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}){ |
4a29b63e |
75 | # TODO |
76 | # $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does}); |
2efc0af1 |
77 | } |
1b9e472d |
78 | $tc = $args->{type_constraint}; |
2efc0af1 |
79 | |
1b9e472d |
80 | if($args->{coerce}){ |
2efc0af1 |
81 | defined($tc) |
82 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
83 | |
1b9e472d |
84 | $args->{weak_ref} |
121acb8a |
85 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)"); |
2efc0af1 |
86 | } |
87 | |
1b9e472d |
88 | if ($args->{lazy_build}) { |
89 | exists($args->{default}) |
121acb8a |
90 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)"); |
91 | |
1b9e472d |
92 | $args->{lazy} = 1; |
93 | $args->{builder} ||= "_build_${name}"; |
121acb8a |
94 | if ($name =~ /^_/) { |
1b9e472d |
95 | $args->{clearer} ||= "_clear${name}"; |
96 | $args->{predicate} ||= "_has${name}"; |
121acb8a |
97 | } |
98 | else { |
1b9e472d |
99 | $args->{clearer} ||= "clear_${name}"; |
100 | $args->{predicate} ||= "has_${name}"; |
121acb8a |
101 | } |
2efc0af1 |
102 | } |
103 | |
1b9e472d |
104 | if ($args->{auto_deref}) { |
121acb8a |
105 | defined($tc) |
106 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)"); |
2efc0af1 |
107 | |
121acb8a |
108 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') ) |
109 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"); |
2efc0af1 |
110 | } |
111 | |
1b9e472d |
112 | if (exists $args->{trigger}) { |
113 | ('CODE' eq ref $args->{trigger}) |
121acb8a |
114 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)"); |
2efc0af1 |
115 | } |
45959ffa |
116 | |
1b9e472d |
117 | if ($args->{lazy}) { |
118 | (exists $args->{default} || defined $args->{builder}) |
121acb8a |
119 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it"); |
2efc0af1 |
120 | } |
90fe520e |
121 | |
87ca293b |
122 | # XXX: for backward compatibility (with method modifiers) |
123 | if($class->can('canonicalize_args') != \&canonicalize_args){ |
124 | %{$args} = $class->canonicalize_args($name, %{$args}); |
125 | } |
126 | return; |
127 | } |
128 | |
129 | sub new { |
130 | my $class = shift; |
131 | my $name = shift; |
132 | |
133 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
134 | |
135 | $class->_process_options($name, \%args); |
136 | |
137 | $args{name} = $name; |
138 | |
139 | my $instance = bless \%args, $class; |
2efc0af1 |
140 | |
1b9e472d |
141 | # extra attributes |
142 | if($class ne __PACKAGE__){ |
87ca293b |
143 | $class->meta->_initialize_instance($instance,\%args); |
90fe520e |
144 | } |
c3398f5b |
145 | |
2efc0af1 |
146 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
147 | # my @bad = ...; |
2efc0af1 |
148 | # if(@bad){ |
149 | # @bad = sort @bad; |
150 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
151 | # } |
152 | |
1b9e472d |
153 | return $instance |
c3398f5b |
154 | } |
155 | |
90fe520e |
156 | # readers |
157 | |
f6715552 |
158 | sub name { $_[0]->{name} } |
159 | sub associated_class { $_[0]->{associated_class} } |
90fe520e |
160 | |
161 | sub accessor { $_[0]->{accessor} } |
162 | sub reader { $_[0]->{reader} } |
163 | sub writer { $_[0]->{writer} } |
164 | sub predicate { $_[0]->{predicate} } |
165 | sub clearer { $_[0]->{clearer} } |
166 | sub handles { $_[0]->{handles} } |
167 | |
f6715552 |
168 | sub _is_metadata { $_[0]->{is} } |
169 | sub is_required { $_[0]->{required} } |
170 | sub default { $_[0]->{default} } |
171 | sub is_lazy { $_[0]->{lazy} } |
172 | sub is_lazy_build { $_[0]->{lazy_build} } |
f6715552 |
173 | sub is_weak_ref { $_[0]->{weak_ref} } |
174 | sub init_arg { $_[0]->{init_arg} } |
175 | sub type_constraint { $_[0]->{type_constraint} } |
2efc0af1 |
176 | |
f6715552 |
177 | sub trigger { $_[0]->{trigger} } |
178 | sub builder { $_[0]->{builder} } |
179 | sub should_auto_deref { $_[0]->{auto_deref} } |
2efc0af1 |
180 | sub should_coerce { $_[0]->{coerce} } |
c3398f5b |
181 | |
1b9e472d |
182 | sub get_read_method { $_[0]->{reader} || $_[0]->{accessor} } |
183 | sub get_write_method { $_[0]->{writer} || $_[0]->{accessor} } |
184 | |
90fe520e |
185 | # predicates |
186 | |
187 | sub has_accessor { exists $_[0]->{accessor} } |
188 | sub has_reader { exists $_[0]->{reader} } |
189 | sub has_writer { exists $_[0]->{writer} } |
f6715552 |
190 | sub has_predicate { exists $_[0]->{predicate} } |
191 | sub has_clearer { exists $_[0]->{clearer} } |
192 | sub has_handles { exists $_[0]->{handles} } |
90fe520e |
193 | |
194 | sub has_default { exists $_[0]->{default} } |
f6715552 |
195 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
196 | sub has_trigger { exists $_[0]->{trigger} } |
197 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
198 | |
1b9e472d |
199 | sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} } |
200 | sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} } |
201 | |
1bfebf5f |
202 | sub _create_args { |
203 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
204 | $_[0]->{_create_args} |
205 | } |
206 | |
87ca293b |
207 | sub interpolate_class{ |
1b9e472d |
208 | my($class, $name, $args) = @_; |
c3398f5b |
209 | |
1b9e472d |
210 | if(my $metaclass = delete $args->{metaclass}){ |
211 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
212 | } |
1bfebf5f |
213 | |
87ca293b |
214 | my @traits; |
1b9e472d |
215 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
216 | |
1b9e472d |
217 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
218 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
219 | |
1b9e472d |
220 | next if $class->does($trait); |
74be9f76 |
221 | |
1b9e472d |
222 | push @traits, $trait; |
223 | |
224 | # are there options? |
225 | push @traits, $traits_ref->[++$i] |
226 | if ref($traits_ref->[$i+1]); |
c3398f5b |
227 | } |
c3398f5b |
228 | |
1b9e472d |
229 | if (@traits) { |
230 | $class = Mouse::Meta::Class->create_anon_class( |
231 | superclasses => [ $class ], |
232 | roles => \@traits, |
233 | cache => 1, |
234 | )->name; |
1b9e472d |
235 | } |
74be9f76 |
236 | } |
237 | |
87ca293b |
238 | return( $class, @traits ); |
1b9e472d |
239 | } |
240 | |
241 | sub canonicalize_args{ |
242 | my ($self, $name, %args) = @_; |
243 | |
244 | Carp::cluck("$self->canonicalize_args has been deprecated." |
87ca293b |
245 | . "Use \$self->_process_options instead."); |
1b9e472d |
246 | |
247 | return %args; |
248 | } |
249 | |
250 | sub create { |
251 | my ($self, $class, $name, %args) = @_; |
252 | |
253 | Carp::cluck("$self->create has been deprecated." |
254 | . "Use \$meta->add_attribute and \$attr->install_accessors instead."); |
255 | |
256 | # noop |
257 | return $self; |
c3398f5b |
258 | } |
259 | |
20e25eb9 |
260 | sub verify_against_type_constraint { |
f55f60dd |
261 | my ($self, $value) = @_; |
262 | my $tc = $self->type_constraint; |
263 | return 1 unless $tc; |
5aa30ced |
264 | |
f55f60dd |
265 | local $_ = $value; |
266 | return 1 if $tc->check($value); |
5aa30ced |
267 | |
f55f60dd |
268 | $self->verify_type_constraint_error($self->name, $value, $tc); |
b3b74cc6 |
269 | } |
5aa30ced |
270 | |
b3b74cc6 |
271 | sub verify_type_constraint_error { |
272 | my($self, $name, $value, $type) = @_; |
fce211ae |
273 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
274 | } |
275 | |
8a7f2a8a |
276 | sub coerce_constraint { ## my($self, $value) = @_; |
277 | my $type = $_[0]->{type_constraint} |
278 | or return $_[1]; |
7ca5c5fb |
279 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]); |
4188b837 |
280 | } |
281 | |
af745d5a |
282 | sub _canonicalize_handles { |
283 | my $self = shift; |
284 | my $handles = shift; |
285 | |
286 | if (ref($handles) eq 'HASH') { |
287 | return %$handles; |
288 | } |
289 | elsif (ref($handles) eq 'ARRAY') { |
290 | return map { $_ => $_ } @$handles; |
291 | } |
292 | else { |
fce211ae |
293 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
af745d5a |
294 | } |
295 | } |
296 | |
1b9e472d |
297 | sub clone_and_inherit_options{ |
298 | my $self = shift; |
299 | my $name = shift; |
300 | |
7ca5c5fb |
301 | return ref($self)->new($name, %{$self}, (@_ == 1) ? %{$_[0]} : @_); |
1b9e472d |
302 | } |
303 | |
1bfebf5f |
304 | sub clone_parent { |
305 | my $self = shift; |
306 | my $class = shift; |
307 | my $name = shift; |
308 | my %args = ($self->get_parent_args($class, $name), @_); |
309 | |
1b9e472d |
310 | Carp::cluck("$self->clone_parent has been deprecated." |
311 | . "Use \$meta->add_attribute and \$attr->install_accessors instead."); |
312 | |
313 | |
7ca5c5fb |
314 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
315 | } |
316 | |
317 | sub get_parent_args { |
318 | my $self = shift; |
319 | my $class = shift; |
320 | my $name = shift; |
321 | |
724c77c0 |
322 | for my $super ($class->linearized_isa) { |
bb733405 |
323 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
324 | or next; |
325 | return %{ $super_attr->_create_args }; |
326 | } |
327 | |
fce211ae |
328 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
329 | } |
330 | |
1b9e472d |
331 | sub install_accessors{ |
332 | my($attribute) = @_; |
333 | |
334 | my $metaclass = $attribute->{associated_class}; |
1b9e472d |
335 | |
336 | foreach my $type(qw(accessor reader writer predicate clearer handles)){ |
337 | if(exists $attribute->{$type}){ |
338 | my $installer = '_install_' . $type; |
7ca5c5fb |
339 | |
340 | Mouse::Meta::Method::Accessor->$installer($attribute, $attribute->{$type}, $metaclass); |
341 | |
1b9e472d |
342 | $attribute->{associated_methods}++; |
343 | } |
344 | } |
345 | |
346 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
347 | # backword compatibility |
1b9e472d |
348 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
349 | } |
350 | |
351 | return; |
352 | } |
353 | |
fce211ae |
354 | sub throw_error{ |
355 | my $self = shift; |
356 | |
357 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
358 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
359 | } |
360 | |
c3398f5b |
361 | 1; |
362 | |
363 | __END__ |
364 | |
365 | =head1 NAME |
366 | |
306290e8 |
367 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
368 | |
369 | =head1 METHODS |
370 | |
1820fffe |
371 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
372 | |
306290e8 |
373 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
374 | |
1820fffe |
375 | It adds the following options to the constructor: |
c3398f5b |
376 | |
1820fffe |
377 | =over 4 |
c3398f5b |
378 | |
612d3e1a |
379 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
380 | |
1820fffe |
381 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
382 | C<accessor> names. If the attribute is read-only ('ro') then it will |
383 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
384 | |
1820fffe |
385 | If it is read-write ('rw') then it will have an C<accessor> method |
386 | with the same name. If you provide an explicit C<writer> for a |
387 | read-write attribute, then you will have a C<reader> with the same |
388 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
389 | |
1820fffe |
390 | Use 'bare' when you are deliberately not installing any methods |
391 | (accessor, reader, etc.) associated with this attribute; otherwise, |
392 | Moose will issue a deprecation warning when this attribute is added to a |
393 | metaclass. |
c3398f5b |
394 | |
612d3e1a |
395 | =item C<< isa => Type >> |
ab27a55e |
396 | |
1820fffe |
397 | This option accepts a type. The type can be a string, which should be |
398 | a type name. If the type name is unknown, it is assumed to be a class |
399 | name. |
ab27a55e |
400 | |
1820fffe |
401 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
402 | |
1820fffe |
403 | If you I<also> provide a C<does> option, then your C<isa> option must |
404 | be a class name, and that class must do the role specified with |
405 | C<does>. |
ab27a55e |
406 | |
612d3e1a |
407 | =item C<< does => Role >> |
ab27a55e |
408 | |
1820fffe |
409 | This is short-hand for saying that the attribute's type must be an |
410 | object which does the named role. |
c3398f5b |
411 | |
1820fffe |
412 | B<This option is not yet supported.> |
c3398f5b |
413 | |
612d3e1a |
414 | =item C<< coerce => Bool >> |
ab27a55e |
415 | |
1820fffe |
416 | This option is only valid for objects with a type constraint |
417 | (C<isa>). If this is true, then coercions will be applied whenever |
418 | this attribute is set. |
c3398f5b |
419 | |
1820fffe |
420 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
421 | |
612d3e1a |
422 | =item C<< trigger => CodeRef >> |
ab27a55e |
423 | |
1820fffe |
424 | This option accepts a subroutine reference, which will be called after |
425 | the attribute is set. |
ab27a55e |
426 | |
612d3e1a |
427 | =item C<< required => Bool >> |
ab27a55e |
428 | |
1820fffe |
429 | An attribute which is required must be provided to the constructor. An |
430 | attribute which is required can also have a C<default> or C<builder>, |
431 | which will satisfy its required-ness. |
ab27a55e |
432 | |
1820fffe |
433 | A required attribute must have a C<default>, C<builder> or a |
434 | non-C<undef> C<init_arg> |
ab27a55e |
435 | |
612d3e1a |
436 | =item C<< lazy => Bool >> |
ab27a55e |
437 | |
1820fffe |
438 | A lazy attribute must have a C<default> or C<builder>. When an |
439 | attribute is lazy, the default value will not be calculated until the |
440 | attribute is read. |
93f08899 |
441 | |
612d3e1a |
442 | =item C<< weak_ref => Bool >> |
0fff36e6 |
443 | |
1820fffe |
444 | If this is true, the attribute's value will be stored as a weak |
445 | reference. |
c3398f5b |
446 | |
612d3e1a |
447 | =item C<< auto_deref => Bool >> |
fb706f5c |
448 | |
1820fffe |
449 | If this is true, then the reader will dereference the value when it is |
450 | called. The attribute must have a type constraint which defines the |
451 | attribute as an array or hash reference. |
452 | |
612d3e1a |
453 | =item C<< lazy_build => Bool >> |
1820fffe |
454 | |
455 | Setting this to true makes the attribute lazy and provides a number of |
456 | default methods. |
fb706f5c |
457 | |
1820fffe |
458 | has 'size' => ( |
459 | is => 'ro', |
460 | lazy_build => 1, |
461 | ); |
93d190e0 |
462 | |
1820fffe |
463 | is equivalent to this: |
93d190e0 |
464 | |
1820fffe |
465 | has 'size' => ( |
466 | is => 'ro', |
467 | lazy => 1, |
468 | builder => '_build_size', |
469 | clearer => 'clear_size', |
470 | predicate => 'has_size', |
471 | ); |
93d190e0 |
472 | |
1820fffe |
473 | =back |
474 | |
475 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
476 | |
477 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
478 | on success, otherwise C<confess>es. |
93d190e0 |
479 | |
1820fffe |
480 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
481 | |
612d3e1a |
482 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
483 | Accessors and helper methods are installed. Some error checking is done. |
484 | |
1820fffe |
485 | =head1 SEE ALSO |
f7b11a21 |
486 | |
1820fffe |
487 | L<Moose::Meta::Attribute> |
f7b11a21 |
488 | |
c3398f5b |
489 | =cut |
490 | |