Commit | Line | Data |
c0e30cf5 |
1 | |
2 | package Moose::Meta::Attribute; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
78cd1d3b |
7 | use Scalar::Util 'blessed', 'weaken', 'reftype'; |
a15dff8d |
8 | use Carp 'confess'; |
7dbbdcab |
9 | use Sub::Name 'subname'; |
a909a4df |
10 | use overload (); |
a15dff8d |
11 | |
cbd141ca |
12 | our $VERSION = '0.23'; |
d44714be |
13 | our $AUTHORITY = 'cpan:STEVAN'; |
78cd1d3b |
14 | |
8ee73eeb |
15 | use Moose::Meta::Method::Accessor; |
d5c30e52 |
16 | use Moose::Util (); |
a3c7e2fe |
17 | use Moose::Util::TypeConstraints (); |
bc1e29b5 |
18 | |
c0e30cf5 |
19 | use base 'Class::MOP::Attribute'; |
20 | |
452bac1b |
21 | # options which are not directly used |
22 | # but we store them for metadata purposes |
98aae381 |
23 | __PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata')); |
24 | __PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata')); |
25 | __PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); |
452bac1b |
26 | |
27 | # these are actual options for the attrs |
1a563243 |
28 | __PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); |
29 | __PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); |
26fbace8 |
30 | __PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' )); |
1a563243 |
31 | __PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); |
32 | __PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' )); |
33 | __PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref')); |
82168dbb |
34 | __PACKAGE__->meta->add_attribute('type_constraint' => ( |
35 | reader => 'type_constraint', |
36 | predicate => 'has_type_constraint', |
37 | )); |
8c9d74e7 |
38 | __PACKAGE__->meta->add_attribute('trigger' => ( |
39 | reader => 'trigger', |
40 | predicate => 'has_trigger', |
41 | )); |
452bac1b |
42 | __PACKAGE__->meta->add_attribute('handles' => ( |
43 | reader => 'handles', |
44 | predicate => 'has_handles', |
45 | )); |
ddbdc0cb |
46 | __PACKAGE__->meta->add_attribute('documentation' => ( |
47 | reader => 'documentation', |
48 | predicate => 'has_documentation', |
49 | )); |
82a5b1a7 |
50 | __PACKAGE__->meta->add_attribute('traits' => ( |
51 | reader => 'applied_traits', |
52 | predicate => 'has_applied_traits', |
53 | )); |
82168dbb |
54 | |
587e457d |
55 | # NOTE: |
56 | # we need to have a ->does method in here to |
57 | # more easily support traits, and the introspection |
58 | # of those traits. So in order to do this we |
59 | # just alias Moose::Object's version of it. |
60 | # - SL |
61 | *does = \&Moose::Object::does; |
62 | |
78cd1d3b |
63 | sub new { |
f3c4e20e |
64 | my ($class, $name, %options) = @_; |
c32c2c61 |
65 | $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS |
f3c4e20e |
66 | return $class->SUPER::new($name, %options); |
1d768fb1 |
67 | } |
68 | |
d5c30e52 |
69 | sub interpolate_class_and_new { |
70 | my ($class, $name, @args) = @_; |
71 | |
c32c2c61 |
72 | my ( $new_class, @traits ) = $class->interpolate_class(@args); |
73 | |
74 | $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); |
d5c30e52 |
75 | } |
76 | |
77 | sub interpolate_class { |
78 | my ($class, %options) = @_; |
79 | |
c32c2c61 |
80 | $class = ref($class) || $class; |
81 | |
82 | if ( my $metaclass_name = delete $options{metaclass} ) { |
83 | my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); |
84 | |
85 | if ( $class ne $new_class ) { |
86 | if ( $new_class->can("interpolate_class") ) { |
87 | return $new_class->interpolate_class(%options); |
88 | } else { |
89 | $class = $new_class; |
90 | } |
91 | } |
d5c30e52 |
92 | } |
93 | |
c32c2c61 |
94 | my @traits; |
95 | |
d5c30e52 |
96 | if (my $traits = $options{traits}) { |
c32c2c61 |
97 | if ( @traits = grep { not $class->does($_) } map { |
d5c30e52 |
98 | Moose::Util::resolve_metatrait_alias( Attribute => $_ ) |
99 | or |
100 | $_ |
c32c2c61 |
101 | } @$traits ) { |
102 | my $anon_class = Moose::Meta::Class->create_anon_class( |
103 | superclasses => [ $class ], |
104 | roles => [ @traits ], |
105 | cache => 1, |
106 | ); |
107 | |
108 | $class = $anon_class->name; |
109 | } |
d5c30e52 |
110 | } |
c32c2c61 |
111 | |
112 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
113 | } |
114 | |
ce0e8d63 |
115 | sub clone_and_inherit_options { |
116 | my ($self, %options) = @_; |
c32c2c61 |
117 | my %copy = %options; |
118 | # you can change default, required, coerce, documentation, lazy, handles, builder, type_constraint (explicitly or using isa/does), metaclass and traits |
ce0e8d63 |
119 | my %actual_options; |
c32c2c61 |
120 | foreach my $legal_option (qw(default coerce required documentation lazy handles builder type_constraint)) { |
ce0e8d63 |
121 | if (exists $options{$legal_option}) { |
122 | $actual_options{$legal_option} = $options{$legal_option}; |
123 | delete $options{$legal_option}; |
124 | } |
125 | } |
26fbace8 |
126 | |
ce0e8d63 |
127 | if ($options{isa}) { |
128 | my $type_constraint; |
8de73ff1 |
129 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
130 | $type_constraint = $options{isa}; |
131 | } |
132 | else { |
d40ce9d5 |
133 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
134 | (defined $type_constraint) |
135 | || confess "Could not find the type constraint '" . $options{isa} . "'"; |
136 | } |
5e98d2b6 |
137 | |
8de73ff1 |
138 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
139 | delete $options{isa}; |
140 | } |
2ea379cb |
141 | |
142 | if ($options{does}) { |
143 | my $type_constraint; |
144 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
145 | $type_constraint = $options{does}; |
146 | } |
147 | else { |
d40ce9d5 |
148 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
149 | (defined $type_constraint) |
150 | || confess "Could not find the type constraint '" . $options{does} . "'"; |
151 | } |
152 | |
153 | $actual_options{type_constraint} = $type_constraint; |
154 | delete $options{does}; |
155 | } |
c32c2c61 |
156 | |
cbd141ca |
157 | # NOTE: |
158 | # this doesn't apply to Class::MOP::Attributes, |
159 | # so we can ignore it for them. |
160 | # - SL |
161 | if ($self->can('interpolate_class')) { |
162 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
163 | |
cbd141ca |
164 | my %seen; |
165 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
166 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
167 | |
cbd141ca |
168 | delete @options{qw(metaclass traits)}; |
169 | } |
c32c2c61 |
170 | |
26fbace8 |
171 | (scalar keys %options == 0) |
ce0e8d63 |
172 | || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; |
c32c2c61 |
173 | |
174 | |
ce0e8d63 |
175 | $self->clone(%actual_options); |
1d768fb1 |
176 | } |
177 | |
c32c2c61 |
178 | sub clone { |
179 | my ( $self, %params ) = @_; |
180 | |
181 | my $class = $params{metaclass} || ref $self; |
182 | |
183 | if ( 0 and $class eq ref $self ) { |
184 | return $self->SUPER::clone(%params); |
185 | } else { |
186 | my ( @init, @non_init ); |
187 | |
188 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
189 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
190 | } |
191 | |
192 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
193 | |
194 | my $name = delete $new_params{name}; |
195 | |
196 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
197 | |
198 | foreach my $attr ( @non_init ) { |
199 | $attr->set_value($clone, $attr->get_value($self)); |
200 | } |
201 | |
202 | |
203 | return $clone; |
204 | } |
205 | } |
206 | |
1d768fb1 |
207 | sub _process_options { |
208 | my ($class, $name, $options) = @_; |
8de73ff1 |
209 | |
f3c4e20e |
210 | if (exists $options->{is}) { |
8de73ff1 |
211 | if ($options->{is} eq 'ro') { |
212 | $options->{reader} ||= $name; |
213 | (!exists $options->{trigger}) |
7dbda458 |
214 | || confess "Cannot have a trigger on a read-only attribute $name"; |
8de73ff1 |
215 | } |
216 | elsif ($options->{is} eq 'rw') { |
217 | $options->{accessor} = $name; |
218 | ((reftype($options->{trigger}) || '') eq 'CODE') |
219 | || confess "Trigger must be a CODE ref" |
220 | if exists $options->{trigger}; |
221 | } |
222 | else { |
7dbda458 |
223 | confess "I do not understand this option (is => " . $options->{is} . ") on attribute $name" |
8de73ff1 |
224 | } |
f3c4e20e |
225 | } |
8de73ff1 |
226 | |
f3c4e20e |
227 | if (exists $options->{isa}) { |
f3c4e20e |
228 | if (exists $options->{does}) { |
229 | if (eval { $options->{isa}->can('does') }) { |
230 | ($options->{isa}->does($options->{does})) |
7dbda458 |
231 | || confess "Cannot have an isa option and a does option if the isa does not do the does on attribute $name"; |
f3c4e20e |
232 | } |
233 | else { |
7dbda458 |
234 | confess "Cannot have an isa option which cannot ->does() on attribute $name"; |
26fbace8 |
235 | } |
26fbace8 |
236 | } |
8de73ff1 |
237 | |
f3c4e20e |
238 | # allow for anon-subtypes here ... |
239 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
240 | $options->{type_constraint} = $options->{isa}; |
241 | } |
242 | else { |
620db045 |
243 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
244 | } |
f3c4e20e |
245 | } |
246 | elsif (exists $options->{does}) { |
247 | # allow for anon-subtypes here ... |
248 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
249 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
250 | } |
251 | else { |
620db045 |
252 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
253 | } |
f3c4e20e |
254 | } |
8de73ff1 |
255 | |
f3c4e20e |
256 | if (exists $options->{coerce} && $options->{coerce}) { |
257 | (exists $options->{type_constraint}) |
7dbda458 |
258 | || confess "You cannot have coercion without specifying a type constraint on attribute $name"; |
259 | confess "You cannot have a weak reference to a coerced value on attribute $name" |
8de73ff1 |
260 | if $options->{weak_ref}; |
f3c4e20e |
261 | } |
8de73ff1 |
262 | |
f3c4e20e |
263 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
264 | (exists $options->{type_constraint}) |
7dbda458 |
265 | || confess "You cannot auto-dereference without specifying a type constraint on attribute $name"; |
f3c4e20e |
266 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
267 | $options->{type_constraint}->is_a_type_of('HashRef')) |
7dbda458 |
268 | || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute $name"; |
f3c4e20e |
269 | } |
8de73ff1 |
270 | |
f3c4e20e |
271 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
7dbda458 |
272 | confess("You can not use lazy_build and default for the same attribute $name") |
8de73ff1 |
273 | if exists $options->{default}; |
a6c84c69 |
274 | $options->{lazy} = 1; |
275 | $options->{required} = 1; |
276 | $options->{builder} ||= "_build_${name}"; |
277 | if ($name =~ /^_/) { |
f3c4e20e |
278 | $options->{clearer} ||= "_clear${name}"; |
279 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
280 | } |
281 | else { |
f3c4e20e |
282 | $options->{clearer} ||= "clear_${name}"; |
283 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
284 | } |
f3c4e20e |
285 | } |
8de73ff1 |
286 | |
f3c4e20e |
287 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
288 | (exists $options->{default} || defined $options->{builder} ) |
7dbda458 |
289 | || confess "You cannot have lazy attribute ($name) without specifying a default value for it"; |
f3c4e20e |
290 | } |
26fbace8 |
291 | |
9edba990 |
292 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
7dbda458 |
293 | confess "You cannot have a required attribute ($name) without a default, builder, or an init_arg"; |
9edba990 |
294 | } |
295 | |
78cd1d3b |
296 | } |
c0e30cf5 |
297 | |
d500266f |
298 | sub initialize_instance_slot { |
ddd0ec20 |
299 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
300 | my $init_arg = $self->init_arg(); |
301 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
302 | |
26fbace8 |
303 | my $val; |
1ed0b94f |
304 | my $value_is_set; |
625d571f |
305 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
306 | $val = $params->{$init_arg}; |
2c78d811 |
307 | $value_is_set = 1; |
d500266f |
308 | } |
309 | else { |
310 | # skip it if it's lazy |
311 | return if $self->is_lazy; |
312 | # and die if it's required and doesn't have a default value |
26fbace8 |
313 | confess "Attribute (" . $self->name . ") is required" |
314 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
315 | |
1ed0b94f |
316 | # if nothing was in the %params, we can use the |
317 | # attribute's default value (if it has one) |
318 | if ($self->has_default) { |
319 | $val = $self->default($instance); |
320 | $value_is_set = 1; |
a6c84c69 |
321 | } |
322 | elsif ($self->has_builder) { |
323 | if (my $builder = $instance->can($self->builder)){ |
1ed0b94f |
324 | $val = $instance->$builder; |
325 | $value_is_set = 1; |
a6c84c69 |
326 | } |
327 | else { |
0b26305c |
328 | confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'"); |
1ed0b94f |
329 | } |
a0748c37 |
330 | } |
26fbace8 |
331 | } |
332 | |
1ed0b94f |
333 | return unless $value_is_set; |
334 | |
335 | if ($self->has_type_constraint) { |
336 | my $type_constraint = $self->type_constraint; |
337 | if ($self->should_coerce && $type_constraint->has_coercion) { |
338 | $val = $type_constraint->coerce($val); |
d500266f |
339 | } |
ab76842e |
340 | $type_constraint->check($val) |
688fcdda |
341 | || confess "Attribute (" |
342 | . $self->name |
343 | . ") does not pass the type constraint because: " |
344 | . $type_constraint->get_message($val); |
1ed0b94f |
345 | } |
ddd0ec20 |
346 | |
759e4e8f |
347 | $self->set_initial_value($instance, $val); |
26fbace8 |
348 | $meta_instance->weaken_slot_value($instance, $self->name) |
a6c84c69 |
349 | if ref $val && $self->is_weak_ref; |
d500266f |
350 | } |
351 | |
d617b644 |
352 | ## Slot management |
9e93dd19 |
353 | |
8abe9636 |
354 | # FIXME: |
355 | # this duplicates too much code from |
356 | # Class::MOP::Attribute, we need to |
357 | # refactor these bits eventually. |
358 | # - SL |
359 | sub _set_initial_slot_value { |
360 | my ($self, $meta_instance, $instance, $value) = @_; |
361 | |
362 | my $slot_name = $self->name; |
363 | |
364 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
365 | unless $self->has_initializer; |
366 | |
367 | my ($type_constraint, $can_coerce); |
368 | if ($self->has_type_constraint) { |
369 | $type_constraint = $self->type_constraint; |
370 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
371 | } |
372 | |
373 | my $callback = sub { |
374 | my $val = shift; |
375 | if ($type_constraint) { |
376 | $val = $type_constraint->coerce($val) |
377 | if $can_coerce; |
378 | $type_constraint->check($val) |
379 | || confess "Attribute (" |
380 | . $slot_name |
381 | . ") does not pass the type constraint because: " |
382 | . $type_constraint->get_message($val); |
383 | } |
384 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
385 | }; |
386 | |
387 | my $initializer = $self->initializer; |
388 | |
389 | # most things will just want to set a value, so make it first arg |
390 | $instance->$initializer($value, $callback, $self); |
391 | } |
392 | |
946289d1 |
393 | sub set_value { |
394 | my ($self, $instance, $value) = @_; |
26fbace8 |
395 | |
946289d1 |
396 | my $attr_name = $self->name; |
26fbace8 |
397 | |
946289d1 |
398 | if ($self->is_required) { |
26fbace8 |
399 | defined($value) |
946289d1 |
400 | || confess "Attribute ($attr_name) is required, so cannot be set to undef"; |
401 | } |
26fbace8 |
402 | |
946289d1 |
403 | if ($self->has_type_constraint) { |
26fbace8 |
404 | |
946289d1 |
405 | my $type_constraint = $self->type_constraint; |
26fbace8 |
406 | |
946289d1 |
407 | if ($self->should_coerce) { |
26fbace8 |
408 | $value = $type_constraint->coerce($value); |
688fcdda |
409 | } |
42bc21a4 |
410 | $type_constraint->_compiled_type_constraint->($value) |
688fcdda |
411 | || confess "Attribute (" |
412 | . $self->name |
413 | . ") does not pass the type constraint because " |
ab76842e |
414 | . $type_constraint->get_message($value); |
946289d1 |
415 | } |
26fbace8 |
416 | |
946289d1 |
417 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
418 | ->get_meta_instance; |
26fbace8 |
419 | |
420 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
421 | |
946289d1 |
422 | if (ref $value && $self->is_weak_ref) { |
26fbace8 |
423 | $meta_instance->weaken_slot_value($instance, $attr_name); |
946289d1 |
424 | } |
26fbace8 |
425 | |
946289d1 |
426 | if ($self->has_trigger) { |
427 | $self->trigger->($instance, $value, $self); |
428 | } |
429 | } |
430 | |
431 | sub get_value { |
432 | my ($self, $instance) = @_; |
26fbace8 |
433 | |
946289d1 |
434 | if ($self->is_lazy) { |
8de73ff1 |
435 | unless ($self->has_value($instance)) { |
436 | if ($self->has_default) { |
437 | my $default = $self->default($instance); |
759e4e8f |
438 | $self->set_initial_value($instance, $default); |
8de73ff1 |
439 | } |
440 | if ( $self->has_builder ){ |
a6c84c69 |
441 | if (my $builder = $instance->can($self->builder)){ |
759e4e8f |
442 | $self->set_initial_value($instance, $instance->$builder); |
a6c84c69 |
443 | } |
444 | else { |
445 | confess(blessed($instance) |
446 | . " does not support builder method '" |
447 | . $self->builder |
448 | . "' for attribute '" |
449 | . $self->name |
450 | . "'"); |
26fbace8 |
451 | } |
a6c84c69 |
452 | } |
453 | else { |
759e4e8f |
454 | $self->set_initial_value($instance, undef); |
26fbace8 |
455 | } |
8de73ff1 |
456 | } |
946289d1 |
457 | } |
26fbace8 |
458 | |
946289d1 |
459 | if ($self->should_auto_deref) { |
26fbace8 |
460 | |
946289d1 |
461 | my $type_constraint = $self->type_constraint; |
462 | |
463 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
464 | my $rv = $self->SUPER::get_value($instance); |
465 | return unless defined $rv; |
466 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
467 | } |
946289d1 |
468 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
469 | my $rv = $self->SUPER::get_value($instance); |
470 | return unless defined $rv; |
471 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
472 | } |
946289d1 |
473 | else { |
474 | confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; |
475 | } |
26fbace8 |
476 | |
946289d1 |
477 | } |
478 | else { |
26fbace8 |
479 | |
946289d1 |
480 | return $self->SUPER::get_value($instance); |
26fbace8 |
481 | } |
946289d1 |
482 | } |
a15dff8d |
483 | |
26fbace8 |
484 | ## installing accessors |
c0e30cf5 |
485 | |
d617b644 |
486 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
487 | |
452bac1b |
488 | sub install_accessors { |
489 | my $self = shift; |
26fbace8 |
490 | $self->SUPER::install_accessors(@_); |
491 | |
452bac1b |
492 | if ($self->has_handles) { |
26fbace8 |
493 | |
452bac1b |
494 | # NOTE: |
495 | # Here we canonicalize the 'handles' option |
26fbace8 |
496 | # this will sort out any details and always |
497 | # return an hash of methods which we want |
452bac1b |
498 | # to delagate to, see that method for details |
499 | my %handles = $self->_canonicalize_handles(); |
26fbace8 |
500 | |
f3c4e20e |
501 | # find the accessor method for this attribute |
502 | my $accessor = $self->get_read_method_ref; |
503 | # then unpack it if we need too ... |
504 | $accessor = $accessor->body if blessed $accessor; |
26fbace8 |
505 | |
452bac1b |
506 | # install the delegation ... |
507 | my $associated_class = $self->associated_class; |
508 | foreach my $handle (keys %handles) { |
509 | my $method_to_call = $handles{$handle}; |
7dbbdcab |
510 | my $class_name = $associated_class->name; |
511 | my $name = "${class_name}::${handle}"; |
26fbace8 |
512 | |
452bac1b |
513 | (!$associated_class->has_method($handle)) |
514 | || confess "You cannot overwrite a locally defined method ($handle) with a delegation"; |
26fbace8 |
515 | |
d022f632 |
516 | # NOTE: |
517 | # handles is not allowed to delegate |
26fbace8 |
518 | # any of these methods, as they will |
519 | # override the ones in your class, which |
d022f632 |
520 | # is almost certainly not what you want. |
4fe78472 |
521 | |
522 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
523 | #cluck("Not delegating method '$handle' because it is a core method") and |
524 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
525 | |
452bac1b |
526 | if ((reftype($method_to_call) || '') eq 'CODE') { |
7dbbdcab |
527 | $associated_class->add_method($handle => subname $name, $method_to_call); |
452bac1b |
528 | } |
529 | else { |
140001f0 |
530 | # NOTE: |
531 | # we used to do a goto here, but the |
532 | # goto didn't handle failure correctly |
533 | # (it just returned nothing), so I took |
534 | # that out. However, the more I thought |
535 | # about it, the less I liked it doing |
536 | # the goto, and I prefered the act of |
537 | # delegation being actually represented |
538 | # in the stack trace. |
539 | # - SL |
7dbbdcab |
540 | $associated_class->add_method($handle => subname $name, sub { |
f3c4e20e |
541 | my $proxy = (shift)->$accessor(); |
ccf49e80 |
542 | (defined $proxy) |
543 | || confess "Cannot delegate $handle to $method_to_call because " . |
544 | "the value of " . $self->name . " is not defined"; |
f4f3e701 |
545 | $proxy->$method_to_call(@_); |
452bac1b |
546 | }); |
547 | } |
548 | } |
549 | } |
26fbace8 |
550 | |
452bac1b |
551 | return; |
552 | } |
553 | |
98aae381 |
554 | # private methods to help delegation ... |
555 | |
452bac1b |
556 | sub _canonicalize_handles { |
557 | my $self = shift; |
558 | my $handles = $self->handles; |
c84f324f |
559 | if (my $handle_type = ref($handles)) { |
560 | if ($handle_type eq 'HASH') { |
561 | return %{$handles}; |
562 | } |
563 | elsif ($handle_type eq 'ARRAY') { |
564 | return map { $_ => $_ } @{$handles}; |
565 | } |
566 | elsif ($handle_type eq 'Regexp') { |
567 | ($self->has_type_constraint) |
568 | || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)"; |
26fbace8 |
569 | return map { ($_ => $_) } |
c84f324f |
570 | grep { /$handles/ } $self->_get_delegate_method_list; |
571 | } |
572 | elsif ($handle_type eq 'CODE') { |
573 | return $handles->($self, $self->_find_delegate_metaclass); |
574 | } |
575 | else { |
576 | confess "Unable to canonicalize the 'handles' option with $handles"; |
577 | } |
452bac1b |
578 | } |
579 | else { |
c84f324f |
580 | my $role_meta = eval { $handles->meta }; |
581 | if ($@) { |
26fbace8 |
582 | confess "Unable to canonicalize the 'handles' option with $handles because : $@"; |
c84f324f |
583 | } |
584 | |
585 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
586 | || confess "Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role"; |
26fbace8 |
587 | |
c84f324f |
588 | return map { $_ => $_ } ( |
26fbace8 |
589 | $role_meta->get_method_list, |
c84f324f |
590 | $role_meta->get_required_method_list |
591 | ); |
452bac1b |
592 | } |
593 | } |
594 | |
595 | sub _find_delegate_metaclass { |
596 | my $self = shift; |
98aae381 |
597 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
598 | # if the class does have |
452bac1b |
599 | # a meta method, use it |
600 | return $class->meta if $class->can('meta'); |
26fbace8 |
601 | # otherwise we might be |
452bac1b |
602 | # dealing with a non-Moose |
26fbace8 |
603 | # class, and need to make |
452bac1b |
604 | # our own metaclass |
605 | return Moose::Meta::Class->initialize($class); |
606 | } |
98aae381 |
607 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
608 | # our role will always have |
452bac1b |
609 | # a meta method |
98aae381 |
610 | return $role->meta; |
452bac1b |
611 | } |
612 | else { |
613 | confess "Cannot find delegate metaclass for attribute " . $self->name; |
614 | } |
615 | } |
616 | |
617 | sub _get_delegate_method_list { |
618 | my $self = shift; |
619 | my $meta = $self->_find_delegate_metaclass; |
620 | if ($meta->isa('Class::MOP::Class')) { |
093b12c2 |
621 | return map { $_->{name} } # NOTE: !never! delegate &meta |
26fbace8 |
622 | grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' } |
452bac1b |
623 | $meta->compute_all_applicable_methods; |
624 | } |
625 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
626 | return $meta->get_method_list; |
452bac1b |
627 | } |
628 | else { |
629 | confess "Unable to recognize the delegate metaclass '$meta'"; |
630 | } |
631 | } |
632 | |
c0e30cf5 |
633 | 1; |
634 | |
635 | __END__ |
636 | |
637 | =pod |
638 | |
639 | =head1 NAME |
640 | |
6ba6d68c |
641 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
642 | |
643 | =head1 DESCRIPTION |
644 | |
26fbace8 |
645 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
646 | extensions. |
6ba6d68c |
647 | |
26fbace8 |
648 | For the most part, the only time you will ever encounter an |
649 | instance of this class is if you are doing some serious deep |
650 | introspection. To really understand this class, you need to refer |
6ba6d68c |
651 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
652 | |
c0e30cf5 |
653 | =head1 METHODS |
654 | |
6ba6d68c |
655 | =head2 Overridden methods |
656 | |
26fbace8 |
657 | These methods override methods in L<Class::MOP::Attribute> and add |
658 | Moose specific features. You can safely assume though that they |
6ba6d68c |
659 | will behave just as L<Class::MOP::Attribute> does. |
660 | |
c0e30cf5 |
661 | =over 4 |
662 | |
663 | =item B<new> |
664 | |
c32c2c61 |
665 | =item B<clone> |
666 | |
6e2840b7 |
667 | =item B<does> |
668 | |
d500266f |
669 | =item B<initialize_instance_slot> |
670 | |
452bac1b |
671 | =item B<install_accessors> |
672 | |
39b3bc94 |
673 | =item B<accessor_metaclass> |
674 | |
946289d1 |
675 | =item B<get_value> |
676 | |
677 | =item B<set_value> |
678 | |
bcbaa845 |
679 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
680 | if($@) { |
681 | print "Oops: $@\n"; |
682 | } |
683 | |
684 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
685 | |
686 | Before setting the value, a check is made on the type constraint of |
687 | the attribute, if it has one, to see if the value passes it. If the |
688 | value fails to pass, the set operation dies with a L<Carp/confess>. |
689 | |
690 | Any coercion to convert values is done before checking the type constraint. |
691 | |
692 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
693 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
694 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
695 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::RecipeX> |
696 | for an example. |
697 | |
a15dff8d |
698 | =back |
699 | |
6ba6d68c |
700 | =head2 Additional Moose features |
701 | |
26fbace8 |
702 | Moose attributes support type-constraint checking, weak reference |
703 | creation and type coercion. |
6ba6d68c |
704 | |
a15dff8d |
705 | =over 4 |
706 | |
d5c30e52 |
707 | =item B<interpolate_class_and_new> |
708 | |
709 | =item B<interpolate_class> |
710 | |
711 | When called as a class method causes interpretation of the C<metaclass> and |
712 | C<traits> options. |
713 | |
9e93dd19 |
714 | =item B<clone_and_inherit_options> |
715 | |
26fbace8 |
716 | This is to support the C<has '+foo'> feature, it clones an attribute |
717 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
718 | to the attribute. |
719 | |
a15dff8d |
720 | =item B<has_type_constraint> |
721 | |
6ba6d68c |
722 | Returns true if this meta-attribute has a type constraint. |
723 | |
a15dff8d |
724 | =item B<type_constraint> |
725 | |
26fbace8 |
726 | A read-only accessor for this meta-attribute's type constraint. For |
727 | more information on what you can do with this, see the documentation |
6ba6d68c |
728 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
729 | |
452bac1b |
730 | =item B<has_handles> |
731 | |
732 | Returns true if this meta-attribute performs delegation. |
733 | |
734 | =item B<handles> |
735 | |
736 | This returns the value which was passed into the handles option. |
737 | |
6ba6d68c |
738 | =item B<is_weak_ref> |
a15dff8d |
739 | |
02a0fb52 |
740 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
741 | |
ca01a97b |
742 | =item B<is_required> |
743 | |
02a0fb52 |
744 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
745 | |
746 | =item B<is_lazy> |
747 | |
02a0fb52 |
748 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
749 | |
26fbace8 |
750 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
751 | |
752 | =item B<is_lazy_build> |
753 | |
754 | Returns true if this meta-attribute should be initialized lazily through |
755 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
756 | make your attribute required and lazy. In addition it will set the builder, clearer |
757 | and predicate options for you using the following convention. |
758 | |
759 | #If your attribute name starts with an underscore: |
760 | has '_foo' => (lazy_build => 1); |
761 | #is the same as |
58f85113 |
762 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo); |
26fbace8 |
763 | # or |
58f85113 |
764 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
765 | |
766 | #If your attribute name does not start with an underscore: |
58f85113 |
767 | has 'foo' => (lazy_build => 1); |
768 | #is the same as |
769 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo); |
26fbace8 |
770 | # or |
58f85113 |
771 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
772 | |
773 | The reason for the different naming of the C<builder> is that the C<builder> |
774 | method is a private method while the C<clearer> and C<predicate> methods |
775 | are public methods. |
26fbace8 |
776 | |
777 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
778 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
779 | |
34a66aa3 |
780 | =item B<should_coerce> |
4b598ea3 |
781 | |
02a0fb52 |
782 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
783 | |
536f0b17 |
784 | =item B<should_auto_deref> |
785 | |
26fbace8 |
786 | Returns true if this meta-attribute should perform automatic |
787 | auto-dereferencing. |
536f0b17 |
788 | |
26fbace8 |
789 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
790 | either I<ArrayRef> or I<HashRef>. |
791 | |
8c9d74e7 |
792 | =item B<has_trigger> |
793 | |
02a0fb52 |
794 | Returns true if this meta-attribute has a trigger set. |
795 | |
8c9d74e7 |
796 | =item B<trigger> |
797 | |
26fbace8 |
798 | This is a CODE reference which will be executed every time the |
799 | value of an attribute is assigned. The CODE ref will get two values, |
800 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
801 | bi-directional relations. |
802 | |
ddbdc0cb |
803 | =item B<documentation> |
804 | |
26fbace8 |
805 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
806 | It serves no direct purpose right now, but it might in the future |
807 | in some kind of automated documentation system perhaps. |
808 | |
809 | =item B<has_documentation> |
810 | |
811 | Returns true if this meta-attribute has any documentation. |
812 | |
88f23977 |
813 | =item B<applied_traits> |
814 | |
815 | This will return the ARRAY ref of all the traits applied to this |
816 | attribute, or if no traits have been applied, it returns C<undef>. |
817 | |
818 | =item B<has_applied_traits> |
819 | |
820 | Returns true if this meta-attribute has any traits applied. |
821 | |
c0e30cf5 |
822 | =back |
823 | |
824 | =head1 BUGS |
825 | |
26fbace8 |
826 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
827 | exception. If you find a bug please either email me, or add the bug |
828 | to cpan-RT. |
829 | |
c0e30cf5 |
830 | =head1 AUTHOR |
831 | |
832 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
833 | |
98aae381 |
834 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
835 | |
c0e30cf5 |
836 | =head1 COPYRIGHT AND LICENSE |
837 | |
778db3ac |
838 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
839 | |
840 | L<http://www.iinteractive.com> |
841 | |
842 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
843 | it under the same terms as Perl itself. |
c0e30cf5 |
844 | |
8a7a9c53 |
845 | =cut |