Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
c3398f5b |
2 | use strict; |
3 | use warnings; |
3b8fe109 |
4 | require overload; |
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5 | |
6 | use Carp 'confess'; |
6c169c50 |
7 | use Scalar::Util (); |
684db121 |
8 | use Mouse::Meta::TypeConstraint; |
ca5a9ec1 |
9 | use Mouse::Meta::Method::Accessor; |
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10 | |
11 | sub new { |
2608b115 |
12 | my ($class, $name, %options) = @_; |
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13 | |
2608b115 |
14 | $options{name} = $name; |
2e7e86c6 |
15 | |
2608b115 |
16 | $options{init_arg} = $name |
17 | unless exists $options{init_arg}; |
45959ffa |
18 | |
2608b115 |
19 | $options{is} ||= ''; |
c3398f5b |
20 | |
2608b115 |
21 | bless \%options, $class; |
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22 | } |
23 | |
f6715552 |
24 | sub name { $_[0]->{name} } |
25 | sub associated_class { $_[0]->{associated_class} } |
26 | sub _is_metadata { $_[0]->{is} } |
27 | sub is_required { $_[0]->{required} } |
28 | sub default { $_[0]->{default} } |
29 | sub is_lazy { $_[0]->{lazy} } |
30 | sub is_lazy_build { $_[0]->{lazy_build} } |
31 | sub predicate { $_[0]->{predicate} } |
32 | sub clearer { $_[0]->{clearer} } |
33 | sub handles { $_[0]->{handles} } |
34 | sub is_weak_ref { $_[0]->{weak_ref} } |
35 | sub init_arg { $_[0]->{init_arg} } |
36 | sub type_constraint { $_[0]->{type_constraint} } |
4c03ed87 |
37 | sub find_type_constraint { |
38 | Carp::carp("This method was deprecated"); |
39 | $_[0]->type_constraint(); |
40 | } |
f6715552 |
41 | sub trigger { $_[0]->{trigger} } |
42 | sub builder { $_[0]->{builder} } |
43 | sub should_auto_deref { $_[0]->{auto_deref} } |
44 | sub should_coerce { $_[0]->{should_coerce} } |
c3398f5b |
45 | |
f6715552 |
46 | sub has_default { exists $_[0]->{default} } |
47 | sub has_predicate { exists $_[0]->{predicate} } |
48 | sub has_clearer { exists $_[0]->{clearer} } |
49 | sub has_handles { exists $_[0]->{handles} } |
50 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
51 | sub has_trigger { exists $_[0]->{trigger} } |
52 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
53 | |
1bfebf5f |
54 | sub _create_args { |
55 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
56 | $_[0]->{_create_args} |
57 | } |
58 | |
7f7406a5 |
59 | sub inlined_name { |
60 | my $self = shift; |
61 | my $name = $self->name; |
62 | my $key = "'" . $name . "'"; |
63 | return $key; |
64 | } |
65 | |
c3398f5b |
66 | sub generate_predicate { |
67 | my $attribute = shift; |
d10fd510 |
68 | my $key = $attribute->inlined_name; |
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69 | |
d10fd510 |
70 | my $predicate = 'sub { exists($_[0]->{'.$key.'}) }'; |
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71 | |
71b948d1 |
72 | my $sub = eval $predicate; |
73 | confess $@ if $@; |
74 | return $sub; |
c3398f5b |
75 | } |
76 | |
77 | sub generate_clearer { |
78 | my $attribute = shift; |
d10fd510 |
79 | my $key = $attribute->inlined_name; |
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80 | |
d10fd510 |
81 | my $clearer = 'sub { delete($_[0]->{'.$key.'}) }'; |
c3398f5b |
82 | |
71b948d1 |
83 | my $sub = eval $clearer; |
84 | confess $@ if $@; |
85 | return $sub; |
c3398f5b |
86 | } |
87 | |
88 | sub generate_handles { |
89 | my $attribute = shift; |
2434d21b |
90 | my $reader = $attribute->name; |
c3cc3642 |
91 | my %handles = $attribute->_canonicalize_handles($attribute->handles); |
c3398f5b |
92 | |
93 | my %method_map; |
94 | |
c3cc3642 |
95 | for my $local_method (keys %handles) { |
96 | my $remote_method = $handles{$local_method}; |
c3398f5b |
97 | |
98 | my $method = 'sub { |
99 | my $self = shift; |
0ecefe82 |
100 | $self->'.$reader.'->'.$remote_method.'(@_) |
c3398f5b |
101 | }'; |
102 | |
103 | $method_map{$local_method} = eval $method; |
71b948d1 |
104 | confess $@ if $@; |
c3398f5b |
105 | } |
106 | |
107 | return \%method_map; |
108 | } |
109 | |
110 | sub create { |
111 | my ($self, $class, $name, %args) = @_; |
112 | |
1bfebf5f |
113 | $args{name} = $name; |
181502b9 |
114 | $args{associated_class} = $class; |
1bfebf5f |
115 | |
93d190e0 |
116 | %args = $self->canonicalize_args($name, %args); |
1bbaa8ed |
117 | $self->validate_args($name, \%args); |
45ea8620 |
118 | |
32af3489 |
119 | $args{should_coerce} = delete $args{coerce} |
4188b837 |
120 | if exists $args{coerce}; |
121 | |
eec1bb49 |
122 | if (exists $args{isa}) { |
c1c94293 |
123 | confess "Got isa => $args{isa}, but Mouse does not yet support parameterized types for containers other than ArrayRef and HashRef (rt.cpan.org #39795)" |
315b97c2 |
124 | if $args{isa} =~ /^([^\[]+)\[.+\]$/ && |
125 | $1 ne 'ArrayRef' && |
a510e63c |
126 | $1 ne 'HashRef' && |
127 | $1 ne 'Maybe' |
128 | ; |
5fa003bf |
129 | |
eec1bb49 |
130 | my $type_constraint = delete $args{isa}; |
684db121 |
131 | $args{type_constraint}= Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($type_constraint); |
eec1bb49 |
132 | } |
186657a9 |
133 | |
2608b115 |
134 | my $attribute = $self->new($name, %args); |
1bfebf5f |
135 | |
724c77c0 |
136 | $attribute->_create_args(\%args); |
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137 | |
724c77c0 |
138 | $class->add_attribute($attribute); |
b2500191 |
139 | |
c3398f5b |
140 | # install an accessor |
2434d21b |
141 | if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') { |
ca5a9ec1 |
142 | my $code = Mouse::Meta::Method::Accessor->generate_accessor_method_inline( |
143 | $attribute, |
144 | ); |
145 | $class->add_method($name => $code); |
c3398f5b |
146 | } |
147 | |
c3398f5b |
148 | for my $method (qw/predicate clearer/) { |
2434d21b |
149 | my $predicate = "has_$method"; |
150 | if ($attribute->$predicate) { |
c3398f5b |
151 | my $generator = "generate_$method"; |
152 | my $coderef = $attribute->$generator; |
724c77c0 |
153 | $class->add_method($attribute->$method => $coderef); |
c3398f5b |
154 | } |
155 | } |
156 | |
2434d21b |
157 | if ($attribute->has_handles) { |
c3398f5b |
158 | my $method_map = $attribute->generate_handles; |
159 | for my $method_name (keys %$method_map) { |
724c77c0 |
160 | $class->add_method($method_name => $method_map->{$method_name}); |
c3398f5b |
161 | } |
162 | } |
163 | |
164 | return $attribute; |
165 | } |
166 | |
93d190e0 |
167 | sub canonicalize_args { |
168 | my $self = shift; |
169 | my $name = shift; |
170 | my %args = @_; |
171 | |
172 | if ($args{lazy_build}) { |
173 | $args{lazy} = 1; |
174 | $args{required} = 1; |
175 | $args{builder} = "_build_${name}" |
176 | if !exists($args{builder}); |
177 | if ($name =~ /^_/) { |
178 | $args{clearer} = "_clear${name}" if !exists($args{clearer}); |
179 | $args{predicate} = "_has${name}" if !exists($args{predicate}); |
180 | } |
181 | else { |
182 | $args{clearer} = "clear_${name}" if !exists($args{clearer}); |
183 | $args{predicate} = "has_${name}" if !exists($args{predicate}); |
184 | } |
185 | } |
186 | |
187 | return %args; |
188 | } |
189 | |
8fd9e611 |
190 | sub validate_args { |
191 | my $self = shift; |
192 | my $name = shift; |
1bbaa8ed |
193 | my $args = shift; |
8fd9e611 |
194 | |
93d190e0 |
195 | confess "You can not use lazy_build and default for the same attribute ($name)" |
1bbaa8ed |
196 | if $args->{lazy_build} && exists $args->{default}; |
93d190e0 |
197 | |
8fd9e611 |
198 | confess "You cannot have lazy attribute ($name) without specifying a default value for it" |
1bbaa8ed |
199 | if $args->{lazy} |
200 | && !exists($args->{default}) |
201 | && !exists($args->{builder}); |
8fd9e611 |
202 | |
203 | confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])" |
1bbaa8ed |
204 | if ref($args->{default}) |
205 | && ref($args->{default}) ne 'CODE'; |
8fd9e611 |
206 | |
97661b77 |
207 | confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)" |
1bbaa8ed |
208 | if $args->{auto_deref} && !exists($args->{isa}); |
8fd9e611 |
209 | |
97661b77 |
210 | confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)" |
1bbaa8ed |
211 | if $args->{auto_deref} |
212 | && $args->{isa} ne 'ArrayRef' |
213 | && $args->{isa} ne 'HashRef'; |
8fd9e611 |
214 | |
506db557 |
215 | if ($args->{trigger}) { |
a08e715f |
216 | if (ref($args->{trigger}) eq 'HASH') { |
217 | Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported."; |
844fa049 |
218 | } |
506db557 |
219 | |
844fa049 |
220 | confess "Trigger must be a CODE ref on attribute ($name)" |
a08e715f |
221 | if ref($args->{trigger}) ne 'CODE'; |
506db557 |
222 | } |
6c5498d0 |
223 | |
8fd9e611 |
224 | return 1; |
225 | } |
226 | |
20e25eb9 |
227 | sub verify_against_type_constraint { |
f55f60dd |
228 | my ($self, $value) = @_; |
229 | my $tc = $self->type_constraint; |
230 | return 1 unless $tc; |
5aa30ced |
231 | |
f55f60dd |
232 | local $_ = $value; |
233 | return 1 if $tc->check($value); |
5aa30ced |
234 | |
f55f60dd |
235 | $self->verify_type_constraint_error($self->name, $value, $tc); |
b3b74cc6 |
236 | } |
5aa30ced |
237 | |
b3b74cc6 |
238 | sub verify_type_constraint_error { |
239 | my($self, $name, $value, $type) = @_; |
29607c02 |
240 | Carp::confess("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
241 | } |
242 | |
8a7f2a8a |
243 | sub coerce_constraint { ## my($self, $value) = @_; |
244 | my $type = $_[0]->{type_constraint} |
245 | or return $_[1]; |
684db121 |
246 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]); |
4188b837 |
247 | } |
248 | |
af745d5a |
249 | sub _canonicalize_handles { |
250 | my $self = shift; |
251 | my $handles = shift; |
252 | |
253 | if (ref($handles) eq 'HASH') { |
254 | return %$handles; |
255 | } |
256 | elsif (ref($handles) eq 'ARRAY') { |
257 | return map { $_ => $_ } @$handles; |
258 | } |
259 | else { |
260 | confess "Unable to canonicalize the 'handles' option with $handles"; |
261 | } |
262 | } |
263 | |
1bfebf5f |
264 | sub clone_parent { |
265 | my $self = shift; |
266 | my $class = shift; |
267 | my $name = shift; |
268 | my %args = ($self->get_parent_args($class, $name), @_); |
269 | |
270 | $self->create($class, $name, %args); |
271 | } |
272 | |
273 | sub get_parent_args { |
274 | my $self = shift; |
275 | my $class = shift; |
276 | my $name = shift; |
277 | |
724c77c0 |
278 | for my $super ($class->linearized_isa) { |
bb733405 |
279 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
280 | or next; |
281 | return %{ $super_attr->_create_args }; |
282 | } |
283 | |
284 | confess "Could not find an attribute by the name of '$name' to inherit from"; |
285 | } |
286 | |
c3398f5b |
287 | 1; |
288 | |
289 | __END__ |
290 | |
291 | =head1 NAME |
292 | |
306290e8 |
293 | Mouse::Meta::Attribute - attribute metaclass |
c3398f5b |
294 | |
295 | =head1 METHODS |
296 | |
306290e8 |
297 | =head2 new %args -> Mouse::Meta::Attribute |
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298 | |
306290e8 |
299 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
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300 | |
306290e8 |
301 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
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302 | |
303 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
304 | installed. Some error checking is done. |
305 | |
306 | =head2 name -> AttributeName |
307 | |
181502b9 |
308 | =head2 associated_class -> OwnerClass |
c3398f5b |
309 | |
ab27a55e |
310 | =head2 is_required -> Bool |
c3398f5b |
311 | |
ab27a55e |
312 | =head2 default -> Item |
c3398f5b |
313 | |
ab27a55e |
314 | =head2 has_default -> Bool |
315 | |
316 | =head2 is_lazy -> Bool |
317 | |
318 | =head2 predicate -> MethodName | Undef |
319 | |
320 | =head2 has_predicate -> Bool |
321 | |
322 | =head2 clearer -> MethodName | Undef |
323 | |
324 | =head2 has_clearer -> Bool |
c3398f5b |
325 | |
326 | =head2 handles -> { LocalName => RemoteName } |
327 | |
ab27a55e |
328 | =head2 has_handles -> Bool |
329 | |
3645b316 |
330 | =head2 is_weak_ref -> Bool |
c3398f5b |
331 | |
332 | =head2 init_arg -> Str |
333 | |
ab27a55e |
334 | =head2 type_constraint -> Str |
335 | |
336 | =head2 has_type_constraint -> Bool |
337 | |
338 | =head2 trigger => CODE | Undef |
339 | |
340 | =head2 has_trigger -> Bool |
341 | |
342 | =head2 builder => MethodName | Undef |
343 | |
344 | =head2 has_builder -> Bool |
345 | |
93f08899 |
346 | =head2 is_lazy_build => Bool |
347 | |
0fff36e6 |
348 | =head2 should_auto_deref -> Bool |
349 | |
c3398f5b |
350 | Informational methods. |
351 | |
352 | =head2 generate_accessor -> CODE |
353 | |
354 | Creates a new code reference for the attribute's accessor. |
355 | |
356 | =head2 generate_predicate -> CODE |
357 | |
358 | Creates a new code reference for the attribute's predicate. |
359 | |
360 | =head2 generate_clearer -> CODE |
361 | |
362 | Creates a new code reference for the attribute's clearer. |
363 | |
364 | =head2 generate_handles -> { MethodName => CODE } |
365 | |
366 | Creates a new code reference for each of the attribute's handles methods. |
367 | |
20e25eb9 |
368 | =head2 verify_against_type_constraint Item -> 1 | ERROR |
fb706f5c |
369 | |
370 | Checks that the given value passes this attribute's type constraint. Returns 1 |
371 | on success, otherwise C<confess>es. |
372 | |
93d190e0 |
373 | =head2 canonicalize_args Name, %args -> %args |
374 | |
375 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
376 | canonicalized into C<lazy>, C<builder>, etc. |
377 | |
1bbaa8ed |
378 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
379 | |
380 | Checks that the arguments to create the attribute (ie those specified by |
381 | C<has>) are valid. |
382 | |
f7b11a21 |
383 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
384 | |
385 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
386 | Accessors and helper methods are installed. Some error checking is done. |
387 | |
388 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
389 | |
390 | Returns the options that the parent class of C<OwnerClass> used for attribute |
391 | C<AttributeName>. |
392 | |
c3398f5b |
393 | =cut |
394 | |