Commit | Line | Data |
8b978dd5 |
1 | |
2 | package Class::MOP::Attribute; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
2eb717d5 |
7 | use Carp 'confess'; |
9ec169fe |
8 | use Scalar::Util 'blessed', 'reftype', 'weaken'; |
2eb717d5 |
9 | |
56dcfc1a |
10 | our $VERSION = '0.12'; |
f0480c45 |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
8b978dd5 |
12 | |
b1897d4d |
13 | use base 'Class::MOP::Object'; |
14 | |
727919c5 |
15 | sub meta { |
16 | require Class::MOP::Class; |
aa448b16 |
17 | Class::MOP::Class->initialize(blessed($_[0]) || $_[0]); |
727919c5 |
18 | } |
2eb717d5 |
19 | |
727919c5 |
20 | # NOTE: (meta-circularity) |
16e960bd |
21 | # This method will be replaced in the |
727919c5 |
22 | # boostrap section of Class::MOP, by |
23 | # a new version which uses the |
24 | # &Class::MOP::Class::construct_instance |
25 | # method to build an attribute meta-object |
26 | # which itself is described with attribute |
27 | # meta-objects. |
28 | # - Ain't meta-circularity grand? :) |
8b978dd5 |
29 | sub new { |
30 | my $class = shift; |
31 | my $name = shift; |
32 | my %options = @_; |
33 | |
cbd9f942 |
34 | (defined $name && $name) |
8b978dd5 |
35 | || confess "You must provide a name for the attribute"; |
5659d76e |
36 | $options{init_arg} = $name |
37 | if not exists $options{init_arg}; |
2eb717d5 |
38 | |
148b4697 |
39 | (is_default_a_coderef(\%options)) |
40 | || confess("References are not allowed as default values, you must ". |
41 | "wrap then in a CODE reference (ex: sub { [] } and not [])") |
42 | if exists $options{default} && ref $options{default}; |
43 | |
8b978dd5 |
44 | bless { |
c50c603e |
45 | name => $name, |
46 | accessor => $options{accessor}, |
47 | reader => $options{reader}, |
48 | writer => $options{writer}, |
49 | predicate => $options{predicate}, |
7d28758b |
50 | clearer => $options{clearer}, |
c50c603e |
51 | init_arg => $options{init_arg}, |
9ec169fe |
52 | default => $options{default}, |
53 | # keep a weakened link to the |
54 | # class we are associated with |
55 | associated_class => undef, |
8b978dd5 |
56 | } => $class; |
57 | } |
58 | |
7b31baf4 |
59 | # NOTE: |
5659d76e |
60 | # this is a primative (and kludgy) clone operation |
16e960bd |
61 | # for now, it will be replaced in the Class::MOP |
5659d76e |
62 | # bootstrap with a proper one, however we know |
63 | # that this one will work fine for now. |
64 | sub clone { |
65 | my $self = shift; |
66 | my %options = @_; |
67 | (blessed($self)) |
68 | || confess "Can only clone an instance"; |
69 | return bless { %{$self}, %options } => blessed($self); |
70 | } |
71 | |
bd4e03f9 |
72 | sub initialize_instance_slot { |
f892c0f0 |
73 | my ($self, $meta_instance, $instance, $params) = @_; |
291073fc |
74 | my $init_arg = $self->{init_arg}; |
bd4e03f9 |
75 | # try to fetch the init arg from the %params ... |
76 | my $val; |
77 | $val = $params->{$init_arg} if exists $params->{$init_arg}; |
78 | # if nothing was in the %params, we can use the |
79 | # attribute's default value (if it has one) |
bb8dacfa |
80 | if (!defined $val && defined $self->{default}) { |
2d711cc8 |
81 | $val = $self->default($instance); |
82 | } |
43715282 |
83 | $meta_instance->set_slot_value($instance, $self->name, $val); |
bd4e03f9 |
84 | } |
85 | |
5659d76e |
86 | # NOTE: |
7b31baf4 |
87 | # the next bunch of methods will get bootstrapped |
88 | # away in the Class::MOP bootstrapping section |
89 | |
c50c603e |
90 | sub name { $_[0]->{name} } |
91 | |
7b31baf4 |
92 | sub associated_class { $_[0]->{associated_class} } |
93 | |
727919c5 |
94 | sub has_accessor { defined($_[0]->{accessor}) ? 1 : 0 } |
95 | sub has_reader { defined($_[0]->{reader}) ? 1 : 0 } |
96 | sub has_writer { defined($_[0]->{writer}) ? 1 : 0 } |
c50c603e |
97 | sub has_predicate { defined($_[0]->{predicate}) ? 1 : 0 } |
7d28758b |
98 | sub has_clearer { defined($_[0]->{clearer}) ? 1 : 0 } |
727919c5 |
99 | sub has_init_arg { defined($_[0]->{init_arg}) ? 1 : 0 } |
100 | sub has_default { defined($_[0]->{default}) ? 1 : 0 } |
c50c603e |
101 | |
102 | sub accessor { $_[0]->{accessor} } |
103 | sub reader { $_[0]->{reader} } |
104 | sub writer { $_[0]->{writer} } |
105 | sub predicate { $_[0]->{predicate} } |
7d28758b |
106 | sub clearer { $_[0]->{clearer} } |
c50c603e |
107 | sub init_arg { $_[0]->{init_arg} } |
108 | |
7b31baf4 |
109 | # end bootstrapped away method section. |
110 | # (all methods below here are kept intact) |
111 | |
c0cbf4d9 |
112 | sub is_default_a_coderef { |
1396f86b |
113 | ('CODE' eq (reftype($_[0]->{default}) || '')) |
c0cbf4d9 |
114 | } |
115 | |
c50c603e |
116 | sub default { |
c0cbf4d9 |
117 | my ($self, $instance) = @_; |
118 | if ($instance && $self->is_default_a_coderef) { |
727919c5 |
119 | # if the default is a CODE ref, then |
120 | # we pass in the instance and default |
121 | # can return a value based on that |
122 | # instance. Somewhat crude, but works. |
c0cbf4d9 |
123 | return $self->{default}->($instance); |
c50c603e |
124 | } |
125 | $self->{default}; |
126 | } |
8b978dd5 |
127 | |
c57c8b10 |
128 | # slots |
129 | |
130 | sub slots { (shift)->name } |
131 | |
9ec169fe |
132 | # class association |
727919c5 |
133 | |
9ec169fe |
134 | sub attach_to_class { |
135 | my ($self, $class) = @_; |
136 | (blessed($class) && $class->isa('Class::MOP::Class')) |
137 | || confess "You must pass a Class::MOP::Class instance (or a subclass)"; |
138 | weaken($self->{associated_class} = $class); |
139 | } |
140 | |
141 | sub detach_from_class { |
142 | my $self = shift; |
143 | $self->{associated_class} = undef; |
144 | } |
145 | |
16e960bd |
146 | ## Slot management |
147 | |
148 | sub set_value { |
1396f86b |
149 | my ($self, $instance, $value) = @_; |
16e960bd |
150 | |
151 | Class::MOP::Class->initialize(Scalar::Util::blessed($instance)) |
152 | ->get_meta_instance |
153 | ->set_slot_value( $instance, $self->name, $value ); |
154 | } |
155 | |
156 | sub get_value { |
1396f86b |
157 | my ($self, $instance) = @_; |
16e960bd |
158 | |
159 | Class::MOP::Class->initialize(Scalar::Util::blessed($instance)) |
160 | ->get_meta_instance |
1396f86b |
161 | ->get_slot_value($instance, $self->name); |
16e960bd |
162 | } |
163 | |
9ec169fe |
164 | ## Method generation helpers |
165 | |
166 | sub generate_accessor_method { |
16e960bd |
167 | my $attr = shift; |
43715282 |
168 | return sub { |
1396f86b |
169 | $attr->set_value($_[0], $_[1]) if scalar(@_) == 2; |
170 | $attr->get_value($_[0]); |
43715282 |
171 | }; |
9ec169fe |
172 | } |
173 | |
c0cbf4d9 |
174 | sub generate_accessor_method_inline { |
175 | my $self = shift; |
176 | my $attr_name = $self->name; |
177 | my $meta_instance = $self->associated_class->instance_metaclass; |
178 | |
179 | my $code = eval 'sub {' |
4d47b77f |
180 | . $meta_instance->inline_set_slot_value('$_[0]', "'$attr_name'", '$_[1]') . ' if scalar(@_) == 2; ' |
181 | . $meta_instance->inline_get_slot_value('$_[0]', "'$attr_name'") |
c0cbf4d9 |
182 | . '}'; |
183 | confess "Could not generate inline accessor because : $@" if $@; |
184 | |
185 | return $code; |
186 | } |
187 | |
9ec169fe |
188 | sub generate_reader_method { |
16e960bd |
189 | my $attr = shift; |
43715282 |
190 | return sub { |
191 | confess "Cannot assign a value to a read-only accessor" if @_ > 1; |
1396f86b |
192 | $attr->get_value($_[0]); |
43715282 |
193 | }; |
9ec169fe |
194 | } |
195 | |
c0cbf4d9 |
196 | sub generate_reader_method_inline { |
197 | my $self = shift; |
198 | my $attr_name = $self->name; |
199 | my $meta_instance = $self->associated_class->instance_metaclass; |
200 | |
201 | my $code = eval 'sub {' |
202 | . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;' |
4d47b77f |
203 | . $meta_instance->inline_get_slot_value('$_[0]', "'$attr_name'") |
c0cbf4d9 |
204 | . '}'; |
205 | confess "Could not generate inline accessor because : $@" if $@; |
206 | |
207 | return $code; |
208 | } |
209 | |
9ec169fe |
210 | sub generate_writer_method { |
16e960bd |
211 | my $attr = shift; |
212 | return sub { |
1396f86b |
213 | $attr->set_value($_[0], $_[1]); |
43715282 |
214 | }; |
9ec169fe |
215 | } |
216 | |
c0cbf4d9 |
217 | sub generate_writer_method_inline { |
218 | my $self = shift; |
219 | my $attr_name = $self->name; |
220 | my $meta_instance = $self->associated_class->instance_metaclass; |
221 | |
222 | my $code = eval 'sub {' |
4d47b77f |
223 | . $meta_instance->inline_set_slot_value('$_[0]', "'$attr_name'", '$_[1]') |
c0cbf4d9 |
224 | . '}'; |
225 | confess "Could not generate inline accessor because : $@" if $@; |
226 | |
227 | return $code; |
228 | } |
229 | |
9ec169fe |
230 | sub generate_predicate_method { |
08388f17 |
231 | my $self = shift; |
b880e0de |
232 | my $attr_name = $self->name; |
43715282 |
233 | return sub { |
234 | defined Class::MOP::Class->initialize(Scalar::Util::blessed($_[0])) |
235 | ->get_meta_instance |
236 | ->get_slot_value($_[0], $attr_name) ? 1 : 0; |
237 | }; |
9ec169fe |
238 | } |
239 | |
7d28758b |
240 | sub generate_clearer_method { |
241 | my $self = shift; |
242 | my $attr_name = $self->name; |
243 | return sub { |
244 | Class::MOP::Class->initialize(Scalar::Util::blessed($_[0])) |
245 | ->get_meta_instance |
246 | ->deinitialize_slot($_[0], $attr_name); |
247 | }; |
248 | } |
249 | |
c0cbf4d9 |
250 | sub generate_predicate_method_inline { |
251 | my $self = shift; |
252 | my $attr_name = $self->name; |
253 | my $meta_instance = $self->associated_class->instance_metaclass; |
254 | |
255 | my $code = eval 'sub {' |
4d47b77f |
256 | . 'defined ' . $meta_instance->inline_get_slot_value('$_[0]', "'$attr_name'") . ' ? 1 : 0' |
c0cbf4d9 |
257 | . '}'; |
7d28758b |
258 | confess "Could not generate inline predicate because : $@" if $@; |
259 | |
260 | return $code; |
261 | } |
262 | |
263 | sub generate_clearer_method_inline { |
264 | my $self = shift; |
265 | my $attr_name = $self->name; |
266 | my $meta_instance = $self->associated_class->instance_metaclass; |
267 | |
268 | my $code = eval 'sub {' |
269 | . $meta_instance->inline_deinitialize_slot('$_[0]', "'$attr_name'") |
270 | . '}'; |
271 | confess "Could not generate inline clearer because : $@" if $@; |
c0cbf4d9 |
272 | |
273 | return $code; |
274 | } |
275 | |
9ec169fe |
276 | sub process_accessors { |
c0cbf4d9 |
277 | my ($self, $type, $accessor, $generate_as_inline_methods) = @_; |
013b1897 |
278 | if (reftype($accessor)) { |
279 | (reftype($accessor) eq 'HASH') |
7d28758b |
280 | || confess "bad accessor/reader/writer/predicate/clearer format, must be a HASH ref"; |
4d47b77f |
281 | my ($name, $method) = %{$accessor}; |
a4258ffd |
282 | return ($name, Class::MOP::Attribute::Accessor->wrap($method)); |
2eb717d5 |
283 | } |
9ec169fe |
284 | else { |
c0cbf4d9 |
285 | my $inline_me = ($generate_as_inline_methods && $self->associated_class->instance_metaclass->is_inlinable); |
286 | my $generator = $self->can('generate_' . $type . '_method' . ($inline_me ? '_inline' : '')); |
9ec169fe |
287 | ($generator) |
288 | || confess "There is no method generator for the type='$type'"; |
289 | if (my $method = $self->$generator($self->name)) { |
a4258ffd |
290 | return ($accessor => Class::MOP::Attribute::Accessor->wrap($method)); |
9ec169fe |
291 | } |
343203ee |
292 | confess "Could not create the '$type' method for " . $self->name . " because : $@"; |
9ec169fe |
293 | } |
294 | } |
295 | |
296 | sub install_accessors { |
c0cbf4d9 |
297 | my $self = shift; |
298 | my $inline = shift; |
299 | my $class = $self->associated_class; |
c50c603e |
300 | |
9ec169fe |
301 | $class->add_method( |
c0cbf4d9 |
302 | $self->process_accessors('accessor' => $self->accessor(), $inline) |
9ec169fe |
303 | ) if $self->has_accessor(); |
304 | |
305 | $class->add_method( |
c0cbf4d9 |
306 | $self->process_accessors('reader' => $self->reader(), $inline) |
9ec169fe |
307 | ) if $self->has_reader(); |
308 | |
309 | $class->add_method( |
c0cbf4d9 |
310 | $self->process_accessors('writer' => $self->writer(), $inline) |
9ec169fe |
311 | ) if $self->has_writer(); |
312 | |
313 | $class->add_method( |
c0cbf4d9 |
314 | $self->process_accessors('predicate' => $self->predicate(), $inline) |
9ec169fe |
315 | ) if $self->has_predicate(); |
c0cbf4d9 |
316 | |
7d28758b |
317 | $class->add_method( |
318 | $self->process_accessors('clearer' => $self->clearer(), $inline) |
319 | ) if $self->has_clearer(); |
320 | |
9ec169fe |
321 | return; |
2eb717d5 |
322 | } |
323 | |
b51af7f9 |
324 | { |
325 | my $_remove_accessor = sub { |
326 | my ($accessor, $class) = @_; |
c50c603e |
327 | if (reftype($accessor) && reftype($accessor) eq 'HASH') { |
328 | ($accessor) = keys %{$accessor}; |
329 | } |
b51af7f9 |
330 | my $method = $class->get_method($accessor); |
331 | $class->remove_method($accessor) |
2eb717d5 |
332 | if (blessed($method) && $method->isa('Class::MOP::Attribute::Accessor')); |
b51af7f9 |
333 | }; |
c50c603e |
334 | |
b51af7f9 |
335 | sub remove_accessors { |
9ec169fe |
336 | my $self = shift; |
337 | $_remove_accessor->($self->accessor(), $self->associated_class()) if $self->has_accessor(); |
338 | $_remove_accessor->($self->reader(), $self->associated_class()) if $self->has_reader(); |
339 | $_remove_accessor->($self->writer(), $self->associated_class()) if $self->has_writer(); |
340 | $_remove_accessor->($self->predicate(), $self->associated_class()) if $self->has_predicate(); |
7d28758b |
341 | $_remove_accessor->($self->clearer(), $self->associated_class()) if $self->has_clearer(); |
b51af7f9 |
342 | return; |
343 | } |
344 | |
8b978dd5 |
345 | } |
346 | |
2eb717d5 |
347 | package Class::MOP::Attribute::Accessor; |
348 | |
349 | use strict; |
350 | use warnings; |
351 | |
727919c5 |
352 | use Class::MOP::Method; |
353 | |
b6164407 |
354 | our $VERSION = '0.02'; |
355 | our $AUTHORITY = 'cpan:STEVAN'; |
2eb717d5 |
356 | |
c4970aef |
357 | use base 'Class::MOP::Method'; |
2eb717d5 |
358 | |
8b978dd5 |
359 | 1; |
360 | |
361 | __END__ |
362 | |
363 | =pod |
364 | |
365 | =head1 NAME |
366 | |
367 | Class::MOP::Attribute - Attribute Meta Object |
368 | |
369 | =head1 SYNOPSIS |
370 | |
371 | Class::MOP::Attribute->new('$foo' => ( |
fe122940 |
372 | accessor => 'foo', # dual purpose get/set accessor |
373 | predicate => 'has_foo' # predicate check for defined-ness |
374 | init_arg => '-foo', # class->new will look for a -foo key |
375 | default => 'BAR IS BAZ!' # if no -foo key is provided, use this |
8b978dd5 |
376 | )); |
377 | |
378 | Class::MOP::Attribute->new('$.bar' => ( |
fe122940 |
379 | reader => 'bar', # getter |
380 | writer => 'set_bar', # setter |
381 | predicate => 'has_bar' # predicate check for defined-ness |
382 | init_arg => ':bar', # class->new will look for a :bar key |
8b978dd5 |
383 | # no default value means it is undef |
384 | )); |
385 | |
386 | =head1 DESCRIPTION |
387 | |
fe122940 |
388 | The Attribute Protocol is almost entirely an invention of this module, |
389 | and is completely optional to this MOP. This is because Perl 5 does not |
390 | have consistent notion of what is an attribute of a class. There are |
391 | so many ways in which this is done, and very few (if any) are |
392 | easily discoverable by this module. |
552e3d24 |
393 | |
394 | So, all that said, this module attempts to inject some order into this |
fe122940 |
395 | chaos, by introducing a consistent API which can be used to create |
396 | object attributes. |
552e3d24 |
397 | |
398 | =head1 METHODS |
399 | |
400 | =head2 Creation |
401 | |
402 | =over 4 |
403 | |
fe122940 |
404 | =item B<new ($name, ?%options)> |
405 | |
406 | An attribute must (at the very least), have a C<$name>. All other |
a2e85e6c |
407 | C<%options> are contained added as key-value pairs. Acceptable keys |
fe122940 |
408 | are as follows: |
409 | |
410 | =over 4 |
411 | |
412 | =item I<init_arg> |
413 | |
414 | This should be a string value representing the expected key in |
415 | an initialization hash. For instance, if we have an I<init_arg> |
416 | value of C<-foo>, then the following code will Just Work. |
417 | |
418 | MyClass->meta->construct_instance(-foo => "Hello There"); |
419 | |
7b31baf4 |
420 | In an init_arg is not assigned, it will automatically use the |
421 | value of C<$name>. |
422 | |
fe122940 |
423 | =item I<default> |
424 | |
425 | The value of this key is the default value which |
426 | C<Class::MOP::Class::construct_instance> will initialize the |
427 | attribute to. |
428 | |
429 | B<NOTE:> |
430 | If the value is a simple scalar (string or number), then it can |
431 | be just passed as is. However, if you wish to initialize it with |
432 | a HASH or ARRAY ref, then you need to wrap that inside a CODE |
433 | reference, like so: |
434 | |
435 | Class::MOP::Attribute->new('@foo' => ( |
436 | default => sub { [] }, |
437 | )); |
438 | |
439 | # or ... |
440 | |
441 | Class::MOP::Attribute->new('%foo' => ( |
442 | default => sub { {} }, |
443 | )); |
444 | |
445 | If you wish to initialize an attribute with a CODE reference |
446 | itself, then you need to wrap that in a subroutine as well, like |
447 | so: |
448 | |
449 | Class::MOP::Attribute->new('&foo' => ( |
450 | default => sub { sub { print "Hello World" } }, |
451 | )); |
452 | |
453 | And lastly, if the value of your attribute is dependent upon |
454 | some other aspect of the instance structure, then you can take |
455 | advantage of the fact that when the I<default> value is a CODE |
456 | reference, it is passed the raw (unblessed) instance structure |
457 | as it's only argument. So you can do things like this: |
458 | |
459 | Class::MOP::Attribute->new('$object_identity' => ( |
460 | default => sub { Scalar::Util::refaddr($_[0]) }, |
461 | )); |
462 | |
463 | This last feature is fairly limited as there is no gurantee of |
464 | the order of attribute initializations, so you cannot perform |
465 | any kind of dependent initializations. However, if this is |
466 | something you need, you could subclass B<Class::MOP::Class> and |
467 | this class to acheive it. However, this is currently left as |
468 | an exercise to the reader :). |
469 | |
470 | =back |
471 | |
7d28758b |
472 | The I<accessor>, I<reader>, I<writer>, I<predicate> and I<clearer> keys can |
473 | contain either; the name of the method and an appropriate default one will be |
474 | generated for you, B<or> a HASH ref containing exactly one key (which will be |
475 | used as the name of the method) and one value, which should contain a CODE |
476 | reference which will be installed as the method itself. |
59e7697f |
477 | |
478 | =over 4 |
479 | |
480 | =item I<accessor> |
481 | |
fe122940 |
482 | The I<accessor> is a standard perl-style read/write accessor. It will |
483 | return the value of the attribute, and if a value is passed as an argument, |
484 | it will assign that value to the attribute. |
485 | |
486 | B<NOTE:> |
487 | This method will properly handle the following code, by assigning an |
488 | C<undef> value to the attribute. |
489 | |
490 | $object->set_something(undef); |
491 | |
59e7697f |
492 | =item I<reader> |
493 | |
fe122940 |
494 | This is a basic read-only accessor, it will just return the value of |
495 | the attribute. |
496 | |
59e7697f |
497 | =item I<writer> |
498 | |
fe122940 |
499 | This is a basic write accessor, it accepts a single argument, and |
500 | assigns that value to the attribute. This method does not intentially |
501 | return a value, however perl will return the result of the last |
502 | expression in the subroutine, which returns in this returning the |
503 | same value that it was passed. |
59e7697f |
504 | |
fe122940 |
505 | B<NOTE:> |
506 | This method will properly handle the following code, by assigning an |
507 | C<undef> value to the attribute. |
59e7697f |
508 | |
fe122940 |
509 | $object->set_something(); |
510 | |
511 | =item I<predicate> |
512 | |
513 | This is a basic test to see if the value of the attribute is not |
514 | C<undef>. It will return true (C<1>) if the attribute's value is |
515 | defined, and false (C<0>) otherwise. |
59e7697f |
516 | |
7d28758b |
517 | =item I<clearer> |
518 | |
519 | This is the a method that will uninitialize the attr, reverting lazy values |
520 | back to their "unfulfilled" state. |
521 | |
59e7697f |
522 | =back |
552e3d24 |
523 | |
bd4e03f9 |
524 | =item B<clone (%options)> |
525 | |
526 | =item B<initialize_instance_slot ($instance, $params)> |
527 | |
552e3d24 |
528 | =back |
529 | |
16e960bd |
530 | =head2 Value management |
531 | |
532 | =over 4 |
533 | |
534 | =item set_value $instance, $value |
535 | |
536 | Set the value without going through the accessor. Note that this may be done to |
537 | even attributes with just read only accessors. |
538 | |
539 | =item get_value $instance |
540 | |
541 | Return the value without going through the accessor. Note that this may be done |
542 | even to attributes with just write only accessors. |
543 | |
544 | =back |
545 | |
552e3d24 |
546 | =head2 Informational |
547 | |
fe122940 |
548 | These are all basic read-only value accessors for the values |
549 | passed into C<new>. I think they are pretty much self-explanitory. |
550 | |
552e3d24 |
551 | =over 4 |
552 | |
553 | =item B<name> |
554 | |
555 | =item B<accessor> |
556 | |
557 | =item B<reader> |
558 | |
559 | =item B<writer> |
560 | |
c50c603e |
561 | =item B<predicate> |
562 | |
7d28758b |
563 | =item B<clearer> |
564 | |
552e3d24 |
565 | =item B<init_arg> |
566 | |
495af518 |
567 | =item B<is_default_a_coderef> |
568 | |
fe122940 |
569 | =item B<default (?$instance)> |
570 | |
571 | As noted in the documentation for C<new> above, if the I<default> |
572 | value is a CODE reference, this accessor will pass a single additional |
573 | argument C<$instance> into it and return the value. |
552e3d24 |
574 | |
c57c8b10 |
575 | =item B<slots> |
576 | |
577 | Returns a list of slots required by the attribute. This is usually |
578 | just one, which is the name of the attribute. |
579 | |
552e3d24 |
580 | =back |
581 | |
582 | =head2 Informational predicates |
583 | |
a2e85e6c |
584 | These are all basic predicate methods for the values passed into C<new>. |
fe122940 |
585 | |
552e3d24 |
586 | =over 4 |
587 | |
588 | =item B<has_accessor> |
589 | |
552e3d24 |
590 | =item B<has_reader> |
591 | |
552e3d24 |
592 | =item B<has_writer> |
593 | |
c50c603e |
594 | =item B<has_predicate> |
595 | |
7d28758b |
596 | =item B<has_clearer> |
597 | |
552e3d24 |
598 | =item B<has_init_arg> |
599 | |
552e3d24 |
600 | =item B<has_default> |
601 | |
552e3d24 |
602 | =back |
603 | |
9ec169fe |
604 | =head2 Class association |
605 | |
606 | =over 4 |
607 | |
608 | =item B<associated_class> |
609 | |
610 | =item B<attach_to_class ($class)> |
611 | |
612 | =item B<detach_from_class> |
613 | |
2d711cc8 |
614 | =item B<slot_name> |
615 | |
616 | =item B<allocate_slots> |
617 | |
618 | =item B<deallocate_slots> |
619 | |
9ec169fe |
620 | =back |
621 | |
552e3d24 |
622 | =head2 Attribute Accessor generation |
623 | |
624 | =over 4 |
625 | |
9ec169fe |
626 | =item B<install_accessors> |
2eb717d5 |
627 | |
628 | This allows the attribute to generate and install code for it's own |
a2e85e6c |
629 | I<accessor/reader/writer/predicate> methods. This is called by |
fe122940 |
630 | C<Class::MOP::Class::add_attribute>. |
2eb717d5 |
631 | |
9ec169fe |
632 | This method will call C<process_accessors> for each of the possible |
633 | method types (accessor, reader, writer & predicate). |
634 | |
635 | =item B<process_accessors ($type, $value)> |
636 | |
637 | This takes a C<$type> (accessor, reader, writer or predicate), and |
638 | a C<$value> (the value passed into the constructor for each of the |
639 | different types). It will then either generate the method itself |
640 | (using the C<generate_*_method> methods listed below) or it will |
641 | use the custom method passed through the constructor. |
642 | |
643 | =over 4 |
644 | |
08388f17 |
645 | =item B<generate_accessor_method> |
9ec169fe |
646 | |
08388f17 |
647 | =item B<generate_predicate_method> |
9ec169fe |
648 | |
7d28758b |
649 | =item B<generate_clearer_method> |
650 | |
08388f17 |
651 | =item B<generate_reader_method> |
9ec169fe |
652 | |
08388f17 |
653 | =item B<generate_writer_method> |
9ec169fe |
654 | |
655 | =back |
656 | |
495af518 |
657 | =over 4 |
658 | |
659 | =item B<generate_accessor_method_inline> |
660 | |
661 | =item B<generate_predicate_method_inline> |
662 | |
7d28758b |
663 | =item B<generate_clearer_method_inline> |
664 | |
495af518 |
665 | =item B<generate_reader_method_inline> |
666 | |
667 | =item B<generate_writer_method_inline> |
668 | |
669 | =back |
670 | |
9ec169fe |
671 | =item B<remove_accessors> |
2eb717d5 |
672 | |
673 | This allows the attribute to remove the method for it's own |
7d28758b |
674 | I<accessor/reader/writer/predicate/clearer>. This is called by |
fe122940 |
675 | C<Class::MOP::Class::remove_attribute>. |
2eb717d5 |
676 | |
677 | =back |
678 | |
679 | =head2 Introspection |
680 | |
681 | =over 4 |
552e3d24 |
682 | |
2eb717d5 |
683 | =item B<meta> |
552e3d24 |
684 | |
fe122940 |
685 | This will return a B<Class::MOP::Class> instance which is related |
686 | to this class. |
687 | |
688 | It should also be noted that B<Class::MOP> will actually bootstrap |
689 | this module by installing a number of attribute meta-objects into |
690 | it's metaclass. This will allow this class to reap all the benifits |
691 | of the MOP when subclassing it. |
692 | |
552e3d24 |
693 | =back |
694 | |
1a09d9cc |
695 | =head1 AUTHORS |
8b978dd5 |
696 | |
a2e85e6c |
697 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
8b978dd5 |
698 | |
1a09d9cc |
699 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
700 | |
8b978dd5 |
701 | =head1 COPYRIGHT AND LICENSE |
702 | |
703 | Copyright 2006 by Infinity Interactive, Inc. |
704 | |
705 | L<http://www.iinteractive.com> |
706 | |
707 | This library is free software; you can redistribute it and/or modify |
708 | it under the same terms as Perl itself. |
709 | |
16e960bd |
710 | =cut |
711 | |
7d28758b |
712 | |