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