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"; |
f8dfcfb7 |
36 | |
5659d76e |
37 | $options{init_arg} = $name |
38 | if not exists $options{init_arg}; |
2eb717d5 |
39 | |
148b4697 |
40 | (is_default_a_coderef(\%options)) |
41 | || confess("References are not allowed as default values, you must ". |
42 | "wrap then in a CODE reference (ex: sub { [] } and not [])") |
43 | if exists $options{default} && ref $options{default}; |
44 | |
8b978dd5 |
45 | bless { |
c50c603e |
46 | name => $name, |
47 | accessor => $options{accessor}, |
48 | reader => $options{reader}, |
49 | writer => $options{writer}, |
50 | predicate => $options{predicate}, |
7d28758b |
51 | clearer => $options{clearer}, |
c50c603e |
52 | init_arg => $options{init_arg}, |
9ec169fe |
53 | default => $options{default}, |
54 | # keep a weakened link to the |
55 | # class we are associated with |
56 | associated_class => undef, |
8b978dd5 |
57 | } => $class; |
58 | } |
59 | |
7b31baf4 |
60 | # NOTE: |
5659d76e |
61 | # this is a primative (and kludgy) clone operation |
16e960bd |
62 | # for now, it will be replaced in the Class::MOP |
5659d76e |
63 | # bootstrap with a proper one, however we know |
64 | # that this one will work fine for now. |
65 | sub clone { |
66 | my $self = shift; |
67 | my %options = @_; |
68 | (blessed($self)) |
69 | || confess "Can only clone an instance"; |
70 | return bless { %{$self}, %options } => blessed($self); |
71 | } |
72 | |
bd4e03f9 |
73 | sub initialize_instance_slot { |
f892c0f0 |
74 | my ($self, $meta_instance, $instance, $params) = @_; |
291073fc |
75 | my $init_arg = $self->{init_arg}; |
bd4e03f9 |
76 | # try to fetch the init arg from the %params ... |
77 | my $val; |
78 | $val = $params->{$init_arg} if exists $params->{$init_arg}; |
79 | # if nothing was in the %params, we can use the |
80 | # attribute's default value (if it has one) |
bb8dacfa |
81 | if (!defined $val && defined $self->{default}) { |
2d711cc8 |
82 | $val = $self->default($instance); |
83 | } |
43715282 |
84 | $meta_instance->set_slot_value($instance, $self->name, $val); |
bd4e03f9 |
85 | } |
86 | |
5659d76e |
87 | # NOTE: |
7b31baf4 |
88 | # the next bunch of methods will get bootstrapped |
89 | # away in the Class::MOP bootstrapping section |
90 | |
c50c603e |
91 | sub name { $_[0]->{name} } |
92 | |
7b31baf4 |
93 | sub associated_class { $_[0]->{associated_class} } |
94 | |
727919c5 |
95 | sub has_accessor { defined($_[0]->{accessor}) ? 1 : 0 } |
96 | sub has_reader { defined($_[0]->{reader}) ? 1 : 0 } |
97 | sub has_writer { defined($_[0]->{writer}) ? 1 : 0 } |
c50c603e |
98 | sub has_predicate { defined($_[0]->{predicate}) ? 1 : 0 } |
7d28758b |
99 | sub has_clearer { defined($_[0]->{clearer}) ? 1 : 0 } |
727919c5 |
100 | sub has_init_arg { defined($_[0]->{init_arg}) ? 1 : 0 } |
101 | sub has_default { defined($_[0]->{default}) ? 1 : 0 } |
c50c603e |
102 | |
103 | sub accessor { $_[0]->{accessor} } |
104 | sub reader { $_[0]->{reader} } |
105 | sub writer { $_[0]->{writer} } |
106 | sub predicate { $_[0]->{predicate} } |
7d28758b |
107 | sub clearer { $_[0]->{clearer} } |
c50c603e |
108 | sub init_arg { $_[0]->{init_arg} } |
109 | |
7b31baf4 |
110 | # end bootstrapped away method section. |
111 | # (all methods below here are kept intact) |
112 | |
c0cbf4d9 |
113 | sub is_default_a_coderef { |
1396f86b |
114 | ('CODE' eq (reftype($_[0]->{default}) || '')) |
c0cbf4d9 |
115 | } |
116 | |
c50c603e |
117 | sub default { |
c0cbf4d9 |
118 | my ($self, $instance) = @_; |
119 | if ($instance && $self->is_default_a_coderef) { |
727919c5 |
120 | # if the default is a CODE ref, then |
121 | # we pass in the instance and default |
122 | # can return a value based on that |
123 | # instance. Somewhat crude, but works. |
c0cbf4d9 |
124 | return $self->{default}->($instance); |
c50c603e |
125 | } |
126 | $self->{default}; |
127 | } |
8b978dd5 |
128 | |
c57c8b10 |
129 | # slots |
130 | |
131 | sub slots { (shift)->name } |
132 | |
9ec169fe |
133 | # class association |
727919c5 |
134 | |
9ec169fe |
135 | sub attach_to_class { |
136 | my ($self, $class) = @_; |
137 | (blessed($class) && $class->isa('Class::MOP::Class')) |
138 | || confess "You must pass a Class::MOP::Class instance (or a subclass)"; |
139 | weaken($self->{associated_class} = $class); |
140 | } |
141 | |
142 | sub detach_from_class { |
143 | my $self = shift; |
144 | $self->{associated_class} = undef; |
145 | } |
146 | |
16e960bd |
147 | ## Slot management |
148 | |
149 | sub set_value { |
1396f86b |
150 | my ($self, $instance, $value) = @_; |
16e960bd |
151 | |
152 | Class::MOP::Class->initialize(Scalar::Util::blessed($instance)) |
153 | ->get_meta_instance |
154 | ->set_slot_value( $instance, $self->name, $value ); |
155 | } |
156 | |
157 | sub get_value { |
1396f86b |
158 | my ($self, $instance) = @_; |
16e960bd |
159 | |
160 | Class::MOP::Class->initialize(Scalar::Util::blessed($instance)) |
161 | ->get_meta_instance |
1396f86b |
162 | ->get_slot_value($instance, $self->name); |
16e960bd |
163 | } |
164 | |
9ec169fe |
165 | ## Method generation helpers |
166 | |
167 | sub generate_accessor_method { |
16e960bd |
168 | my $attr = shift; |
43715282 |
169 | return sub { |
1396f86b |
170 | $attr->set_value($_[0], $_[1]) if scalar(@_) == 2; |
171 | $attr->get_value($_[0]); |
43715282 |
172 | }; |
9ec169fe |
173 | } |
174 | |
c0cbf4d9 |
175 | sub generate_accessor_method_inline { |
176 | my $self = shift; |
177 | my $attr_name = $self->name; |
178 | my $meta_instance = $self->associated_class->instance_metaclass; |
179 | |
180 | my $code = eval 'sub {' |
4d47b77f |
181 | . $meta_instance->inline_set_slot_value('$_[0]', "'$attr_name'", '$_[1]') . ' if scalar(@_) == 2; ' |
182 | . $meta_instance->inline_get_slot_value('$_[0]', "'$attr_name'") |
c0cbf4d9 |
183 | . '}'; |
184 | confess "Could not generate inline accessor because : $@" if $@; |
185 | |
186 | return $code; |
187 | } |
188 | |
9ec169fe |
189 | sub generate_reader_method { |
16e960bd |
190 | my $attr = shift; |
43715282 |
191 | return sub { |
192 | confess "Cannot assign a value to a read-only accessor" if @_ > 1; |
1396f86b |
193 | $attr->get_value($_[0]); |
43715282 |
194 | }; |
9ec169fe |
195 | } |
196 | |
c0cbf4d9 |
197 | sub generate_reader_method_inline { |
198 | my $self = shift; |
199 | my $attr_name = $self->name; |
200 | my $meta_instance = $self->associated_class->instance_metaclass; |
201 | |
202 | my $code = eval 'sub {' |
203 | . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;' |
4d47b77f |
204 | . $meta_instance->inline_get_slot_value('$_[0]', "'$attr_name'") |
c0cbf4d9 |
205 | . '}'; |
206 | confess "Could not generate inline accessor because : $@" if $@; |
207 | |
208 | return $code; |
209 | } |
210 | |
9ec169fe |
211 | sub generate_writer_method { |
16e960bd |
212 | my $attr = shift; |
213 | return sub { |
1396f86b |
214 | $attr->set_value($_[0], $_[1]); |
43715282 |
215 | }; |
9ec169fe |
216 | } |
217 | |
c0cbf4d9 |
218 | sub generate_writer_method_inline { |
219 | my $self = shift; |
220 | my $attr_name = $self->name; |
221 | my $meta_instance = $self->associated_class->instance_metaclass; |
222 | |
223 | my $code = eval 'sub {' |
4d47b77f |
224 | . $meta_instance->inline_set_slot_value('$_[0]', "'$attr_name'", '$_[1]') |
c0cbf4d9 |
225 | . '}'; |
226 | confess "Could not generate inline accessor because : $@" if $@; |
227 | |
228 | return $code; |
229 | } |
230 | |
9ec169fe |
231 | sub generate_predicate_method { |
08388f17 |
232 | my $self = shift; |
b880e0de |
233 | my $attr_name = $self->name; |
43715282 |
234 | return sub { |
235 | defined Class::MOP::Class->initialize(Scalar::Util::blessed($_[0])) |
236 | ->get_meta_instance |
237 | ->get_slot_value($_[0], $attr_name) ? 1 : 0; |
238 | }; |
9ec169fe |
239 | } |
240 | |
7d28758b |
241 | sub generate_clearer_method { |
242 | my $self = shift; |
243 | my $attr_name = $self->name; |
244 | return sub { |
245 | Class::MOP::Class->initialize(Scalar::Util::blessed($_[0])) |
246 | ->get_meta_instance |
247 | ->deinitialize_slot($_[0], $attr_name); |
248 | }; |
249 | } |
250 | |
c0cbf4d9 |
251 | sub generate_predicate_method_inline { |
252 | my $self = shift; |
253 | my $attr_name = $self->name; |
254 | my $meta_instance = $self->associated_class->instance_metaclass; |
255 | |
256 | my $code = eval 'sub {' |
4d47b77f |
257 | . 'defined ' . $meta_instance->inline_get_slot_value('$_[0]', "'$attr_name'") . ' ? 1 : 0' |
c0cbf4d9 |
258 | . '}'; |
7d28758b |
259 | confess "Could not generate inline predicate because : $@" if $@; |
260 | |
261 | return $code; |
262 | } |
263 | |
264 | sub generate_clearer_method_inline { |
265 | my $self = shift; |
266 | my $attr_name = $self->name; |
267 | my $meta_instance = $self->associated_class->instance_metaclass; |
268 | |
269 | my $code = eval 'sub {' |
270 | . $meta_instance->inline_deinitialize_slot('$_[0]', "'$attr_name'") |
271 | . '}'; |
272 | confess "Could not generate inline clearer because : $@" if $@; |
c0cbf4d9 |
273 | |
274 | return $code; |
275 | } |
276 | |
9ec169fe |
277 | sub process_accessors { |
c0cbf4d9 |
278 | my ($self, $type, $accessor, $generate_as_inline_methods) = @_; |
013b1897 |
279 | if (reftype($accessor)) { |
280 | (reftype($accessor) eq 'HASH') |
7d28758b |
281 | || confess "bad accessor/reader/writer/predicate/clearer format, must be a HASH ref"; |
4d47b77f |
282 | my ($name, $method) = %{$accessor}; |
a4258ffd |
283 | return ($name, Class::MOP::Attribute::Accessor->wrap($method)); |
2eb717d5 |
284 | } |
9ec169fe |
285 | else { |
c0cbf4d9 |
286 | my $inline_me = ($generate_as_inline_methods && $self->associated_class->instance_metaclass->is_inlinable); |
287 | my $generator = $self->can('generate_' . $type . '_method' . ($inline_me ? '_inline' : '')); |
9ec169fe |
288 | ($generator) |
289 | || confess "There is no method generator for the type='$type'"; |
290 | if (my $method = $self->$generator($self->name)) { |
a4258ffd |
291 | return ($accessor => Class::MOP::Attribute::Accessor->wrap($method)); |
9ec169fe |
292 | } |
343203ee |
293 | confess "Could not create the '$type' method for " . $self->name . " because : $@"; |
9ec169fe |
294 | } |
295 | } |
296 | |
297 | sub install_accessors { |
c0cbf4d9 |
298 | my $self = shift; |
299 | my $inline = shift; |
300 | my $class = $self->associated_class; |
c50c603e |
301 | |
9ec169fe |
302 | $class->add_method( |
c0cbf4d9 |
303 | $self->process_accessors('accessor' => $self->accessor(), $inline) |
9ec169fe |
304 | ) if $self->has_accessor(); |
305 | |
306 | $class->add_method( |
c0cbf4d9 |
307 | $self->process_accessors('reader' => $self->reader(), $inline) |
9ec169fe |
308 | ) if $self->has_reader(); |
309 | |
310 | $class->add_method( |
c0cbf4d9 |
311 | $self->process_accessors('writer' => $self->writer(), $inline) |
9ec169fe |
312 | ) if $self->has_writer(); |
313 | |
314 | $class->add_method( |
c0cbf4d9 |
315 | $self->process_accessors('predicate' => $self->predicate(), $inline) |
9ec169fe |
316 | ) if $self->has_predicate(); |
c0cbf4d9 |
317 | |
7d28758b |
318 | $class->add_method( |
319 | $self->process_accessors('clearer' => $self->clearer(), $inline) |
320 | ) if $self->has_clearer(); |
321 | |
9ec169fe |
322 | return; |
2eb717d5 |
323 | } |
324 | |
b51af7f9 |
325 | { |
326 | my $_remove_accessor = sub { |
327 | my ($accessor, $class) = @_; |
c50c603e |
328 | if (reftype($accessor) && reftype($accessor) eq 'HASH') { |
329 | ($accessor) = keys %{$accessor}; |
330 | } |
b51af7f9 |
331 | my $method = $class->get_method($accessor); |
332 | $class->remove_method($accessor) |
2eb717d5 |
333 | if (blessed($method) && $method->isa('Class::MOP::Attribute::Accessor')); |
b51af7f9 |
334 | }; |
c50c603e |
335 | |
b51af7f9 |
336 | sub remove_accessors { |
9ec169fe |
337 | my $self = shift; |
338 | $_remove_accessor->($self->accessor(), $self->associated_class()) if $self->has_accessor(); |
339 | $_remove_accessor->($self->reader(), $self->associated_class()) if $self->has_reader(); |
340 | $_remove_accessor->($self->writer(), $self->associated_class()) if $self->has_writer(); |
341 | $_remove_accessor->($self->predicate(), $self->associated_class()) if $self->has_predicate(); |
7d28758b |
342 | $_remove_accessor->($self->clearer(), $self->associated_class()) if $self->has_clearer(); |
b51af7f9 |
343 | return; |
344 | } |
345 | |
8b978dd5 |
346 | } |
347 | |
2eb717d5 |
348 | package Class::MOP::Attribute::Accessor; |
349 | |
350 | use strict; |
351 | use warnings; |
352 | |
727919c5 |
353 | use Class::MOP::Method; |
354 | |
b6164407 |
355 | our $VERSION = '0.02'; |
356 | our $AUTHORITY = 'cpan:STEVAN'; |
2eb717d5 |
357 | |
c4970aef |
358 | use base 'Class::MOP::Method'; |
2eb717d5 |
359 | |
8b978dd5 |
360 | 1; |
361 | |
362 | __END__ |
363 | |
364 | =pod |
365 | |
366 | =head1 NAME |
367 | |
368 | Class::MOP::Attribute - Attribute Meta Object |
369 | |
370 | =head1 SYNOPSIS |
371 | |
372 | Class::MOP::Attribute->new('$foo' => ( |
fe122940 |
373 | accessor => 'foo', # dual purpose get/set accessor |
374 | predicate => 'has_foo' # predicate check for defined-ness |
375 | init_arg => '-foo', # class->new will look for a -foo key |
376 | default => 'BAR IS BAZ!' # if no -foo key is provided, use this |
8b978dd5 |
377 | )); |
378 | |
379 | Class::MOP::Attribute->new('$.bar' => ( |
fe122940 |
380 | reader => 'bar', # getter |
381 | writer => 'set_bar', # setter |
382 | predicate => 'has_bar' # predicate check for defined-ness |
383 | init_arg => ':bar', # class->new will look for a :bar key |
8b978dd5 |
384 | # no default value means it is undef |
385 | )); |
386 | |
387 | =head1 DESCRIPTION |
388 | |
fe122940 |
389 | The Attribute Protocol is almost entirely an invention of this module, |
390 | and is completely optional to this MOP. This is because Perl 5 does not |
391 | have consistent notion of what is an attribute of a class. There are |
392 | so many ways in which this is done, and very few (if any) are |
393 | easily discoverable by this module. |
552e3d24 |
394 | |
395 | So, all that said, this module attempts to inject some order into this |
fe122940 |
396 | chaos, by introducing a consistent API which can be used to create |
397 | object attributes. |
552e3d24 |
398 | |
399 | =head1 METHODS |
400 | |
401 | =head2 Creation |
402 | |
403 | =over 4 |
404 | |
fe122940 |
405 | =item B<new ($name, ?%options)> |
406 | |
407 | An attribute must (at the very least), have a C<$name>. All other |
a2e85e6c |
408 | C<%options> are contained added as key-value pairs. Acceptable keys |
fe122940 |
409 | are as follows: |
410 | |
411 | =over 4 |
412 | |
413 | =item I<init_arg> |
414 | |
415 | This should be a string value representing the expected key in |
416 | an initialization hash. For instance, if we have an I<init_arg> |
417 | value of C<-foo>, then the following code will Just Work. |
418 | |
419 | MyClass->meta->construct_instance(-foo => "Hello There"); |
420 | |
7b31baf4 |
421 | In an init_arg is not assigned, it will automatically use the |
422 | value of C<$name>. |
423 | |
fe122940 |
424 | =item I<default> |
425 | |
426 | The value of this key is the default value which |
427 | C<Class::MOP::Class::construct_instance> will initialize the |
428 | attribute to. |
429 | |
430 | B<NOTE:> |
431 | If the value is a simple scalar (string or number), then it can |
432 | be just passed as is. However, if you wish to initialize it with |
433 | a HASH or ARRAY ref, then you need to wrap that inside a CODE |
434 | reference, like so: |
435 | |
436 | Class::MOP::Attribute->new('@foo' => ( |
437 | default => sub { [] }, |
438 | )); |
439 | |
440 | # or ... |
441 | |
442 | Class::MOP::Attribute->new('%foo' => ( |
443 | default => sub { {} }, |
444 | )); |
445 | |
446 | If you wish to initialize an attribute with a CODE reference |
447 | itself, then you need to wrap that in a subroutine as well, like |
448 | so: |
449 | |
450 | Class::MOP::Attribute->new('&foo' => ( |
451 | default => sub { sub { print "Hello World" } }, |
452 | )); |
453 | |
454 | And lastly, if the value of your attribute is dependent upon |
455 | some other aspect of the instance structure, then you can take |
456 | advantage of the fact that when the I<default> value is a CODE |
457 | reference, it is passed the raw (unblessed) instance structure |
458 | as it's only argument. So you can do things like this: |
459 | |
460 | Class::MOP::Attribute->new('$object_identity' => ( |
461 | default => sub { Scalar::Util::refaddr($_[0]) }, |
462 | )); |
463 | |
464 | This last feature is fairly limited as there is no gurantee of |
465 | the order of attribute initializations, so you cannot perform |
466 | any kind of dependent initializations. However, if this is |
467 | something you need, you could subclass B<Class::MOP::Class> and |
468 | this class to acheive it. However, this is currently left as |
469 | an exercise to the reader :). |
470 | |
471 | =back |
472 | |
7d28758b |
473 | The I<accessor>, I<reader>, I<writer>, I<predicate> and I<clearer> keys can |
474 | contain either; the name of the method and an appropriate default one will be |
475 | generated for you, B<or> a HASH ref containing exactly one key (which will be |
476 | used as the name of the method) and one value, which should contain a CODE |
477 | reference which will be installed as the method itself. |
59e7697f |
478 | |
479 | =over 4 |
480 | |
481 | =item I<accessor> |
482 | |
fe122940 |
483 | The I<accessor> is a standard perl-style read/write accessor. It will |
484 | return the value of the attribute, and if a value is passed as an argument, |
485 | it will assign that value to the attribute. |
486 | |
487 | B<NOTE:> |
488 | This method will properly handle the following code, by assigning an |
489 | C<undef> value to the attribute. |
490 | |
491 | $object->set_something(undef); |
492 | |
59e7697f |
493 | =item I<reader> |
494 | |
fe122940 |
495 | This is a basic read-only accessor, it will just return the value of |
496 | the attribute. |
497 | |
59e7697f |
498 | =item I<writer> |
499 | |
fe122940 |
500 | This is a basic write accessor, it accepts a single argument, and |
501 | assigns that value to the attribute. This method does not intentially |
502 | return a value, however perl will return the result of the last |
503 | expression in the subroutine, which returns in this returning the |
504 | same value that it was passed. |
59e7697f |
505 | |
fe122940 |
506 | B<NOTE:> |
507 | This method will properly handle the following code, by assigning an |
508 | C<undef> value to the attribute. |
59e7697f |
509 | |
fe122940 |
510 | $object->set_something(); |
511 | |
512 | =item I<predicate> |
513 | |
514 | This is a basic test to see if the value of the attribute is not |
515 | C<undef>. It will return true (C<1>) if the attribute's value is |
516 | defined, and false (C<0>) otherwise. |
59e7697f |
517 | |
7d28758b |
518 | =item I<clearer> |
519 | |
520 | This is the a method that will uninitialize the attr, reverting lazy values |
521 | back to their "unfulfilled" state. |
522 | |
59e7697f |
523 | =back |
552e3d24 |
524 | |
bd4e03f9 |
525 | =item B<clone (%options)> |
526 | |
527 | =item B<initialize_instance_slot ($instance, $params)> |
528 | |
552e3d24 |
529 | =back |
530 | |
16e960bd |
531 | =head2 Value management |
532 | |
533 | =over 4 |
534 | |
535 | =item set_value $instance, $value |
536 | |
537 | Set the value without going through the accessor. Note that this may be done to |
538 | even attributes with just read only accessors. |
539 | |
540 | =item get_value $instance |
541 | |
542 | Return the value without going through the accessor. Note that this may be done |
543 | even to attributes with just write only accessors. |
544 | |
545 | =back |
546 | |
552e3d24 |
547 | =head2 Informational |
548 | |
fe122940 |
549 | These are all basic read-only value accessors for the values |
550 | passed into C<new>. I think they are pretty much self-explanitory. |
551 | |
552e3d24 |
552 | =over 4 |
553 | |
554 | =item B<name> |
555 | |
556 | =item B<accessor> |
557 | |
558 | =item B<reader> |
559 | |
560 | =item B<writer> |
561 | |
c50c603e |
562 | =item B<predicate> |
563 | |
7d28758b |
564 | =item B<clearer> |
565 | |
552e3d24 |
566 | =item B<init_arg> |
567 | |
495af518 |
568 | =item B<is_default_a_coderef> |
569 | |
fe122940 |
570 | =item B<default (?$instance)> |
571 | |
572 | As noted in the documentation for C<new> above, if the I<default> |
573 | value is a CODE reference, this accessor will pass a single additional |
574 | argument C<$instance> into it and return the value. |
552e3d24 |
575 | |
c57c8b10 |
576 | =item B<slots> |
577 | |
578 | Returns a list of slots required by the attribute. This is usually |
579 | just one, which is the name of the attribute. |
580 | |
552e3d24 |
581 | =back |
582 | |
583 | =head2 Informational predicates |
584 | |
a2e85e6c |
585 | These are all basic predicate methods for the values passed into C<new>. |
fe122940 |
586 | |
552e3d24 |
587 | =over 4 |
588 | |
589 | =item B<has_accessor> |
590 | |
552e3d24 |
591 | =item B<has_reader> |
592 | |
552e3d24 |
593 | =item B<has_writer> |
594 | |
c50c603e |
595 | =item B<has_predicate> |
596 | |
7d28758b |
597 | =item B<has_clearer> |
598 | |
552e3d24 |
599 | =item B<has_init_arg> |
600 | |
552e3d24 |
601 | =item B<has_default> |
602 | |
552e3d24 |
603 | =back |
604 | |
9ec169fe |
605 | =head2 Class association |
606 | |
607 | =over 4 |
608 | |
609 | =item B<associated_class> |
610 | |
611 | =item B<attach_to_class ($class)> |
612 | |
613 | =item B<detach_from_class> |
614 | |
2d711cc8 |
615 | =item B<slot_name> |
616 | |
617 | =item B<allocate_slots> |
618 | |
619 | =item B<deallocate_slots> |
620 | |
9ec169fe |
621 | =back |
622 | |
552e3d24 |
623 | =head2 Attribute Accessor generation |
624 | |
625 | =over 4 |
626 | |
9ec169fe |
627 | =item B<install_accessors> |
2eb717d5 |
628 | |
629 | This allows the attribute to generate and install code for it's own |
a2e85e6c |
630 | I<accessor/reader/writer/predicate> methods. This is called by |
fe122940 |
631 | C<Class::MOP::Class::add_attribute>. |
2eb717d5 |
632 | |
9ec169fe |
633 | This method will call C<process_accessors> for each of the possible |
634 | method types (accessor, reader, writer & predicate). |
635 | |
636 | =item B<process_accessors ($type, $value)> |
637 | |
638 | This takes a C<$type> (accessor, reader, writer or predicate), and |
639 | a C<$value> (the value passed into the constructor for each of the |
640 | different types). It will then either generate the method itself |
641 | (using the C<generate_*_method> methods listed below) or it will |
642 | use the custom method passed through the constructor. |
643 | |
644 | =over 4 |
645 | |
08388f17 |
646 | =item B<generate_accessor_method> |
9ec169fe |
647 | |
08388f17 |
648 | =item B<generate_predicate_method> |
9ec169fe |
649 | |
7d28758b |
650 | =item B<generate_clearer_method> |
651 | |
08388f17 |
652 | =item B<generate_reader_method> |
9ec169fe |
653 | |
08388f17 |
654 | =item B<generate_writer_method> |
9ec169fe |
655 | |
656 | =back |
657 | |
495af518 |
658 | =over 4 |
659 | |
660 | =item B<generate_accessor_method_inline> |
661 | |
662 | =item B<generate_predicate_method_inline> |
663 | |
7d28758b |
664 | =item B<generate_clearer_method_inline> |
665 | |
495af518 |
666 | =item B<generate_reader_method_inline> |
667 | |
668 | =item B<generate_writer_method_inline> |
669 | |
670 | =back |
671 | |
9ec169fe |
672 | =item B<remove_accessors> |
2eb717d5 |
673 | |
674 | This allows the attribute to remove the method for it's own |
7d28758b |
675 | I<accessor/reader/writer/predicate/clearer>. This is called by |
fe122940 |
676 | C<Class::MOP::Class::remove_attribute>. |
2eb717d5 |
677 | |
678 | =back |
679 | |
680 | =head2 Introspection |
681 | |
682 | =over 4 |
552e3d24 |
683 | |
2eb717d5 |
684 | =item B<meta> |
552e3d24 |
685 | |
fe122940 |
686 | This will return a B<Class::MOP::Class> instance which is related |
687 | to this class. |
688 | |
689 | It should also be noted that B<Class::MOP> will actually bootstrap |
690 | this module by installing a number of attribute meta-objects into |
691 | it's metaclass. This will allow this class to reap all the benifits |
692 | of the MOP when subclassing it. |
693 | |
552e3d24 |
694 | =back |
695 | |
1a09d9cc |
696 | =head1 AUTHORS |
8b978dd5 |
697 | |
a2e85e6c |
698 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
8b978dd5 |
699 | |
1a09d9cc |
700 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
701 | |
8b978dd5 |
702 | =head1 COPYRIGHT AND LICENSE |
703 | |
704 | Copyright 2006 by Infinity Interactive, Inc. |
705 | |
706 | L<http://www.iinteractive.com> |
707 | |
708 | This library is free software; you can redistribute it and/or modify |
709 | it under the same terms as Perl itself. |
710 | |
16e960bd |
711 | =cut |
712 | |
7d28758b |
713 | |