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 | |
df8260e9 |
10 | our $VERSION = '0.63'; |
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}) { |
965743fb |
111 | @traits = |
112 | grep { not $class->does($_) } |
113 | map { Moose::Util::resolve_metatrait_alias(Attribute => $_) || $_ } |
114 | @$traits; |
115 | |
116 | if (@traits) { |
c32c2c61 |
117 | my $anon_class = Moose::Meta::Class->create_anon_class( |
118 | superclasses => [ $class ], |
119 | roles => [ @traits ], |
120 | cache => 1, |
121 | ); |
122 | |
123 | $class = $anon_class->name; |
124 | } |
d5c30e52 |
125 | } |
c32c2c61 |
126 | |
127 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
128 | } |
129 | |
e606ae5f |
130 | # ... |
131 | |
132 | my @legal_options_for_inheritance = qw( |
133 | default coerce required |
134 | documentation lazy handles |
135 | builder type_constraint |
136 | ); |
137 | |
138 | sub legal_options_for_inheritance { @legal_options_for_inheritance } |
139 | |
140 | # NOTE/TODO |
141 | # This method *must* be able to handle |
142 | # Class::MOP::Attribute instances as |
143 | # well. Yes, I know that is wrong, but |
144 | # apparently we didn't realize it was |
145 | # doing that and now we have some code |
146 | # which is dependent on it. The real |
147 | # solution of course is to push this |
148 | # feature back up into Class::MOP::Attribute |
149 | # but I not right now, I am too lazy. |
150 | # However if you are reading this and |
151 | # looking for something to do,.. please |
152 | # be my guest. |
153 | # - stevan |
ce0e8d63 |
154 | sub clone_and_inherit_options { |
155 | my ($self, %options) = @_; |
e606ae5f |
156 | |
c32c2c61 |
157 | my %copy = %options; |
e606ae5f |
158 | |
ce0e8d63 |
159 | my %actual_options; |
e606ae5f |
160 | |
161 | # NOTE: |
162 | # we may want to extends a Class::MOP::Attribute |
163 | # in which case we need to be able to use the |
164 | # core set of legal options that have always |
165 | # been here. But we allows Moose::Meta::Attribute |
166 | # instances to changes them. |
167 | # - SL |
168 | my @legal_options = $self->can('legal_options_for_inheritance') |
169 | ? $self->legal_options_for_inheritance |
170 | : @legal_options_for_inheritance; |
171 | |
172 | foreach my $legal_option (@legal_options) { |
ce0e8d63 |
173 | if (exists $options{$legal_option}) { |
174 | $actual_options{$legal_option} = $options{$legal_option}; |
175 | delete $options{$legal_option}; |
176 | } |
e606ae5f |
177 | } |
26fbace8 |
178 | |
ce0e8d63 |
179 | if ($options{isa}) { |
180 | my $type_constraint; |
8de73ff1 |
181 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
182 | $type_constraint = $options{isa}; |
183 | } |
184 | else { |
d40ce9d5 |
185 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
186 | (defined $type_constraint) |
be05faea |
187 | || $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa}); |
8de73ff1 |
188 | } |
5e98d2b6 |
189 | |
8de73ff1 |
190 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
191 | delete $options{isa}; |
192 | } |
2ea379cb |
193 | |
194 | if ($options{does}) { |
195 | my $type_constraint; |
196 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
197 | $type_constraint = $options{does}; |
198 | } |
199 | else { |
d40ce9d5 |
200 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
201 | (defined $type_constraint) |
be05faea |
202 | || $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does}); |
2ea379cb |
203 | } |
204 | |
205 | $actual_options{type_constraint} = $type_constraint; |
206 | delete $options{does}; |
207 | } |
c32c2c61 |
208 | |
cbd141ca |
209 | # NOTE: |
210 | # this doesn't apply to Class::MOP::Attributes, |
211 | # so we can ignore it for them. |
212 | # - SL |
213 | if ($self->can('interpolate_class')) { |
214 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
215 | |
cbd141ca |
216 | my %seen; |
217 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
218 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
219 | |
cbd141ca |
220 | delete @options{qw(metaclass traits)}; |
221 | } |
c32c2c61 |
222 | |
26fbace8 |
223 | (scalar keys %options == 0) |
be05faea |
224 | || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options); |
c32c2c61 |
225 | |
226 | |
ce0e8d63 |
227 | $self->clone(%actual_options); |
1d768fb1 |
228 | } |
229 | |
c32c2c61 |
230 | sub clone { |
231 | my ( $self, %params ) = @_; |
232 | |
233 | my $class = $params{metaclass} || ref $self; |
234 | |
235 | if ( 0 and $class eq ref $self ) { |
236 | return $self->SUPER::clone(%params); |
237 | } else { |
238 | my ( @init, @non_init ); |
239 | |
240 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
241 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
242 | } |
243 | |
244 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
245 | |
246 | my $name = delete $new_params{name}; |
247 | |
248 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
249 | |
250 | foreach my $attr ( @non_init ) { |
251 | $attr->set_value($clone, $attr->get_value($self)); |
252 | } |
253 | |
254 | |
255 | return $clone; |
256 | } |
257 | } |
258 | |
1d768fb1 |
259 | sub _process_options { |
260 | my ($class, $name, $options) = @_; |
8de73ff1 |
261 | |
f3c4e20e |
262 | if (exists $options->{is}) { |
21f1e231 |
263 | |
012fcbd1 |
264 | ### ------------------------- |
265 | ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
266 | ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
267 | ## is => rw, accessor => _foo # turns into (accessor => _foo) |
268 | ## is => ro, accessor => _foo # error, accesor is rw |
269 | ### ------------------------- |
21f1e231 |
270 | |
8de73ff1 |
271 | if ($options->{is} eq 'ro') { |
be05faea |
272 | $class->throw_error("Cannot define an accessor name on a read-only attribute, accessors are read/write", data => $options) |
21f1e231 |
273 | if exists $options->{accessor}; |
8de73ff1 |
274 | $options->{reader} ||= $name; |
8de73ff1 |
275 | } |
276 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
277 | if ($options->{writer}) { |
278 | $options->{reader} ||= $name; |
279 | } |
280 | else { |
281 | $options->{accessor} ||= $name; |
282 | } |
8de73ff1 |
283 | } |
284 | else { |
e606ae5f |
285 | $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute ($name)", data => $options->{is}); |
8de73ff1 |
286 | } |
f3c4e20e |
287 | } |
8de73ff1 |
288 | |
f3c4e20e |
289 | if (exists $options->{isa}) { |
f3c4e20e |
290 | if (exists $options->{does}) { |
291 | if (eval { $options->{isa}->can('does') }) { |
292 | ($options->{isa}->does($options->{does})) |
e606ae5f |
293 | || $class->throw_error("Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)", data => $options); |
f3c4e20e |
294 | } |
295 | else { |
e606ae5f |
296 | $class->throw_error("Cannot have an isa option which cannot ->does() on attribute ($name)", data => $options); |
26fbace8 |
297 | } |
26fbace8 |
298 | } |
8de73ff1 |
299 | |
f3c4e20e |
300 | # allow for anon-subtypes here ... |
301 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
302 | $options->{type_constraint} = $options->{isa}; |
303 | } |
304 | else { |
620db045 |
305 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
306 | } |
f3c4e20e |
307 | } |
308 | elsif (exists $options->{does}) { |
309 | # allow for anon-subtypes here ... |
310 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
311 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
312 | } |
313 | else { |
620db045 |
314 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
315 | } |
f3c4e20e |
316 | } |
8de73ff1 |
317 | |
f3c4e20e |
318 | if (exists $options->{coerce} && $options->{coerce}) { |
319 | (exists $options->{type_constraint}) |
e606ae5f |
320 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)", data => $options); |
321 | $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)", data => $options) |
8de73ff1 |
322 | if $options->{weak_ref}; |
f3c4e20e |
323 | } |
8de73ff1 |
324 | |
0b7df53c |
325 | if (exists $options->{trigger}) { |
21f1e231 |
326 | ('CODE' eq ref $options->{trigger}) |
e606ae5f |
327 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger}); |
0b7df53c |
328 | } |
329 | |
f3c4e20e |
330 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
331 | (exists $options->{type_constraint}) |
e606ae5f |
332 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)", data => $options); |
f3c4e20e |
333 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
334 | $options->{type_constraint}->is_a_type_of('HashRef')) |
e606ae5f |
335 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)", data => $options); |
f3c4e20e |
336 | } |
8de73ff1 |
337 | |
f3c4e20e |
338 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
e606ae5f |
339 | $class->throw_error("You can not use lazy_build and default for the same attribute ($name)", data => $options) |
8de73ff1 |
340 | if exists $options->{default}; |
a6c84c69 |
341 | $options->{lazy} = 1; |
342 | $options->{required} = 1; |
343 | $options->{builder} ||= "_build_${name}"; |
344 | if ($name =~ /^_/) { |
f3c4e20e |
345 | $options->{clearer} ||= "_clear${name}"; |
346 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
347 | } |
348 | else { |
f3c4e20e |
349 | $options->{clearer} ||= "clear_${name}"; |
350 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
351 | } |
f3c4e20e |
352 | } |
8de73ff1 |
353 | |
f3c4e20e |
354 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
355 | (exists $options->{default} || defined $options->{builder} ) |
be05faea |
356 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it", data => $options); |
f3c4e20e |
357 | } |
26fbace8 |
358 | |
9edba990 |
359 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
be05faea |
360 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg", data => $options); |
9edba990 |
361 | } |
362 | |
78cd1d3b |
363 | } |
c0e30cf5 |
364 | |
d500266f |
365 | sub initialize_instance_slot { |
ddd0ec20 |
366 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
367 | my $init_arg = $self->init_arg(); |
368 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
369 | |
26fbace8 |
370 | my $val; |
1ed0b94f |
371 | my $value_is_set; |
625d571f |
372 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
373 | $val = $params->{$init_arg}; |
2c78d811 |
374 | $value_is_set = 1; |
d500266f |
375 | } |
376 | else { |
377 | # skip it if it's lazy |
378 | return if $self->is_lazy; |
379 | # and die if it's required and doesn't have a default value |
be05faea |
380 | $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params) |
26fbace8 |
381 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
382 | |
1ed0b94f |
383 | # if nothing was in the %params, we can use the |
384 | # attribute's default value (if it has one) |
385 | if ($self->has_default) { |
386 | $val = $self->default($instance); |
387 | $value_is_set = 1; |
a6c84c69 |
388 | } |
389 | elsif ($self->has_builder) { |
e606ae5f |
390 | $val = $self->_call_builder($instance); |
391 | $value_is_set = 1; |
a0748c37 |
392 | } |
26fbace8 |
393 | } |
394 | |
1ed0b94f |
395 | return unless $value_is_set; |
396 | |
397 | if ($self->has_type_constraint) { |
398 | my $type_constraint = $self->type_constraint; |
399 | if ($self->should_coerce && $type_constraint->has_coercion) { |
400 | $val = $type_constraint->coerce($val); |
d500266f |
401 | } |
ab76842e |
402 | $type_constraint->check($val) |
be05faea |
403 | || $self->throw_error("Attribute (" |
688fcdda |
404 | . $self->name |
405 | . ") does not pass the type constraint because: " |
be05faea |
406 | . $type_constraint->get_message($val), data => $val, object => $instance); |
1ed0b94f |
407 | } |
ddd0ec20 |
408 | |
759e4e8f |
409 | $self->set_initial_value($instance, $val); |
26fbace8 |
410 | $meta_instance->weaken_slot_value($instance, $self->name) |
a6c84c69 |
411 | if ref $val && $self->is_weak_ref; |
d500266f |
412 | } |
413 | |
e606ae5f |
414 | sub _call_builder { |
415 | my ( $self, $instance ) = @_; |
416 | |
417 | my $builder = $self->builder(); |
418 | |
419 | return $instance->$builder() |
420 | if $instance->can( $self->builder ); |
421 | |
422 | $self->throw_error( blessed($instance) |
423 | . " does not support builder method '" |
424 | . $self->builder |
425 | . "' for attribute '" |
426 | . $self->name |
427 | . "'", |
428 | object => $instance, |
429 | ); |
430 | } |
431 | |
d617b644 |
432 | ## Slot management |
9e93dd19 |
433 | |
8abe9636 |
434 | # FIXME: |
435 | # this duplicates too much code from |
436 | # Class::MOP::Attribute, we need to |
437 | # refactor these bits eventually. |
438 | # - SL |
439 | sub _set_initial_slot_value { |
440 | my ($self, $meta_instance, $instance, $value) = @_; |
441 | |
442 | my $slot_name = $self->name; |
443 | |
444 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
445 | unless $self->has_initializer; |
446 | |
447 | my ($type_constraint, $can_coerce); |
448 | if ($self->has_type_constraint) { |
449 | $type_constraint = $self->type_constraint; |
450 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
451 | } |
452 | |
453 | my $callback = sub { |
454 | my $val = shift; |
455 | if ($type_constraint) { |
456 | $val = $type_constraint->coerce($val) |
457 | if $can_coerce; |
458 | $type_constraint->check($val) |
be05faea |
459 | || $self->throw_error("Attribute (" |
8abe9636 |
460 | . $slot_name |
461 | . ") does not pass the type constraint because: " |
be05faea |
462 | . $type_constraint->get_message($val), data => $val, object => $instance); |
8abe9636 |
463 | } |
464 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
465 | }; |
466 | |
467 | my $initializer = $self->initializer; |
468 | |
469 | # most things will just want to set a value, so make it first arg |
470 | $instance->$initializer($value, $callback, $self); |
471 | } |
472 | |
946289d1 |
473 | sub set_value { |
b6af66f8 |
474 | my ($self, $instance, @args) = @_; |
475 | my $value = $args[0]; |
26fbace8 |
476 | |
946289d1 |
477 | my $attr_name = $self->name; |
26fbace8 |
478 | |
b6af66f8 |
479 | if ($self->is_required and not @args) { |
be05faea |
480 | $self->throw_error("Attribute ($attr_name) is required", object => $instance); |
946289d1 |
481 | } |
26fbace8 |
482 | |
946289d1 |
483 | if ($self->has_type_constraint) { |
26fbace8 |
484 | |
946289d1 |
485 | my $type_constraint = $self->type_constraint; |
26fbace8 |
486 | |
946289d1 |
487 | if ($self->should_coerce) { |
26fbace8 |
488 | $value = $type_constraint->coerce($value); |
688fcdda |
489 | } |
42bc21a4 |
490 | $type_constraint->_compiled_type_constraint->($value) |
be05faea |
491 | || $self->throw_error("Attribute (" |
688fcdda |
492 | . $self->name |
493 | . ") does not pass the type constraint because " |
be05faea |
494 | . $type_constraint->get_message($value), object => $instance, data => $value); |
946289d1 |
495 | } |
26fbace8 |
496 | |
946289d1 |
497 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
498 | ->get_meta_instance; |
26fbace8 |
499 | |
500 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
501 | |
946289d1 |
502 | if (ref $value && $self->is_weak_ref) { |
26fbace8 |
503 | $meta_instance->weaken_slot_value($instance, $attr_name); |
946289d1 |
504 | } |
26fbace8 |
505 | |
946289d1 |
506 | if ($self->has_trigger) { |
507 | $self->trigger->($instance, $value, $self); |
508 | } |
509 | } |
510 | |
511 | sub get_value { |
512 | my ($self, $instance) = @_; |
26fbace8 |
513 | |
946289d1 |
514 | if ($self->is_lazy) { |
8de73ff1 |
515 | unless ($self->has_value($instance)) { |
e606ae5f |
516 | my $value; |
8de73ff1 |
517 | if ($self->has_default) { |
e606ae5f |
518 | $value = $self->default($instance); |
3f11800d |
519 | } elsif ( $self->has_builder ) { |
e606ae5f |
520 | $value = $self->_call_builder($instance); |
521 | } |
522 | if ($self->has_type_constraint) { |
523 | my $type_constraint = $self->type_constraint; |
524 | $value = $type_constraint->coerce($value) |
525 | if ($self->should_coerce); |
526 | $type_constraint->check($value) |
4b7538e7 |
527 | || $self->throw_error("Attribute (" . $self->name |
e606ae5f |
528 | . ") does not pass the type constraint because: " |
529 | . $type_constraint->get_message($value), type_constraint => $type_constraint, data => $value); |
26fbace8 |
530 | } |
e606ae5f |
531 | $self->set_initial_value($instance, $value); |
8de73ff1 |
532 | } |
946289d1 |
533 | } |
26fbace8 |
534 | |
946289d1 |
535 | if ($self->should_auto_deref) { |
26fbace8 |
536 | |
946289d1 |
537 | my $type_constraint = $self->type_constraint; |
538 | |
539 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
540 | my $rv = $self->SUPER::get_value($instance); |
541 | return unless defined $rv; |
542 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
543 | } |
946289d1 |
544 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
545 | my $rv = $self->SUPER::get_value($instance); |
546 | return unless defined $rv; |
547 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
548 | } |
946289d1 |
549 | else { |
46cb090f |
550 | $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, type_constraint => $type_constraint); |
946289d1 |
551 | } |
26fbace8 |
552 | |
946289d1 |
553 | } |
554 | else { |
26fbace8 |
555 | |
946289d1 |
556 | return $self->SUPER::get_value($instance); |
26fbace8 |
557 | } |
946289d1 |
558 | } |
a15dff8d |
559 | |
26fbace8 |
560 | ## installing accessors |
c0e30cf5 |
561 | |
d617b644 |
562 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
563 | |
452bac1b |
564 | sub install_accessors { |
565 | my $self = shift; |
26fbace8 |
566 | $self->SUPER::install_accessors(@_); |
e606ae5f |
567 | $self->install_delegation if $self->has_handles; |
568 | return; |
569 | } |
26fbace8 |
570 | |
e1d6f0a3 |
571 | sub remove_accessors { |
572 | my $self = shift; |
573 | $self->SUPER::remove_accessors(@_); |
574 | $self->remove_delegation if $self->has_handles; |
575 | return; |
576 | } |
577 | |
e606ae5f |
578 | sub install_delegation { |
579 | my $self = shift; |
26fbace8 |
580 | |
e606ae5f |
581 | # NOTE: |
582 | # Here we canonicalize the 'handles' option |
583 | # this will sort out any details and always |
584 | # return an hash of methods which we want |
585 | # to delagate to, see that method for details |
586 | my %handles = $self->_canonicalize_handles; |
587 | |
e606ae5f |
588 | |
589 | # install the delegation ... |
590 | my $associated_class = $self->associated_class; |
591 | foreach my $handle (keys %handles) { |
592 | my $method_to_call = $handles{$handle}; |
593 | my $class_name = $associated_class->name; |
594 | my $name = "${class_name}::${handle}"; |
26fbace8 |
595 | |
452bac1b |
596 | (!$associated_class->has_method($handle)) |
cee532a1 |
597 | || $self->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation", method_name => $handle); |
26fbace8 |
598 | |
e606ae5f |
599 | # NOTE: |
600 | # handles is not allowed to delegate |
601 | # any of these methods, as they will |
602 | # override the ones in your class, which |
603 | # is almost certainly not what you want. |
4fe78472 |
604 | |
e606ae5f |
605 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
606 | #cluck("Not delegating method '$handle' because it is a core method") and |
607 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
608 | |
46f7e6a5 |
609 | my $method = $self->_make_delegation_method($handle, $method_to_call); |
a05f85c1 |
610 | |
611 | $self->associated_class->add_method($method->name, $method); |
e606ae5f |
612 | } |
452bac1b |
613 | } |
614 | |
e1d6f0a3 |
615 | sub remove_delegation { |
616 | my $self = shift; |
617 | my %handles = $self->_canonicalize_handles; |
618 | my $associated_class = $self->associated_class; |
619 | foreach my $handle (keys %handles) { |
620 | $self->associated_class->remove_method($handle); |
621 | } |
622 | } |
623 | |
98aae381 |
624 | # private methods to help delegation ... |
625 | |
452bac1b |
626 | sub _canonicalize_handles { |
627 | my $self = shift; |
628 | my $handles = $self->handles; |
c84f324f |
629 | if (my $handle_type = ref($handles)) { |
630 | if ($handle_type eq 'HASH') { |
631 | return %{$handles}; |
632 | } |
633 | elsif ($handle_type eq 'ARRAY') { |
634 | return map { $_ => $_ } @{$handles}; |
635 | } |
636 | elsif ($handle_type eq 'Regexp') { |
637 | ($self->has_type_constraint) |
be05faea |
638 | || $self->throw_error("Cannot delegate methods based on a RegExpr without a type constraint (isa)", data => $handles); |
26fbace8 |
639 | return map { ($_ => $_) } |
c84f324f |
640 | grep { /$handles/ } $self->_get_delegate_method_list; |
641 | } |
642 | elsif ($handle_type eq 'CODE') { |
643 | return $handles->($self, $self->_find_delegate_metaclass); |
644 | } |
645 | else { |
be05faea |
646 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); |
c84f324f |
647 | } |
452bac1b |
648 | } |
649 | else { |
9fa39240 |
650 | Class::MOP::load_class($handles) |
651 | unless Class::MOP::is_class_loaded($handles); |
652 | |
c84f324f |
653 | my $role_meta = eval { $handles->meta }; |
654 | if ($@) { |
be05faea |
655 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles because : $@", data => $handles, error => $@); |
c84f324f |
656 | } |
657 | |
658 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
be05faea |
659 | || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role", data => $handles); |
9fa39240 |
660 | |
c84f324f |
661 | return map { $_ => $_ } ( |
26fbace8 |
662 | $role_meta->get_method_list, |
c84f324f |
663 | $role_meta->get_required_method_list |
664 | ); |
452bac1b |
665 | } |
666 | } |
667 | |
668 | sub _find_delegate_metaclass { |
669 | my $self = shift; |
98aae381 |
670 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
671 | # if the class does have |
452bac1b |
672 | # a meta method, use it |
673 | return $class->meta if $class->can('meta'); |
26fbace8 |
674 | # otherwise we might be |
452bac1b |
675 | # dealing with a non-Moose |
26fbace8 |
676 | # class, and need to make |
452bac1b |
677 | # our own metaclass |
678 | return Moose::Meta::Class->initialize($class); |
679 | } |
98aae381 |
680 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
681 | # our role will always have |
452bac1b |
682 | # a meta method |
98aae381 |
683 | return $role->meta; |
452bac1b |
684 | } |
685 | else { |
be05faea |
686 | $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name); |
452bac1b |
687 | } |
688 | } |
689 | |
690 | sub _get_delegate_method_list { |
691 | my $self = shift; |
692 | my $meta = $self->_find_delegate_metaclass; |
693 | if ($meta->isa('Class::MOP::Class')) { |
e606ae5f |
694 | return map { $_->name } # NOTE: !never! delegate &meta |
695 | grep { $_->package_name ne 'Moose::Object' && $_->name ne 'meta' } |
696 | $meta->get_all_methods; |
452bac1b |
697 | } |
698 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
699 | return $meta->get_method_list; |
452bac1b |
700 | } |
701 | else { |
be05faea |
702 | $self->throw_error("Unable to recognize the delegate metaclass '$meta'", data => $meta); |
452bac1b |
703 | } |
704 | } |
705 | |
a05f85c1 |
706 | sub _make_delegation_method { |
46f7e6a5 |
707 | my ( $self, $handle_name, $method_to_call ) = @_; |
a05f85c1 |
708 | |
709 | my $method_body; |
710 | |
46f7e6a5 |
711 | $method_body = $method_to_call |
712 | if 'CODE' eq ref($method_to_call); |
a05f85c1 |
713 | |
714 | return Moose::Meta::Method::Delegation->new( |
46f7e6a5 |
715 | name => $handle_name, |
716 | package_name => $self->associated_class->name, |
717 | attribute => $self, |
718 | delegate_to_method => $method_to_call, |
a05f85c1 |
719 | ); |
720 | } |
721 | |
21f1e231 |
722 | package Moose::Meta::Attribute::Custom::Moose; |
723 | sub register_implementation { 'Moose::Meta::Attribute' } |
724 | |
c0e30cf5 |
725 | 1; |
726 | |
727 | __END__ |
728 | |
729 | =pod |
730 | |
731 | =head1 NAME |
732 | |
6ba6d68c |
733 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
734 | |
735 | =head1 DESCRIPTION |
736 | |
26fbace8 |
737 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
738 | extensions. |
6ba6d68c |
739 | |
26fbace8 |
740 | For the most part, the only time you will ever encounter an |
741 | instance of this class is if you are doing some serious deep |
742 | introspection. To really understand this class, you need to refer |
6ba6d68c |
743 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
744 | |
c0e30cf5 |
745 | =head1 METHODS |
746 | |
6ba6d68c |
747 | =head2 Overridden methods |
748 | |
26fbace8 |
749 | These methods override methods in L<Class::MOP::Attribute> and add |
750 | Moose specific features. You can safely assume though that they |
6ba6d68c |
751 | will behave just as L<Class::MOP::Attribute> does. |
752 | |
c0e30cf5 |
753 | =over 4 |
754 | |
755 | =item B<new> |
756 | |
c32c2c61 |
757 | =item B<clone> |
758 | |
6e2840b7 |
759 | =item B<does> |
760 | |
d500266f |
761 | =item B<initialize_instance_slot> |
762 | |
452bac1b |
763 | =item B<install_accessors> |
764 | |
e1d6f0a3 |
765 | =item B<remove_accessors> |
766 | |
e606ae5f |
767 | =item B<install_delegation> |
768 | |
e1d6f0a3 |
769 | =item B<remove_delegation> |
770 | |
39b3bc94 |
771 | =item B<accessor_metaclass> |
772 | |
946289d1 |
773 | =item B<get_value> |
774 | |
775 | =item B<set_value> |
776 | |
bcbaa845 |
777 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
778 | if($@) { |
779 | print "Oops: $@\n"; |
780 | } |
781 | |
782 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
783 | |
784 | Before setting the value, a check is made on the type constraint of |
785 | the attribute, if it has one, to see if the value passes it. If the |
46cb090f |
786 | value fails to pass, the set operation dies with a L<throw_error>. |
bcbaa845 |
787 | |
788 | Any coercion to convert values is done before checking the type constraint. |
789 | |
790 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
791 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
792 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
e606ae5f |
793 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::Basics::Recipe4> |
bcbaa845 |
794 | for an example. |
795 | |
a15dff8d |
796 | =back |
797 | |
6ba6d68c |
798 | =head2 Additional Moose features |
799 | |
26fbace8 |
800 | Moose attributes support type-constraint checking, weak reference |
801 | creation and type coercion. |
6ba6d68c |
802 | |
a15dff8d |
803 | =over 4 |
804 | |
be05faea |
805 | =item B<throw_error> |
806 | |
807 | Delegates to C<associated_class> or C<Moose::Meta::Class> if there is none. |
808 | |
d5c30e52 |
809 | =item B<interpolate_class_and_new> |
810 | |
811 | =item B<interpolate_class> |
812 | |
813 | When called as a class method causes interpretation of the C<metaclass> and |
814 | C<traits> options. |
815 | |
9e93dd19 |
816 | =item B<clone_and_inherit_options> |
817 | |
26fbace8 |
818 | This is to support the C<has '+foo'> feature, it clones an attribute |
819 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
820 | to the attribute. |
821 | |
e606ae5f |
822 | =item B<legal_options_for_inheritance> |
823 | |
824 | Whitelist with options you can change. You can overload it in your custom |
825 | metaclass to allow your options be inheritable. |
826 | |
a15dff8d |
827 | =item B<has_type_constraint> |
828 | |
6ba6d68c |
829 | Returns true if this meta-attribute has a type constraint. |
830 | |
a15dff8d |
831 | =item B<type_constraint> |
832 | |
26fbace8 |
833 | A read-only accessor for this meta-attribute's type constraint. For |
834 | more information on what you can do with this, see the documentation |
6ba6d68c |
835 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
836 | |
452bac1b |
837 | =item B<has_handles> |
838 | |
839 | Returns true if this meta-attribute performs delegation. |
840 | |
841 | =item B<handles> |
842 | |
843 | This returns the value which was passed into the handles option. |
844 | |
6ba6d68c |
845 | =item B<is_weak_ref> |
a15dff8d |
846 | |
02a0fb52 |
847 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
848 | |
ca01a97b |
849 | =item B<is_required> |
850 | |
02a0fb52 |
851 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
852 | |
853 | =item B<is_lazy> |
854 | |
02a0fb52 |
855 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
856 | |
26fbace8 |
857 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
858 | |
859 | =item B<is_lazy_build> |
860 | |
861 | Returns true if this meta-attribute should be initialized lazily through |
862 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
863 | make your attribute required and lazy. In addition it will set the builder, clearer |
864 | and predicate options for you using the following convention. |
865 | |
866 | #If your attribute name starts with an underscore: |
867 | has '_foo' => (lazy_build => 1); |
868 | #is the same as |
e606ae5f |
869 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo'); |
26fbace8 |
870 | # or |
58f85113 |
871 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
872 | |
873 | #If your attribute name does not start with an underscore: |
58f85113 |
874 | has 'foo' => (lazy_build => 1); |
875 | #is the same as |
e606ae5f |
876 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo'); |
26fbace8 |
877 | # or |
58f85113 |
878 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
879 | |
880 | The reason for the different naming of the C<builder> is that the C<builder> |
881 | method is a private method while the C<clearer> and C<predicate> methods |
882 | are public methods. |
26fbace8 |
883 | |
884 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
885 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
886 | |
34a66aa3 |
887 | =item B<should_coerce> |
4b598ea3 |
888 | |
02a0fb52 |
889 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
890 | |
536f0b17 |
891 | =item B<should_auto_deref> |
892 | |
26fbace8 |
893 | Returns true if this meta-attribute should perform automatic |
894 | auto-dereferencing. |
536f0b17 |
895 | |
26fbace8 |
896 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
897 | either I<ArrayRef> or I<HashRef>. |
898 | |
8c9d74e7 |
899 | =item B<has_trigger> |
900 | |
02a0fb52 |
901 | Returns true if this meta-attribute has a trigger set. |
902 | |
8c9d74e7 |
903 | =item B<trigger> |
904 | |
26fbace8 |
905 | This is a CODE reference which will be executed every time the |
906 | value of an attribute is assigned. The CODE ref will get two values, |
907 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
908 | bi-directional relations. |
909 | |
ddbdc0cb |
910 | =item B<documentation> |
911 | |
26fbace8 |
912 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
913 | It serves no direct purpose right now, but it might in the future |
914 | in some kind of automated documentation system perhaps. |
915 | |
916 | =item B<has_documentation> |
917 | |
918 | Returns true if this meta-attribute has any documentation. |
919 | |
88f23977 |
920 | =item B<applied_traits> |
921 | |
922 | This will return the ARRAY ref of all the traits applied to this |
923 | attribute, or if no traits have been applied, it returns C<undef>. |
924 | |
925 | =item B<has_applied_traits> |
926 | |
927 | Returns true if this meta-attribute has any traits applied. |
928 | |
c0e30cf5 |
929 | =back |
930 | |
931 | =head1 BUGS |
932 | |
26fbace8 |
933 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
934 | exception. If you find a bug please either email me, or add the bug |
935 | to cpan-RT. |
936 | |
c0e30cf5 |
937 | =head1 AUTHOR |
938 | |
939 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
940 | |
98aae381 |
941 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
942 | |
c0e30cf5 |
943 | =head1 COPYRIGHT AND LICENSE |
944 | |
778db3ac |
945 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
946 | |
947 | L<http://www.iinteractive.com> |
948 | |
949 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
950 | it under the same terms as Perl itself. |
c0e30cf5 |
951 | |
8a7a9c53 |
952 | =cut |