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 | |
7d2a0f10 |
8 | my %valid_options = map { $_ => undef } ( |
9 | 'accessor', |
10 | 'auto_deref', |
11 | 'builder', |
12 | 'clearer', |
13 | 'coerce', |
14 | 'default', |
15 | 'documentation', |
16 | 'does', |
17 | 'handles', |
18 | 'init_arg', |
beb51b30 |
19 | 'insertion_order', |
7d2a0f10 |
20 | 'is', |
21 | 'isa', |
22 | 'lazy', |
23 | 'lazy_build', |
24 | 'name', |
25 | 'predicate', |
26 | 'reader', |
27 | 'required', |
28 | 'traits', |
29 | 'trigger', |
30 | 'type_constraint', |
31 | 'weak_ref', |
32 | 'writer', |
33 | |
34 | # internally used |
35 | 'associated_class', |
36 | 'associated_methods', |
b68e184f |
37 | '__METACLASS__', |
7d2a0f10 |
38 | |
39 | # Moose defines, but Mouse doesn't |
40 | #'definition_context', |
41 | #'initializer', |
7d2a0f10 |
42 | |
43 | # special case for AttributeHelpers |
44 | 'provides', |
45 | 'curries', |
46 | ); |
87ca293b |
47 | |
431e4817 |
48 | our @CARP_NOT = qw(Mouse::Meta::Class); |
49 | |
87ca293b |
50 | sub new { |
51 | my $class = shift; |
52 | my $name = shift; |
53 | |
2053291d |
54 | my $args = $class->Mouse::Object::BUILDARGS(@_); |
ba1f50a2 |
55 | |
2053291d |
56 | $class->_process_options($name, $args); |
87ca293b |
57 | |
2053291d |
58 | $args->{name} = $name; |
87ca293b |
59 | |
7d2a0f10 |
60 | # check options |
61 | # (1) known by core |
62 | my @bad = grep{ !exists $valid_options{$_} } keys %{$args}; |
63 | |
64 | # (2) known by subclasses |
65 | if(@bad && $class ne __PACKAGE__){ |
66 | my %valid_attrs = ( |
67 | map { $_ => undef } |
68 | grep { defined } |
69 | map { $_->init_arg() } |
70 | $class->meta->get_all_attributes() |
71 | ); |
72 | @bad = grep{ !exists $valid_attrs{$_} } @bad; |
73 | } |
74 | |
75 | # (3) bad options found |
76 | if(@bad){ |
431e4817 |
77 | Carp::carp( |
78 | "Found unknown argument(s) passed to '$name' attribute constructor in '$class': " |
79 | . Mouse::Util::english_list(@bad)); |
7d2a0f10 |
80 | } |
81 | |
2053291d |
82 | my $self = bless $args, $class; |
1b9e472d |
83 | if($class ne __PACKAGE__){ |
2053291d |
84 | $class->meta->_initialize_object($self, $args); |
90fe520e |
85 | } |
926290ac |
86 | return $self; |
c3398f5b |
87 | } |
88 | |
fab60206 |
89 | sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor } |
90 | sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor } |
91 | |
92 | sub get_read_method { $_[0]->reader || $_[0]->accessor } |
93 | sub get_write_method { $_[0]->writer || $_[0]->accessor } |
94 | |
95 | sub get_read_method_ref{ |
96 | my($self) = @_; |
e8ad67f0 |
97 | return $self->{_mouse_cache_read_method_ref} |
fab60206 |
98 | ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader'); |
99 | } |
100 | |
101 | sub get_write_method_ref{ |
102 | my($self) = @_; |
e8ad67f0 |
103 | return $self->{_mouse_cache_write_method_ref} |
fab60206 |
104 | ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer'); |
105 | } |
1b9e472d |
106 | |
87ca293b |
107 | sub interpolate_class{ |
8cf51b82 |
108 | my($class, $args) = @_; |
c3398f5b |
109 | |
1b9e472d |
110 | if(my $metaclass = delete $args->{metaclass}){ |
111 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
112 | } |
1bfebf5f |
113 | |
87ca293b |
114 | my @traits; |
1b9e472d |
115 | if(my $traits_ref = delete $args->{traits}){ |
87ca293b |
116 | |
f3f04eed |
117 | for (my $i = 0; $i < @{$traits_ref}; $i++) { |
118 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1); |
b2500191 |
119 | |
f3f04eed |
120 | next if $class->does($trait); |
74be9f76 |
121 | |
f3f04eed |
122 | push @traits, $trait; |
1b9e472d |
123 | |
f3f04eed |
124 | # are there options? |
125 | push @traits, $traits_ref->[++$i] |
126 | if ref($traits_ref->[$i+1]); |
127 | } |
c3398f5b |
128 | |
1b9e472d |
129 | if (@traits) { |
130 | $class = Mouse::Meta::Class->create_anon_class( |
131 | superclasses => [ $class ], |
132 | roles => \@traits, |
133 | cache => 1, |
134 | )->name; |
1b9e472d |
135 | } |
74be9f76 |
136 | } |
137 | |
87ca293b |
138 | return( $class, @traits ); |
1b9e472d |
139 | } |
140 | |
20e25eb9 |
141 | sub verify_against_type_constraint { |
f55f60dd |
142 | my ($self, $value) = @_; |
5aa30ced |
143 | |
ffbbf459 |
144 | my $type_constraint = $self->{type_constraint}; |
4331a3f9 |
145 | return 1 if !$type_constraint; |
ffbbf459 |
146 | return 1 if $type_constraint->check($value); |
5aa30ced |
147 | |
da23cd4a |
148 | $self->_throw_type_constraint_error($value, $type_constraint); |
b3b74cc6 |
149 | } |
5aa30ced |
150 | |
da23cd4a |
151 | sub _throw_type_constraint_error { |
2a96ea85 |
152 | my($self, $value, $type) = @_; |
153 | |
154 | $self->throw_error( |
155 | sprintf q{Attribute (%s) does not pass the type constraint because: %s}, |
156 | $self->name, |
157 | $type->get_message($value), |
158 | ); |
5aa30ced |
159 | } |
160 | |
df7e4729 |
161 | sub illegal_options_for_inheritance { |
b4d32aba |
162 | return qw(reader writer accessor clearer predicate); |
df7e4729 |
163 | } |
164 | |
1b9e472d |
165 | sub clone_and_inherit_options{ |
2053291d |
166 | my $self = shift; |
167 | my $args = $self->Mouse::Object::BUILDARGS(@_); |
8cf51b82 |
168 | |
df7e4729 |
169 | foreach my $illegal($self->illegal_options_for_inheritance) { |
4a07d076 |
170 | if(exists $args->{$illegal} and exists $self->{$illegal}) { |
df7e4729 |
171 | $self->throw_error("Illegal inherited option: $illegal"); |
172 | } |
173 | } |
1b9e472d |
174 | |
4f41d79b |
175 | foreach my $name(keys %{$self}){ |
df7e4729 |
176 | if(!exists $args->{$name}){ |
177 | $args->{$name} = $self->{$name}; # inherit from self |
4f41d79b |
178 | } |
179 | } |
7d2a0f10 |
180 | |
df7e4729 |
181 | my($attribute_class, @traits) = ref($self)->interpolate_class($args); |
182 | $args->{traits} = \@traits if @traits; |
183 | |
7d2a0f10 |
184 | # remove temporary caches |
185 | foreach my $attr(keys %{$args}){ |
e8ad67f0 |
186 | if($attr =~ /\A _mouse_cache_/xms){ |
7d2a0f10 |
187 | delete $args->{$attr}; |
188 | } |
189 | } |
190 | |
df7e4729 |
191 | # remove default if lazy_build => 1 |
192 | if($args->{lazy_build}) { |
193 | delete $args->{default}; |
194 | } |
195 | |
2053291d |
196 | return $attribute_class->new($self->name, $args); |
1b9e472d |
197 | } |
198 | |
751de1a1 |
199 | |
200 | sub _get_accessor_method_ref { |
201 | my($self, $type, $generator) = @_; |
202 | |
203 | my $metaclass = $self->associated_class |
204 | || $self->throw_error('No asocciated class for ' . $self->name); |
205 | |
206 | my $accessor = $self->$type(); |
207 | if($accessor){ |
208 | return $metaclass->get_method_body($accessor); |
209 | } |
210 | else{ |
211 | return $self->accessor_metaclass->$generator($self, $metaclass); |
212 | } |
df77fd72 |
213 | } |
2a464664 |
214 | |
751de1a1 |
215 | sub set_value { |
216 | my($self, $object, $value) = @_; |
217 | return $self->get_write_method_ref()->($object, $value); |
218 | } |
219 | |
220 | sub get_value { |
221 | my($self, $object) = @_; |
222 | return $self->get_read_method_ref()->($object); |
2a464664 |
223 | } |
224 | |
751de1a1 |
225 | sub has_value { |
226 | my($self, $object) = @_; |
e8ad67f0 |
227 | my $accessor_ref = $self->{_mouse_cache_predicate_ref} |
751de1a1 |
228 | ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate'); |
229 | |
060f9228 |
230 | return $accessor_ref->($object); |
751de1a1 |
231 | } |
232 | |
233 | sub clear_value { |
234 | my($self, $object) = @_; |
e8ad67f0 |
235 | my $accessor_ref = $self->{_mouse_cache_crealer_ref} |
751de1a1 |
236 | ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer'); |
237 | |
060f9228 |
238 | return $accessor_ref->($object); |
751de1a1 |
239 | } |
240 | |
04493075 |
241 | sub associate_method{ |
230dd14a |
242 | #my($attribute, $method_name) = @_; |
243 | my($attribute) = @_; |
04493075 |
244 | $attribute->{associated_methods}++; |
245 | return; |
246 | } |
247 | |
1b9e472d |
248 | sub install_accessors{ |
249 | my($attribute) = @_; |
250 | |
93540011 |
251 | my $metaclass = $attribute->associated_class; |
4ab51fb0 |
252 | my $accessor_class = $attribute->accessor_metaclass; |
1b9e472d |
253 | |
4ab51fb0 |
254 | foreach my $type(qw(accessor reader writer predicate clearer)){ |
1b9e472d |
255 | if(exists $attribute->{$type}){ |
4ab51fb0 |
256 | my $generator = '_generate_' . $type; |
257 | my $code = $accessor_class->$generator($attribute, $metaclass); |
258 | $metaclass->add_method($attribute->{$type} => $code); |
e5e22afd |
259 | $attribute->associate_method($attribute->{$type}); |
4ab51fb0 |
260 | } |
261 | } |
7ca5c5fb |
262 | |
4ab51fb0 |
263 | # install delegation |
264 | if(exists $attribute->{handles}){ |
84f321d9 |
265 | my %handles = $attribute->_canonicalize_handles(); |
feaa7084 |
266 | |
cbb81058 |
267 | while(my($handle, $method_to_call) = each %handles){ |
df7e4729 |
268 | if($metaclass->has_method($handle)) { |
269 | $attribute->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation"); |
270 | } |
271 | |
cbb81058 |
272 | $metaclass->add_method($handle => |
273 | $attribute->_make_delegation_method( |
274 | $handle, $method_to_call)); |
4ab51fb0 |
275 | |
cbb81058 |
276 | $attribute->associate_method($handle); |
1b9e472d |
277 | } |
278 | } |
279 | |
1b9e472d |
280 | return; |
281 | } |
282 | |
a4b15169 |
283 | sub delegation_metaclass() { ## no critic |
284 | 'Mouse::Meta::Method::Delegation' |
285 | } |
cbb81058 |
286 | |
287 | sub _canonicalize_handles { |
84f321d9 |
288 | my($self) = @_; |
289 | my $handles = $self->{handles}; |
cbb81058 |
290 | |
84f321d9 |
291 | my $handle_type = ref $handles; |
292 | if ($handle_type eq 'HASH') { |
cbb81058 |
293 | return %$handles; |
294 | } |
84f321d9 |
295 | elsif ($handle_type eq 'ARRAY') { |
cbb81058 |
296 | return map { $_ => $_ } @$handles; |
297 | } |
84f321d9 |
298 | elsif ($handle_type eq 'Regexp') { |
299 | my $meta = $self->_find_delegate_metaclass(); |
cbb81058 |
300 | return map { $_ => $_ } |
301 | grep { !Mouse::Object->can($_) && $_ =~ $handles } |
302 | Mouse::Util::is_a_metarole($meta) |
303 | ? $meta->get_method_list |
304 | : $meta->get_all_method_names; |
305 | } |
84f321d9 |
306 | elsif ($handle_type eq 'CODE') { |
307 | return $handles->( $self, $self->_find_delegate_metaclass() ); |
308 | } |
cbb81058 |
309 | else { |
310 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
311 | } |
312 | } |
313 | |
84f321d9 |
314 | sub _find_delegate_metaclass { |
315 | my($self) = @_; |
316 | my $meta; |
317 | if($self->{isa}) { |
318 | $meta = Mouse::Meta::Class->initialize("$self->{isa}"); |
319 | } |
320 | elsif($self->{does}) { |
321 | $meta = Mouse::Util::get_metaclass_by_name("$self->{does}"); |
322 | } |
323 | defined($meta) or $self->throw_error( |
324 | "Cannot find delegate metaclass for attribute " . $self->name); |
325 | return $meta; |
326 | } |
327 | |
328 | |
cbb81058 |
329 | sub _make_delegation_method { |
330 | my($self, $handle, $method_to_call) = @_; |
637d4f17 |
331 | return Mouse::Util::load_class($self->delegation_metaclass) |
332 | ->_generate_delegation($self, $handle, $method_to_call); |
cbb81058 |
333 | } |
334 | |
c3398f5b |
335 | 1; |
c3398f5b |
336 | __END__ |
337 | |
338 | =head1 NAME |
339 | |
bedd575c |
340 | Mouse::Meta::Attribute - The Mouse attribute metaclass |
c3398f5b |
341 | |
a25ca8d6 |
342 | =head1 VERSION |
343 | |
32ec255c |
344 | This document describes Mouse version 0.75 |
a25ca8d6 |
345 | |
503ed648 |
346 | =head1 DESCRIPTION |
347 | |
348 | This is a meta object protocol for Mouse attributes, |
349 | which is a subset of Moose::Meta::Attribute. |
350 | |
c3398f5b |
351 | =head1 METHODS |
352 | |
1820fffe |
353 | =head2 C<< new(%options) -> Mouse::Meta::Attribute >> |
c3398f5b |
354 | |
306290e8 |
355 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
c3398f5b |
356 | |
1820fffe |
357 | It adds the following options to the constructor: |
c3398f5b |
358 | |
1820fffe |
359 | =over 4 |
c3398f5b |
360 | |
612d3e1a |
361 | =item C<< is => 'ro', 'rw', 'bare' >> |
c3398f5b |
362 | |
1820fffe |
363 | This provides a shorthand for specifying the C<reader>, C<writer>, or |
364 | C<accessor> names. If the attribute is read-only ('ro') then it will |
365 | have a C<reader> method with the same attribute as the name. |
c3398f5b |
366 | |
1820fffe |
367 | If it is read-write ('rw') then it will have an C<accessor> method |
368 | with the same name. If you provide an explicit C<writer> for a |
369 | read-write attribute, then you will have a C<reader> with the same |
370 | name as the attribute, and a C<writer> with the name you provided. |
c3398f5b |
371 | |
1820fffe |
372 | Use 'bare' when you are deliberately not installing any methods |
373 | (accessor, reader, etc.) associated with this attribute; otherwise, |
374 | Moose will issue a deprecation warning when this attribute is added to a |
375 | metaclass. |
c3398f5b |
376 | |
612d3e1a |
377 | =item C<< isa => Type >> |
ab27a55e |
378 | |
1820fffe |
379 | This option accepts a type. The type can be a string, which should be |
380 | a type name. If the type name is unknown, it is assumed to be a class |
381 | name. |
ab27a55e |
382 | |
1820fffe |
383 | This option can also accept a L<Moose::Meta::TypeConstraint> object. |
ab27a55e |
384 | |
1820fffe |
385 | If you I<also> provide a C<does> option, then your C<isa> option must |
386 | be a class name, and that class must do the role specified with |
387 | C<does>. |
ab27a55e |
388 | |
612d3e1a |
389 | =item C<< does => Role >> |
ab27a55e |
390 | |
1820fffe |
391 | This is short-hand for saying that the attribute's type must be an |
392 | object which does the named role. |
c3398f5b |
393 | |
1820fffe |
394 | B<This option is not yet supported.> |
c3398f5b |
395 | |
612d3e1a |
396 | =item C<< coerce => Bool >> |
ab27a55e |
397 | |
1820fffe |
398 | This option is only valid for objects with a type constraint |
399 | (C<isa>). If this is true, then coercions will be applied whenever |
400 | this attribute is set. |
c3398f5b |
401 | |
1820fffe |
402 | You can make both this and the C<weak_ref> option true. |
c3398f5b |
403 | |
612d3e1a |
404 | =item C<< trigger => CodeRef >> |
ab27a55e |
405 | |
1820fffe |
406 | This option accepts a subroutine reference, which will be called after |
407 | the attribute is set. |
ab27a55e |
408 | |
612d3e1a |
409 | =item C<< required => Bool >> |
ab27a55e |
410 | |
1820fffe |
411 | An attribute which is required must be provided to the constructor. An |
412 | attribute which is required can also have a C<default> or C<builder>, |
413 | which will satisfy its required-ness. |
ab27a55e |
414 | |
1820fffe |
415 | A required attribute must have a C<default>, C<builder> or a |
416 | non-C<undef> C<init_arg> |
ab27a55e |
417 | |
612d3e1a |
418 | =item C<< lazy => Bool >> |
ab27a55e |
419 | |
1820fffe |
420 | A lazy attribute must have a C<default> or C<builder>. When an |
421 | attribute is lazy, the default value will not be calculated until the |
422 | attribute is read. |
93f08899 |
423 | |
612d3e1a |
424 | =item C<< weak_ref => Bool >> |
0fff36e6 |
425 | |
1820fffe |
426 | If this is true, the attribute's value will be stored as a weak |
427 | reference. |
c3398f5b |
428 | |
612d3e1a |
429 | =item C<< auto_deref => Bool >> |
fb706f5c |
430 | |
1820fffe |
431 | If this is true, then the reader will dereference the value when it is |
432 | called. The attribute must have a type constraint which defines the |
433 | attribute as an array or hash reference. |
434 | |
612d3e1a |
435 | =item C<< lazy_build => Bool >> |
1820fffe |
436 | |
437 | Setting this to true makes the attribute lazy and provides a number of |
438 | default methods. |
fb706f5c |
439 | |
1820fffe |
440 | has 'size' => ( |
441 | is => 'ro', |
442 | lazy_build => 1, |
443 | ); |
93d190e0 |
444 | |
1820fffe |
445 | is equivalent to this: |
93d190e0 |
446 | |
1820fffe |
447 | has 'size' => ( |
448 | is => 'ro', |
449 | lazy => 1, |
450 | builder => '_build_size', |
451 | clearer => 'clear_size', |
452 | predicate => 'has_size', |
453 | ); |
93d190e0 |
454 | |
1820fffe |
455 | =back |
456 | |
e5e22afd |
457 | =head2 C<< associate_method(MethodName) >> |
31c5194b |
458 | |
459 | Associates a method with the attribute. Typically, this is called internally |
460 | when an attribute generates its accessors. |
461 | |
e5e22afd |
462 | Currently the argument I<MethodName> is ignored in Mouse. |
31c5194b |
463 | |
1820fffe |
464 | =head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >> |
465 | |
466 | Checks that the given value passes this attribute's type constraint. Returns C<true> |
467 | on success, otherwise C<confess>es. |
93d190e0 |
468 | |
1820fffe |
469 | =head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >> |
f7b11a21 |
470 | |
612d3e1a |
471 | Creates a new attribute in the owner class, inheriting options from parent classes. |
f7b11a21 |
472 | Accessors and helper methods are installed. Some error checking is done. |
473 | |
9ae9702e |
474 | =head2 C<< get_read_method_ref >> |
475 | |
476 | =head2 C<< get_write_method_ref >> |
477 | |
478 | Returns the subroutine reference of a method suitable for reading or |
479 | writing the attribute's value in the associated class. These methods |
480 | always return a subroutine reference, regardless of whether or not the |
df77fd72 |
481 | attribute is read- or write-only. |
482 | |
1820fffe |
483 | =head1 SEE ALSO |
f7b11a21 |
484 | |
1820fffe |
485 | L<Moose::Meta::Attribute> |
f7b11a21 |
486 | |
31c5194b |
487 | L<Class::MOP::Attribute> |
488 | |
c3398f5b |
489 | =cut |
490 | |