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 | |
19fabdd3 |
11 | our $VERSION = '0.52'; |
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 ) : $class ); |
d5c30e52 |
117 | } |
118 | |
ce0e8d63 |
119 | sub clone_and_inherit_options { |
120 | my ($self, %options) = @_; |
c32c2c61 |
121 | my %copy = %options; |
122 | # you can change default, required, coerce, documentation, lazy, handles, builder, type_constraint (explicitly or using isa/does), metaclass and traits |
ce0e8d63 |
123 | my %actual_options; |
c32c2c61 |
124 | foreach my $legal_option (qw(default coerce required documentation lazy handles builder type_constraint)) { |
ce0e8d63 |
125 | if (exists $options{$legal_option}) { |
126 | $actual_options{$legal_option} = $options{$legal_option}; |
127 | delete $options{$legal_option}; |
128 | } |
129 | } |
26fbace8 |
130 | |
ce0e8d63 |
131 | if ($options{isa}) { |
132 | my $type_constraint; |
8de73ff1 |
133 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
134 | $type_constraint = $options{isa}; |
135 | } |
136 | else { |
d40ce9d5 |
137 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
138 | (defined $type_constraint) |
139 | || confess "Could not find the type constraint '" . $options{isa} . "'"; |
140 | } |
5e98d2b6 |
141 | |
8de73ff1 |
142 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
143 | delete $options{isa}; |
144 | } |
2ea379cb |
145 | |
146 | if ($options{does}) { |
147 | my $type_constraint; |
148 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
149 | $type_constraint = $options{does}; |
150 | } |
151 | else { |
d40ce9d5 |
152 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
153 | (defined $type_constraint) |
154 | || confess "Could not find the type constraint '" . $options{does} . "'"; |
155 | } |
156 | |
157 | $actual_options{type_constraint} = $type_constraint; |
158 | delete $options{does}; |
159 | } |
c32c2c61 |
160 | |
cbd141ca |
161 | # NOTE: |
162 | # this doesn't apply to Class::MOP::Attributes, |
163 | # so we can ignore it for them. |
164 | # - SL |
165 | if ($self->can('interpolate_class')) { |
166 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
167 | |
cbd141ca |
168 | my %seen; |
169 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
170 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
171 | |
cbd141ca |
172 | delete @options{qw(metaclass traits)}; |
173 | } |
c32c2c61 |
174 | |
26fbace8 |
175 | (scalar keys %options == 0) |
ce0e8d63 |
176 | || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; |
c32c2c61 |
177 | |
178 | |
ce0e8d63 |
179 | $self->clone(%actual_options); |
1d768fb1 |
180 | } |
181 | |
c32c2c61 |
182 | sub clone { |
183 | my ( $self, %params ) = @_; |
184 | |
185 | my $class = $params{metaclass} || ref $self; |
186 | |
187 | if ( 0 and $class eq ref $self ) { |
188 | return $self->SUPER::clone(%params); |
189 | } else { |
190 | my ( @init, @non_init ); |
191 | |
192 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
193 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
194 | } |
195 | |
196 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
197 | |
198 | my $name = delete $new_params{name}; |
199 | |
200 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
201 | |
202 | foreach my $attr ( @non_init ) { |
203 | $attr->set_value($clone, $attr->get_value($self)); |
204 | } |
205 | |
206 | |
207 | return $clone; |
208 | } |
209 | } |
210 | |
1d768fb1 |
211 | sub _process_options { |
212 | my ($class, $name, $options) = @_; |
8de73ff1 |
213 | |
f3c4e20e |
214 | if (exists $options->{is}) { |
21f1e231 |
215 | |
012fcbd1 |
216 | ### ------------------------- |
217 | ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
218 | ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
219 | ## is => rw, accessor => _foo # turns into (accessor => _foo) |
220 | ## is => ro, accessor => _foo # error, accesor is rw |
221 | ### ------------------------- |
21f1e231 |
222 | |
8de73ff1 |
223 | if ($options->{is} eq 'ro') { |
21f1e231 |
224 | confess "Cannot define an accessor name on a read-only attribute, accessors are read/write" |
225 | if exists $options->{accessor}; |
8de73ff1 |
226 | $options->{reader} ||= $name; |
8de73ff1 |
227 | } |
228 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
229 | if ($options->{writer}) { |
230 | $options->{reader} ||= $name; |
231 | } |
232 | else { |
233 | $options->{accessor} ||= $name; |
234 | } |
8de73ff1 |
235 | } |
236 | else { |
173709ca |
237 | confess "I do not understand this option (is => " . $options->{is} . ") on attribute ($name)" |
8de73ff1 |
238 | } |
f3c4e20e |
239 | } |
8de73ff1 |
240 | |
f3c4e20e |
241 | if (exists $options->{isa}) { |
f3c4e20e |
242 | if (exists $options->{does}) { |
243 | if (eval { $options->{isa}->can('does') }) { |
244 | ($options->{isa}->does($options->{does})) |
173709ca |
245 | || confess "Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)"; |
f3c4e20e |
246 | } |
247 | else { |
173709ca |
248 | confess "Cannot have an isa option which cannot ->does() on attribute ($name)"; |
26fbace8 |
249 | } |
26fbace8 |
250 | } |
8de73ff1 |
251 | |
f3c4e20e |
252 | # allow for anon-subtypes here ... |
253 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
254 | $options->{type_constraint} = $options->{isa}; |
255 | } |
256 | else { |
620db045 |
257 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
258 | } |
f3c4e20e |
259 | } |
260 | elsif (exists $options->{does}) { |
261 | # allow for anon-subtypes here ... |
262 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
263 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
264 | } |
265 | else { |
620db045 |
266 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
267 | } |
f3c4e20e |
268 | } |
8de73ff1 |
269 | |
f3c4e20e |
270 | if (exists $options->{coerce} && $options->{coerce}) { |
271 | (exists $options->{type_constraint}) |
173709ca |
272 | || confess "You cannot have coercion without specifying a type constraint on attribute ($name)"; |
273 | confess "You cannot have a weak reference to a coerced value on attribute ($name)" |
8de73ff1 |
274 | if $options->{weak_ref}; |
f3c4e20e |
275 | } |
8de73ff1 |
276 | |
0b7df53c |
277 | if (exists $options->{trigger}) { |
21f1e231 |
278 | ('CODE' eq ref $options->{trigger}) |
173709ca |
279 | || confess "Trigger must be a CODE ref on attribute ($name)"; |
0b7df53c |
280 | } |
281 | |
f3c4e20e |
282 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
283 | (exists $options->{type_constraint}) |
173709ca |
284 | || confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)"; |
f3c4e20e |
285 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
286 | $options->{type_constraint}->is_a_type_of('HashRef')) |
173709ca |
287 | || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"; |
f3c4e20e |
288 | } |
8de73ff1 |
289 | |
f3c4e20e |
290 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
173709ca |
291 | confess("You can not use lazy_build and default for the same attribute ($name)") |
8de73ff1 |
292 | if exists $options->{default}; |
a6c84c69 |
293 | $options->{lazy} = 1; |
294 | $options->{required} = 1; |
295 | $options->{builder} ||= "_build_${name}"; |
296 | if ($name =~ /^_/) { |
f3c4e20e |
297 | $options->{clearer} ||= "_clear${name}"; |
298 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
299 | } |
300 | else { |
f3c4e20e |
301 | $options->{clearer} ||= "clear_${name}"; |
302 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
303 | } |
f3c4e20e |
304 | } |
8de73ff1 |
305 | |
f3c4e20e |
306 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
307 | (exists $options->{default} || defined $options->{builder} ) |
7dbda458 |
308 | || confess "You cannot have lazy attribute ($name) without specifying a default value for it"; |
f3c4e20e |
309 | } |
26fbace8 |
310 | |
9edba990 |
311 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
7dbda458 |
312 | confess "You cannot have a required attribute ($name) without a default, builder, or an init_arg"; |
9edba990 |
313 | } |
314 | |
78cd1d3b |
315 | } |
c0e30cf5 |
316 | |
d500266f |
317 | sub initialize_instance_slot { |
ddd0ec20 |
318 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
319 | my $init_arg = $self->init_arg(); |
320 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
321 | |
26fbace8 |
322 | my $val; |
1ed0b94f |
323 | my $value_is_set; |
625d571f |
324 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
325 | $val = $params->{$init_arg}; |
2c78d811 |
326 | $value_is_set = 1; |
d500266f |
327 | } |
328 | else { |
329 | # skip it if it's lazy |
330 | return if $self->is_lazy; |
331 | # and die if it's required and doesn't have a default value |
26fbace8 |
332 | confess "Attribute (" . $self->name . ") is required" |
333 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
334 | |
1ed0b94f |
335 | # if nothing was in the %params, we can use the |
336 | # attribute's default value (if it has one) |
337 | if ($self->has_default) { |
338 | $val = $self->default($instance); |
339 | $value_is_set = 1; |
a6c84c69 |
340 | } |
341 | elsif ($self->has_builder) { |
342 | if (my $builder = $instance->can($self->builder)){ |
1ed0b94f |
343 | $val = $instance->$builder; |
344 | $value_is_set = 1; |
a6c84c69 |
345 | } |
346 | else { |
0b26305c |
347 | confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'"); |
1ed0b94f |
348 | } |
a0748c37 |
349 | } |
26fbace8 |
350 | } |
351 | |
1ed0b94f |
352 | return unless $value_is_set; |
353 | |
354 | if ($self->has_type_constraint) { |
355 | my $type_constraint = $self->type_constraint; |
356 | if ($self->should_coerce && $type_constraint->has_coercion) { |
357 | $val = $type_constraint->coerce($val); |
d500266f |
358 | } |
ab76842e |
359 | $type_constraint->check($val) |
688fcdda |
360 | || confess "Attribute (" |
361 | . $self->name |
362 | . ") does not pass the type constraint because: " |
363 | . $type_constraint->get_message($val); |
1ed0b94f |
364 | } |
ddd0ec20 |
365 | |
759e4e8f |
366 | $self->set_initial_value($instance, $val); |
26fbace8 |
367 | $meta_instance->weaken_slot_value($instance, $self->name) |
a6c84c69 |
368 | if ref $val && $self->is_weak_ref; |
d500266f |
369 | } |
370 | |
d617b644 |
371 | ## Slot management |
9e93dd19 |
372 | |
8abe9636 |
373 | # FIXME: |
374 | # this duplicates too much code from |
375 | # Class::MOP::Attribute, we need to |
376 | # refactor these bits eventually. |
377 | # - SL |
378 | sub _set_initial_slot_value { |
379 | my ($self, $meta_instance, $instance, $value) = @_; |
380 | |
381 | my $slot_name = $self->name; |
382 | |
383 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
384 | unless $self->has_initializer; |
385 | |
386 | my ($type_constraint, $can_coerce); |
387 | if ($self->has_type_constraint) { |
388 | $type_constraint = $self->type_constraint; |
389 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
390 | } |
391 | |
392 | my $callback = sub { |
393 | my $val = shift; |
394 | if ($type_constraint) { |
395 | $val = $type_constraint->coerce($val) |
396 | if $can_coerce; |
397 | $type_constraint->check($val) |
398 | || confess "Attribute (" |
399 | . $slot_name |
400 | . ") does not pass the type constraint because: " |
401 | . $type_constraint->get_message($val); |
402 | } |
403 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
404 | }; |
405 | |
406 | my $initializer = $self->initializer; |
407 | |
408 | # most things will just want to set a value, so make it first arg |
409 | $instance->$initializer($value, $callback, $self); |
410 | } |
411 | |
946289d1 |
412 | sub set_value { |
b6af66f8 |
413 | my ($self, $instance, @args) = @_; |
414 | my $value = $args[0]; |
26fbace8 |
415 | |
946289d1 |
416 | my $attr_name = $self->name; |
26fbace8 |
417 | |
b6af66f8 |
418 | if ($self->is_required and not @args) { |
419 | confess "Attribute ($attr_name) is required"; |
946289d1 |
420 | } |
26fbace8 |
421 | |
946289d1 |
422 | if ($self->has_type_constraint) { |
26fbace8 |
423 | |
946289d1 |
424 | my $type_constraint = $self->type_constraint; |
26fbace8 |
425 | |
946289d1 |
426 | if ($self->should_coerce) { |
26fbace8 |
427 | $value = $type_constraint->coerce($value); |
688fcdda |
428 | } |
42bc21a4 |
429 | $type_constraint->_compiled_type_constraint->($value) |
688fcdda |
430 | || confess "Attribute (" |
431 | . $self->name |
432 | . ") does not pass the type constraint because " |
ab76842e |
433 | . $type_constraint->get_message($value); |
946289d1 |
434 | } |
26fbace8 |
435 | |
946289d1 |
436 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
437 | ->get_meta_instance; |
26fbace8 |
438 | |
439 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
440 | |
946289d1 |
441 | if (ref $value && $self->is_weak_ref) { |
26fbace8 |
442 | $meta_instance->weaken_slot_value($instance, $attr_name); |
946289d1 |
443 | } |
26fbace8 |
444 | |
946289d1 |
445 | if ($self->has_trigger) { |
446 | $self->trigger->($instance, $value, $self); |
447 | } |
448 | } |
449 | |
450 | sub get_value { |
451 | my ($self, $instance) = @_; |
26fbace8 |
452 | |
946289d1 |
453 | if ($self->is_lazy) { |
8de73ff1 |
454 | unless ($self->has_value($instance)) { |
455 | if ($self->has_default) { |
456 | my $default = $self->default($instance); |
759e4e8f |
457 | $self->set_initial_value($instance, $default); |
3f11800d |
458 | } elsif ( $self->has_builder ) { |
a6c84c69 |
459 | if (my $builder = $instance->can($self->builder)){ |
759e4e8f |
460 | $self->set_initial_value($instance, $instance->$builder); |
3f11800d |
461 | } |
a6c84c69 |
462 | else { |
463 | confess(blessed($instance) |
464 | . " does not support builder method '" |
465 | . $self->builder |
466 | . "' for attribute '" |
467 | . $self->name |
468 | . "'"); |
26fbace8 |
469 | } |
a6c84c69 |
470 | } |
471 | else { |
759e4e8f |
472 | $self->set_initial_value($instance, undef); |
26fbace8 |
473 | } |
8de73ff1 |
474 | } |
946289d1 |
475 | } |
26fbace8 |
476 | |
946289d1 |
477 | if ($self->should_auto_deref) { |
26fbace8 |
478 | |
946289d1 |
479 | my $type_constraint = $self->type_constraint; |
480 | |
481 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
482 | my $rv = $self->SUPER::get_value($instance); |
483 | return unless defined $rv; |
484 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
485 | } |
946289d1 |
486 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
487 | my $rv = $self->SUPER::get_value($instance); |
488 | return unless defined $rv; |
489 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
490 | } |
946289d1 |
491 | else { |
492 | confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; |
493 | } |
26fbace8 |
494 | |
946289d1 |
495 | } |
496 | else { |
26fbace8 |
497 | |
946289d1 |
498 | return $self->SUPER::get_value($instance); |
26fbace8 |
499 | } |
946289d1 |
500 | } |
a15dff8d |
501 | |
26fbace8 |
502 | ## installing accessors |
c0e30cf5 |
503 | |
d617b644 |
504 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
505 | |
452bac1b |
506 | sub install_accessors { |
507 | my $self = shift; |
26fbace8 |
508 | $self->SUPER::install_accessors(@_); |
d3e7fe85 |
509 | $self->install_delegation if $self->has_handles; |
510 | return; |
511 | } |
26fbace8 |
512 | |
d3e7fe85 |
513 | sub install_delegation { |
514 | my $self = shift; |
26fbace8 |
515 | |
d3e7fe85 |
516 | # NOTE: |
517 | # Here we canonicalize the 'handles' option |
518 | # this will sort out any details and always |
519 | # return an hash of methods which we want |
520 | # to delagate to, see that method for details |
521 | my %handles = $self->_canonicalize_handles(); |
522 | |
523 | # find the accessor method for this attribute |
524 | my $accessor = $self->get_read_method_ref; |
525 | # then unpack it if we need too ... |
526 | $accessor = $accessor->body if blessed $accessor; |
527 | |
528 | # install the delegation ... |
529 | my $associated_class = $self->associated_class; |
530 | foreach my $handle (keys %handles) { |
531 | my $method_to_call = $handles{$handle}; |
532 | my $class_name = $associated_class->name; |
533 | my $name = "${class_name}::${handle}"; |
534 | |
535 | (!$associated_class->has_method($handle)) |
536 | || confess "You cannot overwrite a locally defined method ($handle) with a delegation"; |
26fbace8 |
537 | |
d3e7fe85 |
538 | # NOTE: |
539 | # handles is not allowed to delegate |
540 | # any of these methods, as they will |
541 | # override the ones in your class, which |
542 | # is almost certainly not what you want. |
4fe78472 |
543 | |
d3e7fe85 |
544 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
545 | #cluck("Not delegating method '$handle' because it is a core method") and |
546 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
547 | |
d3e7fe85 |
548 | if ('CODE' eq ref($method_to_call)) { |
549 | $associated_class->add_method($handle => Class::MOP::subname($name, $method_to_call)); |
452bac1b |
550 | } |
d3e7fe85 |
551 | else { |
552 | # NOTE: |
553 | # we used to do a goto here, but the |
554 | # goto didn't handle failure correctly |
555 | # (it just returned nothing), so I took |
556 | # that out. However, the more I thought |
557 | # about it, the less I liked it doing |
558 | # the goto, and I prefered the act of |
559 | # delegation being actually represented |
560 | # in the stack trace. |
561 | # - SL |
562 | $associated_class->add_method($handle => Class::MOP::subname($name, sub { |
563 | my $proxy = (shift)->$accessor(); |
564 | (defined $proxy) |
565 | || confess "Cannot delegate $handle to $method_to_call because " . |
566 | "the value of " . $self->name . " is not defined"; |
567 | $proxy->$method_to_call(@_); |
568 | })); |
569 | } |
570 | } |
452bac1b |
571 | } |
572 | |
98aae381 |
573 | # private methods to help delegation ... |
574 | |
452bac1b |
575 | sub _canonicalize_handles { |
576 | my $self = shift; |
577 | my $handles = $self->handles; |
c84f324f |
578 | if (my $handle_type = ref($handles)) { |
579 | if ($handle_type eq 'HASH') { |
580 | return %{$handles}; |
581 | } |
582 | elsif ($handle_type eq 'ARRAY') { |
583 | return map { $_ => $_ } @{$handles}; |
584 | } |
585 | elsif ($handle_type eq 'Regexp') { |
586 | ($self->has_type_constraint) |
587 | || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)"; |
26fbace8 |
588 | return map { ($_ => $_) } |
c84f324f |
589 | grep { /$handles/ } $self->_get_delegate_method_list; |
590 | } |
591 | elsif ($handle_type eq 'CODE') { |
592 | return $handles->($self, $self->_find_delegate_metaclass); |
593 | } |
594 | else { |
595 | confess "Unable to canonicalize the 'handles' option with $handles"; |
596 | } |
452bac1b |
597 | } |
598 | else { |
c84f324f |
599 | my $role_meta = eval { $handles->meta }; |
600 | if ($@) { |
26fbace8 |
601 | confess "Unable to canonicalize the 'handles' option with $handles because : $@"; |
c84f324f |
602 | } |
603 | |
604 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
605 | || confess "Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role"; |
26fbace8 |
606 | |
c84f324f |
607 | return map { $_ => $_ } ( |
26fbace8 |
608 | $role_meta->get_method_list, |
c84f324f |
609 | $role_meta->get_required_method_list |
610 | ); |
452bac1b |
611 | } |
612 | } |
613 | |
614 | sub _find_delegate_metaclass { |
615 | my $self = shift; |
98aae381 |
616 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
617 | # if the class does have |
452bac1b |
618 | # a meta method, use it |
619 | return $class->meta if $class->can('meta'); |
26fbace8 |
620 | # otherwise we might be |
452bac1b |
621 | # dealing with a non-Moose |
26fbace8 |
622 | # class, and need to make |
452bac1b |
623 | # our own metaclass |
624 | return Moose::Meta::Class->initialize($class); |
625 | } |
98aae381 |
626 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
627 | # our role will always have |
452bac1b |
628 | # a meta method |
98aae381 |
629 | return $role->meta; |
452bac1b |
630 | } |
631 | else { |
632 | confess "Cannot find delegate metaclass for attribute " . $self->name; |
633 | } |
634 | } |
635 | |
636 | sub _get_delegate_method_list { |
637 | my $self = shift; |
638 | my $meta = $self->_find_delegate_metaclass; |
639 | if ($meta->isa('Class::MOP::Class')) { |
093b12c2 |
640 | return map { $_->{name} } # NOTE: !never! delegate &meta |
26fbace8 |
641 | grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' } |
452bac1b |
642 | $meta->compute_all_applicable_methods; |
643 | } |
644 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
645 | return $meta->get_method_list; |
452bac1b |
646 | } |
647 | else { |
648 | confess "Unable to recognize the delegate metaclass '$meta'"; |
649 | } |
650 | } |
651 | |
21f1e231 |
652 | package Moose::Meta::Attribute::Custom::Moose; |
653 | sub register_implementation { 'Moose::Meta::Attribute' } |
654 | |
c0e30cf5 |
655 | 1; |
656 | |
657 | __END__ |
658 | |
659 | =pod |
660 | |
661 | =head1 NAME |
662 | |
6ba6d68c |
663 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
664 | |
665 | =head1 DESCRIPTION |
666 | |
26fbace8 |
667 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
668 | extensions. |
6ba6d68c |
669 | |
26fbace8 |
670 | For the most part, the only time you will ever encounter an |
671 | instance of this class is if you are doing some serious deep |
672 | introspection. To really understand this class, you need to refer |
6ba6d68c |
673 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
674 | |
c0e30cf5 |
675 | =head1 METHODS |
676 | |
6ba6d68c |
677 | =head2 Overridden methods |
678 | |
26fbace8 |
679 | These methods override methods in L<Class::MOP::Attribute> and add |
680 | Moose specific features. You can safely assume though that they |
6ba6d68c |
681 | will behave just as L<Class::MOP::Attribute> does. |
682 | |
c0e30cf5 |
683 | =over 4 |
684 | |
685 | =item B<new> |
686 | |
c32c2c61 |
687 | =item B<clone> |
688 | |
6e2840b7 |
689 | =item B<does> |
690 | |
d500266f |
691 | =item B<initialize_instance_slot> |
692 | |
452bac1b |
693 | =item B<install_accessors> |
694 | |
d3e7fe85 |
695 | =item B<install_delegation> |
696 | |
39b3bc94 |
697 | =item B<accessor_metaclass> |
698 | |
946289d1 |
699 | =item B<get_value> |
700 | |
701 | =item B<set_value> |
702 | |
bcbaa845 |
703 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
704 | if($@) { |
705 | print "Oops: $@\n"; |
706 | } |
707 | |
708 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
709 | |
710 | Before setting the value, a check is made on the type constraint of |
711 | the attribute, if it has one, to see if the value passes it. If the |
712 | value fails to pass, the set operation dies with a L<Carp/confess>. |
713 | |
714 | Any coercion to convert values is done before checking the type constraint. |
715 | |
716 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
717 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
718 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
719 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::RecipeX> |
720 | for an example. |
721 | |
a15dff8d |
722 | =back |
723 | |
6ba6d68c |
724 | =head2 Additional Moose features |
725 | |
26fbace8 |
726 | Moose attributes support type-constraint checking, weak reference |
727 | creation and type coercion. |
6ba6d68c |
728 | |
a15dff8d |
729 | =over 4 |
730 | |
d5c30e52 |
731 | =item B<interpolate_class_and_new> |
732 | |
733 | =item B<interpolate_class> |
734 | |
735 | When called as a class method causes interpretation of the C<metaclass> and |
736 | C<traits> options. |
737 | |
9e93dd19 |
738 | =item B<clone_and_inherit_options> |
739 | |
26fbace8 |
740 | This is to support the C<has '+foo'> feature, it clones an attribute |
741 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
742 | to the attribute. |
743 | |
a15dff8d |
744 | =item B<has_type_constraint> |
745 | |
6ba6d68c |
746 | Returns true if this meta-attribute has a type constraint. |
747 | |
a15dff8d |
748 | =item B<type_constraint> |
749 | |
26fbace8 |
750 | A read-only accessor for this meta-attribute's type constraint. For |
751 | more information on what you can do with this, see the documentation |
6ba6d68c |
752 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
753 | |
452bac1b |
754 | =item B<has_handles> |
755 | |
756 | Returns true if this meta-attribute performs delegation. |
757 | |
758 | =item B<handles> |
759 | |
760 | This returns the value which was passed into the handles option. |
761 | |
6ba6d68c |
762 | =item B<is_weak_ref> |
a15dff8d |
763 | |
02a0fb52 |
764 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
765 | |
ca01a97b |
766 | =item B<is_required> |
767 | |
02a0fb52 |
768 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
769 | |
770 | =item B<is_lazy> |
771 | |
02a0fb52 |
772 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
773 | |
26fbace8 |
774 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
775 | |
776 | =item B<is_lazy_build> |
777 | |
778 | Returns true if this meta-attribute should be initialized lazily through |
779 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
780 | make your attribute required and lazy. In addition it will set the builder, clearer |
781 | and predicate options for you using the following convention. |
782 | |
783 | #If your attribute name starts with an underscore: |
784 | has '_foo' => (lazy_build => 1); |
785 | #is the same as |
58f85113 |
786 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo); |
26fbace8 |
787 | # or |
58f85113 |
788 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
789 | |
790 | #If your attribute name does not start with an underscore: |
58f85113 |
791 | has 'foo' => (lazy_build => 1); |
792 | #is the same as |
793 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo); |
26fbace8 |
794 | # or |
58f85113 |
795 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
796 | |
797 | The reason for the different naming of the C<builder> is that the C<builder> |
798 | method is a private method while the C<clearer> and C<predicate> methods |
799 | are public methods. |
26fbace8 |
800 | |
801 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
802 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
803 | |
34a66aa3 |
804 | =item B<should_coerce> |
4b598ea3 |
805 | |
02a0fb52 |
806 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
807 | |
536f0b17 |
808 | =item B<should_auto_deref> |
809 | |
26fbace8 |
810 | Returns true if this meta-attribute should perform automatic |
811 | auto-dereferencing. |
536f0b17 |
812 | |
26fbace8 |
813 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
814 | either I<ArrayRef> or I<HashRef>. |
815 | |
8c9d74e7 |
816 | =item B<has_trigger> |
817 | |
02a0fb52 |
818 | Returns true if this meta-attribute has a trigger set. |
819 | |
8c9d74e7 |
820 | =item B<trigger> |
821 | |
26fbace8 |
822 | This is a CODE reference which will be executed every time the |
823 | value of an attribute is assigned. The CODE ref will get two values, |
824 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
825 | bi-directional relations. |
826 | |
ddbdc0cb |
827 | =item B<documentation> |
828 | |
26fbace8 |
829 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
830 | It serves no direct purpose right now, but it might in the future |
831 | in some kind of automated documentation system perhaps. |
832 | |
833 | =item B<has_documentation> |
834 | |
835 | Returns true if this meta-attribute has any documentation. |
836 | |
88f23977 |
837 | =item B<applied_traits> |
838 | |
839 | This will return the ARRAY ref of all the traits applied to this |
840 | attribute, or if no traits have been applied, it returns C<undef>. |
841 | |
842 | =item B<has_applied_traits> |
843 | |
844 | Returns true if this meta-attribute has any traits applied. |
845 | |
c0e30cf5 |
846 | =back |
847 | |
848 | =head1 BUGS |
849 | |
26fbace8 |
850 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
851 | exception. If you find a bug please either email me, or add the bug |
852 | to cpan-RT. |
853 | |
c0e30cf5 |
854 | =head1 AUTHOR |
855 | |
856 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
857 | |
98aae381 |
858 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
859 | |
c0e30cf5 |
860 | =head1 COPYRIGHT AND LICENSE |
861 | |
778db3ac |
862 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
863 | |
864 | L<http://www.iinteractive.com> |
865 | |
866 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
867 | it under the same terms as Perl itself. |
c0e30cf5 |
868 | |
8a7a9c53 |
869 | =cut |