use strict;
use warnings;
+use B ();
+use Class::Load qw(is_class_loaded load_class);
use Scalar::Util 'blessed', 'weaken';
+use List::MoreUtils 'any';
+use Try::Tiny;
use overload ();
-our $VERSION = '0.65';
-our $AUTHORITY = 'cpan:STEVAN';
-
+use Moose::Deprecated;
use Moose::Meta::Method::Accessor;
use Moose::Meta::Method::Delegation;
use Moose::Util ();
use Moose::Util::TypeConstraints ();
+use Class::MOP::MiniTrait;
+
+use base 'Class::MOP::Attribute', 'Moose::Meta::Mixin::AttributeCore';
+
+Class::MOP::MiniTrait::apply(__PACKAGE__, 'Moose::Meta::Object::Trait');
-use base 'Class::MOP::Attribute';
-
-# options which are not directly used
-# but we store them for metadata purposes
-__PACKAGE__->meta->add_attribute('isa' => (reader => '_isa_metadata'));
-__PACKAGE__->meta->add_attribute('does' => (reader => '_does_metadata'));
-__PACKAGE__->meta->add_attribute('is' => (reader => '_is_metadata'));
-
-# these are actual options for the attrs
-__PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' ));
-__PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' ));
-__PACKAGE__->meta->add_attribute('lazy_build' => (reader => 'is_lazy_build' ));
-__PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce' ));
-__PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' ));
-__PACKAGE__->meta->add_attribute('auto_deref' => (reader => 'should_auto_deref'));
-__PACKAGE__->meta->add_attribute('type_constraint' => (
- reader => 'type_constraint',
- predicate => 'has_type_constraint',
-));
-__PACKAGE__->meta->add_attribute('trigger' => (
- reader => 'trigger',
- predicate => 'has_trigger',
-));
-__PACKAGE__->meta->add_attribute('handles' => (
- reader => 'handles',
- predicate => 'has_handles',
-));
-__PACKAGE__->meta->add_attribute('documentation' => (
- reader => 'documentation',
- predicate => 'has_documentation',
-));
__PACKAGE__->meta->add_attribute('traits' => (
reader => 'applied_traits',
predicate => 'has_applied_traits',
+ Class::MOP::_definition_context(),
));
-# we need to have a ->does method in here to
-# more easily support traits, and the introspection
+# we need to have a ->does method in here to
+# more easily support traits, and the introspection
# of those traits. We extend the does check to look
# for metatrait aliases.
sub does {
my ($self, $role_name) = @_;
- my $name = eval {
+ my $name = try {
Moose::Util::resolve_metatrait_alias(Attribute => $role_name)
};
return 0 if !defined($name); # failed to load class
return $self->Moose::Object::does($name);
}
+sub _error_thrower {
+ my $self = shift;
+ require Moose::Meta::Class;
+ ( ref $self && $self->associated_class ) || "Moose::Meta::Class";
+}
+
sub throw_error {
my $self = shift;
- my $class = ( ref $self && $self->associated_class ) || "Moose::Meta::Class";
+ my $inv = $self->_error_thrower;
unshift @_, "message" if @_ % 2 == 1;
unshift @_, attr => $self if ref $self;
- unshift @_, $class;
- my $handler = $class->can("throw_error"); # to avoid incrementing depth by 1
+ unshift @_, $inv;
+ my $handler = $inv->can("throw_error"); # to avoid incrementing depth by 1
goto $handler;
}
+sub _inline_throw_error {
+ my ( $self, $msg, $args ) = @_;
+
+ my $inv = $self->_error_thrower;
+ # XXX ugh
+ $inv = 'Moose::Meta::Class' unless $inv->can('_inline_throw_error');
+
+ # XXX ugh ugh UGH
+ my $class = $self->associated_class;
+ if ($class) {
+ my $class_name = B::perlstring($class->name);
+ my $attr_name = B::perlstring($self->name);
+ $args = 'attr => Class::MOP::class_of(' . $class_name . ')'
+ . '->find_attribute_by_name(' . $attr_name . '), '
+ . (defined $args ? $args : '');
+ }
+
+ return $inv->_inline_throw_error($msg, $args)
+}
+
sub new {
my ($class, $name, %options) = @_;
$class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS
+
+ delete $options{__hack_no_process_options};
+
+ my %attrs =
+ ( map { $_ => 1 }
+ grep { defined }
+ map { $_->init_arg() }
+ $class->meta()->get_all_attributes()
+ );
+
+ my @bad = sort grep { ! $attrs{$_} } keys %options;
+
+ if (@bad)
+ {
+ my $s = @bad > 1 ? 's' : '';
+ my $list = join "', '", @bad;
+
+ my $package = $options{definition_context}{package};
+ my $context = $options{definition_context}{context}
+ || 'attribute constructor';
+ my $type = $options{definition_context}{type} || 'class';
+
+ my $location = '';
+ if (defined($package)) {
+ $location = " in ";
+ $location .= "$type " if $type;
+ $location .= $package;
+ }
+
+ Carp::cluck "Found unknown argument$s '$list' in the $context for '$name'$location";
+ }
+
return $class->SUPER::new($name, %options);
}
sub interpolate_class_and_new {
- my ($class, $name, @args) = @_;
+ my ($class, $name, %args) = @_;
- my ( $new_class, @traits ) = $class->interpolate_class(@args);
-
- $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) );
+ my ( $new_class, @traits ) = $class->interpolate_class(\%args);
+
+ $new_class->new($name, %args, ( scalar(@traits) ? ( traits => \@traits ) : () ) );
}
sub interpolate_class {
- my ($class, %options) = @_;
+ my ($class, $options) = @_;
$class = ref($class) || $class;
- if ( my $metaclass_name = delete $options{metaclass} ) {
+ if ( my $metaclass_name = delete $options->{metaclass} ) {
my $new_class = Moose::Util::resolve_metaclass_alias( Attribute => $metaclass_name );
-
+
if ( $class ne $new_class ) {
if ( $new_class->can("interpolate_class") ) {
- return $new_class->interpolate_class(%options);
+ return $new_class->interpolate_class($options);
} else {
$class = $new_class;
}
my @traits;
- if (my $traits = $options{traits}) {
+ if (my $traits = $options->{traits}) {
my $i = 0;
+ my $has_foreign_options = 0;
+
while ($i < @$traits) {
my $trait = $traits->[$i++];
next if ref($trait); # options to a trait we discarded
push @traits, $trait;
# are there options?
- push @traits, $traits->[$i++]
- if $traits->[$i] && ref($traits->[$i]);
+ if ($traits->[$i] && ref($traits->[$i])) {
+ $has_foreign_options = 1
+ if any { $_ ne '-alias' && $_ ne '-excludes' } keys %{ $traits->[$i] };
+
+ push @traits, $traits->[$i++];
+ }
}
if (@traits) {
- my $anon_class = Moose::Meta::Class->create_anon_class(
+ my %options = (
superclasses => [ $class ],
roles => [ @traits ],
- cache => 1,
);
+ if ($has_foreign_options) {
+ $options{weaken} = 0;
+ }
+ else {
+ $options{cache} = 1;
+ }
+
+ my $anon_class = Moose::Meta::Class->create_anon_class(%options);
$class = $anon_class->name;
}
}
# ...
-my @legal_options_for_inheritance = qw(
- default coerce required
- documentation lazy handles
- builder type_constraint
- definition_context
-);
-
-sub legal_options_for_inheritance { @legal_options_for_inheritance }
+# method-generating options shouldn't be overridden
+sub illegal_options_for_inheritance {
+ qw(reader writer accessor clearer predicate)
+}
# NOTE/TODO
-# This method *must* be able to handle
-# Class::MOP::Attribute instances as
-# well. Yes, I know that is wrong, but
-# apparently we didn't realize it was
-# doing that and now we have some code
-# which is dependent on it. The real
-# solution of course is to push this
+# This method *must* be able to handle
+# Class::MOP::Attribute instances as
+# well. Yes, I know that is wrong, but
+# apparently we didn't realize it was
+# doing that and now we have some code
+# which is dependent on it. The real
+# solution of course is to push this
# feature back up into Class::MOP::Attribute
# but I not right now, I am too lazy.
-# However if you are reading this and
-# looking for something to do,.. please
+# However if you are reading this and
+# looking for something to do,.. please
# be my guest.
# - stevan
sub clone_and_inherit_options {
my ($self, %options) = @_;
-
- my %copy = %options;
-
- my %actual_options;
-
+
# NOTE:
# we may want to extends a Class::MOP::Attribute
- # in which case we need to be able to use the
- # core set of legal options that have always
+ # in which case we need to be able to use the
+ # core set of legal options that have always
# been here. But we allows Moose::Meta::Attribute
# instances to changes them.
# - SL
- my @legal_options = $self->can('legal_options_for_inheritance')
- ? $self->legal_options_for_inheritance
- : @legal_options_for_inheritance;
-
- foreach my $legal_option (@legal_options) {
- if (exists $options{$legal_option}) {
- $actual_options{$legal_option} = $options{$legal_option};
- delete $options{$legal_option};
- }
- }
+ my @illegal_options = $self->can('illegal_options_for_inheritance')
+ ? $self->illegal_options_for_inheritance
+ : ();
+
+ my @found_illegal_options = grep { exists $options{$_} && exists $self->{$_} ? $_ : undef } @illegal_options;
+ (scalar @found_illegal_options == 0)
+ || $self->throw_error("Illegal inherited options => (" . (join ', ' => @found_illegal_options) . ")", data => \%options);
if ($options{isa}) {
my $type_constraint;
$type_constraint = $options{isa};
}
else {
- $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa});
+ $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa}, { package_defined_in => $options{definition_context}->{package} });
(defined $type_constraint)
|| $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa});
}
- $actual_options{type_constraint} = $type_constraint;
- delete $options{isa};
+ $options{type_constraint} = $type_constraint;
}
-
+
if ($options{does}) {
my $type_constraint;
if (blessed($options{does}) && $options{does}->isa('Moose::Meta::TypeConstraint')) {
$type_constraint = $options{does};
}
else {
- $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does});
+ $type_constraint = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options{does}, { package_defined_in => $options{definition_context}->{package} });
(defined $type_constraint)
|| $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does});
}
- $actual_options{type_constraint} = $type_constraint;
- delete $options{does};
- }
+ $options{type_constraint} = $type_constraint;
+ }
# NOTE:
- # this doesn't apply to Class::MOP::Attributes,
+ # this doesn't apply to Class::MOP::Attributes,
# so we can ignore it for them.
# - SL
if ($self->can('interpolate_class')) {
- ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options);
+ ( $options{metaclass}, my @traits ) = $self->interpolate_class(\%options);
my %seen;
my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits;
- $actual_options{traits} = \@all_traits if @all_traits;
-
- delete @options{qw(metaclass traits)};
+ $options{traits} = \@all_traits if @all_traits;
}
- (scalar keys %options == 0)
- || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options);
-
+ # This method can be called on a CMOP::Attribute object, so we need to
+ # make sure we can call this method.
+ $self->_process_lazy_build_option( $self->name, \%options )
+ if $self->can('_process_lazy_build_option');
- $self->clone(%actual_options);
+ $self->clone(%options);
}
sub clone {
my ( $self, %params ) = @_;
- my $class = $params{metaclass} || ref $self;
-
- if ( 0 and $class eq ref $self ) {
- return $self->SUPER::clone(%params);
- } else {
- my ( @init, @non_init );
+ my $class = delete $params{metaclass} || ref $self;
- foreach my $attr ( grep { $_->has_value($self) } $self->meta->compute_all_applicable_attributes ) {
- push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr;
- }
-
- my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params );
+ my ( @init, @non_init );
- my $name = delete $new_params{name};
+ foreach my $attr ( grep { $_->has_value($self) } Class::MOP::class_of($self)->get_all_attributes ) {
+ push @{ $attr->has_init_arg ? \@init : \@non_init }, $attr;
+ }
- my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 );
+ my %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params );
- foreach my $attr ( @non_init ) {
- $attr->set_value($clone, $attr->get_value($self));
- }
+ my $name = delete $new_params{name};
+ my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 );
- return $clone;
+ foreach my $attr ( @non_init ) {
+ $attr->set_value($clone, $attr->get_value($self));
}
+
+ return $clone;
}
sub _process_options {
- my ($class, $name, $options) = @_;
-
- if (exists $options->{is}) {
-
- ### -------------------------
- ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before
- ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
- ## is => rw, accessor => _foo # turns into (accessor => _foo)
- ## is => ro, accessor => _foo # error, accesor is rw
- ### -------------------------
-
- if ($options->{is} eq 'ro') {
- $class->throw_error("Cannot define an accessor name on a read-only attribute, accessors are read/write", data => $options)
- if exists $options->{accessor};
+ my ( $class, $name, $options ) = @_;
+
+ $class->_process_is_option( $name, $options );
+ $class->_process_isa_option( $name, $options );
+ $class->_process_does_option( $name, $options );
+ $class->_process_coerce_option( $name, $options );
+ $class->_process_trigger_option( $name, $options );
+ $class->_process_auto_deref_option( $name, $options );
+ $class->_process_lazy_build_option( $name, $options );
+ $class->_process_lazy_option( $name, $options );
+ $class->_process_required_option( $name, $options );
+}
+
+sub _process_is_option {
+ my ( $class, $name, $options ) = @_;
+
+ return unless $options->{is};
+
+ ### -------------------------
+ ## is => ro, writer => _foo # turns into (reader => foo, writer => _foo) as before
+ ## is => rw, writer => _foo # turns into (reader => foo, writer => _foo)
+ ## is => rw, accessor => _foo # turns into (accessor => _foo)
+ ## is => ro, accessor => _foo # error, accesor is rw
+ ### -------------------------
+
+ if ( $options->{is} eq 'ro' ) {
+ $class->throw_error(
+ "Cannot define an accessor name on a read-only attribute, accessors are read/write",
+ data => $options )
+ if exists $options->{accessor};
+ $options->{reader} ||= $name;
+ }
+ elsif ( $options->{is} eq 'rw' ) {
+ if ( $options->{writer} ) {
$options->{reader} ||= $name;
}
- elsif ($options->{is} eq 'rw') {
- if ($options->{writer}) {
- $options->{reader} ||= $name;
- }
- else {
- $options->{accessor} ||= $name;
- }
- }
else {
- $class->throw_error("I do not understand this option (is => " . $options->{is} . ") on attribute ($name)", data => $options->{is});
+ $options->{accessor} ||= $name;
}
}
+ elsif ( $options->{is} eq 'bare' ) {
+ return;
+ # do nothing, but don't complain (later) about missing methods
+ }
+ else {
+ $class->throw_error( "I do not understand this option (is => "
+ . $options->{is}
+ . ") on attribute ($name)", data => $options->{is} );
+ }
+}
- if (exists $options->{isa}) {
- if (exists $options->{does}) {
- if (eval { $options->{isa}->can('does') }) {
- ($options->{isa}->does($options->{does}))
- || $class->throw_error("Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)", data => $options);
- }
- else {
- $class->throw_error("Cannot have an isa option which cannot ->does() on attribute ($name)", data => $options);
- }
- }
+sub _process_isa_option {
+ my ( $class, $name, $options ) = @_;
- # allow for anon-subtypes here ...
- if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) {
- $options->{type_constraint} = $options->{isa};
- }
- else {
- $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options->{isa});
- }
- }
- elsif (exists $options->{does}) {
- # allow for anon-subtypes here ...
- if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) {
- $options->{type_constraint} = $options->{does};
+ return unless exists $options->{isa};
+
+ if ( exists $options->{does} ) {
+ if ( try { $options->{isa}->can('does') } ) {
+ ( $options->{isa}->does( $options->{does} ) )
+ || $class->throw_error(
+ "Cannot have an isa option and a does option if the isa does not do the does on attribute ($name)",
+ data => $options );
}
else {
- $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does});
+ $class->throw_error(
+ "Cannot have an isa option which cannot ->does() on attribute ($name)",
+ data => $options );
}
}
- if (exists $options->{coerce} && $options->{coerce}) {
- (exists $options->{type_constraint})
- || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)", data => $options);
- $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)", data => $options)
- if $options->{weak_ref};
+ # allow for anon-subtypes here ...
+ if ( blessed( $options->{isa} )
+ && $options->{isa}->isa('Moose::Meta::TypeConstraint') ) {
+ $options->{type_constraint} = $options->{isa};
}
-
- if (exists $options->{trigger}) {
- ('CODE' eq ref $options->{trigger})
- || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger});
+ else {
+ $options->{type_constraint}
+ = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint(
+ $options->{isa},
+ { package_defined_in => $options->{definition_context}->{package} }
+ );
}
+}
- if (exists $options->{auto_deref} && $options->{auto_deref}) {
- (exists $options->{type_constraint})
- || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)", data => $options);
- ($options->{type_constraint}->is_a_type_of('ArrayRef') ||
- $options->{type_constraint}->is_a_type_of('HashRef'))
- || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)", data => $options);
- }
+sub _process_does_option {
+ my ( $class, $name, $options ) = @_;
- if (exists $options->{lazy_build} && $options->{lazy_build} == 1) {
- $class->throw_error("You can not use lazy_build and default for the same attribute ($name)", data => $options)
- if exists $options->{default};
- $options->{lazy} = 1;
- $options->{required} = 1;
- $options->{builder} ||= "_build_${name}";
- if ($name =~ /^_/) {
- $options->{clearer} ||= "_clear${name}";
- $options->{predicate} ||= "_has${name}";
- }
- else {
- $options->{clearer} ||= "clear_${name}";
- $options->{predicate} ||= "has_${name}";
- }
+ return unless exists $options->{does} && ! exists $options->{isa};
+
+ # allow for anon-subtypes here ...
+ if ( blessed( $options->{does} )
+ && $options->{does}->isa('Moose::Meta::TypeConstraint') ) {
+ $options->{type_constraint} = $options->{does};
}
+ else {
+ $options->{type_constraint}
+ = Moose::Util::TypeConstraints::find_or_create_does_type_constraint(
+ $options->{does},
+ { package_defined_in => $options->{definition_context}->{package} }
+ );
+ }
+}
+
+sub _process_coerce_option {
+ my ( $class, $name, $options ) = @_;
+
+ return unless $options->{coerce};
+
+ ( exists $options->{type_constraint} )
+ || $class->throw_error(
+ "You cannot have coercion without specifying a type constraint on attribute ($name)",
+ data => $options );
+
+ $class->throw_error(
+ "You cannot have a weak reference to a coerced value on attribute ($name)",
+ data => $options )
+ if $options->{weak_ref};
- if (exists $options->{lazy} && $options->{lazy}) {
- (exists $options->{default} || defined $options->{builder} )
- || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it", data => $options);
+ unless ( $options->{type_constraint}->has_coercion ) {
+ my $type = $options->{type_constraint}->name;
+
+ Moose::Deprecated::deprecated(
+ feature => 'coerce without coercion',
+ message =>
+ "You cannot coerce an attribute ($name) unless its type ($type) has a coercion"
+ );
}
+}
+
+sub _process_trigger_option {
+ my ( $class, $name, $options ) = @_;
+
+ return unless exists $options->{trigger};
+
+ ( 'CODE' eq ref $options->{trigger} )
+ || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger});
+}
+
+sub _process_auto_deref_option {
+ my ( $class, $name, $options ) = @_;
+
+ return unless $options->{auto_deref};
+
+ ( exists $options->{type_constraint} )
+ || $class->throw_error(
+ "You cannot auto-dereference without specifying a type constraint on attribute ($name)",
+ data => $options );
+
+ ( $options->{type_constraint}->is_a_type_of('ArrayRef')
+ || $options->{type_constraint}->is_a_type_of('HashRef') )
+ || $class->throw_error(
+ "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)",
+ data => $options );
+}
- if ( $options->{required} && !( ( !exists $options->{init_arg} || defined $options->{init_arg} ) || exists $options->{default} || defined $options->{builder} ) ) {
- $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg", data => $options);
+sub _process_lazy_build_option {
+ my ( $class, $name, $options ) = @_;
+
+ return unless $options->{lazy_build};
+
+ $class->throw_error(
+ "You can not use lazy_build and default for the same attribute ($name)",
+ data => $options )
+ if exists $options->{default};
+
+ $options->{lazy} = 1;
+ $options->{builder} ||= "_build_${name}";
+
+ if ( $name =~ /^_/ ) {
+ $options->{clearer} ||= "_clear${name}";
+ $options->{predicate} ||= "_has${name}";
}
+ else {
+ $options->{clearer} ||= "clear_${name}";
+ $options->{predicate} ||= "has_${name}";
+ }
+}
+sub _process_lazy_option {
+ my ( $class, $name, $options ) = @_;
+
+ return unless $options->{lazy};
+
+ ( exists $options->{default} || defined $options->{builder} )
+ || $class->throw_error(
+ "You cannot have a lazy attribute ($name) without specifying a default value for it",
+ data => $options );
+}
+
+sub _process_required_option {
+ my ( $class, $name, $options ) = @_;
+
+ if (
+ $options->{required}
+ && !(
+ ( !exists $options->{init_arg} || defined $options->{init_arg} )
+ || exists $options->{default}
+ || defined $options->{builder}
+ )
+ ) {
+ $class->throw_error(
+ "You cannot have a required attribute ($name) without a default, builder, or an init_arg",
+ data => $options );
+ }
}
sub initialize_instance_slot {
my $value_is_set;
if ( defined($init_arg) and exists $params->{$init_arg}) {
$val = $params->{$init_arg};
- $value_is_set = 1;
+ $value_is_set = 1;
}
else {
# skip it if it's lazy
if ($self->has_default) {
$val = $self->default($instance);
$value_is_set = 1;
- }
+ }
elsif ($self->has_builder) {
$val = $self->_call_builder($instance);
$value_is_set = 1;
return unless $value_is_set;
- if ($self->has_type_constraint) {
- my $type_constraint = $self->type_constraint;
- if ($self->should_coerce && $type_constraint->has_coercion) {
- $val = $type_constraint->coerce($val);
- }
- $self->verify_against_type_constraint($val, instance => $instance);
- }
+ $val = $self->_coerce_and_verify( $val, $instance );
$self->set_initial_value($instance, $val);
- $meta_instance->weaken_slot_value($instance, $self->name)
- if ref $val && $self->is_weak_ref;
+
+ if ( ref $val && $self->is_weak_ref ) {
+ $self->_weaken_value($instance);
+ }
}
sub _call_builder {
## Slot management
-# FIXME:
-# this duplicates too much code from
-# Class::MOP::Attribute, we need to
-# refactor these bits eventually.
-# - SL
-sub _set_initial_slot_value {
- my ($self, $meta_instance, $instance, $value) = @_;
-
- my $slot_name = $self->name;
-
- return $meta_instance->set_slot_value($instance, $slot_name, $value)
- unless $self->has_initializer;
-
- my ($type_constraint, $can_coerce);
- if ($self->has_type_constraint) {
- $type_constraint = $self->type_constraint;
- $can_coerce = ($self->should_coerce && $type_constraint->has_coercion);
- }
-
- my $callback = sub {
- my $val = shift;
- if ($type_constraint) {
- $val = $type_constraint->coerce($val)
- if $can_coerce;
- $self->verify_against_type_constraint($val, object => $instance);
- }
- $meta_instance->set_slot_value($instance, $slot_name, $val);
+sub _make_initializer_writer_callback {
+ my $self = shift;
+ my ($meta_instance, $instance, $slot_name) = @_;
+ my $old_callback = $self->SUPER::_make_initializer_writer_callback(@_);
+ return sub {
+ $old_callback->($self->_coerce_and_verify($_[0], $instance));
};
-
- my $initializer = $self->initializer;
-
- # most things will just want to set a value, so make it first arg
- $instance->$initializer($value, $callback, $self);
}
sub set_value {
my ($self, $instance, @args) = @_;
my $value = $args[0];
- my $attr_name = $self->name;
+ my $attr_name = quotemeta($self->name);
if ($self->is_required and not @args) {
$self->throw_error("Attribute ($attr_name) is required", object => $instance);
}
- if ($self->has_type_constraint) {
+ $value = $self->_coerce_and_verify( $value, $instance );
- my $type_constraint = $self->type_constraint;
+ my @old;
+ if ( $self->has_trigger && $self->has_value($instance) ) {
+ @old = $self->get_value($instance, 'for trigger');
+ }
+
+ $self->SUPER::set_value($instance, $value);
- if ($self->should_coerce) {
- $value = $type_constraint->coerce($value);
- }
- $type_constraint->_compiled_type_constraint->($value)
- || $self->throw_error("Attribute ("
- . $self->name
- . ") does not pass the type constraint because "
- . $type_constraint->get_message($value), object => $instance, data => $value);
+ if ( ref $value && $self->is_weak_ref ) {
+ $self->_weaken_value($instance);
}
- my $meta_instance = Class::MOP::Class->initialize(blessed($instance))
- ->get_meta_instance;
+ if ($self->has_trigger) {
+ $self->trigger->($instance, $value, @old);
+ }
+}
+
+sub _inline_set_value {
+ my $self = shift;
+ my ($instance, $value, $tc, $coercion, $message, $for_constructor) = @_;
+
+ my $old = '@old';
+ my $copy = '$val';
+ $tc ||= '$type_constraint';
+ $coercion ||= '$type_coercion';
+ $message ||= '$type_message';
+
+ my @code;
+ if ($self->_writer_value_needs_copy) {
+ push @code, $self->_inline_copy_value($value, $copy);
+ $value = $copy;
+ }
+
+ # constructors already handle required checks
+ push @code, $self->_inline_check_required
+ unless $for_constructor;
+
+ push @code, $self->_inline_tc_code($value, $tc, $coercion, $message);
+
+ # constructors do triggers all at once at the end
+ push @code, $self->_inline_get_old_value_for_trigger($instance, $old)
+ unless $for_constructor;
+
+ push @code, (
+ $self->SUPER::_inline_set_value($instance, $value),
+ $self->_inline_weaken_value($instance, $value),
+ );
+
+ # constructors do triggers all at once at the end
+ push @code, $self->_inline_trigger($instance, $value, $old)
+ unless $for_constructor;
+
+ return @code;
+}
+
+sub _writer_value_needs_copy {
+ my $self = shift;
+ return $self->should_coerce;
+}
+
+sub _inline_copy_value {
+ my $self = shift;
+ my ($value, $copy) = @_;
+
+ return 'my ' . $copy . ' = ' . $value . ';'
+}
+
+sub _inline_check_required {
+ my $self = shift;
+
+ return unless $self->is_required;
+
+ my $attr_name = quotemeta($self->name);
- $meta_instance->set_slot_value($instance, $attr_name, $value);
+ return (
+ 'if (@_ < 2) {',
+ $self->_inline_throw_error(
+ '"Attribute (' . $attr_name . ') is required"'
+ ) . ';',
+ '}',
+ );
+}
+
+sub _inline_tc_code {
+ my $self = shift;
+ my ($value, $tc, $coercion, $message, $is_lazy) = @_;
+ return (
+ $self->_inline_check_coercion(
+ $value, $tc, $coercion, $is_lazy,
+ ),
+ $self->_inline_check_constraint(
+ $value, $tc, $message, $is_lazy,
+ ),
+ );
+}
- if (ref $value && $self->is_weak_ref) {
- $meta_instance->weaken_slot_value($instance, $attr_name);
+sub _inline_check_coercion {
+ my $self = shift;
+ my ($value, $tc, $coercion) = @_;
+
+ return unless $self->should_coerce && $self->type_constraint->has_coercion;
+
+ if ( $self->type_constraint->can_be_inlined ) {
+ return (
+ 'if (! (' . $self->type_constraint->_inline_check($value) . ')) {',
+ $value . ' = ' . $coercion . '->(' . $value . ');',
+ '}',
+ );
+ }
+ else {
+ return (
+ 'if (!' . $tc . '->(' . $value . ')) {',
+ $value . ' = ' . $coercion . '->(' . $value . ');',
+ '}',
+ );
}
+}
- if ($self->has_trigger) {
- $self->trigger->($instance, $value, $self);
+sub _inline_check_constraint {
+ my $self = shift;
+ my ($value, $tc, $message) = @_;
+
+ return unless $self->has_type_constraint;
+
+ my $attr_name = quotemeta($self->name);
+
+ if ( $self->type_constraint->can_be_inlined ) {
+ return (
+ 'if (! (' . $self->type_constraint->_inline_check($value) . ')) {',
+ $self->_inline_throw_error(
+ '"Attribute (' . $attr_name . ') does not pass the type '
+ . 'constraint because: " . '
+ . 'do { local $_ = ' . $value . '; '
+ . $message . '->(' . $value . ')'
+ . '}',
+ 'data => ' . $value
+ ) . ';',
+ '}',
+ );
+ }
+ else {
+ return (
+ 'if (!' . $tc . '->(' . $value . ')) {',
+ $self->_inline_throw_error(
+ '"Attribute (' . $attr_name . ') does not pass the type '
+ . 'constraint because: " . '
+ . 'do { local $_ = ' . $value . '; '
+ . $message . '->(' . $value . ')'
+ . '}',
+ 'data => ' . $value
+ ) . ';',
+ '}',
+ );
+ }
+}
+
+sub _inline_get_old_value_for_trigger {
+ my $self = shift;
+ my ($instance, $old) = @_;
+
+ return unless $self->has_trigger;
+
+ return (
+ 'my ' . $old . ' = ' . $self->_inline_instance_has($instance),
+ '? ' . $self->_inline_instance_get($instance),
+ ': ();',
+ );
+}
+
+sub _inline_weaken_value {
+ my $self = shift;
+ my ($instance, $value) = @_;
+
+ return unless $self->is_weak_ref;
+
+ my $mi = $self->associated_class->get_meta_instance;
+ return (
+ $mi->inline_weaken_slot_value($instance, $self->name),
+ 'if ref ' . $value . ';',
+ );
+}
+
+sub _inline_trigger {
+ my $self = shift;
+ my ($instance, $value, $old) = @_;
+
+ return unless $self->has_trigger;
+
+ return '$trigger->(' . $instance . ', ' . $value . ', ' . $old . ');';
+}
+
+sub _eval_environment {
+ my $self = shift;
+
+ my $env = { };
+
+ $env->{'$trigger'} = \($self->trigger)
+ if $self->has_trigger;
+ $env->{'$attr_default'} = \($self->default)
+ if $self->has_default;
+
+ if ($self->has_type_constraint) {
+ my $tc_obj = $self->type_constraint;
+
+ $env->{'$type_constraint'} = \(
+ $tc_obj->_compiled_type_constraint
+ ) unless $tc_obj->can_be_inlined;
+ # these two could probably get inlined versions too
+ $env->{'$type_coercion'} = \(
+ $tc_obj->coercion->_compiled_type_coercion
+ ) if $tc_obj->has_coercion;
+ $env->{'$type_message'} = \(
+ $tc_obj->has_message ? $tc_obj->message : $tc_obj->_default_message
+ );
+
+ $env = { %$env, %{ $tc_obj->inline_environment } };
}
+
+ # XXX ugh, fix these
+ $env->{'$attr'} = \$self
+ if $self->has_initializer && $self->is_lazy;
+ # pretty sure this is only going to be closed over if you use a custom
+ # error class at this point, but we should still get rid of this
+ # at some point
+ $env->{'$meta'} = \($self->associated_class);
+
+ return $env;
+}
+
+sub _weaken_value {
+ my ( $self, $instance ) = @_;
+
+ my $meta_instance = Class::MOP::Class->initialize( blessed($instance) )
+ ->get_meta_instance;
+
+ $meta_instance->weaken_slot_value( $instance, $self->name );
}
sub get_value {
- my ($self, $instance) = @_;
+ my ($self, $instance, $for_trigger) = @_;
if ($self->is_lazy) {
unless ($self->has_value($instance)) {
} elsif ( $self->has_builder ) {
$value = $self->_call_builder($instance);
}
- if ($self->has_type_constraint) {
- my $type_constraint = $self->type_constraint;
- $value = $type_constraint->coerce($value)
- if ($self->should_coerce);
- $self->verify_against_type_constraint($value);
- }
+
+ $value = $self->_coerce_and_verify( $value, $instance );
+
$self->set_initial_value($instance, $value);
+
+ if ( ref $value && $self->is_weak_ref ) {
+ $self->_weaken_value($instance);
+ }
}
}
- if ($self->should_auto_deref) {
+ if ( $self->should_auto_deref && ! $for_trigger ) {
my $type_constraint = $self->type_constraint;
}
}
+sub _inline_get_value {
+ my $self = shift;
+ my ($instance, $tc, $coercion, $message) = @_;
+
+ my $slot_access = $self->_inline_instance_get($instance);
+ $tc ||= '$type_constraint';
+ $coercion ||= '$type_coercion';
+ $message ||= '$type_message';
+
+ return (
+ $self->_inline_check_lazy($instance, $tc, $coercion, $message),
+ $self->_inline_return_auto_deref($slot_access),
+ );
+}
+
+sub _inline_check_lazy {
+ my $self = shift;
+ my ($instance, $tc, $coercion, $message) = @_;
+
+ return unless $self->is_lazy;
+
+ my $slot_exists = $self->_inline_instance_has($instance);
+
+ return (
+ 'if (!' . $slot_exists . ') {',
+ $self->_inline_init_from_default($instance, '$default', $tc, $coercion, $message, 'lazy'),
+ '}',
+ );
+}
+
+sub _inline_init_from_default {
+ my $self = shift;
+ my ($instance, $default, $tc, $coercion, $message, $for_lazy) = @_;
+
+ if (!($self->has_default || $self->has_builder)) {
+ $self->throw_error(
+ 'You cannot have a lazy attribute '
+ . '(' . $self->name . ') '
+ . 'without specifying a default value for it',
+ attr => $self,
+ );
+ }
+
+ return (
+ $self->_inline_generate_default($instance, $default),
+ # intentionally not using _inline_tc_code, since that can be overridden
+ # to do things like possibly only do member tc checks, which isn't
+ # appropriate for checking the result of a default
+ $self->has_type_constraint
+ ? ($self->_inline_check_coercion($default, $tc, $coercion, $for_lazy),
+ $self->_inline_check_constraint($default, $tc, $message, $for_lazy))
+ : (),
+ $self->_inline_init_slot($instance, $default),
+ $self->_inline_weaken_value($instance, $default),
+ );
+}
+
+sub _inline_generate_default {
+ my $self = shift;
+ my ($instance, $default) = @_;
+
+ if ($self->has_default) {
+ my $source = 'my ' . $default . ' = $attr_default';
+ $source .= '->(' . $instance . ')'
+ if $self->is_default_a_coderef;
+ return $source . ';';
+ }
+ elsif ($self->has_builder) {
+ my $builder = B::perlstring($self->builder);
+ my $builder_str = quotemeta($self->builder);
+ my $attr_name_str = quotemeta($self->name);
+ return (
+ 'my ' . $default . ';',
+ 'if (my $builder = ' . $instance . '->can(' . $builder . ')) {',
+ $default . ' = ' . $instance . '->$builder;',
+ '}',
+ 'else {',
+ 'my $class = ref(' . $instance . ') || ' . $instance . ';',
+ $self->_inline_throw_error(
+ '"$class does not support builder method '
+ . '\'' . $builder_str . '\' for attribute '
+ . '\'' . $attr_name_str . '\'"'
+ ) . ';',
+ '}',
+ );
+ }
+ else {
+ $self->throw_error(
+ "Can't generate a default for " . $self->name
+ . " since no default or builder was specified"
+ );
+ }
+}
+
+sub _inline_init_slot {
+ my $self = shift;
+ my ($inv, $value) = @_;
+
+ if ($self->has_initializer) {
+ return '$attr->set_initial_value(' . $inv . ', ' . $value . ');';
+ }
+ else {
+ return $self->_inline_instance_set($inv, $value) . ';';
+ }
+}
+
+sub _inline_return_auto_deref {
+ my $self = shift;
+
+ return 'return ' . $self->_auto_deref(@_) . ';';
+}
+
+sub _auto_deref {
+ my $self = shift;
+ my ($ref_value) = @_;
+
+ return $ref_value unless $self->should_auto_deref;
+
+ my $type_constraint = $self->type_constraint;
+
+ my $sigil;
+ if ($type_constraint->is_a_type_of('ArrayRef')) {
+ $sigil = '@';
+ }
+ elsif ($type_constraint->is_a_type_of('HashRef')) {
+ $sigil = '%';
+ }
+ else {
+ $self->throw_error(
+ 'Can not auto de-reference the type constraint \''
+ . $type_constraint->name
+ . '\'',
+ type_constraint => $type_constraint,
+ );
+ }
+
+ return 'wantarray '
+ . '? ' . $sigil . '{ (' . $ref_value . ') || return } '
+ . ': (' . $ref_value . ')';
+}
+
## installing accessors
sub accessor_metaclass { 'Moose::Meta::Method::Accessor' }
return;
}
+sub _check_associated_methods {
+ my $self = shift;
+ unless (
+ @{ $self->associated_methods }
+ || ($self->_is_metadata || '') eq 'bare'
+ ) {
+ Carp::cluck(
+ 'Attribute (' . $self->name . ') of class '
+ . $self->associated_class->name
+ . ' has no associated methods'
+ . ' (did you mean to provide an "is" argument?)'
+ . "\n"
+ )
+ }
+}
+
+sub _process_accessors {
+ my $self = shift;
+ my ($type, $accessor, $generate_as_inline_methods) = @_;
+
+ $accessor = ( keys %$accessor )[0] if ( ref($accessor) || '' ) eq 'HASH';
+ my $method = $self->associated_class->get_method($accessor);
+
+ if ( $method
+ && $method->isa('Class::MOP::Method::Accessor')
+ && $method->associated_attribute->name ne $self->name ) {
+
+ my $other_attr_name = $method->associated_attribute->name;
+ my $name = $self->name;
+
+ Carp::cluck(
+ "You are overwriting an accessor ($accessor) for the $other_attr_name attribute"
+ . " with a new accessor method for the $name attribute" );
+ }
+
+ if (
+ $method
+ && !$method->is_stub
+ && !$method->isa('Class::MOP::Method::Accessor')
+ && ( !$self->definition_context
+ || $method->package_name eq $self->definition_context->{package} )
+ ) {
+
+ Carp::cluck(
+ "You are overwriting a locally defined method ($accessor) with "
+ . "an accessor" );
+ }
+
+ if ( !$self->associated_class->has_method($accessor)
+ && $self->associated_class->has_package_symbol( '&' . $accessor ) ) {
+
+ Carp::cluck(
+ "You are overwriting a locally defined function ($accessor) with "
+ . "an accessor" );
+ }
+
+ $self->SUPER::_process_accessors(@_);
+}
+
sub remove_accessors {
my $self = shift;
$self->SUPER::remove_accessors(@_);
# install the delegation ...
my $associated_class = $self->associated_class;
- foreach my $handle (keys %handles) {
+ foreach my $handle (sort keys %handles) {
my $method_to_call = $handles{$handle};
my $class_name = $associated_class->name;
my $name = "${class_name}::${handle}";
- (!$associated_class->has_method($handle))
- || $self->throw_error("You cannot overwrite a locally defined method ($handle) with a delegation", method_name => $handle);
+ if ( my $method = $associated_class->get_method($handle) ) {
+ $self->throw_error(
+ "You cannot overwrite a locally defined method ($handle) with a delegation",
+ method_name => $handle
+ ) unless $method->is_stub;
+ }
# NOTE:
# handles is not allowed to delegate
my $method = $self->_make_delegation_method($handle, $method_to_call);
$self->associated_class->add_method($method->name, $method);
- }
+ $self->associate_method($method);
+ }
}
sub remove_delegation {
my %handles = $self->_canonicalize_handles;
my $associated_class = $self->associated_class;
foreach my $handle (keys %handles) {
+ next unless any { $handle eq $_ }
+ map { $_->name }
+ @{ $self->associated_methods };
$self->associated_class->remove_method($handle);
}
}
elsif ($handle_type eq 'CODE') {
return $handles->($self, $self->_find_delegate_metaclass);
}
+ elsif (blessed($handles) && $handles->isa('Moose::Meta::TypeConstraint::DuckType')) {
+ return map { $_ => $_ } @{ $handles->methods };
+ }
+ elsif (blessed($handles) && $handles->isa('Moose::Meta::TypeConstraint::Role')) {
+ $handles = $handles->role;
+ }
else {
$self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles);
}
}
- else {
- Class::MOP::load_class($handles)
- unless Class::MOP::is_class_loaded($handles);
-
- my $role_meta = eval { $handles->meta };
- if ($@) {
- $self->throw_error("Unable to canonicalize the 'handles' option with $handles because : $@", data => $handles, error => $@);
- }
- (blessed $role_meta && $role_meta->isa('Moose::Meta::Role'))
- || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because ->meta is not a Moose::Meta::Role", data => $handles);
-
- return map { $_ => $_ } (
- $role_meta->get_method_list,
- $role_meta->get_required_method_list
- );
- }
-}
+ load_class($handles);
+ my $role_meta = Class::MOP::class_of($handles);
-sub _find_delegate_metaclass {
- my $self = shift;
- if (my $class = $self->_isa_metadata) {
- # if the class does have
- # a meta method, use it
- return $class->meta if $class->can('meta');
- # otherwise we might be
- # dealing with a non-Moose
- # class, and need to make
- # our own metaclass
- return Moose::Meta::Class->initialize($class);
- }
- elsif (my $role = $self->_does_metadata) {
- # our role will always have
- # a meta method
- return $role->meta;
- }
- else {
- $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name);
- }
+ (blessed $role_meta && $role_meta->isa('Moose::Meta::Role'))
+ || $self->throw_error("Unable to canonicalize the 'handles' option with $handles because its metaclass is not a Moose::Meta::Role", data => $handles);
+
+ return map { $_ => $_ }
+ map { $_->name }
+ grep { !$_->isa('Class::MOP::Method::Meta') } (
+ $role_meta->_get_local_methods,
+ $role_meta->get_required_method_list,
+ );
}
sub _get_delegate_method_list {
my $meta = $self->_find_delegate_metaclass;
if ($meta->isa('Class::MOP::Class')) {
return map { $_->name } # NOTE: !never! delegate &meta
- grep { $_->package_name ne 'Moose::Object' && $_->name ne 'meta' }
+ grep { $_->package_name ne 'Moose::Object' && !$_->isa('Class::MOP::Method::Meta') }
$meta->get_all_methods;
}
elsif ($meta->isa('Moose::Meta::Role')) {
}
}
+sub _find_delegate_metaclass {
+ my $self = shift;
+ if (my $class = $self->_isa_metadata) {
+ unless ( is_class_loaded($class) ) {
+ $self->throw_error(
+ sprintf(
+ 'The %s attribute is trying to delegate to a class which has not been loaded - %s',
+ $self->name, $class
+ )
+ );
+ }
+ # we might be dealing with a non-Moose class,
+ # and need to make our own metaclass. if there's
+ # already a metaclass, it will be returned
+ return Class::MOP::Class->initialize($class);
+ }
+ elsif (my $role = $self->_does_metadata) {
+ unless ( is_class_loaded($class) ) {
+ $self->throw_error(
+ sprintf(
+ 'The %s attribute is trying to delegate to a role which has not been loaded - %s',
+ $self->name, $role
+ )
+ );
+ }
+
+ return Class::MOP::class_of($role);
+ }
+ else {
+ $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name);
+ }
+}
+
sub delegation_metaclass { 'Moose::Meta::Method::Delegation' }
sub _make_delegation_method {
my ( $self, $handle_name, $method_to_call ) = @_;
- my $method_body;
+ my @curried_arguments;
- $method_body = $method_to_call
- if 'CODE' eq ref($method_to_call);
+ ($method_to_call, @curried_arguments) = @$method_to_call
+ if 'ARRAY' eq ref($method_to_call);
return $self->delegation_metaclass->new(
name => $handle_name,
package_name => $self->associated_class->name,
attribute => $self,
delegate_to_method => $method_to_call,
+ curried_arguments => \@curried_arguments,
);
}
+sub _coerce_and_verify {
+ my $self = shift;
+ my $val = shift;
+ my $instance = shift;
+
+ return $val unless $self->has_type_constraint;
+
+ $val = $self->type_constraint->coerce($val)
+ if $self->should_coerce && $self->type_constraint->has_coercion;
+
+ $self->verify_against_type_constraint($val, instance => $instance);
+
+ return $val;
+}
+
sub verify_against_type_constraint {
my $self = shift;
my $val = shift;
1;
+# ABSTRACT: The Moose attribute metaclass
+
__END__
=pod
-=head1 NAME
+=head1 DESCRIPTION
-Moose::Meta::Attribute - The Moose attribute metaclass
+This class is a subclass of L<Class::MOP::Attribute> that provides
+additional Moose-specific functionality.
-=head1 DESCRIPTION
+To really understand this class, you will need to start with the
+L<Class::MOP::Attribute> documentation. This class can be understood
+as a set of additional features on top of the basic feature provided
+by that parent class.
-This is a subclass of L<Class::MOP::Attribute> with Moose specific
-extensions.
+=head1 INHERITANCE
-For the most part, the only time you will ever encounter an
-instance of this class is if you are doing some serious deep
-introspection. To really understand this class, you need to refer
-to the L<Class::MOP::Attribute> documentation.
+C<Moose::Meta::Attribute> is a subclass of L<Class::MOP::Attribute>.
=head1 METHODS
-=head2 Overridden methods
+Many of the documented below override methods in
+L<Class::MOP::Attribute> and add Moose specific features.
-These methods override methods in L<Class::MOP::Attribute> and add
-Moose specific features. You can safely assume though that they
-will behave just as L<Class::MOP::Attribute> does.
+=head2 Creation
=over 4
-=item B<new>
+=item B<< Moose::Meta::Attribute->new($name, %options) >>
+
+This method overrides the L<Class::MOP::Attribute> constructor.
+
+Many of the options below are described in more detail in the
+L<Moose::Manual::Attributes> document.
+
+It adds the following options to the constructor:
+
+=over 8
+
+=item * is => 'ro', 'rw', 'bare'
+
+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.
+
+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.
+
+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.
+
+=item * isa => $type
+
+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.
+
+This option can also accept a L<Moose::Meta::TypeConstraint> object.
+
+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>.
+
+=item * does => $role
+
+This is short-hand for saying that the attribute's type must be an
+object which does the named role.
+
+=item * coerce => $bool
+
+This option is only valid for objects with a type constraint
+(C<isa>) that defined a coercion. If this is true, then coercions will be applied whenever
+this attribute is set.
-=item B<clone>
+You can make both this and the C<weak_ref> option true.
-=item B<does>
+=item * trigger => $sub
-=item B<initialize_instance_slot>
+This option accepts a subroutine reference, which will be called after
+the attribute is set.
-=item B<install_accessors>
+=item * required => $bool
-=item B<remove_accessors>
+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.
-=item B<install_delegation>
+A required attribute must have a C<default>, C<builder> or a
+non-C<undef> C<init_arg>
-=item B<remove_delegation>
+=item * lazy => $bool
-=item B<accessor_metaclass>
+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.
-=item B<delegation_metaclass>
+=item * weak_ref => $bool
+
+If this is true, the attribute's value will be stored as a weak
+reference.
+
+=item * auto_deref => $bool
+
+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 * lazy_build => $bool
+
+Setting this to true makes the attribute lazy and provides a number of
+default methods.
+
+ has 'size' => (
+ is => 'ro',
+ lazy_build => 1,
+ );
+
+is equivalent to this:
+
+ has 'size' => (
+ is => 'ro',
+ lazy => 1,
+ builder => '_build_size',
+ clearer => 'clear_size',
+ predicate => 'has_size',
+ );
+
+
+If your attribute name starts with an underscore (C<_>), then the clearer
+and predicate will as well:
+
+ has '_size' => (
+ is => 'ro',
+ lazy_build => 1,
+ );
+
+becomes:
+
+ has '_size' => (
+ is => 'ro',
+ lazy => 1,
+ builder => '_build__size',
+ clearer => '_clear_size',
+ predicate => '_has_size',
+ );
+
+Note the doubled underscore in the builder name. Internally, Moose
+simply prepends the attribute name with "_build_" to come up with the
+builder name.
+
+=item * documentation
+
+An arbitrary string that can be retrieved later by calling C<<
+$attr->documentation >>.
+
+=back
+
+=item B<< $attr->clone(%options) >>
+
+This creates a new attribute based on attribute being cloned. You must
+supply a C<name> option to provide a new name for the attribute.
+
+The C<%options> can only specify options handled by
+L<Class::MOP::Attribute>.
+
+=back
+
+=head2 Value management
+
+=over 4
+
+=item B<< $attr->initialize_instance_slot($meta_instance, $instance, $params) >>
+
+This method is used internally to initialize the attribute's slot in
+the object C<$instance>.
+
+This overrides the L<Class::MOP::Attribute> method to handle lazy
+attributes, weak references, and type constraints.
=item B<get_value>
=item B<set_value>
- eval { $point->meta->get_attribute('x')->set_value($point, 'fourty-two') };
+ eval { $point->meta->get_attribute('x')->set_value($point, 'forty-two') };
if($@) {
print "Oops: $@\n";
}
-I<Attribute (x) does not pass the type constraint (Int) with 'fourty-two'>
+I<Attribute (x) does not pass the type constraint (Int) with 'forty-two'>
Before setting the value, a check is made on the type constraint of
the attribute, if it has one, to see if the value passes it. If the
-value fails to pass, the set operation dies with a L<throw_error>.
+value fails to pass, the set operation dies.
Any coercion to convert values is done before checking the type constraint.
To check a value against a type constraint before setting it, fetch the
attribute instance using L<Class::MOP::Class/find_attribute_by_name>,
fetch the type_constraint from the attribute using L<Moose::Meta::Attribute/type_constraint>
-and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::Basics::Recipe4>
+and call L<Moose::Meta::TypeConstraint/check>. See L<Moose::Cookbook::Basics::Company_Subtypes>
for an example.
=back
-=head2 Additional Moose features
-
-Moose attributes support type-constraint checking, weak reference
-creation and type coercion.
+=head2 Attribute Accessor generation
=over 4
-=item B<throw_error>
+=item B<< $attr->install_accessors >>
-Delegates to C<associated_class> or C<Moose::Meta::Class> if there is none.
+This method overrides the parent to also install delegation methods.
-=item B<interpolate_class_and_new>
+If, after installing all methods, the attribute object has no associated
+methods, it throws an error unless C<< is => 'bare' >> was passed to the
+attribute constructor. (Trying to add an attribute that has no associated
+methods is almost always an error.)
-=item B<interpolate_class>
+=item B<< $attr->remove_accessors >>
-When called as a class method causes interpretation of the C<metaclass> and
-C<traits> options.
+This method overrides the parent to also remove delegation methods.
-=item B<clone_and_inherit_options>
+=item B<< $attr->inline_set($instance_var, $value_var) >>
-This is to support the C<has '+foo'> feature, it clones an attribute
-from a superclass and allows a very specific set of changes to be made
-to the attribute.
+This method return a code snippet suitable for inlining the relevant
+operation. It expect strings containing variable names to be used in the
+inlining, like C<'$self'> or C<'$_[1]'>.
-=item B<legal_options_for_inheritance>
+=item B<< $attr->install_delegation >>
-Whitelist with options you can change. You can overload it in your custom
-metaclass to allow your options be inheritable.
+This method adds its delegation methods to the attribute's associated
+class, if it has any to add.
-=item B<has_type_constraint>
+=item B<< $attr->remove_delegation >>
-Returns true if this meta-attribute has a type constraint.
+This method remove its delegation methods from the attribute's
+associated class.
-=item B<type_constraint>
+=item B<< $attr->accessor_metaclass >>
-A read-only accessor for this meta-attribute's type constraint. For
-more information on what you can do with this, see the documentation
-for L<Moose::Meta::TypeConstraint>.
+Returns the accessor metaclass name, which defaults to
+L<Moose::Meta::Method::Accessor>.
-=item B<verify_against_type_constraint>
+=item B<< $attr->delegation_metaclass >>
-Verifies that the given value is valid under this attribute's type
-constraint, otherwise throws an error.
+Returns the delegation metaclass name, which defaults to
+L<Moose::Meta::Method::Delegation>.
-=item B<has_handles>
+=back
-Returns true if this meta-attribute performs delegation.
+=head2 Additional Moose features
-=item B<handles>
+These methods are not found in the superclass. They support features
+provided by Moose.
-This returns the value which was passed into the handles option.
+=over 4
-=item B<is_weak_ref>
+=item B<< $attr->does($role) >>
-Returns true if this meta-attribute produces a weak reference.
+This indicates whether the I<attribute itself> does the given
+role. The role can be given as a full class name, or as a resolvable
+trait name.
-=item B<is_required>
+Note that this checks the attribute itself, not its type constraint,
+so it is checking the attribute's metaclass and any traits applied to
+the attribute.
-Returns true if this meta-attribute is required to have a value.
+=item B<< Moose::Meta::Class->interpolate_class_and_new($name, %options) >>
-=item B<is_lazy>
+This is an alternate constructor that handles the C<metaclass> and
+C<traits> options.
-Returns true if this meta-attribute should be initialized lazily.
+Effectively, this method is a factory that finds or creates the
+appropriate class for the given C<metaclass> and/or C<traits>.
-NOTE: lazy attributes, B<must> have a C<default> or C<builder> field set.
+Once it has the appropriate class, it will call C<< $class->new($name,
+%options) >> on that class.
-=item B<is_lazy_build>
+=item B<< $attr->clone_and_inherit_options(%options) >>
-Returns true if this meta-attribute should be initialized lazily through
-the builder generated by lazy_build. Using C<lazy_build =E<gt> 1> will
-make your attribute required and lazy. In addition it will set the builder, clearer
-and predicate options for you using the following convention.
+This method supports the C<has '+foo'> feature. It does various bits
+of processing on the supplied C<%options> before ultimately calling
+the C<clone> method.
- #If your attribute name starts with an underscore:
- has '_foo' => (lazy_build => 1);
- #is the same as
- has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', builder => '_build__foo');
- # or
- has '_foo' => (lazy => 1, required => 1, predicate => '_has_foo', clearer => '_clear_foo', default => sub{shift->_build__foo});
+One of its main tasks is to make sure that the C<%options> provided
+does not include the options returned by the
+C<illegal_options_for_inheritance> method.
- #If your attribute name does not start with an underscore:
- has 'foo' => (lazy_build => 1);
- #is the same as
- has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', builder => '_build_foo');
- # or
- has 'foo' => (lazy => 1, required => 1, predicate => 'has_foo', clearer => 'clear_foo', default => sub{shift->_build_foo});
+=item B<< $attr->illegal_options_for_inheritance >>
-The reason for the different naming of the C<builder> is that the C<builder>
-method is a private method while the C<clearer> and C<predicate> methods
-are public methods.
+This returns a blacklist of options that can not be overridden in a
+subclass's attribute definition.
-NOTE: This means your class should provide a method whose name matches the value
-of the builder part, in this case _build__foo or _build_foo.
+This exists to allow a custom metaclass to change or add to the list
+of options which can not be changed.
-=item B<should_coerce>
+=item B<< $attr->type_constraint >>
-Returns true if this meta-attribute should perform type coercion.
+Returns the L<Moose::Meta::TypeConstraint> object for this attribute,
+if it has one.
-=item B<should_auto_deref>
+=item B<< $attr->has_type_constraint >>
-Returns true if this meta-attribute should perform automatic
-auto-dereferencing.
+Returns true if this attribute has a type constraint.
-NOTE: This can only be done for attributes whose type constraint is
-either I<ArrayRef> or I<HashRef>.
+=item B<< $attr->verify_against_type_constraint($value) >>
-=item B<has_trigger>
+Given a value, this method returns true if the value is valid for the
+attribute's type constraint. If the value is not valid, it throws an
+error.
-Returns true if this meta-attribute has a trigger set.
+=item B<< $attr->handles >>
-=item B<trigger>
+This returns the value of the C<handles> option passed to the
+constructor.
-This is a CODE reference which will be executed every time the
-value of an attribute is assigned. The CODE ref will get two values,
-the invocant and the new value. This can be used to handle I<basic>
-bi-directional relations.
+=item B<< $attr->has_handles >>
-=item B<documentation>
+Returns true if this attribute performs delegation.
-This is a string which contains the documentation for this attribute.
-It serves no direct purpose right now, but it might in the future
-in some kind of automated documentation system perhaps.
+=item B<< $attr->is_weak_ref >>
-=item B<has_documentation>
+Returns true if this attribute stores its value as a weak reference.
-Returns true if this meta-attribute has any documentation.
+=item B<< $attr->is_required >>
-=item B<applied_traits>
+Returns true if this attribute is required to have a value.
-This will return the ARRAY ref of all the traits applied to this
-attribute, or if no traits have been applied, it returns C<undef>.
+=item B<< $attr->is_lazy >>
-=item B<has_applied_traits>
+Returns true if this attribute is lazy.
-Returns true if this meta-attribute has any traits applied.
+=item B<< $attr->is_lazy_build >>
-=back
+Returns true if the C<lazy_build> option was true when passed to the
+constructor.
-=head1 BUGS
+=item B<< $attr->should_coerce >>
-All complex software has bugs lurking in it, and this module is no
-exception. If you find a bug please either email me, or add the bug
-to cpan-RT.
+Returns true if the C<coerce> option passed to the constructor was
+true.
-=head1 AUTHOR
+=item B<< $attr->should_auto_deref >>
-Stevan Little E<lt>stevan@iinteractive.comE<gt>
+Returns true if the C<auto_deref> option passed to the constructor was
+true.
-Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
+=item B<< $attr->trigger >>
-=head1 COPYRIGHT AND LICENSE
+This is the subroutine reference that was in the C<trigger> option
+passed to the constructor, if any.
-Copyright 2006-2009 by Infinity Interactive, Inc.
+=item B<< $attr->has_trigger >>
-L<http://www.iinteractive.com>
+Returns true if this attribute has a trigger set.
+
+=item B<< $attr->documentation >>
+
+Returns the value that was in the C<documentation> option passed to
+the constructor, if any.
+
+=item B<< $attr->has_documentation >>
+
+Returns true if this attribute has any documentation.
+
+=item B<< $attr->applied_traits >>
+
+This returns an array reference of all the traits which were applied
+to this attribute. If none were applied, this returns C<undef>.
+
+=item B<< $attr->has_applied_traits >>
+
+Returns true if this attribute has any traits applied.
+
+=back
+
+=head1 BUGS
-This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+See L<Moose/BUGS> for details on reporting bugs.
=cut
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