d3e1a |
432 | =item C<< trigger => CodeRef >> |
ab27a55e |
433 | |
1820fffe |
434 | This option accepts a subroutine reference, which will be called after |
435 | the attribute is set. |
ab27a55e |
436 | |
612d3e1a |
437 | =item C<< required => Bool >> |
ab27a55e |
438 | |
1820fffe |
439 | An attribute which is required must be provided to the constructor. An |
440 | attribute which is required can also have a C<default> or C<builder>, |
441 | which will satisfy its required-ness. |
ab27a55e |
442 | |
1820fffe |
443 | A required attribute must have a C<default>, C<builder> or a |
444 | non-C<undef> C<init_arg> |
ab27a55e |
445 | |
612d3e1a |
446 | =item C<< lazy => Bool >> |
ab27a55e |
447 | |
1820fffe |
448 | A lazy attribute must have a C<default> or C<builder>. When an |
449 | attribute is lazy, the default value will not be calculated until the |
450 | attribute is read. |
93f08899 |
451 | |
612d3e1a |
452 | =item C<< weak_ref => Bool >> |
0fff36e6 |
453 | |
1820fffe |
454 | If this is true, the attribute's value will be stored as a weak |
455 | reference. |
c3398f5b |
456 | |
612d3e1a |
457 | =item C<< auto_deref => Bool >> |
fb706f5c |
458 | |
1820fffe |
459 | If this is true, then the reader will dereference the value when it is |
460 | called. The attribute must have a type constraint which defines the |
461 | attribute as an array or hash reference. |
462 | |
612d3e1a |
463 | =item C<< lazy_build => Bool >> |
1820fffe |
464 | |
465 | Setting this to true makes the attribute lazy and provides a number of |
466 | default methods. |
fb706f5c |
467 | |
1820fffe |
468 | has 'size' => ( |
469 | is => 'ro', |
470 | lazy_build => 1, |
471 | ); |
93d190e0 |
472 | |
1820fffe |
473 | is equivalent to this: |
93d190e0 |
474 | |
1820fffe |
475 | has 'size' => ( |
476 | is => 'ro', |
477 | lazy => 1, |
478 | builder => '_build_size', |
479 | clearer => 'clear_size', |
480 | predicate => 'has_size', |
481 | ); |
93d190e0 |
482 | |
1820fffe |
483 | =back |
484 | |
485 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
486 | |
487 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
488 | on success, otherwise C<confess>es. |
93d190e0 |
489 | |
1820fffe |
490 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
491 | |
612d3e1a |
492 | Creates a new attribute in the owner class, inheriting options from parent classes. |
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493 | Accessors and helper methods are installed. Some error checking is done. |
494 | |
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495 | =head1 SEE ALSO |
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496 | |
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497 | L<Moose::Meta::Attribute> |
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498 | |
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499 | =cut |
500 | |