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 | |
87ca293b |
8 | |
9 | sub new { |
10 | my $class = shift; |
11 | my $name = shift; |
12 | |
13 | my %args = (@_ == 1) ? %{ $_[0] } : @_; |
14 | |
ba1f50a2 |
15 | |
16 | # XXX: for backward compatibility (with method modifiers) |
17 | if($class->can('canonicalize_args') != \&canonicalize_args){ |
18 | %args = $class->canonicalize_args($name, %args); |
19 | } |
20 | |
87ca293b |
21 | $class->_process_options($name, \%args); |
22 | |
23 | $args{name} = $name; |
24 | |
926290ac |
25 | my $self = bless \%args, $class; |
2efc0af1 |
26 | |
1b9e472d |
27 | # extra attributes |
28 | if($class ne __PACKAGE__){ |
926290ac |
29 | $class->meta->_initialize_object($self, \%args); |
90fe520e |
30 | } |
c3398f5b |
31 | |
2efc0af1 |
32 | # XXX: there is no fast way to check attribute validity |
1b9e472d |
33 | # my @bad = ...; |
2efc0af1 |
34 | # if(@bad){ |
35 | # @bad = sort @bad; |
36 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
37 | # } |
38 | |
926290ac |
39 | return $self; |
c3398f5b |
40 | } |
41 | |
43165725 |
42 | sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } |
43 | sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } |
1b9e472d |
44 | |
df77fd72 |
45 | sub _create_args { # DEPRECATED |
1bfebf5f |
46 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
47 | $_[0]->{_create_args} |
48 | } |
49 | |
87ca293b |
50 | sub interpolate_class{ |
8cf51b82 |
51 | my($class, $args) = @_; |
c3398f5b |
52 | |
1b9e472d |
53 | if(my $metaclass = delete $args->{metaclass}){ |
54 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
55 | } |
1bfebf5f |
56 | |
87ca293b |
57 | my @traits; |
1b9e472d |
58 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
59 | |
f3f04eed |
60 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
61 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
62 | |
f3f04eed |
63 | next if $class->does($trait); |
74be9f76 |
64 | |
f3f04eed |
65 | push @traits, $trait; |
1b9e472d |
66 | |
f3f04eed |
67 | # are there options? |
68 | push @traits, $traits_ref->[++$i] |
69 | if ref($traits_ref->[$i+1]); |
70 | } |
c3398f5b |
71 | |
1b9e472d |
72 | if (@traits) { |
73 | $class = Mouse::Meta::Class->create_anon_class( |
74 | superclasses => [ $class ], |
75 | roles => \@traits, |
76 | cache => 1, |
77 | )->name; |
1b9e472d |
78 | } |
74be9f76 |
79 | } |
80 | |
87ca293b |
81 | return( $class, @traits ); |
1b9e472d |
82 | } |
83 | |
df77fd72 |
84 | sub canonicalize_args{ # DEPRECATED |
1b9e472d |
85 | my ($self, $name, %args) = @_; |
86 | |
87 | Carp::cluck("$self->canonicalize_args has been deprecated." |
da23cd4a |
88 | . "Use \$self->_process_options instead."); |
1b9e472d |
89 | |
90 | return %args; |
91 | } |
92 | |
ce5920b7 |
93 | sub create { # DEPRECATED |
1b9e472d |
94 | my ($self, $class, $name, %args) = @_; |
95 | |
96 | Carp::cluck("$self->create has been deprecated." |
da23cd4a |
97 | . "Use \$meta->add_attribute and \$attr->install_accessors instead."); |
1b9e472d |
98 | |
99 | # noop |
100 | return $self; |
c3398f5b |
101 | } |
102 | |
ffbbf459 |
103 | sub _coerce_and_verify { |
104 | my($self, $value, $instance) = @_; |
105 | |
106 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
107 | return $value if !defined $type_constraint; |
ffbbf459 |
108 | |
109 | if ($self->should_coerce && $type_constraint->has_coercion) { |
110 | $value = $type_constraint->coerce($value); |
111 | } |
112 | |
ffbbf459 |
113 | $self->verify_against_type_constraint($value); |
114 | |
115 | return $value; |
116 | } |
117 | |
20e25eb9 |
118 | sub verify_against_type_constraint { |
f55f60dd |
119 | my ($self, $value) = @_; |
5aa30ced |
120 | |
ffbbf459 |
121 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
122 | return 1 if !$type_constraint; |
ffbbf459 |
123 | return 1 if $type_constraint->check($value); |
5aa30ced |
124 | |
da23cd4a |
125 | $self->_throw_type_constraint_error($value, $type_constraint); |
b3b74cc6 |
126 | } |
5aa30ced |
127 | |
da23cd4a |
128 | sub _throw_type_constraint_error { |
2a96ea85 |
129 | my($self, $value, $type) = @_; |
130 | |
131 | $self->throw_error( |
132 | sprintf q{Attribute (%s) does not pass the type constraint because: %s}, |
133 | $self->name, |
134 | $type->get_message($value), |
135 | ); |
5aa30ced |
136 | } |
137 | |
1b9e472d |
138 | sub clone_and_inherit_options{ |
8cf51b82 |
139 | my($self, %args) = @_; |
140 | |
141 | my($attribute_class, @traits) = ref($self)->interpolate_class(\%args); |
1b9e472d |
142 | |
8cf51b82 |
143 | $args{traits} = \@traits if @traits; |
4f41d79b |
144 | # do not inherit the 'handles' attribute |
145 | foreach my $name(keys %{$self}){ |
146 | if(!exists $args{$name} && $name ne 'handles'){ |
147 | $args{$name} = $self->{$name}; |
148 | } |
149 | } |
150 | return $attribute_class->new($self->name, %args); |
1b9e472d |
151 | } |
152 | |
df77fd72 |
153 | sub clone_parent { # DEPRECATED |
1bfebf5f |
154 | my $self = shift; |
155 | my $class = shift; |
156 | my $name = shift; |
157 | my %args = ($self->get_parent_args($class, $name), @_); |
158 | |
1b9e472d |
159 | Carp::cluck("$self->clone_parent has been deprecated." |
da23cd4a |
160 | . "Use \$meta->add_attribute and \$attr->install_accessors instead."); |
1b9e472d |
161 | |
7ca5c5fb |
162 | $self->clone_and_inherited_args($class, $name, %args); |
1bfebf5f |
163 | } |
164 | |
df77fd72 |
165 | sub get_parent_args { # DEPRECATED |
1bfebf5f |
166 | my $self = shift; |
167 | my $class = shift; |
168 | my $name = shift; |
169 | |
724c77c0 |
170 | for my $super ($class->linearized_isa) { |
bb733405 |
171 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
172 | or next; |
173 | return %{ $super_attr->_create_args }; |
174 | } |
175 | |
fce211ae |
176 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
177 | } |
178 | |
2a464664 |
179 | |
0126c27c |
180 | sub get_read_method { |
751de1a1 |
181 | return $_[0]->reader || $_[0]->accessor |
df77fd72 |
182 | } |
0126c27c |
183 | sub get_write_method { |
751de1a1 |
184 | return $_[0]->writer || $_[0]->accessor |
185 | } |
186 | |
187 | sub _get_accessor_method_ref { |
188 | my($self, $type, $generator) = @_; |
189 | |
190 | my $metaclass = $self->associated_class |
191 | || $self->throw_error('No asocciated class for ' . $self->name); |
192 | |
193 | my $accessor = $self->$type(); |
194 | if($accessor){ |
195 | return $metaclass->get_method_body($accessor); |
196 | } |
197 | else{ |
198 | return $self->accessor_metaclass->$generator($self, $metaclass); |
199 | } |
df77fd72 |
200 | } |
2a464664 |
201 | |
202 | sub get_read_method_ref{ |
203 | my($self) = @_; |
751de1a1 |
204 | return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader'); |
2a464664 |
205 | } |
206 | |
207 | sub get_write_method_ref{ |
208 | my($self) = @_; |
751de1a1 |
209 | return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer'); |
210 | } |
2a464664 |
211 | |
751de1a1 |
212 | sub set_value { |
213 | my($self, $object, $value) = @_; |
214 | return $self->get_write_method_ref()->($object, $value); |
215 | } |
216 | |
217 | sub get_value { |
218 | my($self, $object) = @_; |
219 | return $self->get_read_method_ref()->($object); |
2a464664 |
220 | } |
221 | |
751de1a1 |
222 | sub has_value { |
223 | my($self, $object) = @_; |
060f9228 |
224 | my $accessor_ref = $self->{_predicate_ref} |
751de1a1 |
225 | ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate'); |
226 | |
060f9228 |
227 | return $accessor_ref->($object); |
751de1a1 |
228 | } |
229 | |
230 | sub clear_value { |
231 | my($self, $object) = @_; |
060f9228 |
232 | my $accessor_ref = $self->{_crealer_ref} |
751de1a1 |
233 | ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer'); |
234 | |
060f9228 |
235 | return $accessor_ref->($object); |
751de1a1 |
236 | } |
237 | |
238 | |
04493075 |
239 | sub associate_method{ |
e5e22afd |
240 | my ($attribute, $method_name) = @_; |
04493075 |
241 | $attribute->{associated_methods}++; |
242 | return; |
243 | } |
244 | |
1b9e472d |
245 | sub install_accessors{ |
246 | my($attribute) = @_; |
247 | |
93540011 |
248 | my $metaclass = $attribute->associated_class; |
4ab51fb0 |
249 | my $accessor_class = $attribute->accessor_metaclass; |
1b9e472d |
250 | |
4ab51fb0 |
251 | foreach my $type(qw(accessor reader writer predicate clearer)){ |
1b9e472d |
252 | if(exists $attribute->{$type}){ |
4ab51fb0 |
253 | my $generator = '_generate_' . $type; |
254 | my $code = $accessor_class->$generator($attribute, $metaclass); |
255 | $metaclass->add_method($attribute->{$type} => $code); |
e5e22afd |
256 | $attribute->associate_method($attribute->{$type}); |
4ab51fb0 |
257 | } |
258 | } |
7ca5c5fb |
259 | |
4ab51fb0 |
260 | # install delegation |
261 | if(exists $attribute->{handles}){ |
262 | my %handles = $attribute->_canonicalize_handles($attribute->{handles}); |
feaa7084 |
263 | |
cbb81058 |
264 | while(my($handle, $method_to_call) = each %handles){ |
265 | $metaclass->add_method($handle => |
266 | $attribute->_make_delegation_method( |
267 | $handle, $method_to_call)); |
4ab51fb0 |
268 | |
cbb81058 |
269 | $attribute->associate_method($handle); |
1b9e472d |
270 | } |
271 | } |
272 | |
273 | if($attribute->can('create') != \&create){ |
7ca5c5fb |
274 | # backword compatibility |
1b9e472d |
275 | $attribute->create($metaclass, $attribute->name, %{$attribute}); |
276 | } |
277 | |
278 | return; |
279 | } |
280 | |
cbb81058 |
281 | sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' } |
282 | |
283 | sub _canonicalize_handles { |
284 | my($self, $handles) = @_; |
285 | |
286 | if (ref($handles) eq 'HASH') { |
287 | return %$handles; |
288 | } |
289 | elsif (ref($handles) eq 'ARRAY') { |
290 | return map { $_ => $_ } @$handles; |
291 | } |
7bc01428 |
292 | elsif ( ref($handles) eq 'CODE' ) { |
293 | my $class_or_role = ( $self->{isa} || $self->{does} ) |
294 | || $self->throw_error( "Cannot find delegate metaclass for attribute " . $self->name ); |
295 | return $handles->( $self, Mouse::Meta::Class->initialize("$class_or_role")); |
296 | } |
cbb81058 |
297 | elsif (ref($handles) eq 'Regexp') { |
298 | my $class_or_role = ($self->{isa} || $self->{does}) |
299 | || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)"); |
300 | |
301 | my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify |
302 | return map { $_ => $_ } |
303 | grep { !Mouse::Object->can($_) && $_ =~ $handles } |
304 | Mouse::Util::is_a_metarole($meta) |
305 | ? $meta->get_method_list |
306 | : $meta->get_all_method_names; |
307 | } |
308 | else { |
309 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
310 | } |
311 | } |
312 | |
313 | sub _make_delegation_method { |
314 | my($self, $handle, $method_to_call) = @_; |
315 | my $delegator = $self->delegation_metaclass; |
316 | Mouse::Util::load_class($delegator); |
317 | |
318 | return $delegator->_generate_delegation($self, $handle, $method_to_call); |
319 | } |
320 | |
fce211ae |
321 | sub throw_error{ |
322 | my $self = shift; |
323 | |
324 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
325 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
326 | } |
327 | |
c3398f5b |
328 | 1; |
c3398f5b |
329 | __END__ |
330 | |
331 | =head1 NAME |
332 | |
bedd575c |
333 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
334 | |
a25ca8d6 |
335 | =head1 VERSION |
336 | |
bd76a699 |
337 | This document describes Mouse version 0.47 |
a25ca8d6 |
338 | |
c3398f5b |
339 | =head1 METHODS |
340 | |
1820fffe |
341 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
342 | |
306290e8 |
343 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
344 | |
1820fffe |
345 | It adds the following options to the constructor: |
c3398f5b |
346 | |
1820fffe |
347 | =over 4 |
c3398f5b |
348 | |
612d3e1a |
349 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
350 | |
1820fffe |
351 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
352 | C<accessor> names. If the attribute is read-only ('ro') then it will |
353 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
354 | |
1820fffe |
355 | If it is read-write ('rw') then it will have an C<accessor> method |
356 | with the same name. If you provide an explicit C<writer> for a |
357 | read-write attribute, then you will have a C<reader> with the same |
358 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
359 | |
1820fffe |
360 | Use 'bare' when you are deliberately not installing any methods |
361 | (accessor, reader, etc.) associated with this attribute; otherwise, |
362 | Moose will issue a deprecation warning when this attribute is added to a |
363 | metaclass. |
c3398f5b |
364 | |
612d3e1a |
365 | =item C<< isa => Type >> |
ab27a55e |
366 | |
1820fffe |
367 | This option accepts a type. The type can be a string, which should be |
368 | a type name. If the type name is unknown, it is assumed to be a class |
369 | name. |
ab27a55e |
370 | |
1820fffe |
371 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
372 | |
1820fffe |
373 | If you I<also> provide a C<does> option, then your C<isa> option must |
374 | be a class name, and that class must do the role specified with |
375 | C<does>. |
ab27a55e |
376 | |
612d3e1a |
377 | =item C<< does => Role >> |
ab27a55e |
378 | |
1820fffe |
379 | This is short-hand for saying that the attribute's type must be an |
380 | object which does the named role. |
c3398f5b |
381 | |
1820fffe |
382 | B<This option is not yet supported.> |
c3398f5b |
383 | |
612d3e1a |
384 | =item C<< coerce => Bool >> |
ab27a55e |
385 | |
1820fffe |
386 | This option is only valid for objects with a type constraint |
387 | (C<isa>). If this is true, then coercions will be applied whenever |
388 | this attribute is set. |
c3398f5b |
389 | |
1820fffe |
390 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
391 | |
612d3e1a |
392 | =item C<< trigger => CodeRef >> |
ab27a55e |
393 | |
1820fffe |
394 | This option accepts a subroutine reference, which will be called after |
395 | the attribute is set. |
ab27a55e |
396 | |
612d3e1a |
397 | =item C<< required => Bool >> |
ab27a55e |
398 | |
1820fffe |
399 | An attribute which is required must be provided to the constructor. An |
400 | attribute which is required can also have a C<default> or C<builder>, |
401 | which will satisfy its required-ness. |
ab27a55e |
402 | |
1820fffe |
403 | A required attribute must have a C<default>, C<builder> or a |
404 | non-C<undef> C<init_arg> |
ab27a55e |
405 | |
612d3e1a |
406 | =item C<< lazy => Bool >> |
ab27a55e |
407 | |
1820fffe |
408 | A lazy attribute must have a C<default> or C<builder>. When an |
409 | attribute is lazy, the default value will not be calculated until the |
410 | attribute is read. |
93f08899 |
411 | |
612d3e1a |
412 | =item C<< weak_ref => Bool >> |
0fff36e6 |
413 | |
1820fffe |
414 | If this is true, the attribute's value will be stored as a weak |
415 | reference. |
c3398f5b |
416 | |
612d3e1a |
417 | =item C<< auto_deref => Bool >> |
fb706f5c |
418 | |
1820fffe |
419 | If this is true, then the reader will dereference the value when it is |
420 | called. The attribute must have a type constraint which defines the |
421 | attribute as an array or hash reference. |
422 | |
612d3e1a |
423 | =item C<< lazy_build => Bool >> |
1820fffe |
424 | |
425 | Setting this to true makes the attribute lazy and provides a number of |
426 | default methods. |
fb706f5c |
427 | |
1820fffe |
428 | has 'size' => ( |
429 | is => 'ro', |
430 | lazy_build => 1, |
431 | ); |
93d190e0 |
432 | |
1820fffe |
433 | is equivalent to this: |
93d190e0 |
434 | |
1820fffe |
435 | has 'size' => ( |
436 | is => 'ro', |
437 | lazy => 1, |
438 | builder => '_build_size', |
439 | clearer => 'clear_size', |
440 | predicate => 'has_size', |
441 | ); |
93d190e0 |
442 | |
1820fffe |
443 | =back |
444 | |
e5e22afd |
445 | =head2 C<< associate_method(MethodName) >> |
31c5194b |
446 | |
447 | Associates a method with the attribute. Typically, this is called internally |
448 | when an attribute generates its accessors. |
449 | |
e5e22afd |
450 | Currently the argument I<MethodName> is ignored in Mouse. |
31c5194b |
451 | |
1820fffe |
452 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
453 | |
454 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
455 | on success, otherwise C<confess>es. |
93d190e0 |
456 | |
1820fffe |
457 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
458 | |
612d3e1a |
459 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
460 | Accessors and helper methods are installed. Some error checking is done. |
461 | |
9ae9702e |
462 | =head2 C<< get_read_method_ref >> |
463 | |
464 | =head2 C<< get_write_method_ref >> |
465 | |
466 | Returns the subroutine reference of a method suitable for reading or |
467 | writing the attribute's value in the associated class. These methods |
468 | always return a subroutine reference, regardless of whether or not the |
df77fd72 |
469 | attribute is read- or write-only. |
470 | |
1820fffe |
471 | =head1 SEE ALSO |
f7b11a21 |
472 | |
1820fffe |
473 | L<Moose::Meta::Attribute> |
f7b11a21 |
474 | |
31c5194b |
475 | L<Class::MOP::Attribute> |
476 | |
c3398f5b |
477 | =cut |
478 | |