Commit | Line | Data |
24869f62 |
1 | |
2 | package Class::MOP::Instance; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
fa16e528 |
7 | use Scalar::Util 'weaken', 'blessed'; |
24869f62 |
8 | |
19042e4d |
9 | our $VERSION = '0.92'; |
d519662a |
10 | $VERSION = eval $VERSION; |
f0480c45 |
11 | our $AUTHORITY = 'cpan:STEVAN'; |
24869f62 |
12 | |
d7b2249e |
13 | use base 'Class::MOP::Object'; |
24869f62 |
14 | |
63d08a9e |
15 | sub BUILDARGS { |
d43737b3 |
16 | my ($class, @args) = @_; |
17 | |
18 | if ( @args == 1 ) { |
63d08a9e |
19 | unshift @args, "associated_metaclass"; |
d43737b3 |
20 | } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) { |
21 | # compat mode |
22 | my ( $meta, @attrs ) = @args; |
63d08a9e |
23 | @args = ( associated_metaclass => $meta, attributes => \@attrs ); |
d43737b3 |
24 | } |
25 | |
26 | my %options = @args; |
7c7fd869 |
27 | # FIXME lazy_build |
d43737b3 |
28 | $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ]; |
63d08a9e |
29 | $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build |
30 | |
31 | return \%options; |
32 | } |
33 | |
34 | sub new { |
35 | my $class = shift; |
36 | my $options = $class->BUILDARGS(@_); |
d43737b3 |
37 | |
38 | # FIXME replace with a proper constructor |
b4b5d65a |
39 | my $instance = $class->_new(%$options); |
40 | |
41 | # FIXME weak_ref => 1, |
42 | weaken($instance->{'associated_metaclass'}); |
43 | |
44 | return $instance; |
45 | } |
46 | |
47 | sub _new { |
ec9e38e5 |
48 | my $class = shift; |
49 | return Class::MOP::Class->initialize($class)->new_object(@_) |
50 | if $class ne __PACKAGE__; |
51 | |
52 | my $params = @_ == 1 ? $_[0] : {@_}; |
53 | return bless { |
fc3ddd1d |
54 | # NOTE: |
55 | # I am not sure that it makes |
56 | # sense to pass in the meta |
8d2d4c67 |
57 | # The ideal would be to just |
58 | # pass in the class name, but |
59 | # that is placing too much of |
60 | # an assumption on bless(), |
fc3ddd1d |
61 | # which is *probably* a safe |
8d2d4c67 |
62 | # assumption,.. but you can |
fc3ddd1d |
63 | # never tell <:) |
ec9e38e5 |
64 | 'associated_metaclass' => $params->{associated_metaclass}, |
65 | 'attributes' => $params->{attributes}, |
66 | 'slots' => $params->{slots}, |
67 | 'slot_hash' => $params->{slot_hash}, |
8d2d4c67 |
68 | } => $class; |
24869f62 |
69 | } |
70 | |
74890687 |
71 | sub _class_name { $_[0]->{_class_name} ||= $_[0]->associated_metaclass->name } |
72 | |
87cfe982 |
73 | #sub create_instance { |
74 | # my $self = shift; |
75 | # bless {}, $self->_class_name; |
76 | #} |
2d711cc8 |
77 | |
e2e260f6 |
78 | #sub clone_instance { |
79 | # my ($self, $instance) = @_; |
80 | # bless { %$instance }, $self->_class_name; |
81 | #} |
f7259199 |
82 | |
2d711cc8 |
83 | # operations on meta instance |
84 | |
eb49acde |
85 | sub get_all_slots { |
86 | my $self = shift; |
7c7fd869 |
87 | return @{$self->{'slots'}}; |
f7259199 |
88 | } |
89 | |
0b5d46da |
90 | sub get_all_attributes { |
91 | my $self = shift; |
92 | return @{$self->{attributes}}; |
93 | } |
94 | |
f7259199 |
95 | sub is_valid_slot { |
96 | my ($self, $slot_name) = @_; |
7c7fd869 |
97 | exists $self->{'slot_hash'}->{$slot_name}; |
839ea973 |
98 | } |
99 | |
2d711cc8 |
100 | # operations on created instances |
101 | |
87cfe982 |
102 | #sub get_slot_value { |
103 | # my ($self, $instance, $slot_name) = @_; |
104 | # $instance->{$slot_name}; |
105 | #} |
106 | # |
107 | #sub set_slot_value { |
108 | # my ($self, $instance, $slot_name, $value) = @_; |
109 | # $instance->{$slot_name} = $value; |
110 | #} |
2bab2be6 |
111 | |
2d711cc8 |
112 | sub initialize_slot { |
49c93440 |
113 | my ($self, $instance, $slot_name) = @_; |
a007159d |
114 | return; |
2d711cc8 |
115 | } |
116 | |
87cfe982 |
117 | #sub deinitialize_slot { |
118 | # my ( $self, $instance, $slot_name ) = @_; |
119 | # delete $instance->{$slot_name}; |
120 | #} |
7d28758b |
121 | |
c174112e |
122 | sub initialize_all_slots { |
123 | my ($self, $instance) = @_; |
124 | foreach my $slot_name ($self->get_all_slots) { |
125 | $self->initialize_slot($instance, $slot_name); |
126 | } |
127 | } |
128 | |
7d28758b |
129 | sub deinitialize_all_slots { |
130 | my ($self, $instance) = @_; |
131 | foreach my $slot_name ($self->get_all_slots) { |
132 | $self->deinitialize_slot($instance, $slot_name); |
133 | } |
134 | } |
135 | |
87cfe982 |
136 | #sub is_slot_initialized { |
137 | # my ($self, $instance, $slot_name, $value) = @_; |
138 | # exists $instance->{$slot_name}; |
139 | #} |
839ea973 |
140 | |
87cfe982 |
141 | #sub weaken_slot_value { |
142 | # my ($self, $instance, $slot_name) = @_; |
143 | # weaken $instance->{$slot_name}; |
144 | #} |
5582521c |
145 | |
146 | sub strengthen_slot_value { |
69e3ab0a |
147 | my ($self, $instance, $slot_name) = @_; |
148 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
5582521c |
149 | } |
150 | |
3d9e4646 |
151 | sub rebless_instance_structure { |
152 | my ($self, $instance, $metaclass) = @_; |
feb93c85 |
153 | |
154 | # we use $_[1] here because of t/306_rebless_overload.t regressions on 5.8.8 |
155 | bless $_[1], $metaclass->name; |
3d9e4646 |
156 | } |
157 | |
da5680be |
158 | sub is_dependent_on_superclasses { |
159 | return; # for meta instances that require updates on inherited slot changes |
160 | } |
161 | |
ee7c0467 |
162 | # inlinable operation snippets |
163 | |
c0cbf4d9 |
164 | sub is_inlinable { 1 } |
165 | |
166 | sub inline_create_instance { |
167 | my ($self, $class_variable) = @_; |
168 | 'bless {} => ' . $class_variable; |
169 | } |
170 | |
ee7c0467 |
171 | sub inline_slot_access { |
172 | my ($self, $instance, $slot_name) = @_; |
5143ee94 |
173 | sprintf q[%s->{"%s"}], $instance, quotemeta($slot_name); |
ee7c0467 |
174 | } |
175 | |
176 | sub inline_get_slot_value { |
177 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
178 | $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
179 | } |
180 | |
181 | sub inline_set_slot_value { |
182 | my ($self, $instance, $slot_name, $value) = @_; |
8d2d4c67 |
183 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
ee7c0467 |
184 | } |
185 | |
186 | sub inline_initialize_slot { |
187 | my ($self, $instance, $slot_name) = @_; |
a007159d |
188 | return ''; |
ee7c0467 |
189 | } |
190 | |
7d28758b |
191 | sub inline_deinitialize_slot { |
192 | my ($self, $instance, $slot_name) = @_; |
193 | "delete " . $self->inline_slot_access($instance, $slot_name); |
194 | } |
ee7c0467 |
195 | sub inline_is_slot_initialized { |
196 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
197 | "exists " . $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
198 | } |
199 | |
200 | sub inline_weaken_slot_value { |
201 | my ($self, $instance, $slot_name) = @_; |
202 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
203 | } |
204 | |
205 | sub inline_strengthen_slot_value { |
206 | my ($self, $instance, $slot_name) = @_; |
207 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
208 | } |
209 | |
bc3c58a0 |
210 | sub inline_rebless_instance_structure { |
211 | my ($self, $instance, $class_variable) = @_; |
212 | "bless $instance => $class_variable"; |
213 | } |
214 | |
24869f62 |
215 | 1; |
216 | |
217 | __END__ |
218 | |
219 | =pod |
220 | |
8d2d4c67 |
221 | =head1 NAME |
24869f62 |
222 | |
223 | Class::MOP::Instance - Instance Meta Object |
224 | |
24869f62 |
225 | =head1 DESCRIPTION |
226 | |
1cbf42df |
227 | The Instance Protocol controls the creation of object instances, and |
88bb3cf1 |
228 | the storage of attribute values in those instances. |
229 | |
230 | Using this API directly in your own code violates encapsulation, and |
231 | we recommend that you use the appropriate APIs in L<Class::MOP::Class> |
232 | and L<Class::MOP::Attribute> instead. Those APIs in turn call the |
233 | methods in this class as appropriate. |
234 | |
235 | This class also participates in generating inlined code by providing |
236 | snippets of code to access an object instance. |
9fa4d0b4 |
237 | |
24869f62 |
238 | =head1 METHODS |
239 | |
88bb3cf1 |
240 | =head2 Object construction |
241 | |
24869f62 |
242 | =over 4 |
243 | |
88bb3cf1 |
244 | =item B<< Class::MOP::Instance->new(%options) >> |
9fa4d0b4 |
245 | |
88bb3cf1 |
246 | This method creates a new meta-instance object. |
9fa4d0b4 |
247 | |
88bb3cf1 |
248 | It accepts the following keys in C<%options>: |
63d08a9e |
249 | |
88bb3cf1 |
250 | =over 8 |
63d08a9e |
251 | |
88bb3cf1 |
252 | =item * associated_metaclass |
9fa4d0b4 |
253 | |
88bb3cf1 |
254 | The L<Class::MOP::Class> object for which instances will be created. |
9fa4d0b4 |
255 | |
88bb3cf1 |
256 | =item * attributes |
9fa4d0b4 |
257 | |
88bb3cf1 |
258 | An array reference of L<Class::MOP::Attribute> objects. These are the |
259 | attributes which can be stored in each instance. |
9fa4d0b4 |
260 | |
88bb3cf1 |
261 | =back |
24869f62 |
262 | |
88bb3cf1 |
263 | =back |
58287a97 |
264 | |
88bb3cf1 |
265 | =head2 Creating and altering instances |
0e76a376 |
266 | |
88bb3cf1 |
267 | =over 4 |
839ea973 |
268 | |
88bb3cf1 |
269 | =item B<< $metainstance->create_instance >> |
0e76a376 |
270 | |
88bb3cf1 |
271 | This method returns a reference blessed into the associated |
272 | metaclass's class. |
becd03c6 |
273 | |
88bb3cf1 |
274 | The default is to use a hash reference. Subclasses can override this. |
f7259199 |
275 | |
88bb3cf1 |
276 | =item B<< $metainstance->clone_instance($instance) >> |
277 | |
278 | Given an instance, this method creates a new object by making |
279 | I<shallow> clone of the original. |
127d39a7 |
280 | |
9fa4d0b4 |
281 | =back |
839ea973 |
282 | |
98bf345b |
283 | =head2 Introspection |
58287a97 |
284 | |
9fa4d0b4 |
285 | =over 4 |
286 | |
88bb3cf1 |
287 | =item B<< $metainstance->associated_metaclass >> |
c23184fc |
288 | |
88bb3cf1 |
289 | This returns the L<Class::MOP::Class> object associated with the |
290 | meta-instance object. |
127d39a7 |
291 | |
88bb3cf1 |
292 | =item B<< $metainstance->get_all_slots >> |
9fa4d0b4 |
293 | |
88bb3cf1 |
294 | This returns a list of slot names stored in object instances. In |
295 | almost all cases, slot names correspond directly attribute names. |
58287a97 |
296 | |
88bb3cf1 |
297 | =item B<< $metainstance->is_valid_slot($slot_name) >> |
f7259199 |
298 | |
127d39a7 |
299 | This will return true if C<$slot_name> is a valid slot name. |
300 | |
88bb3cf1 |
301 | =item B<< $metainstance->get_all_attributes >> |
da5680be |
302 | |
88bb3cf1 |
303 | This returns a list of attributes corresponding to the attributes |
304 | passed to the constructor. |
0202ee96 |
305 | |
24869f62 |
306 | =back |
307 | |
9fa4d0b4 |
308 | =head2 Operations on Instance Structures |
309 | |
88bb3cf1 |
310 | It's important to understand that the meta-instance object is a |
311 | different entity from the actual instances it creates. For this |
312 | reason, any operations on the C<$instance_structure> always require |
313 | that the object instance be passed to the method. |
127d39a7 |
314 | |
24869f62 |
315 | =over 4 |
316 | |
88bb3cf1 |
317 | =item B<< $metainstance->get_slot_value($instance_structure, $slot_name) >> |
318 | |
319 | =item B<< $metainstance->set_slot_value($instance_structure, $slot_name, $value) >> |
24869f62 |
320 | |
88bb3cf1 |
321 | =item B<< $metainstance->initialize_slot($instance_structure, $slot_name) >> |
9fa4d0b4 |
322 | |
88bb3cf1 |
323 | =item B<< $metainstance->deinitialize_slot($instance_structure, $slot_name) >> |
9fa4d0b4 |
324 | |
88bb3cf1 |
325 | =item B<< $metainstance->initialize_all_slots($instance_structure) >> |
7d28758b |
326 | |
88bb3cf1 |
327 | =item B<< $metainstance->deinitialize_all_slots($instance_structure) >> |
9fa4d0b4 |
328 | |
88bb3cf1 |
329 | =item B<< $metainstance->is_slot_initialized($instance_structure, $slot_name) >> |
7d28758b |
330 | |
88bb3cf1 |
331 | =item B<< $metainstance->weaken_slot_value($instance_structure, $slot_name) >> |
24869f62 |
332 | |
88bb3cf1 |
333 | =item B<< $metainstance->strengthen_slot_value($instance_structure, $slot_name) >> |
ee7c0467 |
334 | |
88bb3cf1 |
335 | =item B<< $metainstance->rebless_instance_structure($instance_structure, $new_metaclass) >> |
ee7c0467 |
336 | |
88bb3cf1 |
337 | The exact details of what each method does should be fairly obvious |
338 | from the method name. |
5fdf066d |
339 | |
ee7c0467 |
340 | =back |
341 | |
88bb3cf1 |
342 | =head2 Inlinable Instance Operations |
ee7c0467 |
343 | |
344 | =over 4 |
345 | |
88bb3cf1 |
346 | =item B<< $metainstance->is_inlinable >> |
c0cbf4d9 |
347 | |
88bb3cf1 |
348 | This is a boolean that indicates whether or not slot access operations |
349 | can be inlined. By default it is true, but subclasses can override |
350 | this. |
c0cbf4d9 |
351 | |
88bb3cf1 |
352 | =item B<< $metainstance->inline_create_instance($class_variable) >> |
495af518 |
353 | |
88bb3cf1 |
354 | This method expects a string that, I<when inlined>, will become a |
355 | class name. This would literally be something like C<'$class'>, not an |
356 | actual class name. |
ee7c0467 |
357 | |
88bb3cf1 |
358 | It returns a snippet of code that creates a new object for the |
359 | class. This is something like C< bless {}, $class_name >. |
ee7c0467 |
360 | |
88bb3cf1 |
361 | =item B<< $metainstance->inline_slot_access($instance_variable, $slot_name) >> |
ee7c0467 |
362 | |
88bb3cf1 |
363 | =item B<< $metainstance->inline_get_slot_value($instance_variable, $slot_name) >> |
ee7c0467 |
364 | |
88bb3cf1 |
365 | =item B<< $metainstance->inline_set_slot_value($instance_variable, $slot_name, $value) >> |
366 | |
367 | =item B<< $metainstance->inline_initialize_slot($instance_variable, $slot_name) >> |
368 | |
369 | =item B<< $metainstance->inline_deinitialize_slot($instance_variable, $slot_name) >> |
370 | |
371 | =item B<< $metainstance->inline_is_slot_initialized($instance_variable, $slot_name) >> |
372 | |
373 | =item B<< $metainstance->inline_weaken_slot_value($instance_variable, $slot_name) >> |
374 | |
375 | =item B<< $metainstance->inline_strengthen_slot_value($instance_variable, $slot_name) >> |
376 | |
377 | These methods all expect two arguments. The first is the name of a |
378 | variable, than when inlined, will represent the object |
379 | instance. Typically this will be a literal string like C<'$_[0]'>. |
380 | |
381 | The second argument is a slot name. |
382 | |
383 | The method returns a snippet of code that, when inlined, performs some |
384 | operation on the instance. |
385 | |
0fab42eb |
386 | =item B<< $metainstance->inline_rebless_instance_structure($instance_variable, $class_variable) >> |
387 | |
388 | This takes the name of a variable that will, when inlined, represent the object |
389 | instance, and the name of a variable that will represent the class to rebless |
390 | into, and returns code to rebless an instance into a class. |
391 | |
88bb3cf1 |
392 | =back |
393 | |
e989c0df |
394 | =head2 XS Instance Operations |
395 | |
396 | =over 4 |
397 | |
398 | =item B<< $metainstance->can_xs() >> |
399 | |
400 | This is an integer that indicates the address of XS virtual table for slot accesses. |
401 | By default it returns a virtual table address to operate hash references, but subclasses |
402 | should override this. |
403 | |
404 | =back |
405 | |
88bb3cf1 |
406 | =head2 Introspection |
407 | |
408 | =over 4 |
7d28758b |
409 | |
88bb3cf1 |
410 | =item B<< Class::MOP::Instance->meta >> |
5582521c |
411 | |
88bb3cf1 |
412 | This will return a L<Class::MOP::Class> instance for this class. |
5582521c |
413 | |
88bb3cf1 |
414 | It should also be noted that L<Class::MOP> will actually bootstrap |
415 | this module by installing a number of attribute meta-objects into its |
416 | metaclass. |
5582521c |
417 | |
24869f62 |
418 | =back |
419 | |
1a09d9cc |
420 | =head1 AUTHORS |
24869f62 |
421 | |
9fa4d0b4 |
422 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
423 | |
24869f62 |
424 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
425 | |
426 | =head1 COPYRIGHT AND LICENSE |
427 | |
070bb6c9 |
428 | Copyright 2006-2009 by Infinity Interactive, Inc. |
24869f62 |
429 | |
430 | L<http://www.iinteractive.com> |
431 | |
432 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
433 | it under the same terms as Perl itself. |
24869f62 |
434 | |
84ef30d1 |
435 | =cut |
5582521c |
436 | |