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, $args) = @_; |
c3398f5b |
14 | |
2efc0af1 |
15 | # taken from Class::MOP::Attribute::new |
16 | |
17 | defined($name) |
18 | or $class->throw_error('You must provide a name for the attribute'); |
2e7e86c6 |
19 | |
1b9e472d |
20 | if(!exists $args->{init_arg}){ |
21 | $args->{init_arg} = $name; |
2efc0af1 |
22 | } |
23 | |
24 | # 'required' requires eigher 'init_arg', 'builder', or 'default' |
1b9e472d |
25 | my $can_be_required = defined( $args->{init_arg} ); |
2efc0af1 |
26 | |
1b9e472d |
27 | if(exists $args->{builder}){ |
121acb8a |
28 | $class->throw_error('builder must be a defined scalar value which is a method name') |
1b9e472d |
29 | if ref $args->{builder} || !(defined $args->{builder}); |
2efc0af1 |
30 | |
31 | $can_be_required++; |
32 | } |
1b9e472d |
33 | elsif(exists $args->{default}){ |
34 | if(ref $args->{default} && ref($args->{default}) ne 'CODE'){ |
2efc0af1 |
35 | $class->throw_error("References are not allowed as default values, you must " |
36 | . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); |
37 | } |
38 | $can_be_required++; |
39 | } |
40 | |
1b9e472d |
41 | if( $args->{required} && !$can_be_required ) { |
121acb8a |
42 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg"); |
2efc0af1 |
43 | } |
44 | |
1b9e472d |
45 | # taken from Mouse::Meta::Attribute->new and _process_args-> |
2efc0af1 |
46 | |
1b9e472d |
47 | if(exists $args->{is}){ |
48 | my $is = $args->{is}; |
2efc0af1 |
49 | |
50 | if($is eq 'ro'){ |
1b9e472d |
51 | $args->{reader} ||= $name; |
2efc0af1 |
52 | } |
53 | elsif($is eq 'rw'){ |
1b9e472d |
54 | if(exists $args->{writer}){ |
55 | $args->{reader} ||= $name; |
2efc0af1 |
56 | } |
57 | else{ |
1b9e472d |
58 | $args->{accessor} ||= $name; |
2efc0af1 |
59 | } |
60 | } |
61 | elsif($is eq 'bare'){ |
62 | # do nothing, but don't complain (later) about missing methods |
63 | } |
64 | else{ |
65 | $is = 'undef' if !defined $is; |
66 | $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); |
67 | } |
68 | } |
69 | |
70 | my $tc; |
1b9e472d |
71 | if(exists $args->{isa}){ |
72 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa}); |
2efc0af1 |
73 | } |
1b9e472d |
74 | elsif(exists $args->{does}){ |
75 | $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
76 | } |
1b9e472d |
77 | $tc = $args->{type_constraint}; |
2efc0af1 |
78 | |
1b9e472d |
79 | if($args->{coerce}){ |
2efc0af1 |
80 | defined($tc) |
81 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
82 | |
1b9e472d |
83 | $args->{weak_ref} |
121acb8a |
84 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
85 | } |
86 | |
1b9e472d |
87 | if ($args->{lazy_build}) { |
88 | exists($args->{default}) |
121acb8a |
89 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
90 | |
1b9e472d |
91 | $args->{lazy} = 1; |
92 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
93 | if ($name =~ /^_/) { |
1b9e472d |
94 | $args->{clearer} ||= "_clear${name}"; |
95 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
96 | } |
97 | else { |
1b9e472d |
98 | $args->{clearer} ||= "clear_${name}"; |
99 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
100 | } |
2efc0af1 |
101 | } |
102 | |
1b9e472d |
103 | if ($args->{auto_deref}) { |
121acb8a |
104 | defined($tc) |
105 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
106 | |
121acb8a |
107 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
108 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
109 | } |
110 | |
1b9e472d |
111 | if (exists $args->{trigger}) { |
112 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
113 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
114 | } |
45959ffa |
115 | |
1b9e472d |
116 | if ($args->{lazy}) { |
117 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
118 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
119 | } |
90fe520e |
120 | |
87ca293b |
121 | # XXX: for backward compatibility (with method modifiers) |
122 | if($class->can('canonicalize_args') != \&canonicalize_args){ |
123 | %{$args} = $class->canonicalize_args($name, %{$args}); |
124 | } |
125 | return; |
126 | } |
127 | |
128 | sub new { |
129 | my $class = shift; |
130 | my $name = shift; |
131 | |
132 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
133 | |
134 | $class->_process_options($name, \%args); |
135 | |
136 | $args{name} = $name; |
137 | |
138 | my $instance = bless \%args, $class; |
2efc0af1 |
139 | |
1b9e472d |
140 | # extra attributes |
141 | if($class ne __PACKAGE__){ |
87ca293b |
142 | $class->meta->_initialize_instance($instance,\%args); |
90fe520e |
143 | } |
c3398f5b |
144 | |
2efc0af1 |
145 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
146 | # my @bad = ...; |
2efc0af1 |
147 | # if(@bad){ |
148 | # @bad = sort @bad; |
149 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
150 | # } |
151 | |
1b9e472d |
152 | return $instance |
c3398f5b |
153 | } |
154 | |
90fe520e |
155 | # readers |
156 | |
f6715552 |
157 | sub name { $_[0]->{name} } |
158 | sub associated_class { $_[0]->{associated_class} } |
90fe520e |
159 | |
160 | sub accessor { $_[0]->{accessor} } |
161 | sub reader { $_[0]->{reader} } |
162 | sub writer { $_[0]->{writer} } |
163 | sub predicate { $_[0]->{predicate} } |
164 | sub clearer { $_[0]->{clearer} } |
165 | sub handles { $_[0]->{handles} } |
166 | |
f6715552 |
167 | sub _is_metadata { $_[0]->{is} } |
168 | sub is_required { $_[0]->{required} } |
169 | sub default { $_[0]->{default} } |
170 | sub is_lazy { $_[0]->{lazy} } |
171 | sub is_lazy_build { $_[0]->{lazy_build} } |
f6715552 |
172 | sub is_weak_ref { $_[0]->{weak_ref} } |
173 | sub init_arg { $_[0]->{init_arg} } |
174 | sub type_constraint { $_[0]->{type_constraint} } |
2efc0af1 |
175 | |
f6715552 |
176 | sub trigger { $_[0]->{trigger} } |
177 | sub builder { $_[0]->{builder} } |
178 | sub should_auto_deref { $_[0]->{auto_deref} } |
2efc0af1 |
179 | sub should_coerce { $_[0]->{coerce} } |
c3398f5b |
180 | |
1b9e472d |
181 | sub get_read_method { $_[0]->{reader} || $_[0]->{accessor} } |
182 | sub get_write_method { $_[0]->{writer} || $_[0]->{accessor} } |
183 | |
90fe520e |
184 | # predicates |
185 | |
186 | sub has_accessor { exists $_[0]->{accessor} } |
187 | sub has_reader { exists $_[0]->{reader} } |
188 | sub has_writer { exists $_[0]->{writer} } |
f6715552 |
189 | sub has_predicate { exists $_[0]->{predicate} } |
190 | sub has_clearer { exists $_[0]->{clearer} } |
191 | sub has_handles { exists $_[0]->{handles} } |
90fe520e |
192 | |
193 | sub has_default { exists $_[0]->{default} } |
f6715552 |
194 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
195 | sub has_trigger { exists $_[0]->{trigger} } |
196 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
197 | |
1b9e472d |
198 | sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} } |
199 | sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} } |
200 | |
1bfebf5f |
201 | sub _create_args { |
202 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
203 | $_[0]->{_create_args} |
204 | } |
205 | |
90fe520e |
206 | sub accessor_metaclass { 'Mouse::Meta::Method::Accessor' } |
207 | |
87ca293b |
208 | sub interpolate_class{ |
1b9e472d |
209 | my($class, $name, $args) = @_; |
c3398f5b |
210 | |
1b9e472d |
211 | if(my $metaclass = delete $args->{metaclass}){ |
212 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
213 | } |
1bfebf5f |
214 | |
87ca293b |
215 | my @traits; |
1b9e472d |
216 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
217 | |
1b9e472d |
218 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
219 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
220 | |
1b9e472d |
221 | next if $class->does($trait); |
74be9f76 |
222 | |
1b9e472d |
223 | push @traits, $trait; |
224 | |
225 | # are there options? |
226 | push @traits, $traits_ref->[++$i] |
227 | if ref($traits_ref->[$i+1]); |
c3398f5b |
228 | } |
c3398f5b |
229 | |
1b9e472d |
230 | if (@traits) { |
231 | $class = Mouse::Meta::Class->create_anon_class( |
232 | superclasses => [ $class ], |
233 | roles => \@traits, |
234 | cache => 1, |
235 | )->name; |
1b9e472d |
236 | } |
74be9f76 |
237 | } |
238 | |
87ca293b |
239 | return( $class, @traits ); |
1b9e472d |
240 | } |
241 | |
242 | sub canonicalize_args{ |
243 | my ($self, $name, %args) = @_; |
244 | |
245 | Carp::cluck("$self->canonicalize_args has been deprecated." |
87ca293b |
246 | . "Use \$self->_process_options instead."); |
1b9e472d |
247 | |
248 | return %args; |
249 | } |
250 | |
251 | sub create { |
252 | my ($self, $class, $name, %args) = @_; |
253 | |
254 | Carp::cluck("$self->create has been deprecated." |
255 | . "Use \$meta->add_attribute and \$attr->install_accessors instead."); |
256 | |
257 | # noop |
258 | return $self; |
c3398f5b |
259 | } |
260 | |
20e25eb9 |
261 | sub verify_against_type_constraint { |
f55f60dd |
262 | my ($self, $value) = @_; |
263 | my $tc = $self->type_constraint; |
264 | return 1 unless $tc; |
5aa30ced |
265 | |
f55f60dd |
266 | local $_ = $value; |
267 | return 1 if $tc->check($value); |
5aa30ced |
268 | |
f55f60dd |
269 | $self->verify_type_constraint_error($self->name, $value, $tc); |
b3b74cc6 |
270 | } |
5aa30ced |
271 | |
b3b74cc6 |
272 | sub verify_type_constraint_error { |
273 | my($self, $name, $value, $type) = @_; |
fce211ae |
274 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
275 | } |
276 | |
8a7f2a8a |
277 | sub coerce_constraint { ## my($self, $value) = @_; |
278 | my $type = $_[0]->{type_constraint} |
279 | or return $_[1]; |
684db121 |
280 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]); |
4188b837 |
281 | } |
282 | |
af745d5a |
283 | sub _canonicalize_handles { |
284 | my $self = shift; |
285 | my $handles = shift; |
286 | |
287 | if (ref($handles) eq 'HASH') { |
288 | return %$handles; |
289 | } |
290 | elsif (ref($handles) eq 'ARRAY') { |
291 | return map { $_ => $_ } @$handles; |
292 | } |
293 | else { |
fce211ae |
294 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
af745d5a |
295 | } |
296 | } |
297 | |
1b9e472d |
298 | sub clone_and_inherit_options{ |
299 | my $self = shift; |
300 | my $name = shift; |
301 | |
302 | return ref($self)->new($name, %{$self}, @_ == 1 ? %{$_[0]} : @_); |
303 | } |
304 | |
1bfebf5f |
305 | sub clone_parent { |
306 | my $self = shift; |
307 | my $class = shift; |
308 | my $name = shift; |
309 | my %args = ($self->get_parent_args($class, $name), @_); |
310 | |
1b9e472d |
311 | Carp::cluck("$self->clone_parent has been deprecated." |
312 | . "Use \$meta->add_attribute and \$attr->install_accessors instead."); |
313 | |
314 | |
1bfebf5f |
315 | $self->create($class, $name, %args); |
316 | } |
317 | |
318 | sub get_parent_args { |
319 | my $self = shift; |
320 | my $class = shift; |
321 | my $name = shift; |
322 | |
724c77c0 |
323 | for my $super ($class->linearized_isa) { |
bb733405 |
324 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
325 | or next; |
326 | return %{ $super_attr->_create_args }; |
327 | } |
328 | |
fce211ae |
329 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
330 | } |
331 | |
1b9e472d |
332 | sub install_accessors{ |
333 | my($attribute) = @_; |
334 | |
335 | my $metaclass = $attribute->{associated_class}; |
336 | my $generator_class = $attribute->accessor_metaclass; |
337 | |
338 | foreach my $type(qw(accessor reader writer predicate clearer handles)){ |
339 | if(exists $attribute->{$type}){ |
340 | my $installer = '_install_' . $type; |
341 | $generator_class->$installer($attribute, $attribute->{$type}, $metaclass); |
342 | $attribute->{associated_methods}++; |
343 | } |
344 | } |
345 | |
346 | if($attribute->can('create') != \&create){ |
347 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
348 | } |
349 | |
350 | return; |
351 | } |
352 | |
fce211ae |
353 | sub throw_error{ |
354 | my $self = shift; |
355 | |
356 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
357 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
358 | } |
359 | |
c3398f5b |
360 | 1; |
361 | |
362 | __END__ |
363 | |
364 | =head1 NAME |
365 | |
306290e8 |
366 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
367 | |
368 | =head1 METHODS |
369 | |
1820fffe |
370 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
371 | |
306290e8 |
372 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
373 | |
1820fffe |
374 | It adds the following options to the constructor: |
c3398f5b |
375 | |
1820fffe |
376 | =over 4 |
c3398f5b |
377 | |
1820fffe |
378 | =item * C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
379 | |
1820fffe |
380 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
381 | C<accessor> names. If the attribute is read-only ('ro') then it will |
382 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
383 | |
1820fffe |
384 | If it is read-write ('rw') then it will have an C<accessor> method |
385 | with the same name. If you provide an explicit C<writer> for a |
386 | read-write attribute, then you will have a C<reader> with the same |
387 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
388 | |
1820fffe |
389 | Use 'bare' when you are deliberately not installing any methods |
390 | (accessor, reader, etc.) associated with this attribute; otherwise, |
391 | Moose will issue a deprecation warning when this attribute is added to a |
392 | metaclass. |
c3398f5b |
393 | |
1820fffe |
394 | =item * C<< isa => Type >> |
ab27a55e |
395 | |
1820fffe |
396 | This option accepts a type. The type can be a string, which should be |
397 | a type name. If the type name is unknown, it is assumed to be a class |
398 | name. |
ab27a55e |
399 | |
1820fffe |
400 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
401 | |
1820fffe |
402 | If you I<also> provide a C<does> option, then your C<isa> option must |
403 | be a class name, and that class must do the role specified with |
404 | C<does>. |
ab27a55e |
405 | |
1820fffe |
406 | =item * C<< does => Role >> |
ab27a55e |
407 | |
1820fffe |
408 | This is short-hand for saying that the attribute's type must be an |
409 | object which does the named role. |
c3398f5b |
410 | |
1820fffe |
411 | B<This option is not yet supported.> |
c3398f5b |
412 | |
1820fffe |
413 | =item * C<< coerce => Bool >> |
ab27a55e |
414 | |
1820fffe |
415 | This option is only valid for objects with a type constraint |
416 | (C<isa>). If this is true, then coercions will be applied whenever |
417 | this attribute is set. |
c3398f5b |
418 | |
1820fffe |
419 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
420 | |
1820fffe |
421 | =item * C<< trigger => CodeRef >> |
ab27a55e |
422 | |
1820fffe |
423 | This option accepts a subroutine reference, which will be called after |
424 | the attribute is set. |
ab27a55e |
425 | |
1820fffe |
426 | =item * C<< required => Bool >> |
ab27a55e |
427 | |
1820fffe |
428 | An attribute which is required must be provided to the constructor. An |
429 | attribute which is required can also have a C<default> or C<builder>, |
430 | which will satisfy its required-ness. |
ab27a55e |
431 | |
1820fffe |
432 | A required attribute must have a C<default>, C<builder> or a |
433 | non-C<undef> C<init_arg> |
ab27a55e |
434 | |
1820fffe |
435 | =item * C<< lazy => Bool >> |
ab27a55e |
436 | |
1820fffe |
437 | A lazy attribute must have a C<default> or C<builder>. When an |
438 | attribute is lazy, the default value will not be calculated until the |
439 | attribute is read. |
93f08899 |
440 | |
1820fffe |
441 | =item * C<< weak_ref => Bool >> |
0fff36e6 |
442 | |
1820fffe |
443 | If this is true, the attribute's value will be stored as a weak |
444 | reference. |
c3398f5b |
445 | |
1820fffe |
446 | =item * C<< auto_deref => Bool >> |
fb706f5c |
447 | |
1820fffe |
448 | If this is true, then the reader will dereference the value when it is |
449 | called. The attribute must have a type constraint which defines the |
450 | attribute as an array or hash reference. |
451 | |
452 | =item * C<< lazy_build => Bool >> |
453 | |
454 | Setting this to true makes the attribute lazy and provides a number of |
455 | default methods. |
fb706f5c |
456 | |
1820fffe |
457 | has 'size' => ( |
458 | is => 'ro', |
459 | lazy_build => 1, |
460 | ); |
93d190e0 |
461 | |
1820fffe |
462 | is equivalent to this: |
93d190e0 |
463 | |
1820fffe |
464 | has 'size' => ( |
465 | is => 'ro', |
466 | lazy => 1, |
467 | builder => '_build_size', |
468 | clearer => 'clear_size', |
469 | predicate => 'has_size', |
470 | ); |
93d190e0 |
471 | |
1820fffe |
472 | =back |
473 | |
474 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
475 | |
476 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
477 | on success, otherwise C<confess>es. |
93d190e0 |
478 | |
1820fffe |
479 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
480 | |
481 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
482 | Accessors and helper methods are installed. Some error checking is done. |
483 | |
1820fffe |
484 | =head1 SEE ALSO |
f7b11a21 |
485 | |
1820fffe |
486 | L<Moose::Meta::Attribute> |
f7b11a21 |
487 | |
c3398f5b |
488 | =cut |
489 | |