Commit | Line | Data |
8b978dd5 |
1 | |
2 | package Class::MOP::Attribute; |
3 | |
4 | use strict; |
5 | use warnings; |
6 | |
2eb717d5 |
7 | use Carp 'confess'; |
c50c603e |
8 | use Scalar::Util 'blessed', 'reftype'; |
2eb717d5 |
9 | |
10 | use Class::MOP::Class; |
11 | use Class::MOP::Method; |
8b978dd5 |
12 | |
13 | our $VERSION = '0.01'; |
14 | |
2eb717d5 |
15 | sub meta { Class::MOP::Class->initialize($_[0]) } |
16 | |
8b978dd5 |
17 | sub new { |
18 | my $class = shift; |
19 | my $name = shift; |
20 | my %options = @_; |
21 | |
cbd9f942 |
22 | (defined $name && $name) |
8b978dd5 |
23 | || confess "You must provide a name for the attribute"; |
2eb717d5 |
24 | (!exists $options{reader} && !exists $options{writer}) |
25 | || confess "You cannot declare an accessor and reader and/or writer functions" |
26 | if exists $options{accessor}; |
27 | |
8b978dd5 |
28 | bless { |
c50c603e |
29 | name => $name, |
30 | accessor => $options{accessor}, |
31 | reader => $options{reader}, |
32 | writer => $options{writer}, |
33 | predicate => $options{predicate}, |
34 | init_arg => $options{init_arg}, |
35 | default => $options{default} |
8b978dd5 |
36 | } => $class; |
37 | } |
38 | |
c50c603e |
39 | sub name { $_[0]->{name} } |
40 | |
41 | sub has_accessor { defined($_[0]->{accessor}) ? 1 : 0 } |
42 | sub has_reader { defined($_[0]->{reader}) ? 1 : 0 } |
43 | sub has_writer { defined($_[0]->{writer}) ? 1 : 0 } |
44 | sub has_predicate { defined($_[0]->{predicate}) ? 1 : 0 } |
45 | sub has_init_arg { defined($_[0]->{init_arg}) ? 1 : 0 } |
46 | sub has_default { defined($_[0]->{default}) ? 1 : 0 } |
47 | |
48 | sub accessor { $_[0]->{accessor} } |
49 | sub reader { $_[0]->{reader} } |
50 | sub writer { $_[0]->{writer} } |
51 | sub predicate { $_[0]->{predicate} } |
52 | sub init_arg { $_[0]->{init_arg} } |
53 | |
54 | sub default { |
55 | my $self = shift; |
56 | if (reftype($self->{default}) && reftype($self->{default}) eq 'CODE') { |
57 | return $self->{default}->(shift); |
58 | } |
59 | $self->{default}; |
60 | } |
8b978dd5 |
61 | |
2eb717d5 |
62 | sub install_accessors { |
63 | my ($self, $class) = @_; |
64 | (blessed($class) && $class->isa('Class::MOP::Class')) |
65 | || confess "You must pass a Class::MOP::Class instance (or a subclass)"; |
66 | |
67 | if ($self->has_accessor()) { |
c50c603e |
68 | my $accessor = $self->accessor(); |
69 | if (reftype($accessor) && reftype($accessor) eq 'HASH') { |
70 | my ($name, $method) = each %{$accessor}; |
71 | $class->add_method($name, Class::MOP::Attribute::Accessor->wrap($method)); |
72 | } |
73 | else { |
74 | $class->add_method($accessor => Class::MOP::Attribute::Accessor->wrap(sub { |
75 | $_[0]->{$self->name} = $_[1] if scalar(@_) == 2; |
76 | $_[0]->{$self->name}; |
77 | })); |
78 | } |
2eb717d5 |
79 | } |
80 | else { |
c50c603e |
81 | if ($self->has_reader()) { |
82 | my $reader = $self->reader(); |
83 | if (reftype($reader) && reftype($reader) eq 'HASH') { |
84 | my ($name, $method) = each %{$reader}; |
85 | $class->add_method($name, Class::MOP::Attribute::Accessor->wrap($method)); |
86 | } |
87 | else { |
88 | $class->add_method($reader => Class::MOP::Attribute::Accessor->wrap(sub { |
89 | $_[0]->{$self->name}; |
90 | })); |
91 | } |
2eb717d5 |
92 | } |
93 | if ($self->has_writer()) { |
c50c603e |
94 | my $writer = $self->writer(); |
95 | if (reftype($writer) && reftype($writer) eq 'HASH') { |
96 | my ($name, $method) = each %{$writer}; |
97 | $class->add_method($name, Class::MOP::Attribute::Accessor->wrap($method)); |
98 | } |
99 | else { |
100 | $class->add_method($writer => Class::MOP::Attribute::Accessor->wrap(sub { |
101 | $_[0]->{$self->name} = $_[1]; |
102 | return; |
103 | })); |
104 | } |
2eb717d5 |
105 | } |
106 | } |
c50c603e |
107 | |
108 | if ($self->has_predicate()) { |
109 | my $predicate = $self->predicate(); |
110 | if (reftype($predicate) && reftype($predicate) eq 'HASH') { |
111 | my ($name, $method) = each %{$predicate}; |
112 | $class->add_method($name, Class::MOP::Attribute::Accessor->wrap($method)); |
113 | } |
114 | else { |
115 | $class->add_method($predicate => Class::MOP::Attribute::Accessor->wrap(sub { |
116 | defined $_[0]->{$self->name} ? 1 : 0; |
117 | })); |
118 | } |
119 | } |
2eb717d5 |
120 | } |
121 | |
122 | sub remove_accessors { |
123 | my ($self, $class) = @_; |
124 | (blessed($class) && $class->isa('Class::MOP::Class')) |
125 | || confess "You must pass a Class::MOP::Class instance (or a subclass)"; |
126 | |
127 | if ($self->has_accessor()) { |
c50c603e |
128 | my $accessor = $self->accessor(); |
129 | if (reftype($accessor) && reftype($accessor) eq 'HASH') { |
130 | ($accessor) = keys %{$accessor}; |
131 | } |
132 | my $method = $class->get_method($accessor); |
133 | $class->remove_method($accessor) |
2eb717d5 |
134 | if (blessed($method) && $method->isa('Class::MOP::Attribute::Accessor')); |
135 | } |
136 | else { |
137 | if ($self->has_reader()) { |
c50c603e |
138 | my $reader = $self->reader(); |
139 | if (reftype($reader) && reftype($reader) eq 'HASH') { |
140 | ($reader) = keys %{$reader}; |
141 | } |
142 | my $method = $class->get_method($reader); |
143 | $class->remove_method($reader) |
2eb717d5 |
144 | if (blessed($method) && $method->isa('Class::MOP::Attribute::Accessor')); |
145 | } |
146 | if ($self->has_writer()) { |
c50c603e |
147 | my $writer = $self->writer(); |
148 | if (reftype($writer) && reftype($writer) eq 'HASH') { |
149 | ($writer) = keys %{$writer}; |
150 | } |
151 | my $method = $class->get_method($writer); |
152 | $class->remove_method($writer) |
2eb717d5 |
153 | if (blessed($method) && $method->isa('Class::MOP::Attribute::Accessor')); |
154 | } |
c50c603e |
155 | } |
156 | |
157 | if ($self->has_predicate()) { |
158 | my $predicate = $self->predicate(); |
159 | if (reftype($predicate) && reftype($predicate) eq 'HASH') { |
160 | ($predicate) = keys %{$predicate}; |
161 | } |
162 | my $method = $class->get_method($predicate); |
163 | $class->remove_method($predicate) |
164 | if (blessed($method) && $method->isa('Class::MOP::Attribute::Accessor')); |
165 | } |
8b978dd5 |
166 | } |
167 | |
2eb717d5 |
168 | package Class::MOP::Attribute::Accessor; |
169 | |
170 | use strict; |
171 | use warnings; |
172 | |
173 | our $VERSION = '0.01'; |
174 | |
175 | our @ISA = ('Class::MOP::Method'); |
176 | |
8b978dd5 |
177 | 1; |
178 | |
179 | __END__ |
180 | |
181 | =pod |
182 | |
183 | =head1 NAME |
184 | |
185 | Class::MOP::Attribute - Attribute Meta Object |
186 | |
187 | =head1 SYNOPSIS |
188 | |
189 | Class::MOP::Attribute->new('$foo' => ( |
190 | accessor => 'foo', # dual purpose get/set accessor |
191 | init_arg => '-foo', # class->new will look for a -foo key |
192 | default => 'BAR IS BAZ!' # if no -foo key is provided, use this |
193 | )); |
194 | |
195 | Class::MOP::Attribute->new('$.bar' => ( |
196 | reader => 'bar', # getter |
197 | writer => 'set_bar', # setter |
198 | init_arg => '-bar', # class->new will look for a -bar key |
199 | # no default value means it is undef |
200 | )); |
201 | |
202 | =head1 DESCRIPTION |
203 | |
552e3d24 |
204 | The Attribute Protocol is almost entirely an invention of this module. This is |
205 | because Perl 5 does not have consistent notion of what is an attribute |
206 | of a class. There are so many ways in which this is done, and very few |
207 | (if any) are discoverable by this module. |
208 | |
209 | So, all that said, this module attempts to inject some order into this |
210 | chaos, by introducing a more consistent approach. |
211 | |
212 | =head1 METHODS |
213 | |
214 | =head2 Creation |
215 | |
216 | =over 4 |
217 | |
218 | =item B<new ($name, %accessor_description, $class_initialization_arg, $default_value)> |
219 | |
220 | =back |
221 | |
222 | =head2 Informational |
223 | |
224 | =over 4 |
225 | |
226 | =item B<name> |
227 | |
228 | =item B<accessor> |
229 | |
230 | =item B<reader> |
231 | |
232 | =item B<writer> |
233 | |
c50c603e |
234 | =item B<predicate> |
235 | |
552e3d24 |
236 | =item B<init_arg> |
237 | |
238 | =item B<default> |
239 | |
240 | =back |
241 | |
242 | =head2 Informational predicates |
243 | |
244 | =over 4 |
245 | |
246 | =item B<has_accessor> |
247 | |
248 | Returns true if this attribute uses a get/set accessor, and false |
249 | otherwise |
250 | |
251 | =item B<has_reader> |
252 | |
253 | Returns true if this attribute has a reader, and false otherwise |
254 | |
255 | =item B<has_writer> |
256 | |
257 | Returns true if this attribute has a writer, and false otherwise |
258 | |
c50c603e |
259 | =item B<has_predicate> |
260 | |
261 | Returns true if this attribute has a predicate, and false otherwise |
262 | |
552e3d24 |
263 | =item B<has_init_arg> |
264 | |
265 | Returns true if this attribute has a class intialization argument, and |
266 | false otherwise |
267 | |
268 | =item B<has_default> |
269 | |
270 | Returns true if this attribute has a default value, and false |
271 | otherwise. |
272 | |
273 | =back |
274 | |
275 | =head2 Attribute Accessor generation |
276 | |
277 | =over 4 |
278 | |
2eb717d5 |
279 | =item B<install_accessors ($class)> |
280 | |
281 | This allows the attribute to generate and install code for it's own |
282 | accessor methods. This is called by C<Class::MOP::Class::add_attribute>. |
283 | |
284 | =item B<remove_accessors ($class)> |
285 | |
286 | This allows the attribute to remove the method for it's own |
287 | accessor. This is called by C<Class::MOP::Class::remove_attribute>. |
288 | |
289 | =back |
290 | |
291 | =head2 Introspection |
292 | |
293 | =over 4 |
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294 | |
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295 | =item B<meta> |
552e3d24 |
296 | |
297 | =back |
298 | |
8b978dd5 |
299 | =head1 AUTHOR |
300 | |
301 | Stevan Little E<gt>stevan@iinteractive.comE<lt> |
302 | |
303 | =head1 COPYRIGHT AND LICENSE |
304 | |
305 | Copyright 2006 by Infinity Interactive, Inc. |
306 | |
307 | L<http://www.iinteractive.com> |
308 | |
309 | This library is free software; you can redistribute it and/or modify |
310 | it under the same terms as Perl itself. |
311 | |
312 | =cut |