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 | |
2e5c1a3f |
9 | our $VERSION = '0.65'; |
f0480c45 |
10 | our $AUTHORITY = 'cpan:STEVAN'; |
24869f62 |
11 | |
d7b2249e |
12 | use base 'Class::MOP::Object'; |
24869f62 |
13 | |
63d08a9e |
14 | sub BUILDARGS { |
d43737b3 |
15 | my ($class, @args) = @_; |
16 | |
17 | if ( @args == 1 ) { |
63d08a9e |
18 | unshift @args, "associated_metaclass"; |
d43737b3 |
19 | } elsif ( @args >= 2 && blessed($args[0]) && $args[0]->isa("Class::MOP::Class") ) { |
20 | # compat mode |
21 | my ( $meta, @attrs ) = @args; |
63d08a9e |
22 | @args = ( associated_metaclass => $meta, attributes => \@attrs ); |
d43737b3 |
23 | } |
24 | |
25 | my %options = @args; |
7c7fd869 |
26 | # FIXME lazy_build |
d43737b3 |
27 | $options{slots} ||= [ map { $_->slots } @{ $options{attributes} || [] } ]; |
63d08a9e |
28 | $options{slot_hash} = { map { $_ => undef } @{ $options{slots} } }; # FIXME lazy_build |
29 | |
30 | return \%options; |
31 | } |
32 | |
33 | sub new { |
34 | my $class = shift; |
35 | my $options = $class->BUILDARGS(@_); |
d43737b3 |
36 | |
37 | # FIXME replace with a proper constructor |
c23184fc |
38 | my $instance = bless { |
fc3ddd1d |
39 | # NOTE: |
40 | # I am not sure that it makes |
41 | # sense to pass in the meta |
8d2d4c67 |
42 | # The ideal would be to just |
43 | # pass in the class name, but |
44 | # that is placing too much of |
45 | # an assumption on bless(), |
fc3ddd1d |
46 | # which is *probably* a safe |
8d2d4c67 |
47 | # assumption,.. but you can |
fc3ddd1d |
48 | # never tell <:) |
63d08a9e |
49 | 'associated_metaclass' => $options->{associated_metaclass}, |
74890687 |
50 | 'attributes' => $options->{attributes}, |
51 | 'slots' => $options->{slots}, |
52 | 'slot_hash' => $options->{slot_hash}, |
8d2d4c67 |
53 | } => $class; |
54 | |
d43737b3 |
55 | # FIXME weak_ref => 1, |
63d08a9e |
56 | weaken($instance->{'associated_metaclass'}); |
8d2d4c67 |
57 | |
c23184fc |
58 | return $instance; |
24869f62 |
59 | } |
60 | |
74890687 |
61 | sub _class_name { $_[0]->{_class_name} ||= $_[0]->associated_metaclass->name } |
62 | |
63 | sub associated_metaclass { $_[0]{'associated_metaclass'} } |
c23184fc |
64 | |
49c93440 |
65 | sub create_instance { |
66 | my $self = shift; |
becd03c6 |
67 | bless {}, $self->_class_name; |
2d711cc8 |
68 | } |
69 | |
becd03c6 |
70 | # for compatibility |
49c93440 |
71 | sub bless_instance_structure { |
72 | my ($self, $instance_structure) = @_; |
74890687 |
73 | bless $instance_structure, $self->_class_name; |
2d711cc8 |
74 | } |
75 | |
f7259199 |
76 | sub clone_instance { |
77 | my ($self, $instance) = @_; |
becd03c6 |
78 | bless { %$instance }, $self->_class_name; |
f7259199 |
79 | } |
80 | |
2d711cc8 |
81 | # operations on meta instance |
82 | |
eb49acde |
83 | sub get_all_slots { |
84 | my $self = shift; |
7c7fd869 |
85 | return @{$self->{'slots'}}; |
f7259199 |
86 | } |
87 | |
88 | sub is_valid_slot { |
89 | my ($self, $slot_name) = @_; |
7c7fd869 |
90 | exists $self->{'slot_hash'}->{$slot_name}; |
839ea973 |
91 | } |
92 | |
2d711cc8 |
93 | # operations on created instances |
94 | |
839ea973 |
95 | sub get_slot_value { |
2bab2be6 |
96 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
97 | $instance->{$slot_name}; |
839ea973 |
98 | } |
99 | |
2bab2be6 |
100 | sub set_slot_value { |
101 | my ($self, $instance, $slot_name, $value) = @_; |
102 | $instance->{$slot_name} = $value; |
103 | } |
104 | |
2d711cc8 |
105 | sub initialize_slot { |
49c93440 |
106 | my ($self, $instance, $slot_name) = @_; |
a007159d |
107 | return; |
2d711cc8 |
108 | } |
109 | |
7d28758b |
110 | sub deinitialize_slot { |
111 | my ( $self, $instance, $slot_name ) = @_; |
112 | delete $instance->{$slot_name}; |
113 | } |
114 | |
c174112e |
115 | sub initialize_all_slots { |
116 | my ($self, $instance) = @_; |
117 | foreach my $slot_name ($self->get_all_slots) { |
118 | $self->initialize_slot($instance, $slot_name); |
119 | } |
120 | } |
121 | |
7d28758b |
122 | sub deinitialize_all_slots { |
123 | my ($self, $instance) = @_; |
124 | foreach my $slot_name ($self->get_all_slots) { |
125 | $self->deinitialize_slot($instance, $slot_name); |
126 | } |
127 | } |
128 | |
49c93440 |
129 | sub is_slot_initialized { |
130 | my ($self, $instance, $slot_name, $value) = @_; |
230472a7 |
131 | exists $instance->{$slot_name}; |
2bab2be6 |
132 | } |
839ea973 |
133 | |
5582521c |
134 | sub weaken_slot_value { |
69e3ab0a |
135 | my ($self, $instance, $slot_name) = @_; |
136 | weaken $instance->{$slot_name}; |
5582521c |
137 | } |
138 | |
139 | sub strengthen_slot_value { |
69e3ab0a |
140 | my ($self, $instance, $slot_name) = @_; |
141 | $self->set_slot_value($instance, $slot_name, $self->get_slot_value($instance, $slot_name)); |
5582521c |
142 | } |
143 | |
3d9e4646 |
144 | sub rebless_instance_structure { |
145 | my ($self, $instance, $metaclass) = @_; |
146 | bless $instance, $metaclass->name; |
147 | } |
148 | |
da5680be |
149 | sub is_dependent_on_superclasses { |
150 | return; # for meta instances that require updates on inherited slot changes |
151 | } |
152 | |
ee7c0467 |
153 | # inlinable operation snippets |
154 | |
c0cbf4d9 |
155 | sub is_inlinable { 1 } |
156 | |
157 | sub inline_create_instance { |
158 | my ($self, $class_variable) = @_; |
159 | 'bless {} => ' . $class_variable; |
160 | } |
161 | |
ee7c0467 |
162 | sub inline_slot_access { |
163 | my ($self, $instance, $slot_name) = @_; |
164 | sprintf "%s->{%s}", $instance, $slot_name; |
165 | } |
166 | |
167 | sub inline_get_slot_value { |
168 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
169 | $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
170 | } |
171 | |
172 | sub inline_set_slot_value { |
173 | my ($self, $instance, $slot_name, $value) = @_; |
8d2d4c67 |
174 | $self->inline_slot_access($instance, $slot_name) . " = $value", |
ee7c0467 |
175 | } |
176 | |
177 | sub inline_initialize_slot { |
178 | my ($self, $instance, $slot_name) = @_; |
a007159d |
179 | return ''; |
ee7c0467 |
180 | } |
181 | |
7d28758b |
182 | sub inline_deinitialize_slot { |
183 | my ($self, $instance, $slot_name) = @_; |
184 | "delete " . $self->inline_slot_access($instance, $slot_name); |
185 | } |
ee7c0467 |
186 | sub inline_is_slot_initialized { |
187 | my ($self, $instance, $slot_name) = @_; |
230472a7 |
188 | "exists " . $self->inline_slot_access($instance, $slot_name); |
ee7c0467 |
189 | } |
190 | |
191 | sub inline_weaken_slot_value { |
192 | my ($self, $instance, $slot_name) = @_; |
193 | sprintf "Scalar::Util::weaken( %s )", $self->inline_slot_access($instance, $slot_name); |
194 | } |
195 | |
196 | sub inline_strengthen_slot_value { |
197 | my ($self, $instance, $slot_name) = @_; |
198 | $self->inline_set_slot_value($instance, $slot_name, $self->inline_slot_access($instance, $slot_name)); |
199 | } |
200 | |
24869f62 |
201 | 1; |
202 | |
203 | __END__ |
204 | |
205 | =pod |
206 | |
8d2d4c67 |
207 | =head1 NAME |
24869f62 |
208 | |
209 | Class::MOP::Instance - Instance Meta Object |
210 | |
24869f62 |
211 | =head1 DESCRIPTION |
212 | |
bc9e7815 |
213 | The meta instance is used by attributes for low level storage. |
214 | |
215 | Using this API generally violates attribute encapsulation and is not |
98bf345b |
216 | recommended, instead look at L<Class::MOP::Attribute/get_value>, |
217 | L<Class::MOP::Attribute/set_value> for the recommended way to fiddle with |
218 | attribute values in a generic way, independent of how/whether accessors have |
bc9e7815 |
219 | been defined. Accessors can be found using L<Class::MOP::Class/get_attribute>. |
9fa4d0b4 |
220 | |
8d2d4c67 |
221 | This may seem like over-abstraction, but by abstracting |
222 | this process into a sub-protocol we make it possible to |
223 | easily switch the details of how an object's instance is |
224 | stored with minimal impact. In most cases just subclassing |
225 | this class will be all you need to do (see the examples; |
226 | F<examples/ArrayBasedStorage.pod> and |
1becdfcc |
227 | F<examples/InsideOutClass.pod> for details). |
9fa4d0b4 |
228 | |
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229 | =head1 METHODS |
230 | |
231 | =over 4 |
232 | |
63d08a9e |
233 | =item B<new %args> |
9fa4d0b4 |
234 | |
8d2d4c67 |
235 | Creates a new instance meta-object and gathers all the slots from |
9fa4d0b4 |
236 | the list of C<@attrs> given. |
237 | |
63d08a9e |
238 | =item B<BUILDARGS> |
239 | |
240 | Processes arguments for compatibility. |
241 | |
9fa4d0b4 |
242 | =item B<meta> |
243 | |
63d08a9e |
244 | Returns the metaclass of L<Class::MOP::Instance>. |
9fa4d0b4 |
245 | |
246 | =back |
247 | |
248 | =head2 Creation of Instances |
249 | |
250 | =over 4 |
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251 | |
58287a97 |
252 | =item B<create_instance> |
253 | |
becd03c6 |
254 | This creates the appropriate structure needed for the instance and blesses it. |
0e76a376 |
255 | |
9fa4d0b4 |
256 | =item B<bless_instance_structure ($instance_structure)> |
839ea973 |
257 | |
9fa4d0b4 |
258 | This does just exactly what it says it does. |
0e76a376 |
259 | |
becd03c6 |
260 | This method has been deprecated but remains for compatibility reasons. None of |
261 | the subclasses of L<Class::MOP::Instance> ever bothered to actually make use of |
262 | it, so it was deemed unnecessary fluff. |
263 | |
f7259199 |
264 | =item B<clone_instance ($instance_structure)> |
265 | |
becd03c6 |
266 | Creates a shallow clone of $instance_structure. |
127d39a7 |
267 | |
9fa4d0b4 |
268 | =back |
839ea973 |
269 | |
98bf345b |
270 | =head2 Introspection |
58287a97 |
271 | |
8d2d4c67 |
272 | NOTE: There might be more methods added to this part of the API, |
9fa4d0b4 |
273 | we will add then when we need them basically. |
58287a97 |
274 | |
9fa4d0b4 |
275 | =over 4 |
276 | |
c23184fc |
277 | =item B<associated_metaclass> |
278 | |
127d39a7 |
279 | This returns the metaclass associated with this instance. |
280 | |
9fa4d0b4 |
281 | =item B<get_all_slots> |
282 | |
8d2d4c67 |
283 | This will return the current list of slots based on what was |
9fa4d0b4 |
284 | given to this object in C<new>. |
58287a97 |
285 | |
f7259199 |
286 | =item B<is_valid_slot ($slot_name)> |
287 | |
127d39a7 |
288 | This will return true if C<$slot_name> is a valid slot name. |
289 | |
da5680be |
290 | =item B<is_dependent_on_superclasses> |
291 | |
292 | This method returns true when the meta instance must be recreated on any |
293 | superclass changes. |
294 | |
295 | Defaults to false. |
296 | |
24869f62 |
297 | =back |
298 | |
9fa4d0b4 |
299 | =head2 Operations on Instance Structures |
300 | |
8d2d4c67 |
301 | An important distinction of this sub-protocol is that the |
302 | instance meta-object is a different entity from the actual |
303 | instance it creates. For this reason, any actions on slots |
9fa4d0b4 |
304 | require that the C<$instance_structure> is passed into them. |
24869f62 |
305 | |
127d39a7 |
306 | The names of these methods pretty much explain exactly |
307 | what they do, if that is not enough then I suggest reading |
308 | the source, it is very straightfoward. |
309 | |
24869f62 |
310 | =over 4 |
311 | |
9fa4d0b4 |
312 | =item B<get_slot_value ($instance_structure, $slot_name)> |
24869f62 |
313 | |
9fa4d0b4 |
314 | =item B<set_slot_value ($instance_structure, $slot_name, $value)> |
315 | |
316 | =item B<initialize_slot ($instance_structure, $slot_name)> |
317 | |
7d28758b |
318 | =item B<deinitialize_slot ($instance_structure, $slot_name)> |
319 | |
9fa4d0b4 |
320 | =item B<initialize_all_slots ($instance_structure)> |
321 | |
7d28758b |
322 | =item B<deinitialize_all_slots ($instance_structure)> |
323 | |
9fa4d0b4 |
324 | =item B<is_slot_initialized ($instance_structure, $slot_name)> |
24869f62 |
325 | |
ee7c0467 |
326 | =item B<weaken_slot_value ($instance_structure, $slot_name)> |
327 | |
328 | =item B<strengthen_slot_value ($instance_structure, $slot_name)> |
329 | |
5fdf066d |
330 | =item B<rebless_instance_structure ($instance_structure, $new_metaclass)> |
331 | |
ee7c0467 |
332 | =back |
333 | |
334 | =head2 Inlineable Instance Operations |
335 | |
336 | =over 4 |
337 | |
c0cbf4d9 |
338 | =item B<is_inlinable> |
339 | |
8d2d4c67 |
340 | Each meta-instance should override this method to tell Class::MOP if it's |
127d39a7 |
341 | possible to inline the slot access. This is currently only used by |
342 | L<Class::MOP::Immutable> when performing optimizations. |
c0cbf4d9 |
343 | |
495af518 |
344 | =item B<inline_create_instance> |
345 | |
ee7c0467 |
346 | =item B<inline_slot_access ($instance_structure, $slot_name)> |
347 | |
348 | =item B<inline_get_slot_value ($instance_structure, $slot_name)> |
349 | |
350 | =item B<inline_set_slot_value ($instance_structure, $slot_name, $value)> |
351 | |
352 | =item B<inline_initialize_slot ($instance_structure, $slot_name)> |
353 | |
7d28758b |
354 | =item B<inline_deinitialize_slot ($instance_structure, $slot_name)> |
355 | |
ee7c0467 |
356 | =item B<inline_is_slot_initialized ($instance_structure, $slot_name)> |
5582521c |
357 | |
ee7c0467 |
358 | =item B<inline_weaken_slot_value ($instance_structure, $slot_name)> |
5582521c |
359 | |
ee7c0467 |
360 | =item B<inline_strengthen_slot_value ($instance_structure, $slot_name)> |
5582521c |
361 | |
24869f62 |
362 | =back |
363 | |
1a09d9cc |
364 | =head1 AUTHORS |
24869f62 |
365 | |
9fa4d0b4 |
366 | Yuval Kogman E<lt>nothingmuch@woobling.comE<gt> |
367 | |
24869f62 |
368 | Stevan Little E<lt>stevan@iinteractive.comE<gt> |
369 | |
370 | =head1 COPYRIGHT AND LICENSE |
371 | |
69e3ab0a |
372 | Copyright 2006-2008 by Infinity Interactive, Inc. |
24869f62 |
373 | |
374 | L<http://www.iinteractive.com> |
375 | |
376 | This library is free software; you can redistribute it and/or modify |
8d2d4c67 |
377 | it under the same terms as Perl itself. |
24869f62 |
378 | |
84ef30d1 |
379 | =cut |
5582521c |
380 | |