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 | |
eaa35e6e |
11 | our $VERSION = '0.50'; |
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 | # NOTE: |
55 | # we need to have a ->does method in here to |
56 | # more easily support traits, and the introspection |
57 | # of those traits. So in order to do this we |
58 | # just alias Moose::Object's version of it. |
59 | # - SL |
60 | *does = \&Moose::Object::does; |
61 | |
be05faea |
62 | sub throw_error { |
63 | my $self = shift; |
64 | my $class = ( ref $self && $self->associated_class ) || "Moose::Meta::Class"; |
65 | unshift @_, "message" if @_ % 2 == 1; |
66 | unshift @_, attr => $self if ref $self; |
67 | unshift @_, $class; |
68 | goto $class->can("throw_error"); # to avoid incrementing depth by 1 |
69 | } |
70 | |
78cd1d3b |
71 | sub new { |
f3c4e20e |
72 | my ($class, $name, %options) = @_; |
c32c2c61 |
73 | $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS |
f3c4e20e |
74 | return $class->SUPER::new($name, %options); |
1d768fb1 |
75 | } |
76 | |
d5c30e52 |
77 | sub interpolate_class_and_new { |
78 | my ($class, $name, @args) = @_; |
79 | |
c32c2c61 |
80 | my ( $new_class, @traits ) = $class->interpolate_class(@args); |
81 | |
82 | $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) ); |
d5c30e52 |
83 | } |
84 | |
85 | sub interpolate_class { |
86 | my ($class, %options) = @_; |
87 | |
c32c2c61 |
88 | $class = ref($class) || $class; |
89 | |
90 | if ( my $metaclass_name = delete $options{metaclass} ) { |
91 | my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name ); |
92 | |
93 | if ( $class ne $new_class ) { |
94 | if ( $new_class->can("interpolate_class") ) { |
95 | return $new_class->interpolate_class(%options); |
96 | } else { |
97 | $class = $new_class; |
98 | } |
99 | } |
d5c30e52 |
100 | } |
101 | |
c32c2c61 |
102 | my @traits; |
103 | |
d5c30e52 |
104 | if (my $traits = $options{traits}) { |
c32c2c61 |
105 | if ( @traits = grep { not $class->does($_) } map { |
d5c30e52 |
106 | Moose::Util::resolve_metatrait_alias( Attribute => $_ ) |
107 | or |
108 | $_ |
c32c2c61 |
109 | } @$traits ) { |
110 | my $anon_class = Moose::Meta::Class->create_anon_class( |
111 | superclasses => [ $class ], |
112 | roles => [ @traits ], |
113 | cache => 1, |
114 | ); |
115 | |
116 | $class = $anon_class->name; |
117 | } |
d5c30e52 |
118 | } |
c32c2c61 |
119 | |
120 | return ( wantarray ? ( $class, @traits ) : $class ); |
d5c30e52 |
121 | } |
122 | |
ce0e8d63 |
123 | sub clone_and_inherit_options { |
124 | my ($self, %options) = @_; |
c32c2c61 |
125 | my %copy = %options; |
126 | # you can change default, required, coerce, documentation, lazy, handles, builder, type_constraint (explicitly or using isa/does), metaclass and traits |
ce0e8d63 |
127 | my %actual_options; |
c32c2c61 |
128 | foreach my $legal_option (qw(default coerce required documentation lazy handles builder type_constraint)) { |
ce0e8d63 |
129 | if (exists $options{$legal_option}) { |
130 | $actual_options{$legal_option} = $options{$legal_option}; |
131 | delete $options{$legal_option}; |
132 | } |
133 | } |
26fbace8 |
134 | |
ce0e8d63 |
135 | if ($options{isa}) { |
136 | my $type_constraint; |
8de73ff1 |
137 | if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) { |
138 | $type_constraint = $options{isa}; |
139 | } |
140 | else { |
d40ce9d5 |
141 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
8de73ff1 |
142 | (defined $type_constraint) |
be05faea |
143 | || $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa}); |
8de73ff1 |
144 | } |
5e98d2b6 |
145 | |
8de73ff1 |
146 | $actual_options{type_constraint} = $type_constraint; |
ce0e8d63 |
147 | delete $options{isa}; |
148 | } |
2ea379cb |
149 | |
150 | if ($options{does}) { |
151 | my $type_constraint; |
152 | if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) { |
153 | $type_constraint = $options{does}; |
154 | } |
155 | else { |
d40ce9d5 |
156 | $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
2ea379cb |
157 | (defined $type_constraint) |
be05faea |
158 | || $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does}); |
2ea379cb |
159 | } |
160 | |
161 | $actual_options{type_constraint} = $type_constraint; |
162 | delete $options{does}; |
163 | } |
c32c2c61 |
164 | |
cbd141ca |
165 | # NOTE: |
166 | # this doesn't apply to Class::MOP::Attributes, |
167 | # so we can ignore it for them. |
168 | # - SL |
169 | if ($self->can('interpolate_class')) { |
170 | ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options); |
c32c2c61 |
171 | |
cbd141ca |
172 | my %seen; |
173 | my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits; |
174 | $actual_options{traits} = \@all_traits if @all_traits; |
c32c2c61 |
175 | |
cbd141ca |
176 | delete @options{qw(metaclass traits)}; |
177 | } |
c32c2c61 |
178 | |
26fbace8 |
179 | (scalar keys %options == 0) |
be05faea |
180 | || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options); |
c32c2c61 |
181 | |
182 | |
ce0e8d63 |
183 | $self->clone(%actual_options); |
1d768fb1 |
184 | } |
185 | |
c32c2c61 |
186 | sub clone { |
187 | my ( $self, %params ) = @_; |
188 | |
189 | my $class = $params{metaclass} || ref $self; |
190 | |
191 | if ( 0 and $class eq ref $self ) { |
192 | return $self->SUPER::clone(%params); |
193 | } else { |
194 | my ( @init, @non_init ); |
195 | |
196 | foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) { |
197 | push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr; |
198 | } |
199 | |
200 | my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params ); |
201 | |
202 | my $name = delete $new_params{name}; |
203 | |
204 | my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 ); |
205 | |
206 | foreach my $attr ( @non_init ) { |
207 | $attr->set_value($clone, $attr->get_value($self)); |
208 | } |
209 | |
210 | |
211 | return $clone; |
212 | } |
213 | } |
214 | |
1d768fb1 |
215 | sub _process_options { |
216 | my ($class, $name, $options) = @_; |
8de73ff1 |
217 | |
f3c4e20e |
218 | if (exists $options->{is}) { |
21f1e231 |
219 | |
220 | =pod |
221 | |
222 | is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before |
223 | is => rw, writer => _foo # turns into (reader => foo, writer => _foo) |
224 | is => rw, accessor => _foo # turns into (accessor => _foo) |
225 | is => ro, accessor => _foo # error, accesor is rw |
226 | |
227 | =cut |
228 | |
8de73ff1 |
229 | if ($options->{is} eq 'ro') { |
be05faea |
230 | $class->throw_error("Cannot define an accessor name on a read-only attribute, accessors are read/write", data => $options) |
21f1e231 |
231 | if exists $options->{accessor}; |
8de73ff1 |
232 | $options->{reader} ||= $name; |
8de73ff1 |
233 | } |
234 | elsif ($options->{is} eq 'rw') { |
21f1e231 |
235 | if ($options->{writer}) { |
236 | $options->{reader} ||= $name; |
237 | } |
238 | else { |
239 | $options->{accessor} ||= $name; |
240 | } |
8de73ff1 |
241 | } |
242 | else { |
be05faea |
243 | $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute $name", data => $options->{is}); |
8de73ff1 |
244 | } |
f3c4e20e |
245 | } |
8de73ff1 |
246 | |
f3c4e20e |
247 | if (exists $options->{isa}) { |
f3c4e20e |
248 | if (exists $options->{does}) { |
249 | if (eval { $options->{isa}->can('does') }) { |
250 | ($options->{isa}->does($options->{does})) |
be05faea |
251 | || $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 |
252 | } |
253 | else { |
be05faea |
254 | $class->throw_error("Cannot have an isa option which cannot ->does() on attribute $name", data => $options); |
26fbace8 |
255 | } |
26fbace8 |
256 | } |
8de73ff1 |
257 | |
f3c4e20e |
258 | # allow for anon-subtypes here ... |
259 | if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) { |
8de73ff1 |
260 | $options->{type_constraint} = $options->{isa}; |
261 | } |
262 | else { |
620db045 |
263 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa}); |
8de73ff1 |
264 | } |
f3c4e20e |
265 | } |
266 | elsif (exists $options->{does}) { |
267 | # allow for anon-subtypes here ... |
268 | if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) { |
238b424d |
269 | $options->{type_constraint} = $options->{does}; |
8de73ff1 |
270 | } |
271 | else { |
620db045 |
272 | $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does}); |
8de73ff1 |
273 | } |
f3c4e20e |
274 | } |
8de73ff1 |
275 | |
f3c4e20e |
276 | if (exists $options->{coerce} && $options->{coerce}) { |
277 | (exists $options->{type_constraint}) |
be05faea |
278 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute $name", data => $options); |
279 | $class->throw_error("You cannot have a weak reference to a coerced value on attribute $name", data => $options) |
8de73ff1 |
280 | if $options->{weak_ref}; |
f3c4e20e |
281 | } |
8de73ff1 |
282 | |
0b7df53c |
283 | if (exists $options->{trigger}) { |
21f1e231 |
284 | ('CODE' eq ref $options->{trigger}) |
be05faea |
285 | || $class->throw_error("Trigger must be a CODE ref", data => $options->{trigger}); |
0b7df53c |
286 | } |
287 | |
f3c4e20e |
288 | if (exists $options->{auto_deref} && $options->{auto_deref}) { |
289 | (exists $options->{type_constraint}) |
be05faea |
290 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute $name", data => $options); |
f3c4e20e |
291 | ($options->{type_constraint}->is_a_type_of('ArrayRef') || |
8de73ff1 |
292 | $options->{type_constraint}->is_a_type_of('HashRef')) |
be05faea |
293 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute $name", data => $options); |
f3c4e20e |
294 | } |
8de73ff1 |
295 | |
f3c4e20e |
296 | if (exists $options->{lazy_build} && $options->{lazy_build} == 1) { |
be05faea |
297 | $class->throw_error("You can not use lazy_build and default for the same attribute $name", data => $options) |
8de73ff1 |
298 | if exists $options->{default}; |
a6c84c69 |
299 | $options->{lazy} = 1; |
300 | $options->{required} = 1; |
301 | $options->{builder} ||= "_build_${name}"; |
302 | if ($name =~ /^_/) { |
f3c4e20e |
303 | $options->{clearer} ||= "_clear${name}"; |
304 | $options->{predicate} ||= "_has${name}"; |
a6c84c69 |
305 | } |
306 | else { |
f3c4e20e |
307 | $options->{clearer} ||= "clear_${name}"; |
308 | $options->{predicate} ||= "has_${name}"; |
26fbace8 |
309 | } |
f3c4e20e |
310 | } |
8de73ff1 |
311 | |
f3c4e20e |
312 | if (exists $options->{lazy} && $options->{lazy}) { |
9edba990 |
313 | (exists $options->{default} || defined $options->{builder} ) |
be05faea |
314 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it", data => $options); |
f3c4e20e |
315 | } |
26fbace8 |
316 | |
9edba990 |
317 | if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) { |
be05faea |
318 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg", data => $options); |
9edba990 |
319 | } |
320 | |
78cd1d3b |
321 | } |
c0e30cf5 |
322 | |
d500266f |
323 | sub initialize_instance_slot { |
ddd0ec20 |
324 | my ($self, $meta_instance, $instance, $params) = @_; |
d500266f |
325 | my $init_arg = $self->init_arg(); |
326 | # try to fetch the init arg from the %params ... |
ddd0ec20 |
327 | |
26fbace8 |
328 | my $val; |
1ed0b94f |
329 | my $value_is_set; |
625d571f |
330 | if ( defined($init_arg) and exists $params->{$init_arg}) { |
d500266f |
331 | $val = $params->{$init_arg}; |
2c78d811 |
332 | $value_is_set = 1; |
d500266f |
333 | } |
334 | else { |
335 | # skip it if it's lazy |
336 | return if $self->is_lazy; |
337 | # and die if it's required and doesn't have a default value |
be05faea |
338 | $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params) |
26fbace8 |
339 | if $self->is_required && !$self->has_default && !$self->has_builder; |
ddd0ec20 |
340 | |
1ed0b94f |
341 | # if nothing was in the %params, we can use the |
342 | # attribute's default value (if it has one) |
343 | if ($self->has_default) { |
344 | $val = $self->default($instance); |
345 | $value_is_set = 1; |
a6c84c69 |
346 | } |
347 | elsif ($self->has_builder) { |
348 | if (my $builder = $instance->can($self->builder)){ |
1ed0b94f |
349 | $val = $instance->$builder; |
350 | $value_is_set = 1; |
a6c84c69 |
351 | } |
352 | else { |
be05faea |
353 | $self->throw_error(blessed($instance)." does not support builder method '".$self->builder."' for attribute '" . $self->name . "'", object => $instance, data => $params); |
1ed0b94f |
354 | } |
a0748c37 |
355 | } |
26fbace8 |
356 | } |
357 | |
1ed0b94f |
358 | return unless $value_is_set; |
359 | |
360 | if ($self->has_type_constraint) { |
361 | my $type_constraint = $self->type_constraint; |
362 | if ($self->should_coerce && $type_constraint->has_coercion) { |
363 | $val = $type_constraint->coerce($val); |
d500266f |
364 | } |
ab76842e |
365 | $type_constraint->check($val) |
be05faea |
366 | || $self->throw_error("Attribute (" |
688fcdda |
367 | . $self->name |
368 | . ") does not pass the type constraint because: " |
be05faea |
369 | . $type_constraint->get_message($val), data => $val, object => $instance); |
1ed0b94f |
370 | } |
ddd0ec20 |
371 | |
759e4e8f |
372 | $self->set_initial_value($instance, $val); |
26fbace8 |
373 | $meta_instance->weaken_slot_value($instance, $self->name) |
a6c84c69 |
374 | if ref $val && $self->is_weak_ref; |
d500266f |
375 | } |
376 | |
d617b644 |
377 | ## Slot management |
9e93dd19 |
378 | |
8abe9636 |
379 | # FIXME: |
380 | # this duplicates too much code from |
381 | # Class::MOP::Attribute, we need to |
382 | # refactor these bits eventually. |
383 | # - SL |
384 | sub _set_initial_slot_value { |
385 | my ($self, $meta_instance, $instance, $value) = @_; |
386 | |
387 | my $slot_name = $self->name; |
388 | |
389 | return $meta_instance->set_slot_value($instance, $slot_name, $value) |
390 | unless $self->has_initializer; |
391 | |
392 | my ($type_constraint, $can_coerce); |
393 | if ($self->has_type_constraint) { |
394 | $type_constraint = $self->type_constraint; |
395 | $can_coerce = ($self->should_coerce && $type_constraint->has_coercion); |
396 | } |
397 | |
398 | my $callback = sub { |
399 | my $val = shift; |
400 | if ($type_constraint) { |
401 | $val = $type_constraint->coerce($val) |
402 | if $can_coerce; |
403 | $type_constraint->check($val) |
be05faea |
404 | || $self->throw_error("Attribute (" |
8abe9636 |
405 | . $slot_name |
406 | . ") does not pass the type constraint because: " |
be05faea |
407 | . $type_constraint->get_message($val), data => $val, object => $instance); |
8abe9636 |
408 | } |
409 | $meta_instance->set_slot_value($instance, $slot_name, $val); |
410 | }; |
411 | |
412 | my $initializer = $self->initializer; |
413 | |
414 | # most things will just want to set a value, so make it first arg |
415 | $instance->$initializer($value, $callback, $self); |
416 | } |
417 | |
946289d1 |
418 | sub set_value { |
b6af66f8 |
419 | my ($self, $instance, @args) = @_; |
420 | my $value = $args[0]; |
26fbace8 |
421 | |
946289d1 |
422 | my $attr_name = $self->name; |
26fbace8 |
423 | |
b6af66f8 |
424 | if ($self->is_required and not @args) { |
be05faea |
425 | $self->throw_error("Attribute ($attr_name) is required", object => $instance); |
946289d1 |
426 | } |
26fbace8 |
427 | |
946289d1 |
428 | if ($self->has_type_constraint) { |
26fbace8 |
429 | |
946289d1 |
430 | my $type_constraint = $self->type_constraint; |
26fbace8 |
431 | |
946289d1 |
432 | if ($self->should_coerce) { |
26fbace8 |
433 | $value = $type_constraint->coerce($value); |
688fcdda |
434 | } |
42bc21a4 |
435 | $type_constraint->_compiled_type_constraint->($value) |
be05faea |
436 | || $self->throw_error("Attribute (" |
688fcdda |
437 | . $self->name |
438 | . ") does not pass the type constraint because " |
be05faea |
439 | . $type_constraint->get_message($value), object => $instance, data => $value); |
946289d1 |
440 | } |
26fbace8 |
441 | |
946289d1 |
442 | my $meta_instance = Class::MOP::Class->initialize(blessed($instance)) |
443 | ->get_meta_instance; |
26fbace8 |
444 | |
445 | $meta_instance->set_slot_value($instance, $attr_name, $value); |
446 | |
946289d1 |
447 | if (ref $value && $self->is_weak_ref) { |
26fbace8 |
448 | $meta_instance->weaken_slot_value($instance, $attr_name); |
946289d1 |
449 | } |
26fbace8 |
450 | |
946289d1 |
451 | if ($self->has_trigger) { |
452 | $self->trigger->($instance, $value, $self); |
453 | } |
454 | } |
455 | |
456 | sub get_value { |
457 | my ($self, $instance) = @_; |
26fbace8 |
458 | |
946289d1 |
459 | if ($self->is_lazy) { |
8de73ff1 |
460 | unless ($self->has_value($instance)) { |
461 | if ($self->has_default) { |
462 | my $default = $self->default($instance); |
759e4e8f |
463 | $self->set_initial_value($instance, $default); |
3f11800d |
464 | } elsif ( $self->has_builder ) { |
a6c84c69 |
465 | if (my $builder = $instance->can($self->builder)){ |
759e4e8f |
466 | $self->set_initial_value($instance, $instance->$builder); |
3f11800d |
467 | } |
a6c84c69 |
468 | else { |
be05faea |
469 | $self->throw_error(blessed($instance) |
a6c84c69 |
470 | . " does not support builder method '" |
471 | . $self->builder |
472 | . "' for attribute '" |
473 | . $self->name |
be05faea |
474 | . "'", object => $instance); |
26fbace8 |
475 | } |
a6c84c69 |
476 | } |
477 | else { |
759e4e8f |
478 | $self->set_initial_value($instance, undef); |
26fbace8 |
479 | } |
8de73ff1 |
480 | } |
946289d1 |
481 | } |
26fbace8 |
482 | |
946289d1 |
483 | if ($self->should_auto_deref) { |
26fbace8 |
484 | |
946289d1 |
485 | my $type_constraint = $self->type_constraint; |
486 | |
487 | if ($type_constraint->is_a_type_of('ArrayRef')) { |
488 | my $rv = $self->SUPER::get_value($instance); |
489 | return unless defined $rv; |
490 | return wantarray ? @{ $rv } : $rv; |
26fbace8 |
491 | } |
946289d1 |
492 | elsif ($type_constraint->is_a_type_of('HashRef')) { |
493 | my $rv = $self->SUPER::get_value($instance); |
494 | return unless defined $rv; |
495 | return wantarray ? %{ $rv } : $rv; |
26fbace8 |
496 | } |
946289d1 |
497 | else { |
be05faea |
498 | $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, data => $type_constraint); |
946289d1 |
499 | } |
26fbace8 |
500 | |
946289d1 |
501 | } |
502 | else { |
26fbace8 |
503 | |
946289d1 |
504 | return $self->SUPER::get_value($instance); |
26fbace8 |
505 | } |
946289d1 |
506 | } |
a15dff8d |
507 | |
26fbace8 |
508 | ## installing accessors |
c0e30cf5 |
509 | |
d617b644 |
510 | sub accessor_metaclass { 'Moose::Meta::Method::Accessor' } |
d7f17ebb |
511 | |
452bac1b |
512 | sub install_accessors { |
513 | my $self = shift; |
26fbace8 |
514 | $self->SUPER::install_accessors(@_); |
515 | |
452bac1b |
516 | if ($self->has_handles) { |
26fbace8 |
517 | |
452bac1b |
518 | # NOTE: |
519 | # Here we canonicalize the 'handles' option |
26fbace8 |
520 | # this will sort out any details and always |
521 | # return an hash of methods which we want |
452bac1b |
522 | # to delagate to, see that method for details |
523 | my %handles = $self->_canonicalize_handles(); |
26fbace8 |
524 | |
f3c4e20e |
525 | # find the accessor method for this attribute |
526 | my $accessor = $self->get_read_method_ref; |
527 | # then unpack it if we need too ... |
528 | $accessor = $accessor->body if blessed $accessor; |
26fbace8 |
529 | |
452bac1b |
530 | # install the delegation ... |
531 | my $associated_class = $self->associated_class; |
532 | foreach my $handle (keys %handles) { |
533 | my $method_to_call = $handles{$handle}; |
7dbbdcab |
534 | my $class_name = $associated_class->name; |
535 | my $name = "${class_name}::${handle}"; |
26fbace8 |
536 | |
452bac1b |
537 | (!$associated_class->has_method($handle)) |
be05faea |
538 | || $self->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation", method => $handle); |
26fbace8 |
539 | |
d022f632 |
540 | # NOTE: |
541 | # handles is not allowed to delegate |
26fbace8 |
542 | # any of these methods, as they will |
543 | # override the ones in your class, which |
d022f632 |
544 | # is almost certainly not what you want. |
4fe78472 |
545 | |
546 | # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something |
547 | #cluck("Not delegating method '$handle' because it is a core method") and |
548 | next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle); |
26fbace8 |
549 | |
21f1e231 |
550 | if ('CODE' eq ref($method_to_call)) { |
1b2aea39 |
551 | $associated_class->add_method($handle => Class::MOP::subname($name, $method_to_call)); |
452bac1b |
552 | } |
553 | else { |
140001f0 |
554 | # NOTE: |
555 | # we used to do a goto here, but the |
556 | # goto didn't handle failure correctly |
557 | # (it just returned nothing), so I took |
558 | # that out. However, the more I thought |
559 | # about it, the less I liked it doing |
560 | # the goto, and I prefered the act of |
561 | # delegation being actually represented |
562 | # in the stack trace. |
563 | # - SL |
1b2aea39 |
564 | $associated_class->add_method($handle => Class::MOP::subname($name, sub { |
be05faea |
565 | my $instance = shift; |
566 | my $proxy = $instance->$accessor(); |
ccf49e80 |
567 | (defined $proxy) |
be05faea |
568 | || $self->throw_error("Cannot delegate $handle to $method_to_call because " . |
569 | "the value of " . $self->name . " is not defined", method => $method_to_call, object => $instance); |
f4f3e701 |
570 | $proxy->$method_to_call(@_); |
1b2aea39 |
571 | })); |
452bac1b |
572 | } |
573 | } |
574 | } |
26fbace8 |
575 | |
452bac1b |
576 | return; |
577 | } |
578 | |
98aae381 |
579 | # private methods to help delegation ... |
580 | |
452bac1b |
581 | sub _canonicalize_handles { |
582 | my $self = shift; |
583 | my $handles = $self->handles; |
c84f324f |
584 | if (my $handle_type = ref($handles)) { |
585 | if ($handle_type eq 'HASH') { |
586 | return %{$handles}; |
587 | } |
588 | elsif ($handle_type eq 'ARRAY') { |
589 | return map { $_ => $_ } @{$handles}; |
590 | } |
591 | elsif ($handle_type eq 'Regexp') { |
592 | ($self->has_type_constraint) |
be05faea |
593 | || $self->throw_error("Cannot delegate methods based on a RegExpr without a type constraint (isa)", data => $handles); |
26fbace8 |
594 | return map { ($_ => $_) } |
c84f324f |
595 | grep { /$handles/ } $self->_get_delegate_method_list; |
596 | } |
597 | elsif ($handle_type eq 'CODE') { |
598 | return $handles->($self, $self->_find_delegate_metaclass); |
599 | } |
600 | else { |
be05faea |
601 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles); |
c84f324f |
602 | } |
452bac1b |
603 | } |
604 | else { |
c84f324f |
605 | my $role_meta = eval { $handles->meta }; |
606 | if ($@) { |
be05faea |
607 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles because : $@", data => $handles, error => $@); |
c84f324f |
608 | } |
609 | |
610 | (blessed $role_meta && $role_meta->isa('Moose::Meta::Role')) |
be05faea |
611 | || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role", data => $handles); |
26fbace8 |
612 | |
c84f324f |
613 | return map { $_ => $_ } ( |
26fbace8 |
614 | $role_meta->get_method_list, |
c84f324f |
615 | $role_meta->get_required_method_list |
616 | ); |
452bac1b |
617 | } |
618 | } |
619 | |
620 | sub _find_delegate_metaclass { |
621 | my $self = shift; |
98aae381 |
622 | if (my $class = $self->_isa_metadata) { |
26fbace8 |
623 | # if the class does have |
452bac1b |
624 | # a meta method, use it |
625 | return $class->meta if $class->can('meta'); |
26fbace8 |
626 | # otherwise we might be |
452bac1b |
627 | # dealing with a non-Moose |
26fbace8 |
628 | # class, and need to make |
452bac1b |
629 | # our own metaclass |
630 | return Moose::Meta::Class->initialize($class); |
631 | } |
98aae381 |
632 | elsif (my $role = $self->_does_metadata) { |
26fbace8 |
633 | # our role will always have |
452bac1b |
634 | # a meta method |
98aae381 |
635 | return $role->meta; |
452bac1b |
636 | } |
637 | else { |
be05faea |
638 | $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name); |
452bac1b |
639 | } |
640 | } |
641 | |
642 | sub _get_delegate_method_list { |
643 | my $self = shift; |
644 | my $meta = $self->_find_delegate_metaclass; |
645 | if ($meta->isa('Class::MOP::Class')) { |
093b12c2 |
646 | return map { $_->{name} } # NOTE: !never! delegate &meta |
26fbace8 |
647 | grep { $_->{class} ne 'Moose::Object' && $_->{name} ne 'meta' } |
452bac1b |
648 | $meta->compute_all_applicable_methods; |
649 | } |
650 | elsif ($meta->isa('Moose::Meta::Role')) { |
26fbace8 |
651 | return $meta->get_method_list; |
452bac1b |
652 | } |
653 | else { |
be05faea |
654 | $self->throw_error("Unable to recognize the delegate metaclass '$meta'", data => $meta); |
452bac1b |
655 | } |
656 | } |
657 | |
21f1e231 |
658 | package Moose::Meta::Attribute::Custom::Moose; |
659 | sub register_implementation { 'Moose::Meta::Attribute' } |
660 | |
c0e30cf5 |
661 | 1; |
662 | |
663 | __END__ |
664 | |
665 | =pod |
666 | |
667 | =head1 NAME |
668 | |
6ba6d68c |
669 | Moose::Meta::Attribute - The Moose attribute metaclass |
c0e30cf5 |
670 | |
671 | =head1 DESCRIPTION |
672 | |
26fbace8 |
673 | This is a subclass of L<Class::MOP::Attribute> with Moose specific |
674 | extensions. |
6ba6d68c |
675 | |
26fbace8 |
676 | For the most part, the only time you will ever encounter an |
677 | instance of this class is if you are doing some serious deep |
678 | introspection. To really understand this class, you need to refer |
6ba6d68c |
679 | to the L<Class::MOP::Attribute> documentation. |
e522431d |
680 | |
c0e30cf5 |
681 | =head1 METHODS |
682 | |
6ba6d68c |
683 | =head2 Overridden methods |
684 | |
26fbace8 |
685 | These methods override methods in L<Class::MOP::Attribute> and add |
686 | Moose specific features. You can safely assume though that they |
6ba6d68c |
687 | will behave just as L<Class::MOP::Attribute> does. |
688 | |
c0e30cf5 |
689 | =over 4 |
690 | |
691 | =item B<new> |
692 | |
c32c2c61 |
693 | =item B<clone> |
694 | |
6e2840b7 |
695 | =item B<does> |
696 | |
d500266f |
697 | =item B<initialize_instance_slot> |
698 | |
452bac1b |
699 | =item B<install_accessors> |
700 | |
39b3bc94 |
701 | =item B<accessor_metaclass> |
702 | |
946289d1 |
703 | =item B<get_value> |
704 | |
705 | =item B<set_value> |
706 | |
bcbaa845 |
707 | eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') }; |
708 | if($@) { |
709 | print "Oops: $@\n"; |
710 | } |
711 | |
712 | I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'> |
713 | |
714 | Before setting the value, a check is made on the type constraint of |
715 | the attribute, if it has one, to see if the value passes it. If the |
716 | value fails to pass, the set operation dies with a L<Carp/confess>. |
717 | |
718 | Any coercion to convert values is done before checking the type constraint. |
719 | |
720 | To check a value against a type constraint before setting it, fetch the |
ec00fa75 |
721 | attribute instance using L<Class::MOP::Class/find_attribute_by_name>, |
bcbaa845 |
722 | fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint> |
723 | and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::RecipeX> |
724 | for an example. |
725 | |
a15dff8d |
726 | =back |
727 | |
6ba6d68c |
728 | =head2 Additional Moose features |
729 | |
26fbace8 |
730 | Moose attributes support type-constraint checking, weak reference |
731 | creation and type coercion. |
6ba6d68c |
732 | |
a15dff8d |
733 | =over 4 |
734 | |
be05faea |
735 | =item B<throw_error> |
736 | |
737 | Delegates to C<associated_class> or C<Moose::Meta::Class> if there is none. |
738 | |
d5c30e52 |
739 | =item B<interpolate_class_and_new> |
740 | |
741 | =item B<interpolate_class> |
742 | |
743 | When called as a class method causes interpretation of the C<metaclass> and |
744 | C<traits> options. |
745 | |
9e93dd19 |
746 | =item B<clone_and_inherit_options> |
747 | |
26fbace8 |
748 | This is to support the C<has '+foo'> feature, it clones an attribute |
749 | from a superclass and allows a very specific set of changes to be made |
9e93dd19 |
750 | to the attribute. |
751 | |
a15dff8d |
752 | =item B<has_type_constraint> |
753 | |
6ba6d68c |
754 | Returns true if this meta-attribute has a type constraint. |
755 | |
a15dff8d |
756 | =item B<type_constraint> |
757 | |
26fbace8 |
758 | A read-only accessor for this meta-attribute's type constraint. For |
759 | more information on what you can do with this, see the documentation |
6ba6d68c |
760 | for L<Moose::Meta::TypeConstraint>. |
a15dff8d |
761 | |
452bac1b |
762 | =item B<has_handles> |
763 | |
764 | Returns true if this meta-attribute performs delegation. |
765 | |
766 | =item B<handles> |
767 | |
768 | This returns the value which was passed into the handles option. |
769 | |
6ba6d68c |
770 | =item B<is_weak_ref> |
a15dff8d |
771 | |
02a0fb52 |
772 | Returns true if this meta-attribute produces a weak reference. |
4b598ea3 |
773 | |
ca01a97b |
774 | =item B<is_required> |
775 | |
02a0fb52 |
776 | Returns true if this meta-attribute is required to have a value. |
ca01a97b |
777 | |
778 | =item B<is_lazy> |
779 | |
02a0fb52 |
780 | Returns true if this meta-attribute should be initialized lazily. |
ca01a97b |
781 | |
26fbace8 |
782 | NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set. |
783 | |
784 | =item B<is_lazy_build> |
785 | |
786 | Returns true if this meta-attribute should be initialized lazily through |
787 | the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will |
788 | make your attribute required and lazy. In addition it will set the builder, clearer |
789 | and predicate options for you using the following convention. |
790 | |
791 | #If your attribute name starts with an underscore: |
792 | has '_foo' => (lazy_build => 1); |
793 | #is the same as |
58f85113 |
794 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo); |
26fbace8 |
795 | # or |
58f85113 |
796 | has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo}); |
26fbace8 |
797 | |
798 | #If your attribute name does not start with an underscore: |
58f85113 |
799 | has 'foo' => (lazy_build => 1); |
800 | #is the same as |
801 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo); |
26fbace8 |
802 | # or |
58f85113 |
803 | has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo}); |
804 | |
805 | The reason for the different naming of the C<builder> is that the C<builder> |
806 | method is a private method while the C<clearer> and C<predicate> methods |
807 | are public methods. |
26fbace8 |
808 | |
809 | NOTE: This means your class should provide a method whose name matches the value |
58f85113 |
810 | of the builder part, in this case _build__foo or _build_foo. |
ca01a97b |
811 | |
34a66aa3 |
812 | =item B<should_coerce> |
4b598ea3 |
813 | |
02a0fb52 |
814 | Returns true if this meta-attribute should perform type coercion. |
6ba6d68c |
815 | |
536f0b17 |
816 | =item B<should_auto_deref> |
817 | |
26fbace8 |
818 | Returns true if this meta-attribute should perform automatic |
819 | auto-dereferencing. |
536f0b17 |
820 | |
26fbace8 |
821 | NOTE: This can only be done for attributes whose type constraint is |
536f0b17 |
822 | either I<ArrayRef> or I<HashRef>. |
823 | |
8c9d74e7 |
824 | =item B<has_trigger> |
825 | |
02a0fb52 |
826 | Returns true if this meta-attribute has a trigger set. |
827 | |
8c9d74e7 |
828 | =item B<trigger> |
829 | |
26fbace8 |
830 | This is a CODE reference which will be executed every time the |
831 | value of an attribute is assigned. The CODE ref will get two values, |
832 | the invocant and the new value. This can be used to handle I<basic> |
02a0fb52 |
833 | bi-directional relations. |
834 | |
ddbdc0cb |
835 | =item B<documentation> |
836 | |
26fbace8 |
837 | This is a string which contains the documentation for this attribute. |
ddbdc0cb |
838 | It serves no direct purpose right now, but it might in the future |
839 | in some kind of automated documentation system perhaps. |
840 | |
841 | =item B<has_documentation> |
842 | |
843 | Returns true if this meta-attribute has any documentation. |
844 | |
88f23977 |
845 | =item B<applied_traits> |
846 | |
847 | This will return the ARRAY ref of all the traits applied to this |
848 | attribute, or if no traits have been applied, it returns C<undef>. |
849 | |
850 | =item B<has_applied_traits> |
851 | |
852 | Returns true if this meta-attribute has any traits applied. |
853 | |
c0e30cf5 |
854 | =back |
855 | |
856 | =head1 BUGS |
857 | |
26fbace8 |
858 | All complex software has bugs lurking in it, and this module is no |
c0e30cf5 |
859 | exception. If you find a bug please either email me, or add the bug |
860 | to cpan-RT. |
861 | |
c0e30cf5 |
862 | =head1 AUTHOR |
863 | |
864 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
865 | |
98aae381 |
866 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
867 | |
c0e30cf5 |
868 | =head1 COPYRIGHT AND LICENSE |
869 | |
778db3ac |
870 | Copyright 2006-2008 by Infinity Interactive, Inc. |
c0e30cf5 |
871 | |
872 | L<http://www.iinteractive.com> |
873 | |
874 | This library is free software; you can redistribute it and/or modify |
26fbace8 |
875 | it under the same terms as Perl itself. |
c0e30cf5 |
876 | |
8a7a9c53 |
877 | =cut |