package Mouse::Meta::Attribute;
-use strict;
-use warnings;
+use Mouse::Util qw(:meta); # enables strict and warnings
+
+use Carp ();
-use Carp 'confess';
-use Scalar::Util ();
use Mouse::Meta::TypeConstraint;
+my %valid_options = map { $_ => undef } (
+ 'accessor',
+ 'auto_deref',
+ 'builder',
+ 'clearer',
+ 'coerce',
+ 'default',
+ 'documentation',
+ 'does',
+ 'handles',
+ 'init_arg',
+ 'is',
+ 'isa',
+ 'lazy',
+ 'lazy_build',
+ 'name',
+ 'predicate',
+ 'reader',
+ 'required',
+ 'traits',
+ 'trigger',
+ 'type_constraint',
+ 'weak_ref',
+ 'writer',
+
+ # internally used
+ 'associated_class',
+ 'associated_methods',
+
+ # Moose defines, but Mouse doesn't
+ #'definition_context',
+ #'initializer',
+ #'insertion_order',
+
+ # special case for AttributeHelpers
+ 'provides',
+ 'curries',
+);
+
sub new {
- my ($class, $name, %options) = @_;
+ my $class = shift;
+ my $name = shift;
- $options{name} = $name;
+ my $args = $class->Mouse::Object::BUILDARGS(@_);
- $options{init_arg} = $name
- unless exists $options{init_arg};
+ # XXX: for backward compatibility (with method modifiers)
+ if($class->can('canonicalize_args') != \&canonicalize_args){
+ %{$args} = $class->canonicalize_args($name, %{$args});
+ }
- $options{is} ||= '';
+ $class->_process_options($name, $args);
- bless \%options, $class;
-}
+ $args->{name} = $name;
+
+ # check options
+ # (1) known by core
+ my @bad = grep{ !exists $valid_options{$_} } keys %{$args};
+
+ # (2) known by subclasses
+ if(@bad && $class ne __PACKAGE__){
+ my %valid_attrs = (
+ map { $_ => undef }
+ grep { defined }
+ map { $_->init_arg() }
+ $class->meta->get_all_attributes()
+ );
+ @bad = grep{ !exists $valid_attrs{$_} } @bad;
+ }
+
+ # (3) bad options found
+ if(@bad){
+ @bad = sort @bad;
+ Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad");
+ }
+
+ my $self = bless $args, $class;
-sub name { $_[0]->{name} }
-sub associated_class { $_[0]->{associated_class} }
-sub _is_metadata { $_[0]->{is} }
-sub is_required { $_[0]->{required} }
-sub default { $_[0]->{default} }
-sub is_lazy { $_[0]->{lazy} }
-sub is_lazy_build { $_[0]->{lazy_build} }
-sub predicate { $_[0]->{predicate} }
-sub clearer { $_[0]->{clearer} }
-sub handles { $_[0]->{handles} }
-sub is_weak_ref { $_[0]->{weak_ref} }
-sub init_arg { $_[0]->{init_arg} }
-sub type_constraint { $_[0]->{type_constraint} }
-sub find_type_constraint {
- Carp::carp("This method was deprecated");
- $_[0]->type_constraint();
+ # extra attributes
+ if($class ne __PACKAGE__){
+ $class->meta->_initialize_object($self, $args);
+ }
+
+ return $self;
}
-sub trigger { $_[0]->{trigger} }
-sub builder { $_[0]->{builder} }
-sub should_auto_deref { $_[0]->{auto_deref} }
-sub should_coerce { $_[0]->{should_coerce} }
-
-sub has_default { exists $_[0]->{default} }
-sub has_predicate { exists $_[0]->{predicate} }
-sub has_clearer { exists $_[0]->{clearer} }
-sub has_handles { exists $_[0]->{handles} }
-sub has_type_constraint { exists $_[0]->{type_constraint} }
-sub has_trigger { exists $_[0]->{trigger} }
-sub has_builder { exists $_[0]->{builder} }
-
-sub _create_args {
+
+sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor }
+sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor }
+
+sub _create_args { # DEPRECATED
$_[0]->{_create_args} = $_[1] if @_ > 1;
$_[0]->{_create_args}
}
-sub _inlined_name {
- my $self = shift;
- return sprintf '"%s"', quotemeta $self->name;
-}
+sub interpolate_class{
+ my($class, $args) = @_;
-sub _generate_accessor{
- my ($attribute) = @_;
-
- my $name = $attribute->name;
- my $default = $attribute->default;
- my $constraint = $attribute->type_constraint;
- my $builder = $attribute->builder;
- my $trigger = $attribute->trigger;
- my $is_weak = $attribute->is_weak_ref;
- my $should_deref = $attribute->should_auto_deref;
- my $should_coerce = $attribute->should_coerce;
-
- my $compiled_type_constraint = $constraint ? $constraint->{_compiled_type_constraint} : undef;
-
- my $self = '$_[0]';
- my $key = $attribute->_inlined_name;
-
- my $accessor =
- '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" .
- "sub {\n";
- if ($attribute->_is_metadata eq 'rw') {
- $accessor .=
- '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" .
- 'if (scalar(@_) >= 2) {' . "\n";
-
- my $value = '$_[1]';
-
- if ($constraint) {
- if ($should_coerce) {
- $accessor .=
- "\n".
- '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" .
- 'my $val = Mouse::Util::TypeConstraints->typecast_constraints("'.$attribute->associated_class->name.'", $attribute->{type_constraint}, '.$value.');';
- $value = '$val';
- }
- if ($compiled_type_constraint) {
- $accessor .=
- "\n".
- '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" .
- 'unless ($compiled_type_constraint->('.$value.')) {
- $attribute->verify_type_constraint_error($name, '.$value.', $attribute->{type_constraint});
- }' . "\n";
- } else {
- $accessor .=
- "\n".
- '#line ' . __LINE__ . ' "' . __FILE__ . "\"\n" .
- 'unless ($constraint->check('.$value.')) {
- $attribute->verify_type_constraint_error($name, '.$value.', $attribute->{type_constraint});
- }' . "\n";
- }
- }
+ if(my $metaclass = delete $args->{metaclass}){
+ $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass );
+ }
- # if there's nothing left to do for the attribute we can return during
- # this setter
- $accessor .= 'return ' if !$is_weak && !$trigger && !$should_deref;
+ my @traits;
+ if(my $traits_ref = delete $args->{traits}){
- $accessor .= $self.'->{'.$key.'} = '.$value.';' . "\n";
+ for (my $i = 0; $i < @{$traits_ref}; $i++) {
+ my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1);
- if ($is_weak) {
- $accessor .= 'Scalar::Util::weaken('.$self.'->{'.$key.'}) if ref('.$self.'->{'.$key.'});' . "\n";
- }
+ next if $class->does($trait);
+
+ push @traits, $trait;
- if ($trigger) {
- $accessor .= '$trigger->('.$self.', '.$value.');' . "\n";
+ # are there options?
+ push @traits, $traits_ref->[++$i]
+ if ref($traits_ref->[$i+1]);
}
- $accessor .= "}\n";
- }
- else {
- $accessor .= 'Carp::confess("Cannot assign a value to a read-only accessor") if scalar(@_) >= 2;' . "\n";
+ if (@traits) {
+ $class = Mouse::Meta::Class->create_anon_class(
+ superclasses => [ $class ],
+ roles => \@traits,
+ cache => 1,
+ )->name;
+ }
}
- if ($attribute->is_lazy) {
- $accessor .= $self.'->{'.$key.'} = ';
+ return( $class, @traits );
+}
- $accessor .= $attribute->has_builder
- ? $self.'->$builder'
- : ref($default) eq 'CODE'
- ? '$default->('.$self.')'
- : '$default';
- $accessor .= ' if !exists '.$self.'->{'.$key.'};' . "\n";
- }
+sub canonicalize_args{ # DEPRECATED
+ my ($self, $name, %args) = @_;
- if ($should_deref) {
- if (ref($constraint) && $constraint->name =~ '^ArrayRef\b') {
- $accessor .= 'if (wantarray) {
- return @{ '.$self.'->{'.$key.'} || [] };
- }';
- }
- else {
- $accessor .= 'if (wantarray) {
- return %{ '.$self.'->{'.$key.'} || {} };
- }';
- }
- }
+ Carp::cluck("$self->canonicalize_args has been deprecated."
+ . "Use \$self->_process_options instead.");
- $accessor .= 'return '.$self.'->{'.$key.'};
- }';
+ return %args;
+}
+
+sub create { # DEPRECATED
+ my ($self, $class, $name, %args) = @_;
+
+ Carp::cluck("$self->create has been deprecated."
+ . "Use \$meta->add_attribute and \$attr->install_accessors instead.");
- my $sub = eval $accessor;
- Carp::confess($@) if $@;
- return $sub;
+ # noop
+ return $self;
}
+sub _coerce_and_verify {
+ my($self, $value, $instance) = @_;
-sub _generate_predicate {
- my $attribute = shift;
- my $key = $attribute->_inlined_name;
+ my $type_constraint = $self->{type_constraint};
+ return $value if !defined $type_constraint;
- my $predicate = 'sub { exists($_[0]->{'.$key.'}) }';
+ if ($self->should_coerce && $type_constraint->has_coercion) {
+ $value = $type_constraint->coerce($value);
+ }
+
+ $self->verify_against_type_constraint($value);
- my $sub = eval $predicate;
- confess $@ if $@;
- return $sub;
+ return $value;
}
-sub _generate_clearer {
- my $attribute = shift;
- my $key = $attribute->_inlined_name;
+sub verify_against_type_constraint {
+ my ($self, $value) = @_;
- my $clearer = 'sub { delete($_[0]->{'.$key.'}) }';
+ my $type_constraint = $self->{type_constraint};
+ return 1 if !$type_constraint;
+ return 1 if $type_constraint->check($value);
- my $sub = eval $clearer;
- confess $@ if $@;
- return $sub;
+ $self->_throw_type_constraint_error($value, $type_constraint);
}
-sub _generate_handles {
- my $attribute = shift;
- my $reader = $attribute->name;
- my %handles = $attribute->_canonicalize_handles($attribute->handles);
+sub _throw_type_constraint_error {
+ my($self, $value, $type) = @_;
- my %method_map;
+ $self->throw_error(
+ sprintf q{Attribute (%s) does not pass the type constraint because: %s},
+ $self->name,
+ $type->get_message($value),
+ );
+}
- for my $local_method (keys %handles) {
- my $remote_method = $handles{$local_method};
+sub clone_and_inherit_options{
+ my $self = shift;
+ my $args = $self->Mouse::Object::BUILDARGS(@_);
- my $method = 'sub {
- my $self = shift;
- $self->'.$reader.'->'.$remote_method.'(@_)
- }';
+ my($attribute_class, @traits) = ref($self)->interpolate_class($args);
- $method_map{$local_method} = eval $method;
- confess $@ if $@;
+ $args->{traits} = \@traits if @traits;
+ # do not inherit the 'handles' attribute
+ foreach my $name(keys %{$self}){
+ if(!exists $args->{$name} && $name ne 'handles'){
+ $args->{$name} = $self->{$name};
+ }
}
- return \%method_map;
-}
+ # remove temporary caches
+ foreach my $attr(keys %{$args}){
+ if($attr =~ /\A _/xms){
+ delete $args->{$attr};
+ }
+ }
-sub create {
- my ($self, $class, $name, %args) = @_;
+ return $attribute_class->new($self->name, $args);
+}
- $args{name} = $name;
- $args{associated_class} = $class;
+sub clone_parent { # DEPRECATED
+ my $self = shift;
+ my $class = shift;
+ my $name = shift;
+ my %args = ($self->get_parent_args($class, $name), @_);
- %args = $self->canonicalize_args($name, %args);
- $self->validate_args($name, \%args);
+ Carp::cluck("$self->clone_parent has been deprecated."
+ . "Use \$meta->add_attribute and \$attr->install_accessors instead.");
- $args{should_coerce} = delete $args{coerce}
- if exists $args{coerce};
+ $self->clone_and_inherited_args($class, $name, %args);
+}
- if (exists $args{isa}) {
- confess "Got isa => $args{isa}, but Mouse does not yet support parameterized types for containers other than ArrayRef and HashRef (rt.cpan.org #39795)"
- if $args{isa} =~ /^([^\[]+)\[.+\]$/ &&
- $1 ne 'ArrayRef' &&
- $1 ne 'HashRef' &&
- $1 ne 'Maybe'
- ;
+sub get_parent_args { # DEPRECATED
+ my $self = shift;
+ my $class = shift;
+ my $name = shift;
- my $type_constraint = delete $args{isa};
- $args{type_constraint}= Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($type_constraint);
+ for my $super ($class->linearized_isa) {
+ my $super_attr = $super->can("meta") && $super->meta->get_attribute($name)
+ or next;
+ return %{ $super_attr->_create_args };
}
- my $attribute = $self->new($name, %args);
+ $self->throw_error("Could not find an attribute by the name of '$name' to inherit from");
+}
- $attribute->_create_args(\%args);
- $class->add_attribute($attribute);
+sub get_read_method {
+ return $_[0]->reader || $_[0]->accessor
+}
+sub get_write_method {
+ return $_[0]->writer || $_[0]->accessor
+}
- my $associated_methods = 0;
+sub _get_accessor_method_ref {
+ my($self, $type, $generator) = @_;
- my $is_metadata = $attribute->_is_metadata || '';
+ my $metaclass = $self->associated_class
+ || $self->throw_error('No asocciated class for ' . $self->name);
- # install an accessor
- if ($is_metadata eq 'rw' || $is_metadata eq 'ro') {
- my $code = $attribute->_generate_accessor();
- $class->add_method($name => $code);
- $associated_methods++;
+ my $accessor = $self->$type();
+ if($accessor){
+ return $metaclass->get_method_body($accessor);
}
-
- for my $method (qw/predicate clearer/) {
- my $predicate = "has_$method";
- if ($attribute->$predicate) {
- my $generator = "_generate_$method";
- my $coderef = $attribute->$generator;
- $class->add_method($attribute->$method => $coderef);
- $associated_methods++;
- }
+ else{
+ return $self->accessor_metaclass->$generator($self, $metaclass);
}
+}
- if ($attribute->has_handles) {
- my $method_map = $attribute->_generate_handles;
- for my $method_name (keys %$method_map) {
- $class->add_method($method_name => $method_map->{$method_name});
- $associated_methods++;
- }
- }
+sub get_read_method_ref{
+ my($self) = @_;
+ return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader');
+}
- if($associated_methods == 0 && $is_metadata ne 'bare'){
- confess(qq{Attribute ($name) of class }.$class->name.qq{ has no associated methods (did you mean to provide an "is" argument?)});
- }
+sub get_write_method_ref{
+ my($self) = @_;
+ return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer');
+}
- return $attribute;
+sub set_value {
+ my($self, $object, $value) = @_;
+ return $self->get_write_method_ref()->($object, $value);
}
-sub canonicalize_args {
- my $self = shift;
- my $name = shift;
- my %args = @_;
-
- if ($args{lazy_build}) {
- $args{lazy} = 1;
- $args{required} = 1;
- $args{builder} = "_build_${name}"
- if !exists($args{builder});
- if ($name =~ /^_/) {
- $args{clearer} = "_clear${name}" if !exists($args{clearer});
- $args{predicate} = "_has${name}" if !exists($args{predicate});
- }
- else {
- $args{clearer} = "clear_${name}" if !exists($args{clearer});
- $args{predicate} = "has_${name}" if !exists($args{predicate});
- }
- }
+sub get_value {
+ my($self, $object) = @_;
+ return $self->get_read_method_ref()->($object);
+}
- return %args;
+sub has_value {
+ my($self, $object) = @_;
+ my $accessor_ref = $self->{_predicate_ref}
+ ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate');
+
+ return $accessor_ref->($object);
}
-sub validate_args {
- my $self = shift;
- my $name = shift;
- my $args = shift;
+sub clear_value {
+ my($self, $object) = @_;
+ my $accessor_ref = $self->{_crealer_ref}
+ ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer');
- confess "You can not use lazy_build and default for the same attribute ($name)"
- if $args->{lazy_build} && exists $args->{default};
+ return $accessor_ref->($object);
+}
- confess "You cannot have lazy attribute ($name) without specifying a default value for it"
- if $args->{lazy}
- && !exists($args->{default})
- && !exists($args->{builder});
- confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
- if ref($args->{default})
- && ref($args->{default}) ne 'CODE';
+sub associate_method{
+ my ($attribute, $method_name) = @_;
+ $attribute->{associated_methods}++;
+ return;
+}
- confess "You cannot auto-dereference without specifying a type constraint on attribute ($name)"
- if $args->{auto_deref} && !exists($args->{isa});
+sub install_accessors{
+ my($attribute) = @_;
- confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)"
- if $args->{auto_deref}
- && $args->{isa} !~ /^(?:ArrayRef|HashRef)(?:\[.*\])?$/;
+ my $metaclass = $attribute->associated_class;
+ my $accessor_class = $attribute->accessor_metaclass;
- if ($args->{trigger}) {
- if (ref($args->{trigger}) eq 'HASH') {
- Carp::carp "HASH-based form of trigger has been removed. Only the coderef form of triggers are now supported.";
+ foreach my $type(qw(accessor reader writer predicate clearer)){
+ if(exists $attribute->{$type}){
+ my $generator = '_generate_' . $type;
+ my $code = $accessor_class->$generator($attribute, $metaclass);
+ $metaclass->add_method($attribute->{$type} => $code);
+ $attribute->associate_method($attribute->{$type});
}
-
- confess "Trigger must be a CODE ref on attribute ($name)"
- if ref($args->{trigger}) ne 'CODE';
}
- return 1;
-}
+ # install delegation
+ if(exists $attribute->{handles}){
+ my %handles = $attribute->_canonicalize_handles($attribute->{handles});
-sub verify_against_type_constraint {
- my ($self, $value) = @_;
- my $tc = $self->type_constraint;
- return 1 unless $tc;
+ while(my($handle, $method_to_call) = each %handles){
+ $metaclass->add_method($handle =>
+ $attribute->_make_delegation_method(
+ $handle, $method_to_call));
- local $_ = $value;
- return 1 if $tc->check($value);
+ $attribute->associate_method($handle);
+ }
+ }
- $self->verify_type_constraint_error($self->name, $value, $tc);
-}
+ if($attribute->can('create') != \&create){
+ # backword compatibility
+ $attribute->create($metaclass, $attribute->name, %{$attribute});
+ }
-sub verify_type_constraint_error {
- my($self, $name, $value, $type) = @_;
- Carp::confess("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value));
+ return;
}
-sub coerce_constraint { ## my($self, $value) = @_;
- my $type = $_[0]->{type_constraint}
- or return $_[1];
- return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]);
-}
+sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' }
sub _canonicalize_handles {
- my $self = shift;
- my $handles = shift;
+ my($self, $handles) = @_;
if (ref($handles) eq 'HASH') {
return %$handles;
elsif (ref($handles) eq 'ARRAY') {
return map { $_ => $_ } @$handles;
}
+ elsif ( ref($handles) eq 'CODE' ) {
+ my $class_or_role = ( $self->{isa} || $self->{does} )
+ || $self->throw_error( "Cannot find delegate metaclass for attribute " . $self->name );
+ return $handles->( $self, Mouse::Meta::Class->initialize("$class_or_role"));
+ }
+ elsif (ref($handles) eq 'Regexp') {
+ my $class_or_role = ($self->{isa} || $self->{does})
+ || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)");
+
+ my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify
+ return map { $_ => $_ }
+ grep { !Mouse::Object->can($_) && $_ =~ $handles }
+ Mouse::Util::is_a_metarole($meta)
+ ? $meta->get_method_list
+ : $meta->get_all_method_names;
+ }
else {
- confess "Unable to canonicalize the 'handles' option with $handles";
+ $self->throw_error("Unable to canonicalize the 'handles' option with $handles");
}
}
-sub clone_parent {
- my $self = shift;
- my $class = shift;
- my $name = shift;
- my %args = ($self->get_parent_args($class, $name), @_);
+sub _make_delegation_method {
+ my($self, $handle, $method_to_call) = @_;
+ my $delegator = $self->delegation_metaclass;
+ Mouse::Util::load_class($delegator);
- $self->create($class, $name, %args);
+ return $delegator->_generate_delegation($self, $handle, $method_to_call);
}
-sub get_parent_args {
- my $self = shift;
- my $class = shift;
- my $name = shift;
-
- for my $super ($class->linearized_isa) {
- my $super_attr = $super->can("meta") && $super->meta->get_attribute($name)
- or next;
- return %{ $super_attr->_create_args };
- }
+sub throw_error{
+ my $self = shift;
- confess "Could not find an attribute by the name of '$name' to inherit from";
+ my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class';
+ $metaclass->throw_error(@_, depth => 1);
}
1;
-
__END__
=head1 NAME
-Mouse::Meta::Attribute - attribute metaclass
+Mouse::Meta::Attribute - The Mouse attribute metaclass
+
+=head1 VERSION
+
+This document describes Mouse version 0.50_02
=head1 METHODS
-=head2 new %args -> Mouse::Meta::Attribute
+=head2 C<< new(%options) -> Mouse::Meta::Attribute >>
Instantiates a new Mouse::Meta::Attribute. Does nothing else.
-=head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
+It adds the following options to the constructor:
-Creates a new attribute in OwnerClass. Accessors and helper methods are
-installed. Some error checking is done.
+=over 4
-=head2 name -> AttributeName
+=item C<< is => 'ro', 'rw', 'bare' >>
-=head2 associated_class -> OwnerClass
+This provides a shorthand for specifying the C<reader>, C<writer>, or
+C<accessor> names. If the attribute is read-only ('ro') then it will
+have a C<reader> method with the same attribute as the name.
-=head2 is_required -> Bool
+If it is read-write ('rw') then it will have an C<accessor> method
+with the same name. If you provide an explicit C<writer> for a
+read-write attribute, then you will have a C<reader> with the same
+name as the attribute, and a C<writer> with the name you provided.
-=head2 default -> Item
+Use 'bare' when you are deliberately not installing any methods
+(accessor, reader, etc.) associated with this attribute; otherwise,
+Moose will issue a deprecation warning when this attribute is added to a
+metaclass.
-=head2 has_default -> Bool
+=item C<< isa => Type >>
-=head2 is_lazy -> Bool
+This option accepts a type. The type can be a string, which should be
+a type name. If the type name is unknown, it is assumed to be a class
+name.
-=head2 predicate -> MethodName | Undef
+This option can also accept a L<Moose::Meta::TypeConstraint> object.
-=head2 has_predicate -> Bool
+If you I<also> provide a C<does> option, then your C<isa> option must
+be a class name, and that class must do the role specified with
+C<does>.
-=head2 clearer -> MethodName | Undef
+=item C<< does => Role >>
-=head2 has_clearer -> Bool
+This is short-hand for saying that the attribute's type must be an
+object which does the named role.
-=head2 handles -> { LocalName => RemoteName }
+B<This option is not yet supported.>
-=head2 has_handles -> Bool
+=item C<< coerce => Bool >>
-=head2 is_weak_ref -> Bool
+This option is only valid for objects with a type constraint
+(C<isa>). If this is true, then coercions will be applied whenever
+this attribute is set.
-=head2 init_arg -> Str
+You can make both this and the C<weak_ref> option true.
-=head2 type_constraint -> Str
+=item C<< trigger => CodeRef >>
-=head2 has_type_constraint -> Bool
+This option accepts a subroutine reference, which will be called after
+the attribute is set.
-=head2 trigger => CODE | Undef
+=item C<< required => Bool >>
-=head2 has_trigger -> Bool
+An attribute which is required must be provided to the constructor. An
+attribute which is required can also have a C<default> or C<builder>,
+which will satisfy its required-ness.
-=head2 builder => MethodName | Undef
+A required attribute must have a C<default>, C<builder> or a
+non-C<undef> C<init_arg>
-=head2 has_builder -> Bool
+=item C<< lazy => Bool >>
-=head2 is_lazy_build => Bool
+A lazy attribute must have a C<default> or C<builder>. When an
+attribute is lazy, the default value will not be calculated until the
+attribute is read.
-=head2 should_auto_deref -> Bool
+=item C<< weak_ref => Bool >>
-Informational methods.
+If this is true, the attribute's value will be stored as a weak
+reference.
-=head2 verify_against_type_constraint Item -> 1 | ERROR
+=item C<< auto_deref => Bool >>
-Checks that the given value passes this attribute's type constraint. Returns 1
-on success, otherwise C<confess>es.
+If this is true, then the reader will dereference the value when it is
+called. The attribute must have a type constraint which defines the
+attribute as an array or hash reference.
+
+=item C<< lazy_build => Bool >>
+
+Setting this to true makes the attribute lazy and provides a number of
+default methods.
+
+ has 'size' => (
+ is => 'ro',
+ lazy_build => 1,
+ );
+
+is equivalent to this:
+
+ has 'size' => (
+ is => 'ro',
+ lazy => 1,
+ builder => '_build_size',
+ clearer => 'clear_size',
+ predicate => 'has_size',
+ );
-=head2 canonicalize_args Name, %args -> %args
+=back
-Canonicalizes some arguments to create. In particular, C<lazy_build> is
-canonicalized into C<lazy>, C<builder>, etc.
+=head2 C<< associate_method(MethodName) >>
-=head2 validate_args Name, \%args -> 1 | ERROR
+Associates a method with the attribute. Typically, this is called internally
+when an attribute generates its accessors.
-Checks that the arguments to create the attribute (ie those specified by
-C<has>) are valid.
+Currently the argument I<MethodName> is ignored in Mouse.
-=head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
+=head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >>
-Creates a new attribute in OwnerClass, inheriting options from parent classes.
+Checks that the given value passes this attribute's type constraint. Returns C<true>
+on success, otherwise C<confess>es.
+
+=head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >>
+
+Creates a new attribute in the owner class, inheriting options from parent classes.
Accessors and helper methods are installed. Some error checking is done.
-=head2 get_parent_args OwnerClass, AttributeName -> Hash
+=head2 C<< get_read_method_ref >>
+
+=head2 C<< get_write_method_ref >>
+
+Returns the subroutine reference of a method suitable for reading or
+writing the attribute's value in the associated class. These methods
+always return a subroutine reference, regardless of whether or not the
+attribute is read- or write-only.
+
+=head1 SEE ALSO
+
+L<Moose::Meta::Attribute>
-Returns the options that the parent class of C<OwnerClass> used for attribute
-C<AttributeName>.
+L<Class::MOP::Attribute>
=cut
projects / gitmo/Mouse.git / blobdiff