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 | |
e606ae5f |
10 | our $VERSION = '0.57'; |
d44714be |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
78cd1d3b |
12 | |
8ee73eeb |
13 | use Moose::Meta::Method::Accessor; |
d5c30e52 |
14 | use Moose::Util (); |
a3c7e2fe |
15 | use Moose::Util::TypeConstraints (); |
bc1e29b5 |
16 | |
c0e30cf5 |
17 | use base 'Class::MOP::Attribute'; |
18 | |
452bac1b |
19 | # options which are not directly used |
20 | # but we store them for metadata purposes |
98aae381 |
21 | __PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata')); |
22 | __PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata')); |
23 | __PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); |
452bac1b |
24 | |
25 | # these are actual options for the attrs |
1a563243 |
26 | __PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); |
27 | __PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); |
26fbace8 |
28 | __PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' )); |
1a563243 |
29 | __PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); |
30 | __PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' )); |
31 | __PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref')); |
82168dbb |
32 | __PACKAGE__->meta->add_attribute('type_constraint' => ( |
33 | reader => 'type_constraint', |
34 | predicate => 'has_type_constraint', |
35 | )); |
8c9d74e7 |
36 | __PACKAGE__->meta->add_attribute('trigger' => ( |
37 | reader => 'trigger', |
38 | predicate => 'has_trigger', |
39 | )); |
452bac1b |
40 | __PACKAGE__->meta->add_attribute('handles' => ( |
41 | reader => 'handles', |
42 | predicate => 'has_handles', |
43 | )); |
ddbdc0cb |
44 | __PACKAGE__->meta->add_attribute('documentation' => ( |
45 | reader => 'documentation', |
46 | predicate => 'has_documentation', |
47 | )); |
82a5b1a7 |
48 | __PACKAGE__->meta->add_attribute('traits' => ( |
49 | reader => 'applied_traits', |
50 | predicate => 'has_applied_traits', |
51 | )); |
82168dbb |
52 | |
587e457d |
53 | # we need to have a ->does method in here to |
54 | # more easily support traits, and the introspection |
0db4f1d7 |
55 | # of those traits. We extend the does check to look |
56 | # for metatrait aliases. |
57 | sub does { |
58 | my ($self, $role_name) = @_; |
59 | my $name = eval { |
60 | Moose::Util::resolve_metatrait_alias(Attribute => $role_name) |
61 | }; |
62 | return 0 if !defined($name); # failed to load class |
63 | return Moose::Object::does($self, $name); |
64 | } |
587e457d |
65 | |
be05faea |
66 | sub throw_error { |
67 | my $self = shift; |
68 | my $class = ( ref $self && $self->associated_class ) || "Moose::Meta::Class"; |
69 | unshift @_, "message" if @_ % 2 == 1; |
70 | unshift @_, attr => $self if ref $self; |
71 | unshift @_, $class; |
72 | goto $class->can("throw_error"); # to avoid incrementing depth by 1 |
73 | } |
74 | |
78cd1d3b |
75 | sub new { |
f3c4e20e |
76 | my ($class, $name, %options) = @_; |
c32c2c61 |
77 | $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS |
f3c4e20e |
78 | return $class->SUPER::new($name, %options); |
1d768fb1 |
79 | } |
80 | |
d5c30e52 |
81 | sub interpolate_class_and_new { |
82 | my ($class, $name, @args) = @_; |
83 | |
c32c2c61 |
84 | my ( $new_class, @traits ) = $class->interpolate_class(@args); |
85 | |
86 | $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); |
d5c30e52 |
87 | } |
88 | |
89 | sub interpolate_class { |
90 | my ($class, %options) = @_; |
91 | |
c32c2c61 |
92 | $class = ref($class) || $class; |
93 | |
94 | if ( my $metaclass_name = delete $options{metaclass} ) { |
95 | my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); |
96 | |
97 | if ( $class ne $new_class ) { |
98 | if ( $new_class->can("interpolate_class") ) { |
99 | return $new_class->interpolate_class(%options); |
100 | } else { |
101 | $class = $new_class; |
102 | } |
103 | } |
d5c30e52 |
104 | } |
105 | |
c32c2c61 |
106 | my @traits; |
107 | |
d5c30e52 |
108 | if (my $traits = $options{traits}) { |
c32c2c61 |
109 | if ( @traits = grep { not $class->does($_) } map { |
d5c30e52 |
110 | Moose::Util::resolve_metatrait_alias( Attribute => $_ ) |
111 | or |
112 | $_ |
c32c2c61 |
113 | } @$traits ) { |
114 | my $anon_class = Moose::Meta::Class->create_anon_class( |
115 | superclasses => [ $class ], |
116 | roles => [ @traits ], |
117 | cache => 1, |
118 | ); |
119 | |
120 | $class = $anon_class->name; |
121 | } |
d5c30e52 |
122 | } |
c32c2c61 |
123 | |
124 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
125 | } |
126 | |
e606ae5f |
127 | # ... |
128 | |
129 | my @legal_options_for_inheritance = qw( |
130 | default coerce required |
131 | documentation lazy handles |
132 | builder type_constraint |
133 | ); |
134 | |
135 | sub legal_options_for_inheritance { @legal_options_for_inheritance } |
136 | |
137 | # NOTE/TODO |
138 | # This method *must* be able to handle |
139 | # Class::MOP::Attribute instances as |
140 | # well. Yes, I know that is wrong, but |
141 | # apparently we didn't realize it was |
142 | # doing that and now we have some code |
143 | # which is dependent on it. The real |
144 | # solution of course is to push this |
145 | # feature back up into Class::MOP::Attribute |
146 | # but I not right now, I am too lazy. |
147 | # However if you are reading this and |
148 | # looking for something to do,.. please |
149 | # be my guest. |
150 | # - stevan |
ce0e8d63 |
151 | sub clone_and_inherit_options { |
152 | my ($self, %options) = @_; |
e606ae5f |
153 | |
c32c2c61 |
154 | my %copy = %options; |
e606ae5f |
155 | |
ce0e8d63 |
156 | my %actual_options; |
e606ae5f |
157 | |
158 | # NOTE: |
159 | # we may want to extends a Class::MOP::Attribute |
160 | # in which case we need to be able to use the |
161 | # core set of legal options that have always |
162 | # been here. But we allows Moose::Meta::Attribute |
163 | # instances to changes them. |
164 | # - SL |
165 | my @legal_options = $self->can('legal_options_for_inheritance') |
166 | ? $self->legal_options_for_inheritance |
167 | : @legal_options_for_inheritance; |
168 | |
169 | foreach my $legal_option (@legal_options) { |
ce0e8d63 |
170 | if (exists $options{$legal_option}) { |
171 | $actual_options{$legal_option} = $options{$legal_option}; |
172 | delete $options{$legal_option}; |
173 | } |
e606ae5f |
174 | } |
26fbace8 |
175 | |
ce0e8d63 |
176 | if ($options{isa}) { |
177 | my $type_constraint; |
8de73ff1 |
178 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
179 | $type_constraint = $options{isa}; |
180 | } |
181 | else { |
d40ce9d5 |
182 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
183 | (defined $type_constraint) |
be05faea |
184 | || $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa}); |
8de73ff1 |
185 | } |
5e98d2b6 |
186 | |
8de73ff1 |
187 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
188 | delete $options{isa}; |
189 | } |
2ea379cb |
190 | |
191 | if ($options{does}) { |
192 | my $type_constraint; |
193 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
194 | $type_constraint = $options{does}; |
195 | } |
196 | else { |
d40ce9d5 |
197 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
198 | (defined $type_constraint) |
be05faea |
199 | || $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does}); |
2ea379cb |
200 | } |
201 | |
202 | $actual_options{type_constraint} = $type_constraint; |
203 | delete $options{does}; |
204 | } |
c32c2c61 |
205 | |
cbd141ca |
206 | # NOTE: |
207 | # this doesn't apply to Class::MOP::Attributes, |
208 | # so we can ignore it for them. |
209 | # - SL |
210 | if ($self->can('interpolate_class')) { |
211 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
212 | |
cbd141ca |
213 | my %seen; |
214 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
215 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
216 | |
cbd141ca |
217 | delete @options{qw(metaclass traits)}; |
218 | } |
c32c2c61 |
219 | |
26fbace8 |
220 | (scalar keys %options == 0) |
be05faea |
221 | || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options); |
c32c2c61 |
222 | |
223 | |
ce0e8d63 |
224 | $self->clone(%actual_options); |
1d768fb1 |
225 | } |
226 | |
c32c2c61 |
227 | sub clone { |
228 | my ( $self, %params ) = @_; |
229 | |
230 | my $class = $params{metaclass} || ref $self; |
231 | |
232 | if ( 0 and $class eq ref $self ) { |
233 | return $self->SUPER::clone(%params); |
234 | } else { |
235 | my ( @init, @non_init ); |
236 | |
237 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
238 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
239 | } |
240 | |
241 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
242 | |
243 | my $name = delete $new_params{name}; |
244 | |
245 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
246 | |
247 | foreach my $attr ( @non_init ) { |
248 | $attr->set_value($clone, $attr->get_value($self)); |
249 | } |
250 | |
251 | |
252 | return $clone; |
253 | } |
254 | } |
255 | |
1d768fb1 |
256 | sub _process_options { |
257 | my ($class, $name, $options) = @_; |
8de73ff1 |
258 | |
f3c4e20e |
259 | if (exists $options->{is}) { |
21f1e231 |
260 | |
012fcbd1 |
261 | ### ------------------------- |
262 | ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
263 | ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
264 | ## is => rw, accessor => _foo # turns into (accessor => _foo) |
265 | ## is => ro, accessor => _foo # error, accesor is rw |
266 | ### ------------------------- |
21f1e231 |
267 | |
8de73ff1 |
268 | if ($options->{is} eq 'ro') { |
be05faea |
269 | $class->throw_error("Cannot define an accessor name on a read-only attribute, accessors are read/write", data => $options) |
21f1e231 |
270 | if exists $options->{accessor}; |
8de73ff1 |
271 | $options->{reader} ||= $name; |
8de73ff1 |
272 | } |
273 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
274 | if ($options->{writer}) { |
275 | $options->{reader} ||= $name; |
276 | } |
277 | else { |
278 | $options->{accessor} ||= $name; |
279 | } |
8de73ff1 |
280 | } |
281 | else { |
e606ae5f |
282 | $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute ($name)", data => $options->{is}); |
8de73ff1 |
283 | } |
f3c4e20e |
284 | } |
8de73ff1 |
285 | |
f3c4e20e |
286 | if (exists $options->{isa}) { |
f3c4e20e |
287 | if (exists $options->{does}) { |
288 | if (eval { $options->{isa}->can('does') }) { |
289 | ($options->{isa}->does($options->{does})) |
e606ae5f |
290 | || $class->throw_error("Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)", data => $options); |
f3c4e20e |
291 | } |
292 | else { |
e606ae5f |
293 | $class->throw_error("Cannot have an isa option which cannot ->does() on attribute ($name)", data => $options); |
26fbace8 |
294 | } |
26fbace8 |
295 | } |
8de73ff1 |
296 | |
f3c4e20e |
297 | # allow for anon-subtypes here ... |
298 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
299 | $options->{type_constraint} = $options->{isa}; |
300 | } |
301 | else { |
620db045 |
302 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
303 | } |
f3c4e20e |
304 | } |
305 | elsif (exists $options->{does}) { |
306 | # allow for anon-subtypes here ... |
307 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
308 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
309 | } |
310 | else { |
620db045 |
311 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
312 | } |
f3c4e20e |
313 | } |
8de73ff1 |
314 | |
f3c4e20e |
315 | if (exists $options->{coerce} && $options->{coerce}) { |
316 | (exists $options->{type_constraint}) |
e606ae5f |
317 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)", data => $options); |
318 | $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)", data => $options) |
8de73ff1 |
319 | if $options->{weak_ref}; |
f3c4e20e |
320 | } |
8de73ff1 |
321 | |
0b7df53c |
322 | if (exists $options->{trigger}) { |
21f1e231 |
323 | ('CODE' eq ref $options->{trigger}) |
e606ae5f |
324 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger}); |
0b7df53c |
325 | } |
326 | |
f3c4e20e |
327 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
328 | (exists $options->{type_constraint}) |
e606ae5f |
329 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)", data => $options); |
f3c4e20e |
330 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
331 | $options->{type_constraint}->is_a_type_of('HashRef')) |
e606ae5f |
332 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)", data => $options); |
f3c4e20e |
333 | } |
8de73ff1 |
334 | |
f3c4e20e |
335 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
e606ae5f |
336 | $class->throw_error("You can not use lazy_build and default for the same attribute ($name)", data => $options) |
8de73ff1 |
337 | if exists $options->{default}; |
a6c84c69 |
338 | $options->{lazy} = 1; |
339 | $options->{required} = 1; |
340 | $options->{builder} ||= "_build_${name}"; |
341 | if ($name =~ /^_/) { |
f3c4e20e |
342 | $options->{clearer} ||= "_clear${name}"; |
343 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
344 | } |
345 | else { |
f3c4e20e |
346 | $options->{clearer} ||= "clear_${name}"; |
347 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
348 | } |
f3c4e20e |
349 | } |
8de73ff1 |
350 | |
f3c4e20e |
351 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
352 | (exists $options->{default} || defined $options->{builder} ) |
be05faea |
353 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it", data => $options); |
f3c4e20e |
354 | } |
26fbace8 |
355 | |
9edba990 |
356 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
be05faea |
357 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg", data => $options); |
9edba990 |
358 | } |
359 | |
78cd1d3b |
360 | } |
c0e30cf5 |
361 | |
d500266f |
362 | sub initialize_instance_slot { |
ddd0ec20 |
363 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
364 | my $init_arg = $self->init_arg(); |
365 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
366 | |
26fbace8 |
367 | my $val; |
1ed0b94f |
368 | my $value_is_set; |
625d571f |
369 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
370 | $val = $params->{$init_arg}; |
2c78d811 |
371 | $value_is_set = 1; |
d500266f |
372 | } |
373 | else { |
374 | # skip it if it's lazy |
375 | return if $self->is_lazy; |
376 | # and die if it's required and doesn't have a default value |
be05faea |
377 | $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params) |
26fbace8 |
378 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
379 | |
1ed0b94f |
380 | # if nothing was in the %params, we can use the |
381 | # attribute's default value (if it has one) |
382 | if ($self->has_default) { |
383 | $val = $self->default($instance); |
384 | $value_is_set = 1; |
a6c84c69 |
385 | } |
386 | elsif ($self->has_builder) { |
e606ae5f |
387 | $val = $self->_call_builder($instance); |
388 | $value_is_set = 1; |
a0748c37 |
389 | } |
26fbace8 |
390 | } |
391 | |
1ed0b94f |
392 | return unless $value_is_set; |
393 | |
394 | if ($self->has_type_constraint) { |
395 | my $type_constraint = $self->type_constraint; |
396 | if ($self->should_coerce && $type_constraint->has_coercion) { |
397 | $val = $type_constraint->coerce($val); |
d500266f |
398 | } |
ab76842e |
399 | $type_constraint->check($val) |
be05faea |
400 | || $self->throw_error("Attribute (" |
688fcdda |
401 | . $self->name |
402 | . ") does not pass the type constraint because: " |
be05faea |
403 | . $type_constraint->get_message($val), data => $val, object => $instance); |
1ed0b94f |
404 | } |
ddd0ec20 |
405 | |
759e4e8f |
406 | $self->set_initial_value($instance, $val); |
26fbace8 |
407 | $meta_instance->weaken_slot_value($instance, $self->name) |
a6c84c69 |
408 | if ref $val && $self->is_weak_ref; |
d500266f |
409 | } |
410 | |
e606ae5f |
411 | sub _call_builder { |
412 | my ( $self, $instance ) = @_; |
413 | |
414 | my $builder = $self->builder(); |
415 | |
416 | return $instance->$builder() |
417 | if $instance->can( $self->builder ); |
418 | |
419 | $self->throw_error( blessed($instance) |
420 | . " does not support builder method '" |
421 | . $self->builder |
422 | . "' for attribute '" |
423 | . $self->name |
424 | . "'", |
425 | object => $instance, |
426 | ); |
427 | } |
428 | |
d617b644 |
429 | ## Slot management |
9e93dd19 |
430 | |
8abe9636 |
431 | # FIXME: |
432 | # this duplicates too much code from |
433 | # Class::MOP::Attribute, we need to |
434 | # refactor these bits eventually. |
435 | # - SL |
436 | sub _set_initial_slot_value { |
437 | my ($self, $meta_instance, $instance, $value) = @_; |
438 | |
439 | my $slot_name = $self->name; |
440 | |
441 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
442 | unless $self->has_initializer; |
443 | |
444 | my ($type_constraint, $can_coerce); |
445 | if ($self->has_type_constraint) { |
446 | $type_constraint = $self->type_constraint; |
447 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
448 | } |
449 | |
450 | my $callback = sub { |
451 | my $val = shift; |
452 | if ($type_constraint) { |
453 | $val = $type_constraint->coerce($val) |
454 | if $can_coerce; |
455 | $type_constraint->check($val) |
be05faea |
456 | || $self->throw_error("Attribute (" |
8abe9636 |
457 | . $slot_name |
458 | . ") does not pass the type constraint because: " |
be05faea |
459 | . $type_constraint->get_message($val), data => $val, object => $instance); |
8abe9636 |
460 | } |
461 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
462 | }; |
463 | |
464 | my $initializer = $self->initializer; |
465 | |
466 | # most things will just want to set a value, so make it first arg |
467 | $instance->$initializer($value, $callback, $self); |
468 | } |
469 | |
946289d1 |
470 | sub set_value { |
b6af66f8 |
471 | my ($self, $instance, @args) = @_; |
472 | my $value = $args[0]; |
26fbace8 |
473 | |
946289d1 |
474 | my $attr_name = $self->name; |
26fbace8 |
475 | |
b6af66f8 |
476 | if ($self->is_required and not @args) { |
be05faea |
477 | $self->throw_error("Attribute ($attr_name) is required", object => $instance); |
946289d1 |
478 | } |
26fbace8 |
479 | |
946289d1 |
480 | if ($self->has_type_constraint) { |
26fbace8 |
481 | |
946289d1 |
482 | my $type_constraint = $self->type_constraint; |
26fbace8 |
483 | |
946289d1 |
484 | if ($self->should_coerce) { |
26fbace8 |
485 | $value = $type_constraint->coerce($value); |
688fcdda |
486 | } |
42bc21a4 |
487 | $type_constraint->_compiled_type_constraint->($value) |
be05faea |
488 | || $self->throw_error("Attribute (" |
688fcdda |
489 | . $self->name |
490 | . ") does not pass the type constraint because " |
be05faea |
491 | . $type_constraint->get_message($value), object => $instance, data => $value); |
946289d1 |
492 | } |
26fbace8 |
493 | |
946289d1 |
494 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
495 | ->get_meta_instance; |
26fbace8 |
496 | |
497 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
498 | |
946289d1 |
499 | if (ref $value && $self->is_weak_ref) { |
26fbace8 |
500 | $meta_instance->weaken_slot_value($instance, $attr_name); |
946289d1 |
501 | } |
26fbace8 |
502 | |
946289d1 |
503 | if ($self->has_trigger) { |
504 | $self->trigger->($instance, $value, $self); |
505 | } |
506 | } |
507 | |
508 | sub get_value { |
509 | my ($self, $instance) = @_; |
26fbace8 |
510 | |
946289d1 |
511 | if ($self->is_lazy) { |
8de73ff1 |
512 | unless ($self->has_value($instance)) { |
e606ae5f |
513 | my $value; |
8de73ff1 |
514 | if ($self->has_default) { |
e606ae5f |
515 | $value = $self->default($instance); |
3f11800d |
516 | } elsif ( $self->has_builder ) { |
e606ae5f |
517 | $value = $self->_call_builder($instance); |
518 | } |
519 | if ($self->has_type_constraint) { |
520 | my $type_constraint = $self->type_constraint; |
521 | $value = $type_constraint->coerce($value) |
522 | if ($self->should_coerce); |
523 | $type_constraint->check($value) |
524 | || c$self->throw_error("Attribute (" . $self->name |
525 | . ") does not pass the type constraint because: " |
526 | . $type_constraint->get_message($value), type_constraint => $type_constraint, data => $value); |
26fbace8 |
527 | } |
e606ae5f |
528 | $self->set_initial_value($instance, $value); |
8de73ff1 |
529 | } |
946289d1 |
530 | } |
26fbace8 |
531 | |
946289d1 |
532 | if ($self->should_auto_deref) { |
26fbace8 |
533 | |
946289d1 |
534 | my $type_constraint = $self->type_constraint; |
535 | |
536 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
537 | my $rv = $self->SUPER::get_value($instance); |
538 | return unless defined $rv; |
539 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
540 | } |
946289d1 |
541 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
542 | my $rv = $self->SUPER::get_value($instance); |
543 | return unless defined $rv; |
544 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
545 | } |
946289d1 |
546 | else { |
46cb090f |
547 | $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, type_constraint => $type_constraint); |
946289d1 |
548 | } |
26fbace8 |
549 | |
946289d1 |
550 | } |
551 | else { |
26fbace8 |
552 | |
946289d1 |
553 | return $self->SUPER::get_value($instance); |
26fbace8 |
554 | } |
946289d1 |
555 | } |
a15dff8d |
556 | |
26fbace8 |
557 | ## installing accessors |
c0e30cf5 |
558 | |
d617b644 |
559 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
560 | |
452bac1b |
561 | sub install_accessors { |
562 | my $self = shift; |
26fbace8 |
563 | $self->SUPER::install_accessors(@_); |
e606ae5f |
564 | $self->install_delegation if $self->has_handles; |
565 | return; |
566 | } |
26fbace8 |
567 | |
e606ae5f |
568 | sub install_delegation { |
569 | my $self = shift; |
26fbace8 |
570 | |
e606ae5f |
571 | # NOTE: |
572 | # Here we canonicalize the 'handles' option |
573 | # this will sort out any details and always |
574 | # return an hash of methods which we want |
575 | # to delagate to, see that method for details |
576 | my %handles = $self->_canonicalize_handles; |
577 | |
578 | # find the accessor method for this attribute |
579 | my $accessor = $self->_get_delegate_accessor; |
580 | |
581 | # install the delegation ... |
582 | my $associated_class = $self->associated_class; |
583 | foreach my $handle (keys %handles) { |
584 | my $method_to_call = $handles{$handle}; |
585 | my $class_name = $associated_class->name; |
586 | my $name = "${class_name}::${handle}"; |
26fbace8 |
587 | |
452bac1b |
588 | (!$associated_class->has_method($handle)) |
cee532a1 |
589 | || $self->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation", method_name => $handle); |
26fbace8 |
590 | |
e606ae5f |
591 | # NOTE: |
592 | # handles is not allowed to delegate |
593 | # any of these methods, as they will |
594 | # override the ones in your class, which |
595 | # is almost certainly not what you want. |
4fe78472 |
596 | |
e606ae5f |
597 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
598 | #cluck("Not delegating method '$handle' because it is a core method") and |
599 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
600 | |
e606ae5f |
601 | if ('CODE' eq ref($method_to_call)) { |
602 | $associated_class->add_method($handle => Class::MOP::subname($name, $method_to_call)); |
452bac1b |
603 | } |
e606ae5f |
604 | else { |
605 | # NOTE: |
606 | # we used to do a goto here, but the |
607 | # goto didn't handle failure correctly |
608 | # (it just returned nothing), so I took |
609 | # that out. However, the more I thought |
610 | # about it, the less I liked it doing |
611 | # the goto, and I prefered the act of |
612 | # delegation being actually represented |
613 | # in the stack trace. |
614 | # - SL |
615 | $associated_class->add_method($handle => Class::MOP::subname($name, sub { |
616 | my $instance = shift; |
617 | my $proxy = $instance->$accessor(); |
618 | (defined $proxy) |
619 | || $self->throw_error("Cannot delegate $handle to $method_to_call because " . |
620 | "the value of " . $self->name . " is not defined", method_name => $method_to_call, object => $instance); |
621 | $proxy->$method_to_call(@_); |
622 | })); |
623 | } |
624 | } |
452bac1b |
625 | } |
626 | |
98aae381 |
627 | # private methods to help delegation ... |
628 | |
e606ae5f |
629 | sub _get_delegate_accessor { |
630 | my $self = shift; |
631 | # find the accessor method for this attribute |
632 | my $accessor = $self->get_read_method_ref; |
633 | # then unpack it if we need too ... |
634 | $accessor = $accessor->body if blessed $accessor; |
635 | # return the accessor |
636 | return $accessor; |
637 | } |
638 | |
452bac1b |
639 | sub _canonicalize_handles { |
640 | my $self = shift; |
641 | my $handles = $self->handles; |
c84f324f |
642 | if (my $handle_type = ref($handles)) { |
643 | if ($handle_type eq 'HASH') { |
644 | return %{$handles}; |
645 | } |
646 | elsif ($handle_type eq 'ARRAY') { |
647 | return map { $_ => $_ } @{$handles}; |
648 | } |
649 | elsif ($handle_type eq 'Regexp') { |
650 | ($self->has_type_constraint) |
be05faea |
651 | || $self->throw_error("Cannot delegate methods based on a RegExpr without a type constraint (isa)", data => $handles); |
26fbace8 |
652 | return map { ($_ => $_) } |
c84f324f |
653 | grep { /$handles/ } $self->_get_delegate_method_list; |
654 | } |
655 | elsif ($handle_type eq 'CODE') { |
656 | return $handles->($self, $self->_find_delegate_metaclass); |
657 | } |
658 | else { |
be05faea |
659 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); |
c84f324f |
660 | } |
452bac1b |
661 | } |
662 | else { |
c84f324f |
663 | my $role_meta = eval { $handles->meta }; |
664 | if ($@) { |
be05faea |
665 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles because : $@", data => $handles, error => $@); |
c84f324f |
666 | } |
667 | |
668 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
be05faea |
669 | || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role", data => $handles); |
26fbace8 |
670 | |
c84f324f |
671 | return map { $_ => $_ } ( |
26fbace8 |
672 | $role_meta->get_method_list, |
c84f324f |
673 | $role_meta->get_required_method_list |
674 | ); |
452bac1b |
675 | } |
676 | } |
677 | |
678 | sub _find_delegate_metaclass { |
679 | my $self = shift; |
98aae381 |
680 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
681 | # if the class does have |
452bac1b |
682 | # a meta method, use it |
683 | return $class->meta if $class->can('meta'); |
26fbace8 |
684 | # otherwise we might be |
452bac1b |
685 | # dealing with a non-Moose |
26fbace8 |
686 | # class, and need to make |
452bac1b |
687 | # our own metaclass |
688 | return Moose::Meta::Class->initialize($class); |
689 | } |
98aae381 |
690 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
691 | # our role will always have |
452bac1b |
692 | # a meta method |
98aae381 |
693 | return $role->meta; |
452bac1b |
694 | } |
695 | else { |
be05faea |
696 | $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name); |
452bac1b |
697 | } |
698 | } |
699 | |
700 | sub _get_delegate_method_list { |
701 | my $self = shift; |
702 | my $meta = $self->_find_delegate_metaclass; |
703 | if ($meta->isa('Class::MOP::Class')) { |
e606ae5f |
704 | return map { $_->name } # NOTE: !never! delegate &meta |
705 | grep { $_->package_name ne 'Moose::Object' && $_->name ne 'meta' } |
706 | $meta->get_all_methods; |
452bac1b |
707 | } |
708 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
709 | return $meta->get_method_list; |
452bac1b |
710 | } |
711 | else { |
be05faea |
712 | $self->throw_error("Unable to recognize the delegate metaclass '$meta'", data => $meta); |
452bac1b |
713 | } |
714 | } |
715 | |
21f1e231 |
716 | package Moose::Meta::Attribute::Custom::Moose; |
717 | sub register_implementation { 'Moose::Meta::Attribute' } |
718 | |
c0e30cf5 |
719 | 1; |
720 | |
721 | __END__ |
722 | |
723 | =pod |
724 | |
725 | =head1 NAME |
726 | |
6ba6d68c |
727 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
728 | |
729 | =head1 DESCRIPTION |
730 | |
26fbace8 |
731 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
732 | extensions. |
6ba6d68c |
733 | |
26fbace8 |
734 | For the most part, the only time you will ever encounter an |
735 | instance of this class is if you are doing some serious deep |
736 | introspection. To really understand this class, you need to refer |
6ba6d68c |
737 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
738 | |
c0e30cf5 |
739 | =head1 METHODS |
740 | |
6ba6d68c |
741 | =head2 Overridden methods |
742 | |
26fbace8 |
743 | These methods override methods in L<Class::MOP::Attribute> and add |
744 | Moose specific features. You can safely assume though that they |
6ba6d68c |
745 | will behave just as L<Class::MOP::Attribute> does. |
746 | |
c0e30cf5 |
747 | =over 4 |
748 | |
749 | =item B<new> |
750 | |
c32c2c61 |
751 | =item B<clone> |
752 | |
6e2840b7 |
753 | =item B<does> |
754 | |
d500266f |
755 | =item B<initialize_instance_slot> |
756 | |
452bac1b |
757 | =item B<install_accessors> |
758 | |
e606ae5f |
759 | =item B<install_delegation> |
760 | |
39b3bc94 |
761 | =item B<accessor_metaclass> |
762 | |
946289d1 |
763 | =item B<get_value> |
764 | |
765 | =item B<set_value> |
766 | |
bcbaa845 |
767 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
768 | if($@) { |
769 | print "Oops: $@\n"; |
770 | } |
771 | |
772 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
773 | |
774 | Before setting the value, a check is made on the type constraint of |
775 | the attribute, if it has one, to see if the value passes it. If the |
46cb090f |
776 | value fails to pass, the set operation dies with a L<throw_error>. |
bcbaa845 |
777 | |
778 | Any coercion to convert values is done before checking the type constraint. |
779 | |
780 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
781 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
782 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
e606ae5f |
783 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::Basics::Recipe4> |
bcbaa845 |
784 | for an example. |
785 | |
a15dff8d |
786 | =back |
787 | |
6ba6d68c |
788 | =head2 Additional Moose features |
789 | |
26fbace8 |
790 | Moose attributes support type-constraint checking, weak reference |
791 | creation and type coercion. |
6ba6d68c |
792 | |
a15dff8d |
793 | =over 4 |
794 | |
be05faea |
795 | =item B<throw_error> |
796 | |
797 | Delegates to C<associated_class> or C<Moose::Meta::Class> if there is none. |
798 | |
d5c30e52 |
799 | =item B<interpolate_class_and_new> |
800 | |
801 | =item B<interpolate_class> |
802 | |
803 | When called as a class method causes interpretation of the C<metaclass> and |
804 | C<traits> options. |
805 | |
9e93dd19 |
806 | =item B<clone_and_inherit_options> |
807 | |
26fbace8 |
808 | This is to support the C<has '+foo'> feature, it clones an attribute |
809 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
810 | to the attribute. |
811 | |
e606ae5f |
812 | =item B<legal_options_for_inheritance> |
813 | |
814 | Whitelist with options you can change. You can overload it in your custom |
815 | metaclass to allow your options be inheritable. |
816 | |
a15dff8d |
817 | =item B<has_type_constraint> |
818 | |
6ba6d68c |
819 | Returns true if this meta-attribute has a type constraint. |
820 | |
a15dff8d |
821 | =item B<type_constraint> |
822 | |
26fbace8 |
823 | A read-only accessor for this meta-attribute's type constraint. For |
824 | more information on what you can do with this, see the documentation |
6ba6d68c |
825 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
826 | |
452bac1b |
827 | =item B<has_handles> |
828 | |
829 | Returns true if this meta-attribute performs delegation. |
830 | |
831 | =item B<handles> |
832 | |
833 | This returns the value which was passed into the handles option. |
834 | |
6ba6d68c |
835 | =item B<is_weak_ref> |
a15dff8d |
836 | |
02a0fb52 |
837 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
838 | |
ca01a97b |
839 | =item B<is_required> |
840 | |
02a0fb52 |
841 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
842 | |
843 | =item B<is_lazy> |
844 | |
02a0fb52 |
845 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
846 | |
26fbace8 |
847 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
848 | |
849 | =item B<is_lazy_build> |
850 | |
851 | Returns true if this meta-attribute should be initialized lazily through |
852 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
853 | make your attribute required and lazy. In addition it will set the builder, clearer |
854 | and predicate options for you using the following convention. |
855 | |
856 | #If your attribute name starts with an underscore: |
857 | has '_foo' => (lazy_build => 1); |
858 | #is the same as |
e606ae5f |
859 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo'); |
26fbace8 |
860 | # or |
58f85113 |
861 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
862 | |
863 | #If your attribute name does not start with an underscore: |
58f85113 |
864 | has 'foo' => (lazy_build => 1); |
865 | #is the same as |
e606ae5f |
866 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo'); |
26fbace8 |
867 | # or |
58f85113 |
868 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
869 | |
870 | The reason for the different naming of the C<builder> is that the C<builder> |
871 | method is a private method while the C<clearer> and C<predicate> methods |
872 | are public methods. |
26fbace8 |
873 | |
874 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
875 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
876 | |
34a66aa3 |
877 | =item B<should_coerce> |
4b598ea3 |
878 | |
02a0fb52 |
879 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
880 | |
536f0b17 |
881 | =item B<should_auto_deref> |
882 | |
26fbace8 |
883 | Returns true if this meta-attribute should perform automatic |
884 | auto-dereferencing. |
536f0b17 |
885 | |
26fbace8 |
886 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
887 | either I<ArrayRef> or I<HashRef>. |
888 | |
8c9d74e7 |
889 | =item B<has_trigger> |
890 | |
02a0fb52 |
891 | Returns true if this meta-attribute has a trigger set. |
892 | |
8c9d74e7 |
893 | =item B<trigger> |
894 | |
26fbace8 |
895 | This is a CODE reference which will be executed every time the |
896 | value of an attribute is assigned. The CODE ref will get two values, |
897 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
898 | bi-directional relations. |
899 | |
ddbdc0cb |
900 | =item B<documentation> |
901 | |
26fbace8 |
902 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
903 | It serves no direct purpose right now, but it might in the future |
904 | in some kind of automated documentation system perhaps. |
905 | |
906 | =item B<has_documentation> |
907 | |
908 | Returns true if this meta-attribute has any documentation. |
909 | |
88f23977 |
910 | =item B<applied_traits> |
911 | |
912 | This will return the ARRAY ref of all the traits applied to this |
913 | attribute, or if no traits have been applied, it returns C<undef>. |
914 | |
915 | =item B<has_applied_traits> |
916 | |
917 | Returns true if this meta-attribute has any traits applied. |
918 | |
c0e30cf5 |
919 | =back |
920 | |
921 | =head1 BUGS |
922 | |
26fbace8 |
923 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
924 | exception. If you find a bug please either email me, or add the bug |
925 | to cpan-RT. |
926 | |
c0e30cf5 |
927 | =head1 AUTHOR |
928 | |
929 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
930 | |
98aae381 |
931 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
932 | |
c0e30cf5 |
933 | =head1 COPYRIGHT AND LICENSE |
934 | |
778db3ac |
935 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
936 | |
937 | L<http://www.iinteractive.com> |
938 | |
939 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
940 | it under the same terms as Perl itself. |
c0e30cf5 |
941 | |
8a7a9c53 |
942 | =cut |