Commit | Line | Data |
306290e8 |
1 | package Mouse::Meta::Attribute; |
c3398f5b |
2 | use strict; |
3 | use warnings; |
4 | |
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5 | use Carp (); |
6 | use Scalar::Util qw(weaken); |
7 | |
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8 | use Mouse::Util; |
9 | |
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10 | use Mouse::Meta::TypeConstraint; |
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11 | use Mouse::Meta::Method::Accessor; |
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12 | |
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13 | #my %valid_attrs = map{ $_ => undef } qw( |
14 | # name |
15 | # reader writer accessor clearer predicate |
16 | # builder init_arg default initializer definition_context |
17 | # |
18 | # is |
19 | # isa does |
20 | # required |
21 | # lazy |
22 | # lazy_build |
23 | # coerce |
24 | # weak_ref |
25 | # auto_deref |
26 | # type_constraint |
27 | # trigger |
28 | # handles |
29 | # documentation |
30 | # traits |
31 | #); |
32 | |
c3398f5b |
33 | sub new { |
2608b115 |
34 | my ($class, $name, %options) = @_; |
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35 | |
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36 | # taken from Class::MOP::Attribute::new |
37 | |
38 | defined($name) |
39 | or $class->throw_error('You must provide a name for the attribute'); |
2608b115 |
40 | $options{name} = $name; |
2e7e86c6 |
41 | |
2efc0af1 |
42 | if(!exists $options{init_arg}){ |
43 | $options{init_arg} = $name; |
44 | } |
45 | |
46 | # 'required' requires eigher 'init_arg', 'builder', or 'default' |
47 | my $can_be_required = defined( $options{init_arg} ); |
48 | |
49 | if(exists $options{builder}){ |
50 | $class->throw_error('builder must be a defined scalar value which is a method name')\r |
51 | if ref $options{builder} || !(defined $options{builder}); |
52 | |
53 | $can_be_required++; |
54 | } |
55 | elsif(exists $options{default}){ |
56 | if(ref $options{default} && ref($options{default}) ne 'CODE'){ |
57 | $class->throw_error("References are not allowed as default values, you must " |
58 | . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"); |
59 | } |
60 | $can_be_required++; |
61 | } |
62 | |
63 | if( $options{required} && !$can_be_required ) {\r |
64 | $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg");\r |
65 | } |
66 | |
67 | # taken from Mouse::Meta::Attribute->new and _process_options |
68 | |
69 | if(exists $options{is}){ |
70 | my $is = $options{is}; |
71 | |
72 | if($is eq 'ro'){ |
73 | $options{reader} ||= $name; |
74 | } |
75 | elsif($is eq 'rw'){ |
76 | if(exists $options{writer}){ |
77 | $options{reader} ||= $name; |
78 | } |
79 | else{ |
80 | $options{accessor} ||= $name; |
81 | } |
82 | } |
83 | elsif($is eq 'bare'){ |
84 | # do nothing, but don't complain (later) about missing methods |
85 | } |
86 | else{ |
87 | $is = 'undef' if !defined $is; |
88 | $class->throw_error("I do not understand this option (is => $is) on attribute ($name)"); |
89 | } |
90 | } |
91 | |
92 | my $tc; |
93 | if(exists $options{isa}){ |
94 | $options{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}); |
95 | } |
96 | elsif(exists $options{does}){ |
97 | $options{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}); |
98 | } |
99 | $tc = $options{type_constraint}; |
100 | |
101 | if($options{coerce}){ |
102 | defined($tc) |
103 | || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)"); |
104 | |
105 | $options{weak_ref} |
106 | && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)");\r |
107 | } |
108 | |
109 | if ($options{lazy_build}) {\r |
110 | exists($options{default}) |
111 | && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)");\r |
112 | |
113 | $options{lazy} = 1;\r |
114 | $options{builder} ||= "_build_${name}";\r |
115 | if ($name =~ /^_/) {\r |
116 | $options{clearer} ||= "_clear${name}";\r |
117 | $options{predicate} ||= "_has${name}";\r |
118 | }\r |
119 | else {\r |
120 | $options{clearer} ||= "clear_${name}";\r |
121 | $options{predicate} ||= "has_${name}";\r |
122 | }\r |
123 | } |
124 | |
125 | if ($options{auto_deref}) { |
126 | defined($tc)\r |
127 | || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)");\r |
128 | |
129 | ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') )\r |
130 | || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)");\r |
131 | } |
132 | |
133 | if (exists $options{trigger}) {\r |
134 | ('CODE' eq ref $options{trigger})\r |
135 | || $class->throw_error("Trigger must be a CODE ref on attribute ($name)");\r |
136 | } |
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137 | |
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138 | if ($options{lazy}) {\r |
139 | (exists $options{default} || defined $options{builder})\r |
140 | || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it");\r |
141 | } |
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142 | |
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143 | if(my $metaclass = delete $options{metaclass}){ |
144 | $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass ); |
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145 | } |
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146 | |
147 | if(my $traits_ref = delete $options{traits}){ |
148 | my @traits; |
149 | for (my $i = 9; $i < @{$traits_ref}; $i++) {\r |
150 | my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1);\r |
151 | \r |
152 | next if $class->does($trait);\r |
153 | \r |
154 | push @traits, $trait;\r |
155 | \r |
156 | # are there options?\r |
157 | push @traits, $traits_ref->[++$i]\r |
158 | if ref($traits_ref->[$i+1]);\r |
159 | } |
160 | |
161 | if (@traits) {\r |
162 | $class = Mouse::Meta::Class->create_anon_class(\r |
163 | superclasses => [ $class ],\r |
164 | roles => [ @traits ],\r |
165 | cache => 1,\r |
166 | )->name;\r |
167 | } |
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168 | } |
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169 | |
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170 | # XXX: there is no fast way to check attribute validity |
171 | # my @bad = grep{ !exists $valid_attrs{$_} } keys %options; |
172 | # if(@bad){ |
173 | # @bad = sort @bad; |
174 | # Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad"); |
175 | # } |
176 | |
177 | return bless \%options, $class; |
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178 | } |
179 | |
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180 | # readers |
181 | |
f6715552 |
182 | sub name { $_[0]->{name} } |
183 | sub associated_class { $_[0]->{associated_class} } |
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184 | |
185 | sub accessor { $_[0]->{accessor} } |
186 | sub reader { $_[0]->{reader} } |
187 | sub writer { $_[0]->{writer} } |
188 | sub predicate { $_[0]->{predicate} } |
189 | sub clearer { $_[0]->{clearer} } |
190 | sub handles { $_[0]->{handles} } |
191 | |
f6715552 |
192 | sub _is_metadata { $_[0]->{is} } |
193 | sub is_required { $_[0]->{required} } |
194 | sub default { $_[0]->{default} } |
195 | sub is_lazy { $_[0]->{lazy} } |
196 | sub is_lazy_build { $_[0]->{lazy_build} } |
f6715552 |
197 | sub is_weak_ref { $_[0]->{weak_ref} } |
198 | sub init_arg { $_[0]->{init_arg} } |
199 | sub type_constraint { $_[0]->{type_constraint} } |
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200 | |
f6715552 |
201 | sub trigger { $_[0]->{trigger} } |
202 | sub builder { $_[0]->{builder} } |
203 | sub should_auto_deref { $_[0]->{auto_deref} } |
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204 | sub should_coerce { $_[0]->{coerce} } |
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205 | |
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206 | # predicates |
207 | |
208 | sub has_accessor { exists $_[0]->{accessor} } |
209 | sub has_reader { exists $_[0]->{reader} } |
210 | sub has_writer { exists $_[0]->{writer} } |
f6715552 |
211 | sub has_predicate { exists $_[0]->{predicate} } |
212 | sub has_clearer { exists $_[0]->{clearer} } |
213 | sub has_handles { exists $_[0]->{handles} } |
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214 | |
215 | sub has_default { exists $_[0]->{default} } |
f6715552 |
216 | sub has_type_constraint { exists $_[0]->{type_constraint} } |
217 | sub has_trigger { exists $_[0]->{trigger} } |
218 | sub has_builder { exists $_[0]->{builder} } |
eec1bb49 |
219 | |
1bfebf5f |
220 | sub _create_args { |
221 | $_[0]->{_create_args} = $_[1] if @_ > 1; |
222 | $_[0]->{_create_args} |
223 | } |
224 | |
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225 | sub accessor_metaclass { 'Mouse::Meta::Method::Accessor' } |
226 | |
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227 | sub create { |
228 | my ($self, $class, $name, %args) = @_; |
229 | |
2608b115 |
230 | my $attribute = $self->new($name, %args); |
1bfebf5f |
231 | |
724c77c0 |
232 | $attribute->_create_args(\%args); |
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233 | |
724c77c0 |
234 | $class->add_attribute($attribute); |
2efc0af1 |
235 | weaken($attribute->{associated_class} = $class); |
b2500191 |
236 | |
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237 | my $associated_methods = 0; |
238 | |
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239 | my $generator_class = $self->accessor_metaclass; |
240 | foreach my $type(qw(accessor reader writer predicate clearer handles)){ |
241 | if(exists $attribute->{$type}){ |
242 | my $installer = '_install_' . $type; |
243 | $generator_class->$installer($attribute, $attribute->{$type}, $class); |
74be9f76 |
244 | $associated_methods++; |
c3398f5b |
245 | } |
246 | } |
247 | |
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248 | if($associated_methods == 0 && ($attribute->_is_metadata || '') ne 'bare'){ |
c8c1aeaf |
249 | Carp::cluck(qq{Attribute ($name) of class }.$class->name.qq{ has no associated methods (did you mean to provide an "is" argument?)}); |
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250 | |
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251 | } |
252 | |
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253 | return $attribute; |
254 | } |
255 | |
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256 | sub verify_against_type_constraint { |
f55f60dd |
257 | my ($self, $value) = @_; |
258 | my $tc = $self->type_constraint; |
259 | return 1 unless $tc; |
5aa30ced |
260 | |
f55f60dd |
261 | local $_ = $value; |
262 | return 1 if $tc->check($value); |
5aa30ced |
263 | |
f55f60dd |
264 | $self->verify_type_constraint_error($self->name, $value, $tc); |
b3b74cc6 |
265 | } |
5aa30ced |
266 | |
b3b74cc6 |
267 | sub verify_type_constraint_error { |
268 | my($self, $name, $value, $type) = @_; |
fce211ae |
269 | $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value)); |
5aa30ced |
270 | } |
271 | |
8a7f2a8a |
272 | sub coerce_constraint { ## my($self, $value) = @_; |
273 | my $type = $_[0]->{type_constraint} |
274 | or return $_[1]; |
684db121 |
275 | return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]); |
4188b837 |
276 | } |
277 | |
af745d5a |
278 | sub _canonicalize_handles { |
279 | my $self = shift; |
280 | my $handles = shift; |
281 | |
282 | if (ref($handles) eq 'HASH') { |
283 | return %$handles; |
284 | } |
285 | elsif (ref($handles) eq 'ARRAY') { |
286 | return map { $_ => $_ } @$handles; |
287 | } |
288 | else { |
fce211ae |
289 | $self->throw_error("Unable to canonicalize the 'handles' option with $handles"); |
af745d5a |
290 | } |
291 | } |
292 | |
1bfebf5f |
293 | sub clone_parent { |
294 | my $self = shift; |
295 | my $class = shift; |
296 | my $name = shift; |
297 | my %args = ($self->get_parent_args($class, $name), @_); |
298 | |
299 | $self->create($class, $name, %args); |
300 | } |
301 | |
302 | sub get_parent_args { |
303 | my $self = shift; |
304 | my $class = shift; |
305 | my $name = shift; |
306 | |
724c77c0 |
307 | for my $super ($class->linearized_isa) { |
bb733405 |
308 | my $super_attr = $super->can("meta") && $super->meta->get_attribute($name) |
1bfebf5f |
309 | or next; |
310 | return %{ $super_attr->_create_args }; |
311 | } |
312 | |
fce211ae |
313 | $self->throw_error("Could not find an attribute by the name of '$name' to inherit from"); |
314 | } |
315 | |
316 | sub throw_error{ |
317 | my $self = shift; |
318 | |
319 | my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class'; |
320 | $metaclass->throw_error(@_, depth => 1); |
1bfebf5f |
321 | } |
322 | |
c3398f5b |
323 | 1; |
324 | |
325 | __END__ |
326 | |
327 | =head1 NAME |
328 | |
306290e8 |
329 | Mouse::Meta::Attribute - attribute metaclass |
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330 | |
331 | =head1 METHODS |
332 | |
306290e8 |
333 | =head2 new %args -> Mouse::Meta::Attribute |
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334 | |
306290e8 |
335 | Instantiates a new Mouse::Meta::Attribute. Does nothing else. |
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336 | |
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337 | =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
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338 | |
339 | Creates a new attribute in OwnerClass. Accessors and helper methods are |
340 | installed. Some error checking is done. |
341 | |
342 | =head2 name -> AttributeName |
343 | |
181502b9 |
344 | =head2 associated_class -> OwnerClass |
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345 | |
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346 | =head2 is_required -> Bool |
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347 | |
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348 | =head2 default -> Item |
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349 | |
ab27a55e |
350 | =head2 has_default -> Bool |
351 | |
352 | =head2 is_lazy -> Bool |
353 | |
354 | =head2 predicate -> MethodName | Undef |
355 | |
356 | =head2 has_predicate -> Bool |
357 | |
358 | =head2 clearer -> MethodName | Undef |
359 | |
360 | =head2 has_clearer -> Bool |
c3398f5b |
361 | |
362 | =head2 handles -> { LocalName => RemoteName } |
363 | |
ab27a55e |
364 | =head2 has_handles -> Bool |
365 | |
3645b316 |
366 | =head2 is_weak_ref -> Bool |
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367 | |
368 | =head2 init_arg -> Str |
369 | |
ab27a55e |
370 | =head2 type_constraint -> Str |
371 | |
372 | =head2 has_type_constraint -> Bool |
373 | |
374 | =head2 trigger => CODE | Undef |
375 | |
376 | =head2 has_trigger -> Bool |
377 | |
378 | =head2 builder => MethodName | Undef |
379 | |
380 | =head2 has_builder -> Bool |
381 | |
93f08899 |
382 | =head2 is_lazy_build => Bool |
383 | |
0fff36e6 |
384 | =head2 should_auto_deref -> Bool |
385 | |
c3398f5b |
386 | Informational methods. |
387 | |
20e25eb9 |
388 | =head2 verify_against_type_constraint Item -> 1 | ERROR |
fb706f5c |
389 | |
390 | Checks that the given value passes this attribute's type constraint. Returns 1 |
391 | on success, otherwise C<confess>es. |
392 | |
93d190e0 |
393 | =head2 canonicalize_args Name, %args -> %args |
394 | |
395 | Canonicalizes some arguments to create. In particular, C<lazy_build> is |
396 | canonicalized into C<lazy>, C<builder>, etc. |
397 | |
1bbaa8ed |
398 | =head2 validate_args Name, \%args -> 1 | ERROR |
93d190e0 |
399 | |
400 | Checks that the arguments to create the attribute (ie those specified by |
401 | C<has>) are valid. |
402 | |
f7b11a21 |
403 | =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute |
404 | |
405 | Creates a new attribute in OwnerClass, inheriting options from parent classes. |
406 | Accessors and helper methods are installed. Some error checking is done. |
407 | |
408 | =head2 get_parent_args OwnerClass, AttributeName -> Hash |
409 | |
410 | Returns the options that the parent class of C<OwnerClass> used for attribute |
411 | C<AttributeName>. |
412 | |
c3398f5b |
413 | =cut |
414 | |
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415 | \0\0\0\0 |