1 package Mouse::Meta::Attribute;
13 my $name = $args{name};
15 $args{init_arg} = $name
16 unless exists $args{init_arg};
23 sub name { $_[0]->{name} }
24 sub associated_class { $_[0]->{associated_class} }
25 sub _is_metadata { $_[0]->{is} }
26 sub is_required { $_[0]->{required} }
27 sub default { $_[0]->{default} }
28 sub is_lazy { $_[0]->{lazy} }
29 sub is_lazy_build { $_[0]->{lazy_build} }
30 sub predicate { $_[0]->{predicate} }
31 sub clearer { $_[0]->{clearer} }
32 sub handles { $_[0]->{handles} }
33 sub is_weak_ref { $_[0]->{weak_ref} }
34 sub init_arg { $_[0]->{init_arg} }
35 sub type_constraint { $_[0]->{type_constraint} }
36 sub trigger { $_[0]->{trigger} }
37 sub builder { $_[0]->{builder} }
38 sub should_auto_deref { $_[0]->{auto_deref} }
39 sub should_coerce { $_[0]->{should_coerce} }
41 sub has_default { exists $_[0]->{default} }
42 sub has_predicate { exists $_[0]->{predicate} }
43 sub has_clearer { exists $_[0]->{clearer} }
44 sub has_handles { exists $_[0]->{handles} }
45 sub has_type_constraint { exists $_[0]->{type_constraint} }
46 sub has_trigger { exists $_[0]->{trigger} }
47 sub has_builder { exists $_[0]->{builder} }
49 sub find_type_constraint { $_[0]->{find_type_constraint} }
52 $_[0]->{_create_args} = $_[1] if @_ > 1;
58 my $name = $self->name;
59 my $key = "'" . $name . "'";
63 sub generate_accessor {
64 my $attribute = shift;
66 my $name = $attribute->name;
67 my $default = $attribute->default;
68 my $constraint = $attribute->find_type_constraint;
69 my $builder = $attribute->builder;
70 my $trigger = $attribute->trigger;
71 my $is_weak = $attribute->is_weak_ref;
72 my $should_deref = $attribute->should_auto_deref;
73 my $should_coerce = $attribute->should_coerce;
76 my $key = $attribute->inlined_name;
78 my $accessor = "sub {\n";
79 if ($attribute->_is_metadata eq 'rw') {
80 $accessor .= 'if (scalar(@_) >= 2) {' . "\n";
85 $accessor .= 'my $val = ';
87 $accessor .= 'Mouse::TypeRegistry->typecast_constraints("'.$attribute->associated_class->name.'", $attribute->{find_type_constraint}, $attribute->{type_constraint}, '.$value.');';
89 $accessor .= $value.';';
91 $accessor .= 'local $_ = $val;';
93 unless ($constraint->()) {
94 $attribute->verify_type_constraint_error($name, $_, $attribute->type_constraint);
99 # if there's nothing left to do for the attribute we can return during
101 $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref;
103 $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n";
106 $accessor .= 'Scalar::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n";
110 $accessor .= '$trigger->('.$self.', '.$value.', $attribute);' . "\n";
116 $accessor .= 'confess "Cannot assign a value to a read-only accessor" if scalar(@_) >= 2;' . "\n";
119 if ($attribute->is_lazy) {
120 $accessor .= $self.'->{'.$key.'} = ';
122 $accessor .= $attribute->has_builder
124 : ref($default) eq 'CODE'
125 ? '$default->('.$self.')'
127 $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n";
131 my $type_constraint = $attribute->type_constraint;
132 if (!ref($type_constraint) && $type_constraint eq 'ArrayRef') {
133 $accessor .= 'if (wantarray) {
134 return @{ '.$self.'->{'.$key.'} || [] };
138 $accessor .= 'if (wantarray) {
139 return %{ '.$self.'->{'.$key.'} || {} };
144 $accessor .= 'return '.$self.'->{'.$key.'};
147 my $sub = eval $accessor;
152 sub generate_predicate {
153 my $attribute = shift;
154 my $key = $attribute->inlined_name;
156 my $predicate = 'sub { exists($_[0]->{'.$key.'}) }';
158 my $sub = eval $predicate;
163 sub generate_clearer {
164 my $attribute = shift;
165 my $key = $attribute->inlined_name;
167 my $clearer = 'sub { delete($_[0]->{'.$key.'}) }';
169 my $sub = eval $clearer;
174 sub generate_handles {
175 my $attribute = shift;
176 my $reader = $attribute->name;
177 my %handles = $attribute->_canonicalize_handles($attribute->handles);
181 for my $local_method (keys %handles) {
182 my $remote_method = $handles{$local_method};
186 $self->'.$reader.'->'.$remote_method.'(@_)
189 $method_map{$local_method} = eval $method;
197 my ($self, $class, $name, %args) = @_;
200 $args{associated_class} = $class;
202 %args = $self->canonicalize_args($name, %args);
203 $self->validate_args($name, \%args);
205 $args{should_coerce} = delete $args{coerce}
206 if exists $args{coerce};
208 if (exists $args{isa}) {
209 my $type_constraint = delete $args{isa};
210 $type_constraint =~ s/\s//g;
211 my @type_constraints = split /\|/, $type_constraint;
214 my $optimized_constraints = Mouse::TypeRegistry->optimized_constraints;
215 if (@type_constraints == 1) {
216 $code = $optimized_constraints->{$type_constraints[0]} ||
217 sub { Scalar::Util::blessed($_) && Scalar::Util::blessed($_) eq $type_constraints[0] };
218 $args{type_constraint} = $type_constraints[0];
220 my @code_list = map {
222 $optimized_constraints->{$type} ||
223 sub { Scalar::Util::blessed($_) && Scalar::Util::blessed($_) eq $type }
226 for my $code (@code_list) {
227 return 1 if $code->();
231 $args{type_constraint} = \@type_constraints;
233 $args{find_type_constraint} = $code;
236 my $attribute = $self->new(%args);
238 $attribute->_create_args(\%args);
240 $class->add_attribute($attribute);
242 # install an accessor
243 if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') {
244 my $accessor = $attribute->generate_accessor;
245 $class->add_method($name => $accessor);
248 for my $method (qw/predicate clearer/) {
249 my $predicate = "has_$method";
250 if ($attribute->$predicate) {
251 my $generator = "generate_$method";
252 my $coderef = $attribute->$generator;
253 $class->add_method($attribute->$method => $coderef);
257 if ($attribute->has_handles) {
258 my $method_map = $attribute->generate_handles;
259 for my $method_name (keys %$method_map) {
260 $class->add_method($method_name => $method_map->{$method_name});
267 sub canonicalize_args {
272 if ($args{lazy_build}) {
275 $args{builder} = "_build_${name}"
276 if !exists($args{builder});
278 $args{clearer} = "_clear${name}" if !exists($args{clearer});
279 $args{predicate} = "_has${name}" if !exists($args{predicate});
282 $args{clearer} = "clear_${name}" if !exists($args{clearer});
283 $args{predicate} = "has_${name}" if !exists($args{predicate});
295 confess "You can not use lazy_build and default for the same attribute ($name)"
296 if $args->{lazy_build} && exists $args->{default};
298 confess "You cannot have lazy attribute ($name) without specifying a default value for it"
300 && !exists($args->{default})
301 && !exists($args->{builder});
303 confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
304 if ref($args->{default})
305 && ref($args->{default}) ne 'CODE';
307 confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)"
308 if $args->{auto_deref} && !exists($args->{isa});
310 confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"
311 if $args->{auto_deref}
312 && $args->{isa} ne 'ArrayRef'
313 && $args->{isa} ne 'HashRef';
315 if ($args->{trigger}) {
316 if (ref($args->{trigger}) eq 'HASH') {
317 Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported.";
320 confess "Trigger must be a CODE ref on attribute ($name)"
321 if ref($args->{trigger}) ne 'CODE';
327 sub verify_type_constraint {
328 return 1 unless $_[0]->{type_constraint};
331 return 1 if $_[0]->{find_type_constraint}->($_);
334 $self->verify_type_constraint_error($self->name, $_, $self->type_constraint);
337 sub verify_type_constraint_error {
338 my($self, $name, $value, $type) = @_;
339 $type = ref($type) eq 'ARRAY' ? join '|', @{ $type } : $type;
340 my $display = defined($_) ? overload::StrVal($_) : 'undef';
341 Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display");
344 sub coerce_constraint { ## my($self, $value) = @_;
345 my $type = $_[0]->{type_constraint}
347 return Mouse::TypeRegistry->typecast_constraints($_[0]->associated_class->name, $_[0]->find_type_constraint, $type, $_[1]);
350 sub _canonicalize_handles {
354 if (ref($handles) eq 'HASH') {
357 elsif (ref($handles) eq 'ARRAY') {
358 return map { $_ => $_ } @$handles;
361 confess "Unable to canonicalize the 'handles' option with $handles";
369 my %args = ($self->get_parent_args($class, $name), @_);
371 $self->create($class, $name, %args);
374 sub get_parent_args {
379 for my $super ($class->linearized_isa) {
380 my $super_attr = $super->can("meta") && $super->meta->get_attribute($name)
382 return %{ $super_attr->_create_args };
385 confess "Could not find an attribute by the name of '$name' to inherit from";
394 Mouse::Meta::Attribute - attribute metaclass
398 =head2 new %args -> Mouse::Meta::Attribute
400 Instantiates a new Mouse::Meta::Attribute. Does nothing else.
402 =head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
404 Creates a new attribute in OwnerClass. Accessors and helper methods are
405 installed. Some error checking is done.
407 =head2 name -> AttributeName
409 =head2 associated_class -> OwnerClass
411 =head2 is_required -> Bool
413 =head2 default -> Item
415 =head2 has_default -> Bool
417 =head2 is_lazy -> Bool
419 =head2 predicate -> MethodName | Undef
421 =head2 has_predicate -> Bool
423 =head2 clearer -> MethodName | Undef
425 =head2 has_clearer -> Bool
427 =head2 handles -> { LocalName => RemoteName }
429 =head2 has_handles -> Bool
431 =head2 is_weak_ref -> Bool
433 =head2 init_arg -> Str
435 =head2 type_constraint -> Str
437 =head2 has_type_constraint -> Bool
439 =head2 trigger => CODE | Undef
441 =head2 has_trigger -> Bool
443 =head2 builder => MethodName | Undef
445 =head2 has_builder -> Bool
447 =head2 is_lazy_build => Bool
449 =head2 should_auto_deref -> Bool
451 Informational methods.
453 =head2 generate_accessor -> CODE
455 Creates a new code reference for the attribute's accessor.
457 =head2 generate_predicate -> CODE
459 Creates a new code reference for the attribute's predicate.
461 =head2 generate_clearer -> CODE
463 Creates a new code reference for the attribute's clearer.
465 =head2 generate_handles -> { MethodName => CODE }
467 Creates a new code reference for each of the attribute's handles methods.
469 =head2 find_type_constraint -> CODE
471 Returns a code reference which can be used to check that a given value passes
472 this attribute's type constraint;
474 =head2 verify_type_constraint Item -> 1 | ERROR
476 Checks that the given value passes this attribute's type constraint. Returns 1
477 on success, otherwise C<confess>es.
479 =head2 canonicalize_args Name, %args -> %args
481 Canonicalizes some arguments to create. In particular, C<lazy_build> is
482 canonicalized into C<lazy>, C<builder>, etc.
484 =head2 validate_args Name, \%args -> 1 | ERROR
486 Checks that the arguments to create the attribute (ie those specified by
489 =head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
491 Creates a new attribute in OwnerClass, inheriting options from parent classes.
492 Accessors and helper methods are installed. Some error checking is done.
494 =head2 get_parent_args OwnerClass, AttributeName -> Hash
496 Returns the options that the parent class of C<OwnerClass> used for attribute