Commit | Line | Data |
c0e30cf5 |
1 | |
2 | package Moose::Meta::Attribute; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
21f1e231 |
7 | use Scalar::Util 'blessed', 'weaken'; |
a15dff8d |
8 | use Carp 'confess'; |
a909a4df |
9 | use overload (); |
a15dff8d |
10 | |
330dbb07 |
11 | our $VERSION = '0.55'; |
d44714be |
12 | our $AUTHORITY = 'cpan:STEVAN'; |
78cd1d3b |
13 | |
8ee73eeb |
14 | use Moose::Meta::Method::Accessor; |
d5c30e52 |
15 | use Moose::Util (); |
a3c7e2fe |
16 | use Moose::Util::TypeConstraints (); |
bc1e29b5 |
17 | |
c0e30cf5 |
18 | use base 'Class::MOP::Attribute'; |
19 | |
452bac1b |
20 | # options which are not directly used |
21 | # but we store them for metadata purposes |
98aae381 |
22 | __PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata')); |
23 | __PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata')); |
24 | __PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata')); |
452bac1b |
25 | |
26 | # these are actual options for the attrs |
1a563243 |
27 | __PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' )); |
28 | __PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' )); |
26fbace8 |
29 | __PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' )); |
1a563243 |
30 | __PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' )); |
31 | __PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' )); |
32 | __PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref')); |
82168dbb |
33 | __PACKAGE__->meta->add_attribute('type_constraint' => ( |
34 | reader => 'type_constraint', |
35 | predicate => 'has_type_constraint', |
36 | )); |
8c9d74e7 |
37 | __PACKAGE__->meta->add_attribute('trigger' => ( |
38 | reader => 'trigger', |
39 | predicate => 'has_trigger', |
40 | )); |
452bac1b |
41 | __PACKAGE__->meta->add_attribute('handles' => ( |
42 | reader => 'handles', |
43 | predicate => 'has_handles', |
44 | )); |
ddbdc0cb |
45 | __PACKAGE__->meta->add_attribute('documentation' => ( |
46 | reader => 'documentation', |
47 | predicate => 'has_documentation', |
48 | )); |
82a5b1a7 |
49 | __PACKAGE__->meta->add_attribute('traits' => ( |
50 | reader => 'applied_traits', |
51 | predicate => 'has_applied_traits', |
52 | )); |
82168dbb |
53 | |
587e457d |
54 | # we need to have a ->does method in here to |
55 | # more easily support traits, and the introspection |
0db4f1d7 |
56 | # of those traits. We extend the does check to look |
57 | # for metatrait aliases. |
58 | sub does { |
59 | my ($self, $role_name) = @_; |
60 | my $name = eval { |
61 | Moose::Util::resolve_metatrait_alias(Attribute => $role_name) |
62 | }; |
63 | return 0 if !defined($name); # failed to load class |
64 | return Moose::Object::does($self, $name); |
65 | } |
587e457d |
66 | |
78cd1d3b |
67 | sub new { |
f3c4e20e |
68 | my ($class, $name, %options) = @_; |
c32c2c61 |
69 | $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS |
f3c4e20e |
70 | return $class->SUPER::new($name, %options); |
1d768fb1 |
71 | } |
72 | |
d5c30e52 |
73 | sub interpolate_class_and_new { |
74 | my ($class, $name, @args) = @_; |
75 | |
c32c2c61 |
76 | my ( $new_class, @traits ) = $class->interpolate_class(@args); |
77 | |
78 | $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); |
d5c30e52 |
79 | } |
80 | |
81 | sub interpolate_class { |
82 | my ($class, %options) = @_; |
83 | |
c32c2c61 |
84 | $class = ref($class) || $class; |
85 | |
86 | if ( my $metaclass_name = delete $options{metaclass} ) { |
87 | my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); |
88 | |
89 | if ( $class ne $new_class ) { |
90 | if ( $new_class->can("interpolate_class") ) { |
91 | return $new_class->interpolate_class(%options); |
92 | } else { |
93 | $class = $new_class; |
94 | } |
95 | } |
d5c30e52 |
96 | } |
97 | |
c32c2c61 |
98 | my @traits; |
99 | |
d5c30e52 |
100 | if (my $traits = $options{traits}) { |
c32c2c61 |
101 | if ( @traits = grep { not $class->does($_) } map { |
d5c30e52 |
102 | Moose::Util::resolve_metatrait_alias( Attribute => $_ ) |
103 | or |
104 | $_ |
c32c2c61 |
105 | } @$traits ) { |
106 | my $anon_class = Moose::Meta::Class->create_anon_class( |
107 | superclasses => [ $class ], |
108 | roles => [ @traits ], |
109 | cache => 1, |
110 | ); |
111 | |
112 | $class = $anon_class->name; |
113 | } |
d5c30e52 |
114 | } |
c32c2c61 |
115 | |
116 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
117 | } |
118 | |
713b0244 |
119 | # ... |
120 | |
121 | my @legal_options_for_inheritance = qw( |
122 | default coerce required |
123 | documentation lazy handles |
124 | builder type_constraint |
125 | ); |
126 | |
127 | sub legal_options_for_inheritance { @legal_options_for_inheritance } |
128 | |
129 | # NOTE/TODO |
130 | # This method *must* be able to handle |
131 | # Class::MOP::Attribute instances as |
132 | # well. Yes, I know that is wrong, but |
133 | # apparently we didn't realize it was |
134 | # doing that and now we have some code |
135 | # which is dependent on it. The real |
136 | # solution of course is to push this |
137 | # feature back up into Class::MOP::Attribute |
138 | # but I not right now, I am too lazy. |
139 | # However if you are reading this and |
140 | # looking for something to do,.. please |
141 | # be my guest. |
142 | # - stevan |
ce0e8d63 |
143 | sub clone_and_inherit_options { |
144 | my ($self, %options) = @_; |
713b0244 |
145 | |
c32c2c61 |
146 | my %copy = %options; |
713b0244 |
147 | |
ce0e8d63 |
148 | my %actual_options; |
713b0244 |
149 | |
150 | # NOTE: |
151 | # we may want to extends a Class::MOP::Attribute |
152 | # in which case we need to be able to use the |
153 | # core set of legal options that have always |
154 | # been here. But we allows Moose::Meta::Attribute |
155 | # instances to changes them. |
156 | # - SL |
157 | my @legal_options = $self->can('legal_options_for_inheritance') |
158 | ? $self->legal_options_for_inheritance |
159 | : @legal_options_for_inheritance; |
160 | |
161 | foreach my $legal_option (@legal_options) { |
ce0e8d63 |
162 | if (exists $options{$legal_option}) { |
163 | $actual_options{$legal_option} = $options{$legal_option}; |
164 | delete $options{$legal_option}; |
165 | } |
713b0244 |
166 | } |
26fbace8 |
167 | |
ce0e8d63 |
168 | if ($options{isa}) { |
169 | my $type_constraint; |
8de73ff1 |
170 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
171 | $type_constraint = $options{isa}; |
172 | } |
173 | else { |
d40ce9d5 |
174 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
175 | (defined $type_constraint) |
176 | || confess "Could not find the type constraint '" . $options{isa} . "'"; |
177 | } |
5e98d2b6 |
178 | |
8de73ff1 |
179 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
180 | delete $options{isa}; |
181 | } |
2ea379cb |
182 | |
183 | if ($options{does}) { |
184 | my $type_constraint; |
185 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
186 | $type_constraint = $options{does}; |
187 | } |
188 | else { |
d40ce9d5 |
189 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
190 | (defined $type_constraint) |
191 | || confess "Could not find the type constraint '" . $options{does} . "'"; |
192 | } |
193 | |
194 | $actual_options{type_constraint} = $type_constraint; |
195 | delete $options{does}; |
196 | } |
c32c2c61 |
197 | |
cbd141ca |
198 | # NOTE: |
199 | # this doesn't apply to Class::MOP::Attributes, |
200 | # so we can ignore it for them. |
201 | # - SL |
202 | if ($self->can('interpolate_class')) { |
203 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
204 | |
cbd141ca |
205 | my %seen; |
206 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
207 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
208 | |
cbd141ca |
209 | delete @options{qw(metaclass traits)}; |
210 | } |
c32c2c61 |
211 | |
26fbace8 |
212 | (scalar keys %options == 0) |
ce0e8d63 |
213 | || confess "Illegal inherited options => (" . (join ', ' => keys %options) . ")"; |
c32c2c61 |
214 | |
215 | |
ce0e8d63 |
216 | $self->clone(%actual_options); |
1d768fb1 |
217 | } |
218 | |
c32c2c61 |
219 | sub clone { |
220 | my ( $self, %params ) = @_; |
221 | |
222 | my $class = $params{metaclass} || ref $self; |
223 | |
224 | if ( 0 and $class eq ref $self ) { |
225 | return $self->SUPER::clone(%params); |
226 | } else { |
227 | my ( @init, @non_init ); |
228 | |
229 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
230 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
231 | } |
232 | |
233 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
234 | |
235 | my $name = delete $new_params{name}; |
236 | |
237 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
238 | |
239 | foreach my $attr ( @non_init ) { |
240 | $attr->set_value($clone, $attr->get_value($self)); |
241 | } |
242 | |
243 | |
244 | return $clone; |
245 | } |
246 | } |
247 | |
1d768fb1 |
248 | sub _process_options { |
249 | my ($class, $name, $options) = @_; |
8de73ff1 |
250 | |
f3c4e20e |
251 | if (exists $options->{is}) { |
21f1e231 |
252 | |
012fcbd1 |
253 | ### ------------------------- |
254 | ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
255 | ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
256 | ## is => rw, accessor => _foo # turns into (accessor => _foo) |
257 | ## is => ro, accessor => _foo # error, accesor is rw |
258 | ### ------------------------- |
21f1e231 |
259 | |
8de73ff1 |
260 | if ($options->{is} eq 'ro') { |
21f1e231 |
261 | confess "Cannot define an accessor name on a read-only attribute, accessors are read/write" |
262 | if exists $options->{accessor}; |
8de73ff1 |
263 | $options->{reader} ||= $name; |
8de73ff1 |
264 | } |
265 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
266 | if ($options->{writer}) { |
267 | $options->{reader} ||= $name; |
268 | } |
269 | else { |
270 | $options->{accessor} ||= $name; |
271 | } |
8de73ff1 |
272 | } |
273 | else { |
173709ca |
274 | confess "I do not understand this option (is => " . $options->{is} . ") on attribute ($name)" |
8de73ff1 |
275 | } |
f3c4e20e |
276 | } |
8de73ff1 |
277 | |
f3c4e20e |
278 | if (exists $options->{isa}) { |
f3c4e20e |
279 | if (exists $options->{does}) { |
280 | if (eval { $options->{isa}->can('does') }) { |
281 | ($options->{isa}->does($options->{does})) |
173709ca |
282 | || confess "Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)"; |
f3c4e20e |
283 | } |
284 | else { |
173709ca |
285 | confess "Cannot have an isa option which cannot ->does() on attribute ($name)"; |
26fbace8 |
286 | } |
26fbace8 |
287 | } |
8de73ff1 |
288 | |
f3c4e20e |
289 | # allow for anon-subtypes here ... |
290 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
291 | $options->{type_constraint} = $options->{isa}; |
292 | } |
293 | else { |
620db045 |
294 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
295 | } |
f3c4e20e |
296 | } |
297 | elsif (exists $options->{does}) { |
298 | # allow for anon-subtypes here ... |
299 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
300 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
301 | } |
302 | else { |
620db045 |
303 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
304 | } |
f3c4e20e |
305 | } |
8de73ff1 |
306 | |
f3c4e20e |
307 | if (exists $options->{coerce} && $options->{coerce}) { |
308 | (exists $options->{type_constraint}) |
173709ca |
309 | || confess "You cannot have coercion without specifying a type constraint on attribute ($name)"; |
310 | confess "You cannot have a weak reference to a coerced value on attribute ($name)" |
8de73ff1 |
311 | if $options->{weak_ref}; |
f3c4e20e |
312 | } |
8de73ff1 |
313 | |
0b7df53c |
314 | if (exists $options->{trigger}) { |
c26a8868 |
315 | my $trig = $options->{trigger}; |
316 | if ('HASH' eq ref $trig) { |
317 | my $legal = qr{^(?:before|after|around)$}; |
318 | foreach my $key (keys %$trig) { |
319 | ($key =~ $legal) |
320 | || confess "$key is an illegal trigger specifier" |
321 | . " on attribute ($name)"; |
322 | ('CODE' eq ref $trig->{$key}) |
323 | || confess "$key trigger must be CODE ref" |
324 | . " on attribute ($name)"; |
325 | } |
326 | } |
327 | elsif ('CODE' ne ref $trig) { |
328 | confess "Trigger must be a CODE or HASH ref on attribute ($name)"; |
329 | } |
0b7df53c |
330 | } |
331 | |
f3c4e20e |
332 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
333 | (exists $options->{type_constraint}) |
173709ca |
334 | || confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)"; |
f3c4e20e |
335 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
336 | $options->{type_constraint}->is_a_type_of('HashRef')) |
173709ca |
337 | || confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"; |
f3c4e20e |
338 | } |
8de73ff1 |
339 | |
f3c4e20e |
340 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
173709ca |
341 | confess("You can not use lazy_build and default for the same attribute ($name)") |
8de73ff1 |
342 | if exists $options->{default}; |
a6c84c69 |
343 | $options->{lazy} = 1; |
344 | $options->{required} = 1; |
345 | $options->{builder} ||= "_build_${name}"; |
346 | if ($name =~ /^_/) { |
f3c4e20e |
347 | $options->{clearer} ||= "_clear${name}"; |
348 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
349 | } |
350 | else { |
f3c4e20e |
351 | $options->{clearer} ||= "clear_${name}"; |
352 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
353 | } |
f3c4e20e |
354 | } |
8de73ff1 |
355 | |
f3c4e20e |
356 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
357 | (exists $options->{default} || defined $options->{builder} ) |
7dbda458 |
358 | || confess "You cannot have lazy attribute ($name) without specifying a default value for it"; |
f3c4e20e |
359 | } |
26fbace8 |
360 | |
9edba990 |
361 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
7dbda458 |
362 | confess "You cannot have a required attribute ($name) without a default, builder, or an init_arg"; |
9edba990 |
363 | } |
364 | |
78cd1d3b |
365 | } |
c0e30cf5 |
366 | |
c26a8868 |
367 | sub _with_inline_triggers { |
368 | my ($self, $instance, $value, $attr, $gen_code) = @_; |
369 | my @ga = ($instance, $value, $attr); |
370 | return $gen_code->(@ga) unless $self->has_trigger; |
371 | |
372 | my $trigger_args = "$instance, $value, $attr"; |
373 | |
374 | if ('CODE' eq ref $self->trigger) { |
375 | return $gen_code->(@ga) . "$attr->trigger->($trigger_args);\n"; |
376 | } |
377 | |
378 | my $code = ''; |
379 | my ($before, $around, $after) = @{$self->trigger}{qw(before around after)}; |
380 | |
381 | if ($before) { |
382 | $code .= "$attr->trigger->{before}->($trigger_args);\n"; |
383 | } |
384 | |
385 | if ($around) { |
386 | $code .= "$attr->trigger->{around}->(sub {\n" |
387 | . 'my ($instance, $value, $attr) = @_;' . "\n" |
388 | . $gen_code->('$instance', '$value', '$attr') |
389 | . "}, $trigger_args);\n"; |
390 | } |
391 | else { |
392 | $code .= $gen_code->(@ga); |
393 | } |
394 | |
395 | if ($after) { |
396 | $code .= "$attr->trigger->{after}->($trigger_args);\n"; |
397 | } |
398 | |
399 | return $code; |
400 | } |
401 | |
402 | sub _with_triggers { |
403 | my ($self, $instance, $value, $fn) = @_; |
404 | my @trigger_args = ($instance, $value, $self); |
405 | my ($before, $around, $after); |
406 | |
407 | if ($self->has_trigger) { |
408 | my $trig = $self->trigger; |
409 | |
410 | if ('HASH' eq ref $trig) { |
411 | ($before, $around, $after) = @{$trig}{qw(before around after)} |
412 | } |
413 | else { |
414 | $after = $trig; |
415 | } |
416 | } |
417 | |
418 | if ($before) { |
419 | $before->(@trigger_args); |
420 | } |
421 | |
422 | if ($around) { |
423 | $around->($fn, @trigger_args); |
424 | } |
425 | else { |
426 | $fn->(@trigger_args); |
427 | } |
428 | |
429 | if ($after) { |
430 | $after->(@trigger_args); |
431 | } |
432 | } |
433 | |
d500266f |
434 | sub initialize_instance_slot { |
ddd0ec20 |
435 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
436 | my $init_arg = $self->init_arg(); |
437 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
438 | |
26fbace8 |
439 | my $val; |
1ed0b94f |
440 | my $value_is_set; |
625d571f |
441 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
442 | $val = $params->{$init_arg}; |
2c78d811 |
443 | $value_is_set = 1; |
d500266f |
444 | } |
445 | else { |
446 | # skip it if it's lazy |
447 | return if $self->is_lazy; |
448 | # and die if it's required and doesn't have a default value |
26fbace8 |
449 | confess "Attribute (" . $self->name . ") is required" |
450 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
451 | |
1ed0b94f |
452 | # if nothing was in the %params, we can use the |
453 | # attribute's default value (if it has one) |
454 | if ($self->has_default) { |
455 | $val = $self->default($instance); |
456 | $value_is_set = 1; |
a6c84c69 |
457 | } |
458 | elsif ($self->has_builder) { |
459 | if (my $builder = $instance->can($self->builder)){ |
1ed0b94f |
460 | $val = $instance->$builder; |
461 | $value_is_set = 1; |
a6c84c69 |
462 | } |
463 | else { |
0b26305c |
464 | confess(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'"); |
1ed0b94f |
465 | } |
a0748c37 |
466 | } |
26fbace8 |
467 | } |
468 | |
1ed0b94f |
469 | return unless $value_is_set; |
470 | |
471 | if ($self->has_type_constraint) { |
472 | my $type_constraint = $self->type_constraint; |
473 | if ($self->should_coerce && $type_constraint->has_coercion) { |
474 | $val = $type_constraint->coerce($val); |
d500266f |
475 | } |
ab76842e |
476 | $type_constraint->check($val) |
688fcdda |
477 | || confess "Attribute (" |
478 | . $self->name |
479 | . ") does not pass the type constraint because: " |
480 | . $type_constraint->get_message($val); |
1ed0b94f |
481 | } |
ddd0ec20 |
482 | |
c26a8868 |
483 | $self->_with_triggers($instance, $val, sub { |
484 | my ($ins, $val, $attr) = @_; |
485 | my $mi = Class::MOP::Class->initialize(blessed($ins)) |
486 | ->get_meta_instance; |
487 | $attr->set_initial_value($ins, $val); |
488 | $mi->weaken_slot_value($ins, $attr->name) |
489 | if ref $val && $attr->is_weak_ref; |
490 | }); |
d500266f |
491 | } |
492 | |
d617b644 |
493 | ## Slot management |
9e93dd19 |
494 | |
8abe9636 |
495 | # FIXME: |
496 | # this duplicates too much code from |
497 | # Class::MOP::Attribute, we need to |
498 | # refactor these bits eventually. |
499 | # - SL |
500 | sub _set_initial_slot_value { |
501 | my ($self, $meta_instance, $instance, $value) = @_; |
502 | |
503 | my $slot_name = $self->name; |
504 | |
505 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
506 | unless $self->has_initializer; |
507 | |
508 | my ($type_constraint, $can_coerce); |
509 | if ($self->has_type_constraint) { |
510 | $type_constraint = $self->type_constraint; |
511 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
512 | } |
513 | |
514 | my $callback = sub { |
515 | my $val = shift; |
516 | if ($type_constraint) { |
517 | $val = $type_constraint->coerce($val) |
518 | if $can_coerce; |
519 | $type_constraint->check($val) |
520 | || confess "Attribute (" |
521 | . $slot_name |
522 | . ") does not pass the type constraint because: " |
523 | . $type_constraint->get_message($val); |
524 | } |
525 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
526 | }; |
527 | |
528 | my $initializer = $self->initializer; |
529 | |
530 | # most things will just want to set a value, so make it first arg |
531 | $instance->$initializer($value, $callback, $self); |
532 | } |
533 | |
946289d1 |
534 | sub set_value { |
b6af66f8 |
535 | my ($self, $instance, @args) = @_; |
536 | my $value = $args[0]; |
26fbace8 |
537 | |
946289d1 |
538 | my $attr_name = $self->name; |
26fbace8 |
539 | |
b6af66f8 |
540 | if ($self->is_required and not @args) { |
541 | confess "Attribute ($attr_name) is required"; |
946289d1 |
542 | } |
26fbace8 |
543 | |
946289d1 |
544 | if ($self->has_type_constraint) { |
26fbace8 |
545 | |
946289d1 |
546 | my $type_constraint = $self->type_constraint; |
26fbace8 |
547 | |
946289d1 |
548 | if ($self->should_coerce) { |
26fbace8 |
549 | $value = $type_constraint->coerce($value); |
688fcdda |
550 | } |
42bc21a4 |
551 | $type_constraint->_compiled_type_constraint->($value) |
688fcdda |
552 | || confess "Attribute (" |
553 | . $self->name |
554 | . ") does not pass the type constraint because " |
ab76842e |
555 | . $type_constraint->get_message($value); |
946289d1 |
556 | } |
26fbace8 |
557 | |
c26a8868 |
558 | $self->_with_triggers($instance, $value, sub { |
559 | my ($ins, $val, $attr) = @_; |
560 | my $mi = Class::MOP::Class->initialize(blessed($ins)) |
561 | ->get_meta_instance; |
562 | $mi->set_slot_value($ins, $attr->name, $val); |
563 | $mi->weaken_slot_value($ins, $attr->name) |
564 | if (ref $val && $attr->is_weak_ref); |
565 | }); |
946289d1 |
566 | } |
567 | |
568 | sub get_value { |
569 | my ($self, $instance) = @_; |
26fbace8 |
570 | |
946289d1 |
571 | if ($self->is_lazy) { |
8de73ff1 |
572 | unless ($self->has_value($instance)) { |
573 | if ($self->has_default) { |
574 | my $default = $self->default($instance); |
759e4e8f |
575 | $self->set_initial_value($instance, $default); |
3f11800d |
576 | } elsif ( $self->has_builder ) { |
a6c84c69 |
577 | if (my $builder = $instance->can($self->builder)){ |
759e4e8f |
578 | $self->set_initial_value($instance, $instance->$builder); |
3f11800d |
579 | } |
a6c84c69 |
580 | else { |
581 | confess(blessed($instance) |
582 | . " does not support builder method '" |
583 | . $self->builder |
584 | . "' for attribute '" |
585 | . $self->name |
586 | . "'"); |
26fbace8 |
587 | } |
a6c84c69 |
588 | } |
589 | else { |
759e4e8f |
590 | $self->set_initial_value($instance, undef); |
26fbace8 |
591 | } |
8de73ff1 |
592 | } |
946289d1 |
593 | } |
26fbace8 |
594 | |
946289d1 |
595 | if ($self->should_auto_deref) { |
26fbace8 |
596 | |
946289d1 |
597 | my $type_constraint = $self->type_constraint; |
598 | |
599 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
600 | my $rv = $self->SUPER::get_value($instance); |
601 | return unless defined $rv; |
602 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
603 | } |
946289d1 |
604 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
605 | my $rv = $self->SUPER::get_value($instance); |
606 | return unless defined $rv; |
607 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
608 | } |
946289d1 |
609 | else { |
610 | confess "Can not auto de-reference the type constraint '" . $type_constraint->name . "'"; |
611 | } |
26fbace8 |
612 | |
946289d1 |
613 | } |
614 | else { |
26fbace8 |
615 | |
946289d1 |
616 | return $self->SUPER::get_value($instance); |
26fbace8 |
617 | } |
946289d1 |
618 | } |
a15dff8d |
619 | |
26fbace8 |
620 | ## installing accessors |
c0e30cf5 |
621 | |
d617b644 |
622 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
623 | |
452bac1b |
624 | sub install_accessors { |
625 | my $self = shift; |
26fbace8 |
626 | $self->SUPER::install_accessors(@_); |
d3e7fe85 |
627 | $self->install_delegation if $self->has_handles; |
628 | return; |
629 | } |
26fbace8 |
630 | |
d3e7fe85 |
631 | sub install_delegation { |
632 | my $self = shift; |
26fbace8 |
633 | |
d3e7fe85 |
634 | # NOTE: |
635 | # Here we canonicalize the 'handles' option |
636 | # this will sort out any details and always |
637 | # return an hash of methods which we want |
638 | # to delagate to, see that method for details |
330dbb07 |
639 | my %handles = $self->_canonicalize_handles; |
d3e7fe85 |
640 | |
641 | # find the accessor method for this attribute |
330dbb07 |
642 | my $accessor = $self->_get_delegate_accessor; |
d3e7fe85 |
643 | |
644 | # install the delegation ... |
645 | my $associated_class = $self->associated_class; |
646 | foreach my $handle (keys %handles) { |
647 | my $method_to_call = $handles{$handle}; |
648 | my $class_name = $associated_class->name; |
649 | my $name = "${class_name}::${handle}"; |
650 | |
651 | (!$associated_class->has_method($handle)) |
652 | || confess "You cannot overwrite a locally defined method ($handle) with a delegation"; |
26fbace8 |
653 | |
d3e7fe85 |
654 | # NOTE: |
655 | # handles is not allowed to delegate |
656 | # any of these methods, as they will |
657 | # override the ones in your class, which |
658 | # is almost certainly not what you want. |
4fe78472 |
659 | |
d3e7fe85 |
660 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
661 | #cluck("Not delegating method '$handle' because it is a core method") and |
662 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
663 | |
d3e7fe85 |
664 | if ('CODE' eq ref($method_to_call)) { |
665 | $associated_class->add_method($handle => Class::MOP::subname($name, $method_to_call)); |
452bac1b |
666 | } |
d3e7fe85 |
667 | else { |
668 | # NOTE: |
669 | # we used to do a goto here, but the |
670 | # goto didn't handle failure correctly |
671 | # (it just returned nothing), so I took |
672 | # that out. However, the more I thought |
673 | # about it, the less I liked it doing |
674 | # the goto, and I prefered the act of |
675 | # delegation being actually represented |
676 | # in the stack trace. |
677 | # - SL |
678 | $associated_class->add_method($handle => Class::MOP::subname($name, sub { |
679 | my $proxy = (shift)->$accessor(); |
680 | (defined $proxy) |
681 | || confess "Cannot delegate $handle to $method_to_call because " . |
682 | "the value of " . $self->name . " is not defined"; |
683 | $proxy->$method_to_call(@_); |
684 | })); |
685 | } |
686 | } |
452bac1b |
687 | } |
688 | |
98aae381 |
689 | # private methods to help delegation ... |
690 | |
330dbb07 |
691 | sub _get_delegate_accessor { |
692 | my $self = shift; |
693 | # find the accessor method for this attribute |
694 | my $accessor = $self->get_read_method_ref; |
695 | # then unpack it if we need too ... |
696 | $accessor = $accessor->body if blessed $accessor; |
697 | # return the accessor |
698 | return $accessor; |
699 | } |
700 | |
452bac1b |
701 | sub _canonicalize_handles { |
702 | my $self = shift; |
703 | my $handles = $self->handles; |
c84f324f |
704 | if (my $handle_type = ref($handles)) { |
705 | if ($handle_type eq 'HASH') { |
706 | return %{$handles}; |
707 | } |
708 | elsif ($handle_type eq 'ARRAY') { |
709 | return map { $_ => $_ } @{$handles}; |
710 | } |
711 | elsif ($handle_type eq 'Regexp') { |
712 | ($self->has_type_constraint) |
713 | || confess "Cannot delegate methods based on a RegExpr without a type constraint (isa)"; |
26fbace8 |
714 | return map { ($_ => $_) } |
c84f324f |
715 | grep { /$handles/ } $self->_get_delegate_method_list; |
716 | } |
717 | elsif ($handle_type eq 'CODE') { |
718 | return $handles->($self, $self->_find_delegate_metaclass); |
719 | } |
720 | else { |
721 | confess "Unable to canonicalize the 'handles' option with $handles"; |
722 | } |
452bac1b |
723 | } |
724 | else { |
c84f324f |
725 | my $role_meta = eval { $handles->meta }; |
726 | if ($@) { |
26fbace8 |
727 | confess "Unable to canonicalize the 'handles' option with $handles because : $@"; |
c84f324f |
728 | } |
729 | |
730 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
731 | || confess "Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role"; |
26fbace8 |
732 | |
c84f324f |
733 | return map { $_ => $_ } ( |
26fbace8 |
734 | $role_meta->get_method_list, |
c84f324f |
735 | $role_meta->get_required_method_list |
736 | ); |
452bac1b |
737 | } |
738 | } |
739 | |
740 | sub _find_delegate_metaclass { |
741 | my $self = shift; |
98aae381 |
742 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
743 | # if the class does have |
452bac1b |
744 | # a meta method, use it |
745 | return $class->meta if $class->can('meta'); |
26fbace8 |
746 | # otherwise we might be |
452bac1b |
747 | # dealing with a non-Moose |
26fbace8 |
748 | # class, and need to make |
452bac1b |
749 | # our own metaclass |
750 | return Moose::Meta::Class->initialize($class); |
751 | } |
98aae381 |
752 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
753 | # our role will always have |
452bac1b |
754 | # a meta method |
98aae381 |
755 | return $role->meta; |
452bac1b |
756 | } |
757 | else { |
758 | confess "Cannot find delegate metaclass for attribute " . $self->name; |
759 | } |
760 | } |
761 | |
762 | sub _get_delegate_method_list { |
763 | my $self = shift; |
764 | my $meta = $self->_find_delegate_metaclass; |
765 | if ($meta->isa('Class::MOP::Class')) { |
093b12c2 |
766 | return map { $_->{name} } # NOTE: !never! delegate &meta |
26fbace8 |
767 | grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' } |
452bac1b |
768 | $meta->compute_all_applicable_methods; |
769 | } |
770 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
771 | return $meta->get_method_list; |
452bac1b |
772 | } |
773 | else { |
774 | confess "Unable to recognize the delegate metaclass '$meta'"; |
775 | } |
776 | } |
777 | |
21f1e231 |
778 | package Moose::Meta::Attribute::Custom::Moose; |
779 | sub register_implementation { 'Moose::Meta::Attribute' } |
780 | |
c0e30cf5 |
781 | 1; |
782 | |
783 | __END__ |
784 | |
785 | =pod |
786 | |
787 | =head1 NAME |
788 | |
6ba6d68c |
789 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
790 | |
791 | =head1 DESCRIPTION |
792 | |
26fbace8 |
793 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
794 | extensions. |
6ba6d68c |
795 | |
26fbace8 |
796 | For the most part, the only time you will ever encounter an |
797 | instance of this class is if you are doing some serious deep |
798 | introspection. To really understand this class, you need to refer |
6ba6d68c |
799 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
800 | |
c0e30cf5 |
801 | =head1 METHODS |
802 | |
6ba6d68c |
803 | =head2 Overridden methods |
804 | |
26fbace8 |
805 | These methods override methods in L<Class::MOP::Attribute> and add |
806 | Moose specific features. You can safely assume though that they |
6ba6d68c |
807 | will behave just as L<Class::MOP::Attribute> does. |
808 | |
c0e30cf5 |
809 | =over 4 |
810 | |
811 | =item B<new> |
812 | |
c32c2c61 |
813 | =item B<clone> |
814 | |
6e2840b7 |
815 | =item B<does> |
816 | |
d500266f |
817 | =item B<initialize_instance_slot> |
818 | |
452bac1b |
819 | =item B<install_accessors> |
820 | |
d3e7fe85 |
821 | =item B<install_delegation> |
822 | |
39b3bc94 |
823 | =item B<accessor_metaclass> |
824 | |
946289d1 |
825 | =item B<get_value> |
826 | |
827 | =item B<set_value> |
828 | |
bcbaa845 |
829 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
830 | if($@) { |
831 | print "Oops: $@\n"; |
832 | } |
833 | |
834 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
835 | |
836 | Before setting the value, a check is made on the type constraint of |
837 | the attribute, if it has one, to see if the value passes it. If the |
838 | value fails to pass, the set operation dies with a L<Carp/confess>. |
839 | |
840 | Any coercion to convert values is done before checking the type constraint. |
841 | |
842 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
843 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
844 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
845 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::RecipeX> |
846 | for an example. |
847 | |
a15dff8d |
848 | =back |
849 | |
6ba6d68c |
850 | =head2 Additional Moose features |
851 | |
26fbace8 |
852 | Moose attributes support type-constraint checking, weak reference |
853 | creation and type coercion. |
6ba6d68c |
854 | |
a15dff8d |
855 | =over 4 |
856 | |
d5c30e52 |
857 | =item B<interpolate_class_and_new> |
858 | |
859 | =item B<interpolate_class> |
860 | |
861 | When called as a class method causes interpretation of the C<metaclass> and |
862 | C<traits> options. |
863 | |
9e93dd19 |
864 | =item B<clone_and_inherit_options> |
865 | |
26fbace8 |
866 | This is to support the C<has '+foo'> feature, it clones an attribute |
867 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
868 | to the attribute. |
869 | |
aa08864c |
870 | =item B<legal_options_for_inheritance> |
871 | |
872 | Whitelist with options you can change. You can overload it in your custom |
873 | metaclass to allow your options be inheritable. |
874 | |
a15dff8d |
875 | =item B<has_type_constraint> |
876 | |
6ba6d68c |
877 | Returns true if this meta-attribute has a type constraint. |
878 | |
a15dff8d |
879 | =item B<type_constraint> |
880 | |
26fbace8 |
881 | A read-only accessor for this meta-attribute's type constraint. For |
882 | more information on what you can do with this, see the documentation |
6ba6d68c |
883 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
884 | |
452bac1b |
885 | =item B<has_handles> |
886 | |
887 | Returns true if this meta-attribute performs delegation. |
888 | |
889 | =item B<handles> |
890 | |
891 | This returns the value which was passed into the handles option. |
892 | |
6ba6d68c |
893 | =item B<is_weak_ref> |
a15dff8d |
894 | |
02a0fb52 |
895 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
896 | |
ca01a97b |
897 | =item B<is_required> |
898 | |
02a0fb52 |
899 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
900 | |
901 | =item B<is_lazy> |
902 | |
02a0fb52 |
903 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
904 | |
26fbace8 |
905 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
906 | |
907 | =item B<is_lazy_build> |
908 | |
909 | Returns true if this meta-attribute should be initialized lazily through |
910 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
911 | make your attribute required and lazy. In addition it will set the builder, clearer |
912 | and predicate options for you using the following convention. |
913 | |
914 | #If your attribute name starts with an underscore: |
915 | has '_foo' => (lazy_build => 1); |
916 | #is the same as |
58f85113 |
917 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo); |
26fbace8 |
918 | # or |
58f85113 |
919 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
920 | |
921 | #If your attribute name does not start with an underscore: |
58f85113 |
922 | has 'foo' => (lazy_build => 1); |
923 | #is the same as |
924 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo); |
26fbace8 |
925 | # or |
58f85113 |
926 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
927 | |
928 | The reason for the different naming of the C<builder> is that the C<builder> |
929 | method is a private method while the C<clearer> and C<predicate> methods |
930 | are public methods. |
26fbace8 |
931 | |
932 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
933 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
934 | |
34a66aa3 |
935 | =item B<should_coerce> |
4b598ea3 |
936 | |
02a0fb52 |
937 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
938 | |
536f0b17 |
939 | =item B<should_auto_deref> |
940 | |
26fbace8 |
941 | Returns true if this meta-attribute should perform automatic |
942 | auto-dereferencing. |
536f0b17 |
943 | |
26fbace8 |
944 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
945 | either I<ArrayRef> or I<HashRef>. |
946 | |
8c9d74e7 |
947 | =item B<has_trigger> |
948 | |
02a0fb52 |
949 | Returns true if this meta-attribute has a trigger set. |
950 | |
8c9d74e7 |
951 | =item B<trigger> |
952 | |
26fbace8 |
953 | This is a CODE reference which will be executed every time the |
954 | value of an attribute is assigned. The CODE ref will get two values, |
955 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
956 | bi-directional relations. |
957 | |
953e657e |
958 | This can also be a HASH of CODE refs for before/around/after, much |
959 | in the same vein as method modifiers. After and before work just |
960 | like the plain CODE ref case. Around first gets a CODE ref that |
961 | expects the rest of the args and will assign the value. |
962 | |
ddbdc0cb |
963 | =item B<documentation> |
964 | |
26fbace8 |
965 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
966 | It serves no direct purpose right now, but it might in the future |
967 | in some kind of automated documentation system perhaps. |
968 | |
969 | =item B<has_documentation> |
970 | |
971 | Returns true if this meta-attribute has any documentation. |
972 | |
88f23977 |
973 | =item B<applied_traits> |
974 | |
975 | This will return the ARRAY ref of all the traits applied to this |
976 | attribute, or if no traits have been applied, it returns C<undef>. |
977 | |
978 | =item B<has_applied_traits> |
979 | |
980 | Returns true if this meta-attribute has any traits applied. |
981 | |
c0e30cf5 |
982 | =back |
983 | |
984 | =head1 BUGS |
985 | |
26fbace8 |
986 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
987 | exception. If you find a bug please either email me, or add the bug |
988 | to cpan-RT. |
989 | |
c0e30cf5 |
990 | =head1 AUTHOR |
991 | |
992 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
993 | |
98aae381 |
994 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
995 | |
c0e30cf5 |
996 | =head1 COPYRIGHT AND LICENSE |
997 | |
778db3ac |
998 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
999 | |
1000 | L<http://www.iinteractive.com> |
1001 | |
1002 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
1003 | it under the same terms as Perl itself. |
c0e30cf5 |
1004 | |
8a7a9c53 |
1005 | =cut |