Commit | Line | Data |
c0e30cf5 |
1 | |
2 | package Moose::Meta::Attribute; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
21f1e231 |
7 | use Scalar::Util 'blessed', 'weaken'; |
a15dff8d |
8 | use Carp 'confess'; |
a909a4df |
9 | use overload (); |
a15dff8d |
10 | |
a94188ac |
11 | our $VERSION = '0.56'; |
d44714be |
12 | our $AUTHORITY = 'cpan:STEVAN'; |
78cd1d3b |
13 | |
8ee73eeb |
14 | use Moose::Meta::Method::Accessor; |
d5c30e52 |
15 | use Moose::Util (); |
a3c7e2fe |
16 | use Moose::Util::TypeConstraints (); |
bc1e29b5 |
17 | |
c0e30cf5 |
18 | use base 'Class::MOP::Attribute'; |
19 | |
452bac1b |
20 | # options which are not directly used |
21 | # but we store them for metadata purposes |
98aae381 |
22 | __PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata')); |
23 | __PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata')); |
24 | __PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); |
452bac1b |
25 | |
26 | # these are actual options for the attrs |
1a563243 |
27 | __PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); |
28 | __PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); |
26fbace8 |
29 | __PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' )); |
1a563243 |
30 | __PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); |
31 | __PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' )); |
32 | __PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref')); |
82168dbb |
33 | __PACKAGE__->meta->add_attribute('type_constraint' => ( |
34 | reader => 'type_constraint', |
35 | predicate => 'has_type_constraint', |
36 | )); |
8c9d74e7 |
37 | __PACKAGE__->meta->add_attribute('trigger' => ( |
38 | reader => 'trigger', |
39 | predicate => 'has_trigger', |
40 | )); |
452bac1b |
41 | __PACKAGE__->meta->add_attribute('handles' => ( |
42 | reader => 'handles', |
43 | predicate => 'has_handles', |
44 | )); |
ddbdc0cb |
45 | __PACKAGE__->meta->add_attribute('documentation' => ( |
46 | reader => 'documentation', |
47 | predicate => 'has_documentation', |
48 | )); |
82a5b1a7 |
49 | __PACKAGE__->meta->add_attribute('traits' => ( |
50 | reader => 'applied_traits', |
51 | predicate => 'has_applied_traits', |
52 | )); |
82168dbb |
53 | |
587e457d |
54 | # we need to have a ->does method in here to |
55 | # more easily support traits, and the introspection |
0db4f1d7 |
56 | # of those traits. We extend the does check to look |
57 | # for metatrait aliases. |
58 | sub does { |
59 | my ($self, $role_name) = @_; |
60 | my $name = eval { |
61 | Moose::Util::resolve_metatrait_alias(Attribute => $role_name) |
62 | }; |
63 | return 0 if !defined($name); # failed to load class |
64 | return Moose::Object::does($self, $name); |
65 | } |
587e457d |
66 | |
78cd1d3b |
67 | sub new { |
f3c4e20e |
68 | my ($class, $name, %options) = @_; |
c32c2c61 |
69 | $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS |
f3c4e20e |
70 | return $class->SUPER::new($name, %options); |
1d768fb1 |
71 | } |
72 | |
d5c30e52 |
73 | sub interpolate_class_and_new { |
74 | my ($class, $name, @args) = @_; |
75 | |
c32c2c61 |
76 | my ( $new_class, @traits ) = $class->interpolate_class(@args); |
77 | |
78 | $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); |
d5c30e52 |
79 | } |
80 | |
81 | sub interpolate_class { |
82 | my ($class, %options) = @_; |
83 | |
c32c2c61 |
84 | $class = ref($class) || $class; |
85 | |
86 | if ( my $metaclass_name = delete $options{metaclass} ) { |
87 | my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); |
88 | |
89 | if ( $class ne $new_class ) { |
90 | if ( $new_class->can("interpolate_class") ) { |
91 | return $new_class->interpolate_class(%options); |
92 | } else { |
93 | $class = $new_class; |
94 | } |
95 | } |
d5c30e52 |
96 | } |
97 | |
c32c2c61 |
98 | my @traits; |
99 | |
d5c30e52 |
100 | if (my $traits = $options{traits}) { |
c32c2c61 |
101 | if ( @traits = grep { not $class->does($_) } map { |
d5c30e52 |
102 | Moose::Util::resolve_metatrait_alias( Attribute => $_ ) |
103 | or |
104 | $_ |
c32c2c61 |
105 | } @$traits ) { |
106 | my $anon_class = Moose::Meta::Class->create_anon_class( |
107 | superclasses => [ $class ], |
108 | roles => [ @traits ], |
109 | cache => 1, |
110 | ); |
111 | |
112 | $class = $anon_class->name; |
113 | } |
d5c30e52 |
114 | } |
c32c2c61 |
115 | |
116 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
117 | } |
118 | |
713b0244 |
119 | # ... |
120 | |
121 | my @legal_options_for_inheritance = qw( |
122 | default coerce required |
123 | documentation lazy handles |
124 | builder type_constraint |
125 | ); |
126 | |
127 | sub legal_options_for_inheritance { @legal_options_for_inheritance } |
128 | |
129 | # NOTE/TODO |
130 | # This method *must* be able to handle |
131 | # Class::MOP::Attribute instances as |
132 | # well. Yes, I know that is wrong, but |
133 | # apparently we didn't realize it was |
134 | # doing that and now we have some code |
135 | # which is dependent on it. The real |
136 | # solution of course is to push this |
137 | # feature back up into Class::MOP::Attribute |
138 | # but I not right now, I am too lazy. |
139 | # However if you are reading this and |
140 | # looking for something to do,.. please |
141 | # be my guest. |
142 | # - stevan |
ce0e8d63 |
143 | sub clone_and_inherit_options { |
144 | my ($self, %options) = @_; |
713b0244 |
145 | |
c32c2c61 |
146 | my %copy = %options; |
713b0244 |
147 | |
ce0e8d63 |
148 | my %actual_options; |
713b0244 |
149 | |
150 | # NOTE: |
151 | # we may want to extends a Class::MOP::Attribute |
152 | # in which case we need to be able to use the |
153 | # core set of legal options that have always |
154 | # been here. But we allows Moose::Meta::Attribute |
155 | # instances to changes them. |
156 | # - SL |
157 | my @legal_options = $self->can('legal_options_for_inheritance') |
158 | ? $self->legal_options_for_inheritance |
159 | : @legal_options_for_inheritance; |
160 | |
161 | foreach my $legal_option (@legal_options) { |
ce0e8d63 |
162 | if (exists $options{$legal_option}) { |
163 | $actual_options{$legal_option} = $options{$legal_option}; |
164 | delete $options{$legal_option}; |
165 | } |
713b0244 |
166 | } |
26fbace8 |
167 | |
ce0e8d63 |
168 | if ($options{isa}) { |
169 | my $type_constraint; |
8de73ff1 |
170 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
171 | $type_constraint = $options{isa}; |
172 | } |
173 | else { |
d40ce9d5 |
174 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
175 | (defined $type_constraint) |
176 | || confess "Could not find the type constraint '" . $options{isa} . "'"; |
177 | } |
5e98d2b6 |
178 | |
8de73ff1 |
179 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
180 | delete $options{isa}; |
181 | } |
2ea379cb |
182 | |
183 | if ($options{does}) { |
184 | my $type_constraint; |
185 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
186 | $type_constraint = $options{does}; |
187 | } |
188 | else { |
d40ce9d5 |
189 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
190 | (defined $type_constraint) |
191 | || confess "Could not find the type constraint '" . $options{does} . "'"; |
192 | } |
193 | |
194 | $actual_options{type_constraint} = $type_constraint; |
195 | delete $options{does}; |
196 | } |
c32c2c61 |
197 | |
cbd141ca |
198 | # NOTE: |
199 | # this doesn't apply to Class::MOP::Attributes, |
200 | # so we can ignore it for them. |
201 | # - SL |
202 | if ($self->can('interpolate_class')) { |
203 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
204 | |
cbd141ca |
205 | my %seen; |
206 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
207 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
208 | |
cbd141ca |
209 | delete @options{qw(metaclass traits)}; |
210 | } |
c32c2c61 |
211 | |
26fbace8 |
212 | (scalar keys %options == 0) |
ce0e8d63 |
213 | || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; |
c32c2c61 |
214 | |
215 | |
ce0e8d63 |
216 | $self->clone(%actual_options); |
1d768fb1 |
217 | } |
218 | |
c32c2c61 |
219 | sub clone { |
220 | my ( $self, %params ) = @_; |
221 | |
222 | my $class = $params{metaclass} || ref $self; |
223 | |
224 | if ( 0 and $class eq ref $self ) { |
225 | return $self->SUPER::clone(%params); |
226 | } else { |
227 | my ( @init, @non_init ); |
228 | |
229 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
230 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
231 | } |
232 | |
233 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
234 | |
235 | my $name = delete $new_params{name}; |
236 | |
237 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
238 | |
239 | foreach my $attr ( @non_init ) { |
240 | $attr->set_value($clone, $attr->get_value($self)); |
241 | } |
242 | |
243 | |
244 | return $clone; |
245 | } |
246 | } |
247 | |
1d768fb1 |
248 | sub _process_options { |
249 | my ($class, $name, $options) = @_; |
8de73ff1 |
250 | |
f3c4e20e |
251 | if (exists $options->{is}) { |
21f1e231 |
252 | |
012fcbd1 |
253 | ### ------------------------- |
254 | ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
255 | ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
256 | ## is => rw, accessor => _foo # turns into (accessor => _foo) |
257 | ## is => ro, accessor => _foo # error, accesor is rw |
258 | ### ------------------------- |
21f1e231 |
259 | |
8de73ff1 |
260 | if ($options->{is} eq 'ro') { |
21f1e231 |
261 | confess "Cannot define an accessor name on a read-only attribute, accessors are read/write" |
262 | if exists $options->{accessor}; |
8de73ff1 |
263 | $options->{reader} ||= $name; |
8de73ff1 |
264 | } |
265 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
266 | if ($options->{writer}) { |
267 | $options->{reader} ||= $name; |
268 | } |
269 | else { |
270 | $options->{accessor} ||= $name; |
271 | } |
8de73ff1 |
272 | } |
273 | else { |
173709ca |
274 | confess "I do not understand this option (is => " . $options->{is} . ") on attribute ($name)" |
8de73ff1 |
275 | } |
f3c4e20e |
276 | } |
8de73ff1 |
277 | |
f3c4e20e |
278 | if (exists $options->{isa}) { |
f3c4e20e |
279 | if (exists $options->{does}) { |
280 | if (eval { $options->{isa}->can('does') }) { |
281 | ($options->{isa}->does($options->{does})) |
173709ca |
282 | || confess "Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)"; |
f3c4e20e |
283 | } |
284 | else { |
173709ca |
285 | confess "Cannot have an isa option which cannot ->does() on attribute ($name)"; |
26fbace8 |
286 | } |
26fbace8 |
287 | } |
8de73ff1 |
288 | |
f3c4e20e |
289 | # allow for anon-subtypes here ... |
290 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
291 | $options->{type_constraint} = $options->{isa}; |
292 | } |
293 | else { |
620db045 |
294 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
295 | } |
f3c4e20e |
296 | } |
297 | elsif (exists $options->{does}) { |
298 | # allow for anon-subtypes here ... |
299 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
300 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
301 | } |
302 | else { |
620db045 |
303 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
304 | } |
f3c4e20e |
305 | } |
8de73ff1 |
306 | |
f3c4e20e |
307 | if (exists $options->{coerce} && $options->{coerce}) { |
308 | (exists $options->{type_constraint}) |
173709ca |
309 | || confess "You cannot have coercion without specifying a type constraint on attribute ($name)"; |
310 | confess "You cannot have a weak reference to a coerced value on attribute ($name)" |
8de73ff1 |
311 | if $options->{weak_ref}; |
f3c4e20e |
312 | } |
8de73ff1 |
313 | |
0b7df53c |
314 | if (exists $options->{trigger}) { |
65e14c86 |
315 | ('CODE' eq ref $options->{trigger}) |
316 | || confess "Trigger must be a CODE ref on attribute ($name)"; |
0b7df53c |
317 | } |
318 | |
f3c4e20e |
319 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
320 | (exists $options->{type_constraint}) |
173709ca |
321 | || confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)"; |
f3c4e20e |
322 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
323 | $options->{type_constraint}->is_a_type_of('HashRef')) |
173709ca |
324 | || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"; |
f3c4e20e |
325 | } |
8de73ff1 |
326 | |
f3c4e20e |
327 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
173709ca |
328 | confess("You can not use lazy_build and default for the same attribute ($name)") |
8de73ff1 |
329 | if exists $options->{default}; |
a6c84c69 |
330 | $options->{lazy} = 1; |
331 | $options->{required} = 1; |
332 | $options->{builder} ||= "_build_${name}"; |
333 | if ($name =~ /^_/) { |
f3c4e20e |
334 | $options->{clearer} ||= "_clear${name}"; |
335 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
336 | } |
337 | else { |
f3c4e20e |
338 | $options->{clearer} ||= "clear_${name}"; |
339 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
340 | } |
f3c4e20e |
341 | } |
8de73ff1 |
342 | |
f3c4e20e |
343 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
344 | (exists $options->{default} || defined $options->{builder} ) |
7dbda458 |
345 | || confess "You cannot have lazy attribute ($name) without specifying a default value for it"; |
f3c4e20e |
346 | } |
26fbace8 |
347 | |
9edba990 |
348 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
7dbda458 |
349 | confess "You cannot have a required attribute ($name) without a default, builder, or an init_arg"; |
9edba990 |
350 | } |
351 | |
78cd1d3b |
352 | } |
c0e30cf5 |
353 | |
d500266f |
354 | sub initialize_instance_slot { |
ddd0ec20 |
355 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
356 | my $init_arg = $self->init_arg(); |
357 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
358 | |
26fbace8 |
359 | my $val; |
1ed0b94f |
360 | my $value_is_set; |
625d571f |
361 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
362 | $val = $params->{$init_arg}; |
2c78d811 |
363 | $value_is_set = 1; |
d500266f |
364 | } |
365 | else { |
366 | # skip it if it's lazy |
367 | return if $self->is_lazy; |
368 | # and die if it's required and doesn't have a default value |
26fbace8 |
369 | confess "Attribute (" . $self->name . ") is required" |
370 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
371 | |
1ed0b94f |
372 | # if nothing was in the %params, we can use the |
373 | # attribute's default value (if it has one) |
374 | if ($self->has_default) { |
375 | $val = $self->default($instance); |
376 | $value_is_set = 1; |
a6c84c69 |
377 | } |
378 | elsif ($self->has_builder) { |
379 | if (my $builder = $instance->can($self->builder)){ |
1ed0b94f |
380 | $val = $instance->$builder; |
381 | $value_is_set = 1; |
a6c84c69 |
382 | } |
383 | else { |
0b26305c |
384 | confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'"); |
1ed0b94f |
385 | } |
a0748c37 |
386 | } |
26fbace8 |
387 | } |
388 | |
1ed0b94f |
389 | return unless $value_is_set; |
390 | |
391 | if ($self->has_type_constraint) { |
392 | my $type_constraint = $self->type_constraint; |
393 | if ($self->should_coerce && $type_constraint->has_coercion) { |
394 | $val = $type_constraint->coerce($val); |
d500266f |
395 | } |
ab76842e |
396 | $type_constraint->check($val) |
688fcdda |
397 | || confess "Attribute (" |
398 | . $self->name |
399 | . ") does not pass the type constraint because: " |
400 | . $type_constraint->get_message($val); |
1ed0b94f |
401 | } |
ddd0ec20 |
402 | |
65e14c86 |
403 | $self->set_initial_value($instance, $val); |
404 | $meta_instance->weaken_slot_value($instance, $self->name) |
405 | if ref $val && $self->is_weak_ref; |
d500266f |
406 | } |
407 | |
d617b644 |
408 | ## Slot management |
9e93dd19 |
409 | |
8abe9636 |
410 | # FIXME: |
411 | # this duplicates too much code from |
412 | # Class::MOP::Attribute, we need to |
413 | # refactor these bits eventually. |
414 | # - SL |
415 | sub _set_initial_slot_value { |
416 | my ($self, $meta_instance, $instance, $value) = @_; |
417 | |
418 | my $slot_name = $self->name; |
419 | |
420 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
421 | unless $self->has_initializer; |
422 | |
423 | my ($type_constraint, $can_coerce); |
424 | if ($self->has_type_constraint) { |
425 | $type_constraint = $self->type_constraint; |
426 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
427 | } |
428 | |
429 | my $callback = sub { |
430 | my $val = shift; |
431 | if ($type_constraint) { |
432 | $val = $type_constraint->coerce($val) |
433 | if $can_coerce; |
434 | $type_constraint->check($val) |
435 | || confess "Attribute (" |
436 | . $slot_name |
437 | . ") does not pass the type constraint because: " |
438 | . $type_constraint->get_message($val); |
439 | } |
440 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
441 | }; |
442 | |
443 | my $initializer = $self->initializer; |
444 | |
445 | # most things will just want to set a value, so make it first arg |
446 | $instance->$initializer($value, $callback, $self); |
447 | } |
448 | |
946289d1 |
449 | sub set_value { |
b6af66f8 |
450 | my ($self, $instance, @args) = @_; |
451 | my $value = $args[0]; |
26fbace8 |
452 | |
946289d1 |
453 | my $attr_name = $self->name; |
26fbace8 |
454 | |
b6af66f8 |
455 | if ($self->is_required and not @args) { |
456 | confess "Attribute ($attr_name) is required"; |
946289d1 |
457 | } |
26fbace8 |
458 | |
946289d1 |
459 | if ($self->has_type_constraint) { |
26fbace8 |
460 | |
946289d1 |
461 | my $type_constraint = $self->type_constraint; |
26fbace8 |
462 | |
946289d1 |
463 | if ($self->should_coerce) { |
26fbace8 |
464 | $value = $type_constraint->coerce($value); |
688fcdda |
465 | } |
42bc21a4 |
466 | $type_constraint->_compiled_type_constraint->($value) |
688fcdda |
467 | || confess "Attribute (" |
468 | . $self->name |
469 | . ") does not pass the type constraint because " |
ab76842e |
470 | . $type_constraint->get_message($value); |
946289d1 |
471 | } |
26fbace8 |
472 | |
65e14c86 |
473 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
474 | ->get_meta_instance; |
475 | |
476 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
477 | |
478 | if (ref $value && $self->is_weak_ref) { |
479 | $meta_instance->weaken_slot_value($instance, $attr_name); |
480 | } |
481 | |
482 | if ($self->has_trigger) { |
483 | $self->trigger->($instance, $value, $self); |
484 | } |
946289d1 |
485 | } |
486 | |
487 | sub get_value { |
488 | my ($self, $instance) = @_; |
26fbace8 |
489 | |
946289d1 |
490 | if ($self->is_lazy) { |
8de73ff1 |
491 | unless ($self->has_value($instance)) { |
492 | if ($self->has_default) { |
493 | my $default = $self->default($instance); |
759e4e8f |
494 | $self->set_initial_value($instance, $default); |
3f11800d |
495 | } elsif ( $self->has_builder ) { |
a6c84c69 |
496 | if (my $builder = $instance->can($self->builder)){ |
759e4e8f |
497 | $self->set_initial_value($instance, $instance->$builder); |
3f11800d |
498 | } |
a6c84c69 |
499 | else { |
500 | confess(blessed($instance) |
501 | . " does not support builder method '" |
502 | . $self->builder |
503 | . "' for attribute '" |
504 | . $self->name |
505 | . "'"); |
26fbace8 |
506 | } |
a6c84c69 |
507 | } |
508 | else { |
759e4e8f |
509 | $self->set_initial_value($instance, undef); |
26fbace8 |
510 | } |
8de73ff1 |
511 | } |
946289d1 |
512 | } |
26fbace8 |
513 | |
946289d1 |
514 | if ($self->should_auto_deref) { |
26fbace8 |
515 | |
946289d1 |
516 | my $type_constraint = $self->type_constraint; |
517 | |
518 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
519 | my $rv = $self->SUPER::get_value($instance); |
520 | return unless defined $rv; |
521 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
522 | } |
946289d1 |
523 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
524 | my $rv = $self->SUPER::get_value($instance); |
525 | return unless defined $rv; |
526 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
527 | } |
946289d1 |
528 | else { |
529 | confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; |
530 | } |
26fbace8 |
531 | |
946289d1 |
532 | } |
533 | else { |
26fbace8 |
534 | |
946289d1 |
535 | return $self->SUPER::get_value($instance); |
26fbace8 |
536 | } |
946289d1 |
537 | } |
a15dff8d |
538 | |
26fbace8 |
539 | ## installing accessors |
c0e30cf5 |
540 | |
d617b644 |
541 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
542 | |
452bac1b |
543 | sub install_accessors { |
544 | my $self = shift; |
26fbace8 |
545 | $self->SUPER::install_accessors(@_); |
d3e7fe85 |
546 | $self->install_delegation if $self->has_handles; |
547 | return; |
548 | } |
26fbace8 |
549 | |
d3e7fe85 |
550 | sub install_delegation { |
551 | my $self = shift; |
26fbace8 |
552 | |
d3e7fe85 |
553 | # NOTE: |
554 | # Here we canonicalize the 'handles' option |
555 | # this will sort out any details and always |
556 | # return an hash of methods which we want |
557 | # to delagate to, see that method for details |
330dbb07 |
558 | my %handles = $self->_canonicalize_handles; |
d3e7fe85 |
559 | |
560 | # find the accessor method for this attribute |
330dbb07 |
561 | my $accessor = $self->_get_delegate_accessor; |
d3e7fe85 |
562 | |
563 | # install the delegation ... |
564 | my $associated_class = $self->associated_class; |
565 | foreach my $handle (keys %handles) { |
566 | my $method_to_call = $handles{$handle}; |
567 | my $class_name = $associated_class->name; |
568 | my $name = "${class_name}::${handle}"; |
569 | |
570 | (!$associated_class->has_method($handle)) |
571 | || confess "You cannot overwrite a locally defined method ($handle) with a delegation"; |
26fbace8 |
572 | |
d3e7fe85 |
573 | # NOTE: |
574 | # handles is not allowed to delegate |
575 | # any of these methods, as they will |
576 | # override the ones in your class, which |
577 | # is almost certainly not what you want. |
4fe78472 |
578 | |
d3e7fe85 |
579 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
580 | #cluck("Not delegating method '$handle' because it is a core method") and |
581 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
582 | |
d3e7fe85 |
583 | if ('CODE' eq ref($method_to_call)) { |
584 | $associated_class->add_method($handle => Class::MOP::subname($name, $method_to_call)); |
452bac1b |
585 | } |
d3e7fe85 |
586 | else { |
587 | # NOTE: |
588 | # we used to do a goto here, but the |
589 | # goto didn't handle failure correctly |
590 | # (it just returned nothing), so I took |
591 | # that out. However, the more I thought |
592 | # about it, the less I liked it doing |
593 | # the goto, and I prefered the act of |
594 | # delegation being actually represented |
595 | # in the stack trace. |
596 | # - SL |
597 | $associated_class->add_method($handle => Class::MOP::subname($name, sub { |
598 | my $proxy = (shift)->$accessor(); |
599 | (defined $proxy) |
600 | || confess "Cannot delegate $handle to $method_to_call because " . |
601 | "the value of " . $self->name . " is not defined"; |
602 | $proxy->$method_to_call(@_); |
603 | })); |
604 | } |
605 | } |
452bac1b |
606 | } |
607 | |
98aae381 |
608 | # private methods to help delegation ... |
609 | |
330dbb07 |
610 | sub _get_delegate_accessor { |
611 | my $self = shift; |
612 | # find the accessor method for this attribute |
613 | my $accessor = $self->get_read_method_ref; |
614 | # then unpack it if we need too ... |
615 | $accessor = $accessor->body if blessed $accessor; |
616 | # return the accessor |
617 | return $accessor; |
618 | } |
619 | |
452bac1b |
620 | sub _canonicalize_handles { |
621 | my $self = shift; |
622 | my $handles = $self->handles; |
c84f324f |
623 | if (my $handle_type = ref($handles)) { |
624 | if ($handle_type eq 'HASH') { |
625 | return %{$handles}; |
626 | } |
627 | elsif ($handle_type eq 'ARRAY') { |
628 | return map { $_ => $_ } @{$handles}; |
629 | } |
630 | elsif ($handle_type eq 'Regexp') { |
631 | ($self->has_type_constraint) |
632 | || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)"; |
26fbace8 |
633 | return map { ($_ => $_) } |
c84f324f |
634 | grep { /$handles/ } $self->_get_delegate_method_list; |
635 | } |
636 | elsif ($handle_type eq 'CODE') { |
637 | return $handles->($self, $self->_find_delegate_metaclass); |
638 | } |
639 | else { |
640 | confess "Unable to canonicalize the 'handles' option with $handles"; |
641 | } |
452bac1b |
642 | } |
643 | else { |
c84f324f |
644 | my $role_meta = eval { $handles->meta }; |
645 | if ($@) { |
26fbace8 |
646 | confess "Unable to canonicalize the 'handles' option with $handles because : $@"; |
c84f324f |
647 | } |
648 | |
649 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
650 | || confess "Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role"; |
26fbace8 |
651 | |
c84f324f |
652 | return map { $_ => $_ } ( |
26fbace8 |
653 | $role_meta->get_method_list, |
c84f324f |
654 | $role_meta->get_required_method_list |
655 | ); |
452bac1b |
656 | } |
657 | } |
658 | |
659 | sub _find_delegate_metaclass { |
660 | my $self = shift; |
98aae381 |
661 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
662 | # if the class does have |
452bac1b |
663 | # a meta method, use it |
664 | return $class->meta if $class->can('meta'); |
26fbace8 |
665 | # otherwise we might be |
452bac1b |
666 | # dealing with a non-Moose |
26fbace8 |
667 | # class, and need to make |
452bac1b |
668 | # our own metaclass |
669 | return Moose::Meta::Class->initialize($class); |
670 | } |
98aae381 |
671 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
672 | # our role will always have |
452bac1b |
673 | # a meta method |
98aae381 |
674 | return $role->meta; |
452bac1b |
675 | } |
676 | else { |
677 | confess "Cannot find delegate metaclass for attribute " . $self->name; |
678 | } |
679 | } |
680 | |
681 | sub _get_delegate_method_list { |
682 | my $self = shift; |
683 | my $meta = $self->_find_delegate_metaclass; |
684 | if ($meta->isa('Class::MOP::Class')) { |
3b82ee4f |
685 | return map { $_->name } # NOTE: !never! delegate &meta |
686 | grep { $_->package_name ne 'Moose::Object' && $_->name ne 'meta' } |
687 | $meta->get_all_methods; |
452bac1b |
688 | } |
689 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
690 | return $meta->get_method_list; |
452bac1b |
691 | } |
692 | else { |
693 | confess "Unable to recognize the delegate metaclass '$meta'"; |
694 | } |
695 | } |
696 | |
21f1e231 |
697 | package Moose::Meta::Attribute::Custom::Moose; |
698 | sub register_implementation { 'Moose::Meta::Attribute' } |
699 | |
c0e30cf5 |
700 | 1; |
701 | |
702 | __END__ |
703 | |
704 | =pod |
705 | |
706 | =head1 NAME |
707 | |
6ba6d68c |
708 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
709 | |
710 | =head1 DESCRIPTION |
711 | |
26fbace8 |
712 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
713 | extensions. |
6ba6d68c |
714 | |
26fbace8 |
715 | For the most part, the only time you will ever encounter an |
716 | instance of this class is if you are doing some serious deep |
717 | introspection. To really understand this class, you need to refer |
6ba6d68c |
718 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
719 | |
c0e30cf5 |
720 | =head1 METHODS |
721 | |
6ba6d68c |
722 | =head2 Overridden methods |
723 | |
26fbace8 |
724 | These methods override methods in L<Class::MOP::Attribute> and add |
725 | Moose specific features. You can safely assume though that they |
6ba6d68c |
726 | will behave just as L<Class::MOP::Attribute> does. |
727 | |
c0e30cf5 |
728 | =over 4 |
729 | |
730 | =item B<new> |
731 | |
c32c2c61 |
732 | =item B<clone> |
733 | |
6e2840b7 |
734 | =item B<does> |
735 | |
d500266f |
736 | =item B<initialize_instance_slot> |
737 | |
452bac1b |
738 | =item B<install_accessors> |
739 | |
d3e7fe85 |
740 | =item B<install_delegation> |
741 | |
39b3bc94 |
742 | =item B<accessor_metaclass> |
743 | |
946289d1 |
744 | =item B<get_value> |
745 | |
746 | =item B<set_value> |
747 | |
bcbaa845 |
748 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
749 | if($@) { |
750 | print "Oops: $@\n"; |
751 | } |
752 | |
753 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
754 | |
755 | Before setting the value, a check is made on the type constraint of |
756 | the attribute, if it has one, to see if the value passes it. If the |
757 | value fails to pass, the set operation dies with a L<Carp/confess>. |
758 | |
759 | Any coercion to convert values is done before checking the type constraint. |
760 | |
761 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
762 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
763 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
5cfe3805 |
764 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::Basics::Recipe4> |
bcbaa845 |
765 | for an example. |
766 | |
a15dff8d |
767 | =back |
768 | |
6ba6d68c |
769 | =head2 Additional Moose features |
770 | |
26fbace8 |
771 | Moose attributes support type-constraint checking, weak reference |
772 | creation and type coercion. |
6ba6d68c |
773 | |
a15dff8d |
774 | =over 4 |
775 | |
d5c30e52 |
776 | =item B<interpolate_class_and_new> |
777 | |
778 | =item B<interpolate_class> |
779 | |
780 | When called as a class method causes interpretation of the C<metaclass> and |
781 | C<traits> options. |
782 | |
9e93dd19 |
783 | =item B<clone_and_inherit_options> |
784 | |
26fbace8 |
785 | This is to support the C<has '+foo'> feature, it clones an attribute |
786 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
787 | to the attribute. |
788 | |
aa08864c |
789 | =item B<legal_options_for_inheritance> |
790 | |
791 | Whitelist with options you can change. You can overload it in your custom |
792 | metaclass to allow your options be inheritable. |
793 | |
a15dff8d |
794 | =item B<has_type_constraint> |
795 | |
6ba6d68c |
796 | Returns true if this meta-attribute has a type constraint. |
797 | |
a15dff8d |
798 | =item B<type_constraint> |
799 | |
26fbace8 |
800 | A read-only accessor for this meta-attribute's type constraint. For |
801 | more information on what you can do with this, see the documentation |
6ba6d68c |
802 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
803 | |
452bac1b |
804 | =item B<has_handles> |
805 | |
806 | Returns true if this meta-attribute performs delegation. |
807 | |
808 | =item B<handles> |
809 | |
810 | This returns the value which was passed into the handles option. |
811 | |
6ba6d68c |
812 | =item B<is_weak_ref> |
a15dff8d |
813 | |
02a0fb52 |
814 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
815 | |
ca01a97b |
816 | =item B<is_required> |
817 | |
02a0fb52 |
818 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
819 | |
820 | =item B<is_lazy> |
821 | |
02a0fb52 |
822 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
823 | |
26fbace8 |
824 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
825 | |
826 | =item B<is_lazy_build> |
827 | |
828 | Returns true if this meta-attribute should be initialized lazily through |
829 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
830 | make your attribute required and lazy. In addition it will set the builder, clearer |
831 | and predicate options for you using the following convention. |
832 | |
833 | #If your attribute name starts with an underscore: |
834 | has '_foo' => (lazy_build => 1); |
835 | #is the same as |
4c9e0478 |
836 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo'); |
26fbace8 |
837 | # or |
58f85113 |
838 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
839 | |
840 | #If your attribute name does not start with an underscore: |
58f85113 |
841 | has 'foo' => (lazy_build => 1); |
842 | #is the same as |
4c9e0478 |
843 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo'); |
26fbace8 |
844 | # or |
58f85113 |
845 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
846 | |
847 | The reason for the different naming of the C<builder> is that the C<builder> |
848 | method is a private method while the C<clearer> and C<predicate> methods |
849 | are public methods. |
26fbace8 |
850 | |
851 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
852 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
853 | |
34a66aa3 |
854 | =item B<should_coerce> |
4b598ea3 |
855 | |
02a0fb52 |
856 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
857 | |
536f0b17 |
858 | =item B<should_auto_deref> |
859 | |
26fbace8 |
860 | Returns true if this meta-attribute should perform automatic |
861 | auto-dereferencing. |
536f0b17 |
862 | |
26fbace8 |
863 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
864 | either I<ArrayRef> or I<HashRef>. |
865 | |
8c9d74e7 |
866 | =item B<has_trigger> |
867 | |
02a0fb52 |
868 | Returns true if this meta-attribute has a trigger set. |
869 | |
8c9d74e7 |
870 | =item B<trigger> |
871 | |
26fbace8 |
872 | This is a CODE reference which will be executed every time the |
873 | value of an attribute is assigned. The CODE ref will get two values, |
874 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
875 | bi-directional relations. |
876 | |
ddbdc0cb |
877 | =item B<documentation> |
878 | |
26fbace8 |
879 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
880 | It serves no direct purpose right now, but it might in the future |
881 | in some kind of automated documentation system perhaps. |
882 | |
883 | =item B<has_documentation> |
884 | |
885 | Returns true if this meta-attribute has any documentation. |
886 | |
88f23977 |
887 | =item B<applied_traits> |
888 | |
889 | This will return the ARRAY ref of all the traits applied to this |
890 | attribute, or if no traits have been applied, it returns C<undef>. |
891 | |
892 | =item B<has_applied_traits> |
893 | |
894 | Returns true if this meta-attribute has any traits applied. |
895 | |
c0e30cf5 |
896 | =back |
897 | |
898 | =head1 BUGS |
899 | |
26fbace8 |
900 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
901 | exception. If you find a bug please either email me, or add the bug |
902 | to cpan-RT. |
903 | |
c0e30cf5 |
904 | =head1 AUTHOR |
905 | |
906 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
907 | |
98aae381 |
908 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
909 | |
c0e30cf5 |
910 | =head1 COPYRIGHT AND LICENSE |
911 | |
778db3ac |
912 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
913 | |
914 | L<http://www.iinteractive.com> |
915 | |
916 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
917 | it under the same terms as Perl itself. |
c0e30cf5 |
918 | |
8a7a9c53 |
919 | =cut |