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'; |
a909a4df |
8 | use overload (); |
a15dff8d |
9 | |
1aab4011 |
10 | our $VERSION = '0.64'; |
d44714be |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
78cd1d3b |
12 | |
8ee73eeb |
13 | use Moose::Meta::Method::Accessor; |
a05f85c1 |
14 | use Moose::Meta::Method::Delegation; |
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 |
e8895723 |
64 | return $self->Moose::Object::does($name); |
0db4f1d7 |
65 | } |
587e457d |
66 | |
be05faea |
67 | sub throw_error { |
68 | my $self = shift; |
69 | my $class = ( ref $self && $self->associated_class ) || "Moose::Meta::Class"; |
70 | unshift @_, "message" if @_ % 2 == 1; |
71 | unshift @_, attr => $self if ref $self; |
72 | unshift @_, $class; |
18748ad6 |
73 | my $handler = $class->can("throw_error"); # to avoid incrementing depth by 1 |
74 | goto $handler; |
be05faea |
75 | } |
76 | |
78cd1d3b |
77 | sub new { |
f3c4e20e |
78 | my ($class, $name, %options) = @_; |
c32c2c61 |
79 | $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS |
f3c4e20e |
80 | return $class->SUPER::new($name, %options); |
1d768fb1 |
81 | } |
82 | |
d5c30e52 |
83 | sub interpolate_class_and_new { |
84 | my ($class, $name, @args) = @_; |
85 | |
c32c2c61 |
86 | my ( $new_class, @traits ) = $class->interpolate_class(@args); |
87 | |
88 | $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); |
d5c30e52 |
89 | } |
90 | |
91 | sub interpolate_class { |
92 | my ($class, %options) = @_; |
93 | |
c32c2c61 |
94 | $class = ref($class) || $class; |
95 | |
96 | if ( my $metaclass_name = delete $options{metaclass} ) { |
97 | my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); |
98 | |
99 | if ( $class ne $new_class ) { |
100 | if ( $new_class->can("interpolate_class") ) { |
101 | return $new_class->interpolate_class(%options); |
102 | } else { |
103 | $class = $new_class; |
104 | } |
105 | } |
d5c30e52 |
106 | } |
107 | |
c32c2c61 |
108 | my @traits; |
109 | |
d5c30e52 |
110 | if (my $traits = $options{traits}) { |
8974015d |
111 | my $i = 0; |
112 | while ($i < @$traits) { |
113 | my $trait = $traits->[$i++]; |
114 | next if ref($trait); # options to a trait we discarded |
115 | |
116 | $trait = Moose::Util::resolve_metatrait_alias(Attribute => $trait) |
117 | || $trait; |
118 | |
119 | next if $class->does($trait); |
120 | |
121 | push @traits, $trait; |
122 | |
123 | # are there options? |
124 | push @traits, $traits->[$i++] |
125 | if $traits->[$i] && ref($traits->[$i]); |
126 | } |
965743fb |
127 | |
128 | if (@traits) { |
c32c2c61 |
129 | my $anon_class = Moose::Meta::Class->create_anon_class( |
130 | superclasses => [ $class ], |
131 | roles => [ @traits ], |
132 | cache => 1, |
133 | ); |
134 | |
135 | $class = $anon_class->name; |
136 | } |
d5c30e52 |
137 | } |
c32c2c61 |
138 | |
139 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
140 | } |
141 | |
e606ae5f |
142 | # ... |
143 | |
144 | my @legal_options_for_inheritance = qw( |
145 | default coerce required |
146 | documentation lazy handles |
147 | builder type_constraint |
148 | ); |
149 | |
150 | sub legal_options_for_inheritance { @legal_options_for_inheritance } |
151 | |
152 | # NOTE/TODO |
153 | # This method *must* be able to handle |
154 | # Class::MOP::Attribute instances as |
155 | # well. Yes, I know that is wrong, but |
156 | # apparently we didn't realize it was |
157 | # doing that and now we have some code |
158 | # which is dependent on it. The real |
159 | # solution of course is to push this |
160 | # feature back up into Class::MOP::Attribute |
161 | # but I not right now, I am too lazy. |
162 | # However if you are reading this and |
163 | # looking for something to do,.. please |
164 | # be my guest. |
165 | # - stevan |
ce0e8d63 |
166 | sub clone_and_inherit_options { |
167 | my ($self, %options) = @_; |
e606ae5f |
168 | |
c32c2c61 |
169 | my %copy = %options; |
e606ae5f |
170 | |
ce0e8d63 |
171 | my %actual_options; |
e606ae5f |
172 | |
173 | # NOTE: |
174 | # we may want to extends a Class::MOP::Attribute |
175 | # in which case we need to be able to use the |
176 | # core set of legal options that have always |
177 | # been here. But we allows Moose::Meta::Attribute |
178 | # instances to changes them. |
179 | # - SL |
180 | my @legal_options = $self->can('legal_options_for_inheritance') |
181 | ? $self->legal_options_for_inheritance |
182 | : @legal_options_for_inheritance; |
183 | |
184 | foreach my $legal_option (@legal_options) { |
ce0e8d63 |
185 | if (exists $options{$legal_option}) { |
186 | $actual_options{$legal_option} = $options{$legal_option}; |
187 | delete $options{$legal_option}; |
188 | } |
e606ae5f |
189 | } |
26fbace8 |
190 | |
ce0e8d63 |
191 | if ($options{isa}) { |
192 | my $type_constraint; |
8de73ff1 |
193 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
194 | $type_constraint = $options{isa}; |
195 | } |
196 | else { |
d40ce9d5 |
197 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
198 | (defined $type_constraint) |
be05faea |
199 | || $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa}); |
8de73ff1 |
200 | } |
5e98d2b6 |
201 | |
8de73ff1 |
202 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
203 | delete $options{isa}; |
204 | } |
2ea379cb |
205 | |
206 | if ($options{does}) { |
207 | my $type_constraint; |
208 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
209 | $type_constraint = $options{does}; |
210 | } |
211 | else { |
d40ce9d5 |
212 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
213 | (defined $type_constraint) |
be05faea |
214 | || $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does}); |
2ea379cb |
215 | } |
216 | |
217 | $actual_options{type_constraint} = $type_constraint; |
218 | delete $options{does}; |
219 | } |
c32c2c61 |
220 | |
cbd141ca |
221 | # NOTE: |
222 | # this doesn't apply to Class::MOP::Attributes, |
223 | # so we can ignore it for them. |
224 | # - SL |
225 | if ($self->can('interpolate_class')) { |
226 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
227 | |
cbd141ca |
228 | my %seen; |
229 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
230 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
231 | |
cbd141ca |
232 | delete @options{qw(metaclass traits)}; |
233 | } |
c32c2c61 |
234 | |
26fbace8 |
235 | (scalar keys %options == 0) |
be05faea |
236 | || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options); |
c32c2c61 |
237 | |
238 | |
ce0e8d63 |
239 | $self->clone(%actual_options); |
1d768fb1 |
240 | } |
241 | |
c32c2c61 |
242 | sub clone { |
243 | my ( $self, %params ) = @_; |
244 | |
245 | my $class = $params{metaclass} || ref $self; |
246 | |
247 | if ( 0 and $class eq ref $self ) { |
248 | return $self->SUPER::clone(%params); |
249 | } else { |
250 | my ( @init, @non_init ); |
251 | |
252 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
253 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
254 | } |
255 | |
256 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
257 | |
258 | my $name = delete $new_params{name}; |
259 | |
260 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
261 | |
262 | foreach my $attr ( @non_init ) { |
263 | $attr->set_value($clone, $attr->get_value($self)); |
264 | } |
265 | |
266 | |
267 | return $clone; |
268 | } |
269 | } |
270 | |
1d768fb1 |
271 | sub _process_options { |
272 | my ($class, $name, $options) = @_; |
8de73ff1 |
273 | |
f3c4e20e |
274 | if (exists $options->{is}) { |
21f1e231 |
275 | |
012fcbd1 |
276 | ### ------------------------- |
277 | ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
278 | ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
279 | ## is => rw, accessor => _foo # turns into (accessor => _foo) |
280 | ## is => ro, accessor => _foo # error, accesor is rw |
281 | ### ------------------------- |
21f1e231 |
282 | |
8de73ff1 |
283 | if ($options->{is} eq 'ro') { |
be05faea |
284 | $class->throw_error("Cannot define an accessor name on a read-only attribute, accessors are read/write", data => $options) |
21f1e231 |
285 | if exists $options->{accessor}; |
8de73ff1 |
286 | $options->{reader} ||= $name; |
8de73ff1 |
287 | } |
288 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
289 | if ($options->{writer}) { |
290 | $options->{reader} ||= $name; |
291 | } |
292 | else { |
293 | $options->{accessor} ||= $name; |
294 | } |
8de73ff1 |
295 | } |
296 | else { |
e606ae5f |
297 | $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute ($name)", data => $options->{is}); |
8de73ff1 |
298 | } |
f3c4e20e |
299 | } |
8de73ff1 |
300 | |
f3c4e20e |
301 | if (exists $options->{isa}) { |
f3c4e20e |
302 | if (exists $options->{does}) { |
303 | if (eval { $options->{isa}->can('does') }) { |
304 | ($options->{isa}->does($options->{does})) |
e606ae5f |
305 | || $class->throw_error("Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)", data => $options); |
f3c4e20e |
306 | } |
307 | else { |
e606ae5f |
308 | $class->throw_error("Cannot have an isa option which cannot ->does() on attribute ($name)", data => $options); |
26fbace8 |
309 | } |
26fbace8 |
310 | } |
8de73ff1 |
311 | |
f3c4e20e |
312 | # allow for anon-subtypes here ... |
313 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
314 | $options->{type_constraint} = $options->{isa}; |
315 | } |
316 | else { |
620db045 |
317 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
318 | } |
f3c4e20e |
319 | } |
320 | elsif (exists $options->{does}) { |
321 | # allow for anon-subtypes here ... |
322 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
323 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
324 | } |
325 | else { |
620db045 |
326 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
327 | } |
f3c4e20e |
328 | } |
8de73ff1 |
329 | |
f3c4e20e |
330 | if (exists $options->{coerce} && $options->{coerce}) { |
331 | (exists $options->{type_constraint}) |
e606ae5f |
332 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)", data => $options); |
333 | $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)", data => $options) |
8de73ff1 |
334 | if $options->{weak_ref}; |
f3c4e20e |
335 | } |
8de73ff1 |
336 | |
0b7df53c |
337 | if (exists $options->{trigger}) { |
21f1e231 |
338 | ('CODE' eq ref $options->{trigger}) |
e606ae5f |
339 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger}); |
0b7df53c |
340 | } |
341 | |
f3c4e20e |
342 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
343 | (exists $options->{type_constraint}) |
e606ae5f |
344 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)", data => $options); |
f3c4e20e |
345 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
346 | $options->{type_constraint}->is_a_type_of('HashRef')) |
e606ae5f |
347 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)", data => $options); |
f3c4e20e |
348 | } |
8de73ff1 |
349 | |
f3c4e20e |
350 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
e606ae5f |
351 | $class->throw_error("You can not use lazy_build and default for the same attribute ($name)", data => $options) |
8de73ff1 |
352 | if exists $options->{default}; |
a6c84c69 |
353 | $options->{lazy} = 1; |
354 | $options->{required} = 1; |
355 | $options->{builder} ||= "_build_${name}"; |
356 | if ($name =~ /^_/) { |
f3c4e20e |
357 | $options->{clearer} ||= "_clear${name}"; |
358 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
359 | } |
360 | else { |
f3c4e20e |
361 | $options->{clearer} ||= "clear_${name}"; |
362 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
363 | } |
f3c4e20e |
364 | } |
8de73ff1 |
365 | |
f3c4e20e |
366 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
367 | (exists $options->{default} || defined $options->{builder} ) |
be05faea |
368 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it", data => $options); |
f3c4e20e |
369 | } |
26fbace8 |
370 | |
9edba990 |
371 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
be05faea |
372 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg", data => $options); |
9edba990 |
373 | } |
374 | |
78cd1d3b |
375 | } |
c0e30cf5 |
376 | |
d500266f |
377 | sub initialize_instance_slot { |
ddd0ec20 |
378 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
379 | my $init_arg = $self->init_arg(); |
380 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
381 | |
26fbace8 |
382 | my $val; |
1ed0b94f |
383 | my $value_is_set; |
625d571f |
384 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
385 | $val = $params->{$init_arg}; |
2c78d811 |
386 | $value_is_set = 1; |
d500266f |
387 | } |
388 | else { |
389 | # skip it if it's lazy |
390 | return if $self->is_lazy; |
391 | # and die if it's required and doesn't have a default value |
be05faea |
392 | $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params) |
26fbace8 |
393 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
394 | |
1ed0b94f |
395 | # if nothing was in the %params, we can use the |
396 | # attribute's default value (if it has one) |
397 | if ($self->has_default) { |
398 | $val = $self->default($instance); |
399 | $value_is_set = 1; |
a6c84c69 |
400 | } |
401 | elsif ($self->has_builder) { |
e606ae5f |
402 | $val = $self->_call_builder($instance); |
403 | $value_is_set = 1; |
a0748c37 |
404 | } |
26fbace8 |
405 | } |
406 | |
1ed0b94f |
407 | return unless $value_is_set; |
408 | |
409 | if ($self->has_type_constraint) { |
410 | my $type_constraint = $self->type_constraint; |
411 | if ($self->should_coerce && $type_constraint->has_coercion) { |
412 | $val = $type_constraint->coerce($val); |
d500266f |
413 | } |
5755a9b2 |
414 | $self->verify_against_type_constraint($val, instance => $instance); |
1ed0b94f |
415 | } |
ddd0ec20 |
416 | |
759e4e8f |
417 | $self->set_initial_value($instance, $val); |
26fbace8 |
418 | $meta_instance->weaken_slot_value($instance, $self->name) |
a6c84c69 |
419 | if ref $val && $self->is_weak_ref; |
d500266f |
420 | } |
421 | |
e606ae5f |
422 | sub _call_builder { |
423 | my ( $self, $instance ) = @_; |
424 | |
425 | my $builder = $self->builder(); |
426 | |
427 | return $instance->$builder() |
428 | if $instance->can( $self->builder ); |
429 | |
430 | $self->throw_error( blessed($instance) |
431 | . " does not support builder method '" |
432 | . $self->builder |
433 | . "' for attribute '" |
434 | . $self->name |
435 | . "'", |
436 | object => $instance, |
437 | ); |
438 | } |
439 | |
d617b644 |
440 | ## Slot management |
9e93dd19 |
441 | |
8abe9636 |
442 | # FIXME: |
443 | # this duplicates too much code from |
444 | # Class::MOP::Attribute, we need to |
445 | # refactor these bits eventually. |
446 | # - SL |
447 | sub _set_initial_slot_value { |
448 | my ($self, $meta_instance, $instance, $value) = @_; |
449 | |
450 | my $slot_name = $self->name; |
451 | |
452 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
453 | unless $self->has_initializer; |
454 | |
455 | my ($type_constraint, $can_coerce); |
456 | if ($self->has_type_constraint) { |
457 | $type_constraint = $self->type_constraint; |
458 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
459 | } |
460 | |
461 | my $callback = sub { |
462 | my $val = shift; |
463 | if ($type_constraint) { |
464 | $val = $type_constraint->coerce($val) |
465 | if $can_coerce; |
5755a9b2 |
466 | $self->verify_against_type_constraint($val, object => $instance); |
8abe9636 |
467 | } |
468 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
469 | }; |
470 | |
471 | my $initializer = $self->initializer; |
472 | |
473 | # most things will just want to set a value, so make it first arg |
474 | $instance->$initializer($value, $callback, $self); |
475 | } |
476 | |
946289d1 |
477 | sub set_value { |
b6af66f8 |
478 | my ($self, $instance, @args) = @_; |
479 | my $value = $args[0]; |
26fbace8 |
480 | |
946289d1 |
481 | my $attr_name = $self->name; |
26fbace8 |
482 | |
b6af66f8 |
483 | if ($self->is_required and not @args) { |
be05faea |
484 | $self->throw_error("Attribute ($attr_name) is required", object => $instance); |
946289d1 |
485 | } |
26fbace8 |
486 | |
946289d1 |
487 | if ($self->has_type_constraint) { |
26fbace8 |
488 | |
946289d1 |
489 | my $type_constraint = $self->type_constraint; |
26fbace8 |
490 | |
946289d1 |
491 | if ($self->should_coerce) { |
26fbace8 |
492 | $value = $type_constraint->coerce($value); |
688fcdda |
493 | } |
42bc21a4 |
494 | $type_constraint->_compiled_type_constraint->($value) |
be05faea |
495 | || $self->throw_error("Attribute (" |
688fcdda |
496 | . $self->name |
497 | . ") does not pass the type constraint because " |
be05faea |
498 | . $type_constraint->get_message($value), object => $instance, data => $value); |
946289d1 |
499 | } |
26fbace8 |
500 | |
946289d1 |
501 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
502 | ->get_meta_instance; |
26fbace8 |
503 | |
504 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
505 | |
946289d1 |
506 | if (ref $value && $self->is_weak_ref) { |
26fbace8 |
507 | $meta_instance->weaken_slot_value($instance, $attr_name); |
946289d1 |
508 | } |
26fbace8 |
509 | |
946289d1 |
510 | if ($self->has_trigger) { |
511 | $self->trigger->($instance, $value, $self); |
512 | } |
513 | } |
514 | |
515 | sub get_value { |
516 | my ($self, $instance) = @_; |
26fbace8 |
517 | |
946289d1 |
518 | if ($self->is_lazy) { |
8de73ff1 |
519 | unless ($self->has_value($instance)) { |
e606ae5f |
520 | my $value; |
8de73ff1 |
521 | if ($self->has_default) { |
e606ae5f |
522 | $value = $self->default($instance); |
3f11800d |
523 | } elsif ( $self->has_builder ) { |
e606ae5f |
524 | $value = $self->_call_builder($instance); |
525 | } |
526 | if ($self->has_type_constraint) { |
527 | my $type_constraint = $self->type_constraint; |
528 | $value = $type_constraint->coerce($value) |
529 | if ($self->should_coerce); |
5755a9b2 |
530 | $self->verify_against_type_constraint($value); |
26fbace8 |
531 | } |
e606ae5f |
532 | $self->set_initial_value($instance, $value); |
8de73ff1 |
533 | } |
946289d1 |
534 | } |
26fbace8 |
535 | |
946289d1 |
536 | if ($self->should_auto_deref) { |
26fbace8 |
537 | |
946289d1 |
538 | my $type_constraint = $self->type_constraint; |
539 | |
540 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
541 | my $rv = $self->SUPER::get_value($instance); |
542 | return unless defined $rv; |
543 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
544 | } |
946289d1 |
545 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
546 | my $rv = $self->SUPER::get_value($instance); |
547 | return unless defined $rv; |
548 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
549 | } |
946289d1 |
550 | else { |
46cb090f |
551 | $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, type_constraint => $type_constraint); |
946289d1 |
552 | } |
26fbace8 |
553 | |
946289d1 |
554 | } |
555 | else { |
26fbace8 |
556 | |
946289d1 |
557 | return $self->SUPER::get_value($instance); |
26fbace8 |
558 | } |
946289d1 |
559 | } |
a15dff8d |
560 | |
26fbace8 |
561 | ## installing accessors |
c0e30cf5 |
562 | |
d617b644 |
563 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
564 | |
452bac1b |
565 | sub install_accessors { |
566 | my $self = shift; |
26fbace8 |
567 | $self->SUPER::install_accessors(@_); |
e606ae5f |
568 | $self->install_delegation if $self->has_handles; |
569 | return; |
570 | } |
26fbace8 |
571 | |
e1d6f0a3 |
572 | sub remove_accessors { |
573 | my $self = shift; |
574 | $self->SUPER::remove_accessors(@_); |
575 | $self->remove_delegation if $self->has_handles; |
576 | return; |
577 | } |
578 | |
e606ae5f |
579 | sub install_delegation { |
580 | my $self = shift; |
26fbace8 |
581 | |
e606ae5f |
582 | # NOTE: |
583 | # Here we canonicalize the 'handles' option |
584 | # this will sort out any details and always |
585 | # return an hash of methods which we want |
586 | # to delagate to, see that method for details |
587 | my %handles = $self->_canonicalize_handles; |
588 | |
e606ae5f |
589 | |
590 | # install the delegation ... |
591 | my $associated_class = $self->associated_class; |
592 | foreach my $handle (keys %handles) { |
593 | my $method_to_call = $handles{$handle}; |
594 | my $class_name = $associated_class->name; |
595 | my $name = "${class_name}::${handle}"; |
26fbace8 |
596 | |
452bac1b |
597 | (!$associated_class->has_method($handle)) |
cee532a1 |
598 | || $self->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation", method_name => $handle); |
26fbace8 |
599 | |
e606ae5f |
600 | # NOTE: |
601 | # handles is not allowed to delegate |
602 | # any of these methods, as they will |
603 | # override the ones in your class, which |
604 | # is almost certainly not what you want. |
4fe78472 |
605 | |
e606ae5f |
606 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
607 | #cluck("Not delegating method '$handle' because it is a core method") and |
608 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
609 | |
46f7e6a5 |
610 | my $method = $self->_make_delegation_method($handle, $method_to_call); |
a05f85c1 |
611 | |
612 | $self->associated_class->add_method($method->name, $method); |
e606ae5f |
613 | } |
452bac1b |
614 | } |
615 | |
e1d6f0a3 |
616 | sub remove_delegation { |
617 | my $self = shift; |
618 | my %handles = $self->_canonicalize_handles; |
619 | my $associated_class = $self->associated_class; |
620 | foreach my $handle (keys %handles) { |
621 | $self->associated_class->remove_method($handle); |
622 | } |
623 | } |
624 | |
98aae381 |
625 | # private methods to help delegation ... |
626 | |
452bac1b |
627 | sub _canonicalize_handles { |
628 | my $self = shift; |
629 | my $handles = $self->handles; |
c84f324f |
630 | if (my $handle_type = ref($handles)) { |
631 | if ($handle_type eq 'HASH') { |
632 | return %{$handles}; |
633 | } |
634 | elsif ($handle_type eq 'ARRAY') { |
635 | return map { $_ => $_ } @{$handles}; |
636 | } |
637 | elsif ($handle_type eq 'Regexp') { |
638 | ($self->has_type_constraint) |
0286711b |
639 | || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)", data => $handles); |
26fbace8 |
640 | return map { ($_ => $_) } |
c84f324f |
641 | grep { /$handles/ } $self->_get_delegate_method_list; |
642 | } |
643 | elsif ($handle_type eq 'CODE') { |
644 | return $handles->($self, $self->_find_delegate_metaclass); |
645 | } |
646 | else { |
be05faea |
647 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); |
c84f324f |
648 | } |
452bac1b |
649 | } |
650 | else { |
9fa39240 |
651 | Class::MOP::load_class($handles) |
652 | unless Class::MOP::is_class_loaded($handles); |
653 | |
c84f324f |
654 | my $role_meta = eval { $handles->meta }; |
655 | if ($@) { |
be05faea |
656 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles because : $@", data => $handles, error => $@); |
c84f324f |
657 | } |
658 | |
659 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
be05faea |
660 | || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role", data => $handles); |
9fa39240 |
661 | |
c84f324f |
662 | return map { $_ => $_ } ( |
26fbace8 |
663 | $role_meta->get_method_list, |
c84f324f |
664 | $role_meta->get_required_method_list |
665 | ); |
452bac1b |
666 | } |
667 | } |
668 | |
669 | sub _find_delegate_metaclass { |
670 | my $self = shift; |
98aae381 |
671 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
672 | # if the class does have |
452bac1b |
673 | # a meta method, use it |
674 | return $class->meta if $class->can('meta'); |
26fbace8 |
675 | # otherwise we might be |
452bac1b |
676 | # dealing with a non-Moose |
26fbace8 |
677 | # class, and need to make |
452bac1b |
678 | # our own metaclass |
679 | return Moose::Meta::Class->initialize($class); |
680 | } |
98aae381 |
681 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
682 | # our role will always have |
452bac1b |
683 | # a meta method |
98aae381 |
684 | return $role->meta; |
452bac1b |
685 | } |
686 | else { |
be05faea |
687 | $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name); |
452bac1b |
688 | } |
689 | } |
690 | |
691 | sub _get_delegate_method_list { |
692 | my $self = shift; |
693 | my $meta = $self->_find_delegate_metaclass; |
694 | if ($meta->isa('Class::MOP::Class')) { |
e606ae5f |
695 | return map { $_->name } # NOTE: !never! delegate &meta |
696 | grep { $_->package_name ne 'Moose::Object' && $_->name ne 'meta' } |
697 | $meta->get_all_methods; |
452bac1b |
698 | } |
699 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
700 | return $meta->get_method_list; |
452bac1b |
701 | } |
702 | else { |
be05faea |
703 | $self->throw_error("Unable to recognize the delegate metaclass '$meta'", data => $meta); |
452bac1b |
704 | } |
705 | } |
706 | |
a05f85c1 |
707 | sub _make_delegation_method { |
46f7e6a5 |
708 | my ( $self, $handle_name, $method_to_call ) = @_; |
a05f85c1 |
709 | |
710 | my $method_body; |
711 | |
46f7e6a5 |
712 | $method_body = $method_to_call |
713 | if 'CODE' eq ref($method_to_call); |
a05f85c1 |
714 | |
715 | return Moose::Meta::Method::Delegation->new( |
46f7e6a5 |
716 | name => $handle_name, |
717 | package_name => $self->associated_class->name, |
718 | attribute => $self, |
719 | delegate_to_method => $method_to_call, |
a05f85c1 |
720 | ); |
721 | } |
722 | |
5755a9b2 |
723 | sub verify_against_type_constraint { |
2b86e02b |
724 | my $self = shift; |
725 | my $val = shift; |
726 | |
727 | return 1 if !$self->has_type_constraint; |
728 | |
729 | my $type_constraint = $self->type_constraint; |
730 | |
731 | $type_constraint->check($val) |
732 | || $self->throw_error("Attribute (" |
733 | . $self->name |
734 | . ") does not pass the type constraint because: " |
735 | . $type_constraint->get_message($val), data => $val, @_); |
736 | } |
737 | |
21f1e231 |
738 | package Moose::Meta::Attribute::Custom::Moose; |
739 | sub register_implementation { 'Moose::Meta::Attribute' } |
740 | |
c0e30cf5 |
741 | 1; |
742 | |
743 | __END__ |
744 | |
745 | =pod |
746 | |
747 | =head1 NAME |
748 | |
6ba6d68c |
749 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
750 | |
751 | =head1 DESCRIPTION |
752 | |
26fbace8 |
753 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
754 | extensions. |
6ba6d68c |
755 | |
26fbace8 |
756 | For the most part, the only time you will ever encounter an |
757 | instance of this class is if you are doing some serious deep |
758 | introspection. To really understand this class, you need to refer |
6ba6d68c |
759 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
760 | |
c0e30cf5 |
761 | =head1 METHODS |
762 | |
6ba6d68c |
763 | =head2 Overridden methods |
764 | |
26fbace8 |
765 | These methods override methods in L<Class::MOP::Attribute> and add |
766 | Moose specific features. You can safely assume though that they |
6ba6d68c |
767 | will behave just as L<Class::MOP::Attribute> does. |
768 | |
c0e30cf5 |
769 | =over 4 |
770 | |
771 | =item B<new> |
772 | |
c32c2c61 |
773 | =item B<clone> |
774 | |
6e2840b7 |
775 | =item B<does> |
776 | |
d500266f |
777 | =item B<initialize_instance_slot> |
778 | |
452bac1b |
779 | =item B<install_accessors> |
780 | |
e1d6f0a3 |
781 | =item B<remove_accessors> |
782 | |
e606ae5f |
783 | =item B<install_delegation> |
784 | |
e1d6f0a3 |
785 | =item B<remove_delegation> |
786 | |
39b3bc94 |
787 | =item B<accessor_metaclass> |
788 | |
946289d1 |
789 | =item B<get_value> |
790 | |
791 | =item B<set_value> |
792 | |
bcbaa845 |
793 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
794 | if($@) { |
795 | print "Oops: $@\n"; |
796 | } |
797 | |
798 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
799 | |
800 | Before setting the value, a check is made on the type constraint of |
801 | the attribute, if it has one, to see if the value passes it. If the |
46cb090f |
802 | value fails to pass, the set operation dies with a L<throw_error>. |
bcbaa845 |
803 | |
804 | Any coercion to convert values is done before checking the type constraint. |
805 | |
806 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
807 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
808 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
e606ae5f |
809 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::Basics::Recipe4> |
bcbaa845 |
810 | for an example. |
811 | |
a15dff8d |
812 | =back |
813 | |
6ba6d68c |
814 | =head2 Additional Moose features |
815 | |
26fbace8 |
816 | Moose attributes support type-constraint checking, weak reference |
817 | creation and type coercion. |
6ba6d68c |
818 | |
a15dff8d |
819 | =over 4 |
820 | |
be05faea |
821 | =item B<throw_error> |
822 | |
823 | Delegates to C<associated_class> or C<Moose::Meta::Class> if there is none. |
824 | |
d5c30e52 |
825 | =item B<interpolate_class_and_new> |
826 | |
827 | =item B<interpolate_class> |
828 | |
829 | When called as a class method causes interpretation of the C<metaclass> and |
830 | C<traits> options. |
831 | |
9e93dd19 |
832 | =item B<clone_and_inherit_options> |
833 | |
26fbace8 |
834 | This is to support the C<has '+foo'> feature, it clones an attribute |
835 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
836 | to the attribute. |
837 | |
e606ae5f |
838 | =item B<legal_options_for_inheritance> |
839 | |
840 | Whitelist with options you can change. You can overload it in your custom |
841 | metaclass to allow your options be inheritable. |
842 | |
a15dff8d |
843 | =item B<has_type_constraint> |
844 | |
6ba6d68c |
845 | Returns true if this meta-attribute has a type constraint. |
846 | |
a15dff8d |
847 | =item B<type_constraint> |
848 | |
26fbace8 |
849 | A read-only accessor for this meta-attribute's type constraint. For |
850 | more information on what you can do with this, see the documentation |
6ba6d68c |
851 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
852 | |
5755a9b2 |
853 | =item B<verify_against_type_constraint> |
2b86e02b |
854 | |
43cb5dad |
855 | Verifies that the given value is valid under this attribute's type |
2b86e02b |
856 | constraint, otherwise throws an error. |
857 | |
452bac1b |
858 | =item B<has_handles> |
859 | |
860 | Returns true if this meta-attribute performs delegation. |
861 | |
862 | =item B<handles> |
863 | |
864 | This returns the value which was passed into the handles option. |
865 | |
6ba6d68c |
866 | =item B<is_weak_ref> |
a15dff8d |
867 | |
02a0fb52 |
868 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
869 | |
ca01a97b |
870 | =item B<is_required> |
871 | |
02a0fb52 |
872 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
873 | |
874 | =item B<is_lazy> |
875 | |
02a0fb52 |
876 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
877 | |
26fbace8 |
878 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
879 | |
880 | =item B<is_lazy_build> |
881 | |
882 | Returns true if this meta-attribute should be initialized lazily through |
883 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
884 | make your attribute required and lazy. In addition it will set the builder, clearer |
885 | and predicate options for you using the following convention. |
886 | |
887 | #If your attribute name starts with an underscore: |
888 | has '_foo' => (lazy_build => 1); |
889 | #is the same as |
e606ae5f |
890 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo'); |
26fbace8 |
891 | # or |
58f85113 |
892 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
893 | |
894 | #If your attribute name does not start with an underscore: |
58f85113 |
895 | has 'foo' => (lazy_build => 1); |
896 | #is the same as |
e606ae5f |
897 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo'); |
26fbace8 |
898 | # or |
58f85113 |
899 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
900 | |
901 | The reason for the different naming of the C<builder> is that the C<builder> |
902 | method is a private method while the C<clearer> and C<predicate> methods |
903 | are public methods. |
26fbace8 |
904 | |
905 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
906 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
907 | |
34a66aa3 |
908 | =item B<should_coerce> |
4b598ea3 |
909 | |
02a0fb52 |
910 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
911 | |
536f0b17 |
912 | =item B<should_auto_deref> |
913 | |
26fbace8 |
914 | Returns true if this meta-attribute should perform automatic |
915 | auto-dereferencing. |
536f0b17 |
916 | |
26fbace8 |
917 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
918 | either I<ArrayRef> or I<HashRef>. |
919 | |
8c9d74e7 |
920 | =item B<has_trigger> |
921 | |
02a0fb52 |
922 | Returns true if this meta-attribute has a trigger set. |
923 | |
8c9d74e7 |
924 | =item B<trigger> |
925 | |
26fbace8 |
926 | This is a CODE reference which will be executed every time the |
927 | value of an attribute is assigned. The CODE ref will get two values, |
928 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
929 | bi-directional relations. |
930 | |
ddbdc0cb |
931 | =item B<documentation> |
932 | |
26fbace8 |
933 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
934 | It serves no direct purpose right now, but it might in the future |
935 | in some kind of automated documentation system perhaps. |
936 | |
937 | =item B<has_documentation> |
938 | |
939 | Returns true if this meta-attribute has any documentation. |
940 | |
88f23977 |
941 | =item B<applied_traits> |
942 | |
943 | This will return the ARRAY ref of all the traits applied to this |
944 | attribute, or if no traits have been applied, it returns C<undef>. |
945 | |
946 | =item B<has_applied_traits> |
947 | |
948 | Returns true if this meta-attribute has any traits applied. |
949 | |
c0e30cf5 |
950 | =back |
951 | |
952 | =head1 BUGS |
953 | |
26fbace8 |
954 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
955 | exception. If you find a bug please either email me, or add the bug |
956 | to cpan-RT. |
957 | |
c0e30cf5 |
958 | =head1 AUTHOR |
959 | |
960 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
961 | |
98aae381 |
962 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
963 | |
c0e30cf5 |
964 | =head1 COPYRIGHT AND LICENSE |
965 | |
778db3ac |
966 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
967 | |
968 | L<http://www.iinteractive.com> |
969 | |
970 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
971 | it under the same terms as Perl itself. |
c0e30cf5 |
972 | |
8a7a9c53 |
973 | =cut |