use strict;
use warnings;
-use Scalar::Util 'blessed', 'weaken', 'reftype';
-use Carp 'confess';
+use Scalar::Util 'blessed', 'weaken';
+use overload ();
-our $VERSION = '0.05';
+our $VERSION = '0.79';
+our $AUTHORITY = 'cpan:STEVAN';
+use Moose::Meta::Method::Accessor;
+use Moose::Meta::Method::Delegation;
+use Moose::Util ();
use Moose::Util::TypeConstraints ();
use base 'Class::MOP::Attribute';
-__PACKAGE__->meta->add_attribute('required' => (reader => 'is_required' ));
-__PACKAGE__->meta->add_attribute('lazy' => (reader => 'is_lazy' ));
-__PACKAGE__->meta->add_attribute('coerce' => (reader => 'should_coerce'));
-__PACKAGE__->meta->add_attribute('weak_ref' => (reader => 'is_weak_ref' ));
+# 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',
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',
+));
+
+# 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 {
+ Moose::Util::resolve_metatrait_alias(Attribute => $role_name)
+ };
+ return 0 if !defined($name); # failed to load class
+ return $self->Moose::Object::does($name);
+}
+
+sub throw_error {
+ my $self = shift;
+ my $class = ( ref $self && $self->associated_class ) || "Moose::Meta::Class";
+ 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
+ goto $handler;
+}
sub new {
- my ($class, $name, %options) = @_;
- $class->_process_options($name, \%options);
- $class->SUPER::new($name, %options);
+ my ($class, $name, %options) = @_;
+ $class->_process_options($name, \%options) unless $options{__hack_no_process_options}; # used from clone()... YECHKKK FIXME ICKY YUCK GROSS
+ return $class->SUPER::new($name, %options);
+}
+
+sub interpolate_class_and_new {
+ my ($class, $name, @args) = @_;
+
+ my ( $new_class, @traits ) = $class->interpolate_class(@args);
+
+ $new_class->new($name, @args, ( scalar(@traits) ? ( traits => \@traits ) : () ) );
+}
+
+sub interpolate_class {
+ my ($class, %options) = @_;
+
+ $class = ref($class) || $class;
+
+ 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);
+ } else {
+ $class = $new_class;
+ }
+ }
+ }
+
+ my @traits;
+
+ if (my $traits = $options{traits}) {
+ my $i = 0;
+ while ($i < @$traits) {
+ my $trait = $traits->[$i++];
+ next if ref($trait); # options to a trait we discarded
+
+ $trait = Moose::Util::resolve_metatrait_alias(Attribute => $trait)
+ || $trait;
+
+ next if $class->does($trait);
+
+ push @traits, $trait;
+
+ # are there options?
+ push @traits, $traits->[$i++]
+ if $traits->[$i] && ref($traits->[$i]);
+ }
+
+ if (@traits) {
+ my $anon_class = Moose::Meta::Class->create_anon_class(
+ superclasses => [ $class ],
+ roles => [ @traits ],
+ cache => 1,
+ );
+
+ $class = $anon_class->name;
+ }
+ }
+
+ return ( wantarray ? ( $class, @traits ) : $class );
+}
+
+# ...
+
+my @legal_options_for_inheritance = qw(
+ default coerce required
+ documentation lazy handles
+ builder type_constraint
+ definition_context
+ lazy_build
+);
+
+sub legal_options_for_inheritance { @legal_options_for_inheritance }
+
+# NOTE/TODO
+# This method *must* be able to handle
+# Class::MOP::Attribute instances as
+# well. Yes, I know that is wrong, but
+# apparently we didn't realize it was
+# doing that and now we have some code
+# which is dependent on it. The real
+# solution of course is to push this
+# feature back up into Class::MOP::Attribute
+# but I not right now, I am too lazy.
+# However if you are reading this and
+# looking for something to do,.. please
+# be my guest.
+# - stevan
+sub clone_and_inherit_options {
+ my ($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
+ # 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};
+ }
+ }
+
+ if ($options{isa}) {
+ my $type_constraint;
+ if (blessed($options{isa}) && $options{isa}->isa('Moose::Meta::TypeConstraint')) {
+ $type_constraint = $options{isa};
+ }
+ else {
+ $type_constraint = Moose::Util::TypeConstraints::find_or_create_isa_type_constraint($options{isa});
+ (defined $type_constraint)
+ || $self->throw_error("Could not find the type constraint '" . $options{isa} . "'", data => $options{isa});
+ }
+
+ $actual_options{type_constraint} = $type_constraint;
+ delete $options{isa};
+ }
+
+ if ($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});
+ (defined $type_constraint)
+ || $self->throw_error("Could not find the type constraint '" . $options{does} . "'", data => $options{does});
+ }
+
+ $actual_options{type_constraint} = $type_constraint;
+ delete $options{does};
+ }
+
+ # NOTE:
+ # this doesn't apply to Class::MOP::Attributes,
+ # so we can ignore it for them.
+ # - SL
+ if ($self->can('interpolate_class')) {
+ ( $actual_options{metaclass}, my @traits ) = $self->interpolate_class(%options);
+
+ my %seen;
+ my @all_traits = grep { $seen{$_}++ } @{ $self->applied_traits || [] }, @traits;
+ $actual_options{traits} = \@all_traits if @all_traits;
+
+ delete @options{qw(metaclass traits)};
+ }
+
+ (scalar keys %options == 0)
+ || $self->throw_error("Illegal inherited options => (" . (join ', ' => keys %options) . ")", data => \%options);
+
+
+ $self->clone(%actual_options);
}
sub clone {
- my ($self, %options) = @_;
- $self->_process_options($self->name, \%options);
- $self->SUPER::clone(%options);
+ my ( $self, %params ) = @_;
+
+ my $class = $params{metaclass} || ref $self;
+
+ my ( @init, @non_init );
+
+ 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 %new_params = ( ( map { $_->init_arg => $_->get_value($self) } @init ), %params );
+
+ my $name = delete $new_params{name};
+
+ my $clone = $class->new($name, %new_params, __hack_no_process_options => 1 );
+
+ foreach my $attr ( @non_init ) {
+ $attr->set_value($clone, $attr->get_value($self));
+ }
+
+ return $clone;
}
sub _process_options {
my ($class, $name, $options) = @_;
- if (exists $options->{is}) {
- if ($options->{is} eq 'ro') {
- $options->{reader} = $name;
- (!exists $options->{trigger})
- || confess "Cannot have a trigger on a read-only attribute";
- }
- elsif ($options->{is} eq 'rw') {
- $options->{accessor} = $name;
- ((reftype($options->{trigger}) || '') eq 'CODE')
- || confess "A trigger must be a CODE reference"
- if exists $options->{trigger};
- }
- }
-
- if (exists $options->{isa}) {
-
- if (exists $options->{does}) {
- if (eval { $options->{isa}->can('does') }) {
- ($options->{isa}->does($options->{does}))
- || confess "Cannot have an isa option and a does option if the isa does not do the does";
- }
- else {
- confess "Cannot have an isa option which cannot ->does()";
- }
- }
-
- # allow for anon-subtypes here ...
- if (blessed($options->{isa}) && $options->{isa}->isa('Moose::Meta::TypeConstraint')) {
- $options->{type_constraint} = $options->{isa};
- }
- else {
-
- if ($options->{isa} =~ /\|/) {
- my @type_constraints = split /\s*\|\s*/ => $options->{isa};
- $options->{type_constraint} = Moose::Util::TypeConstraints::create_type_constraint_union(
- @type_constraints
- );
- }
- else {
- # otherwise assume it is a constraint
- my $constraint = Moose::Util::TypeConstraints::find_type_constraint($options->{isa});
- # if the constraing it not found ....
- unless (defined $constraint) {
- # assume it is a foreign class, and make
- # an anon constraint for it
- $constraint = Moose::Util::TypeConstraints::subtype(
- 'Object',
- Moose::Util::TypeConstraints::where { $_->isa($options->{isa}) }
- );
- }
- $options->{type_constraint} = $constraint;
+
+ 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};
+ $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});
+ }
+ }
+
+ 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);
}
- }
- }
- elsif (exists $options->{does}) {
- # allow for anon-subtypes here ...
- if (blessed($options->{does}) && $options->{does}->isa('Moose::Meta::TypeConstraint')) {
- $options->{type_constraint} = $options->{isa};
- }
- else {
- # otherwise assume it is a constraint
- my $constraint = Moose::Util::TypeConstraints::find_type_constraint($options->{does});
- # if the constraing it not found ....
- unless (defined $constraint) {
- # assume it is a foreign class, and make
- # an anon constraint for it
- $constraint = Moose::Util::TypeConstraints::subtype(
- 'Role',
- Moose::Util::TypeConstraints::where { $_->does($options->{does}) }
- );
- }
- $options->{type_constraint} = $constraint;
- }
- }
-
- if (exists $options->{coerce} && $options->{coerce}) {
- (exists $options->{type_constraint})
- || confess "You cannot have coercion without specifying a type constraint";
- (!$options->{type_constraint}->isa('Moose::Meta::TypeConstraint::Union'))
- || confess "You cannot have coercion with a type constraint union";
- confess "You cannot have a weak reference to a coerced value"
- if $options->{weak_ref};
- }
-
- if (exists $options->{lazy} && $options->{lazy}) {
- (exists $options->{default})
- || confess "You cannot have lazy attribute without specifying a default value for it";
- }
+ }
+
+ # allow for anon-subtypes here ...
+ if (blessed($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};
+ }
+ else {
+ $options->{type_constraint} = Moose::Util::TypeConstraints::find_or_create_does_type_constraint($options->{does});
+ }
+ }
+
+ 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};
+ }
+
+ if (exists $options->{trigger}) {
+ ('CODE' eq ref $options->{trigger})
+ || $class->throw_error("Trigger must be a CODE ref on attribute ($name)", data => $options->{trigger});
+ }
+
+ 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);
+ }
+
+ 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}";
+ }
+ }
+
+ 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);
+ }
+
+ 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 => $options);
+ }
+
}
sub initialize_instance_slot {
- my ($self, $class, $instance, $params) = @_;
+ my ($self, $meta_instance, $instance, $params) = @_;
my $init_arg = $self->init_arg();
# try to fetch the init arg from the %params ...
- my $val;
- if (exists $params->{$init_arg}) {
+
+ my $val;
+ my $value_is_set;
+ if ( defined($init_arg) and exists $params->{$init_arg}) {
$val = $params->{$init_arg};
+ $value_is_set = 1;
}
else {
# skip it if it's lazy
return if $self->is_lazy;
# and die if it's required and doesn't have a default value
- confess "Attribute (" . $self->name . ") is required"
- if $self->is_required && !$self->has_default;
- }
- # if nothing was in the %params, we can use the
- # attribute's default value (if it has one)
- if (!defined $val && $self->has_default) {
- $val = $self->default($instance);
- }
- if (defined $val) {
- if ($self->has_type_constraint) {
- my $type_constraint = $self->type_constraint;
- if ($self->should_coerce && $type_constraint->has_coercion) {
- $val = $type_constraint->coercion->coerce($val);
- }
- (defined($type_constraint->check($val)))
- || confess "Attribute (" .
- $self->name .
- ") does not pass the type contraint (" .
- $type_constraint->name .
- ") with '$val'";
+ $self->throw_error("Attribute (" . $self->name . ") is required", object => $instance, data => $params)
+ if $self->is_required && !$self->has_default && !$self->has_builder;
+
+ # if nothing was in the %params, we can use the
+ # attribute's default value (if it has one)
+ if ($self->has_default) {
+ $val = $self->default($instance);
+ $value_is_set = 1;
+ }
+ elsif ($self->has_builder) {
+ $val = $self->_call_builder($instance);
+ $value_is_set = 1;
}
- }
- $instance->{$self->name} = $val;
- if (defined $val && $self->is_weak_ref) {
- weaken($instance->{$self->name});
- }
+ }
+
+ return unless $value_is_set;
+
+ $val = $self->_coerce_and_verify( $val, $instance );
+
+ $self->set_initial_value($instance, $val);
+ $meta_instance->weaken_slot_value($instance, $self->name)
+ if ref $val && $self->is_weak_ref;
}
-sub generate_accessor_method {
- my ($self, $attr_name) = @_;
- my $value_name = $self->should_coerce ? '$val' : '$_[1]';
- my $code = 'sub { '
- . 'if (scalar(@_) == 2) {'
- . ($self->is_required ?
- 'defined($_[1]) || confess "Attribute ($attr_name) is required, so cannot be set to undef";'
- : '')
- . ($self->should_coerce ?
- 'my $val = $self->type_constraint->coercion->coerce($_[1]);'
- : '')
- . ($self->has_type_constraint ?
- ('(defined $self->type_constraint->check(' . $value_name . '))'
- . '|| confess "Attribute ($attr_name) does not pass the type contraint (" . $self->type_constraint->name . ") with \'' . $value_name . '\'"'
- . 'if defined ' . $value_name . ';')
- : '')
- . '$_[0]->{$attr_name} = ' . $value_name . ';'
- . ($self->is_weak_ref ?
- 'weaken($_[0]->{$attr_name});'
- : '')
- . ($self->has_trigger ?
- '$self->trigger->($_[0], ' . $value_name . ', $self);'
- : '')
- . ' }'
- . ($self->is_lazy ?
- '$_[0]->{$attr_name} = ($self->has_default ? $self->default($_[0]) : undef)'
- . 'unless exists $_[0]->{$attr_name};'
- : '')
- . ' $_[0]->{$attr_name};'
- . ' }';
- my $sub = eval $code;
- confess "Could not create writer for '$attr_name' because $@ \n code: $code" if $@;
- return $sub;
+sub _call_builder {
+ my ( $self, $instance ) = @_;
+
+ my $builder = $self->builder();
+
+ return $instance->$builder()
+ if $instance->can( $self->builder );
+
+ $self->throw_error( blessed($instance)
+ . " does not support builder method '"
+ . $self->builder
+ . "' for attribute '"
+ . $self->name
+ . "'",
+ object => $instance,
+ );
}
-sub generate_writer_method {
- my ($self, $attr_name) = @_;
- my $value_name = $self->should_coerce ? '$val' : '$_[1]';
- my $code = 'sub { '
- . ($self->is_required ?
- 'defined($_[1]) || confess "Attribute ($attr_name) is required, so cannot be set to undef";'
- : '')
- . ($self->should_coerce ?
- 'my $val = $self->type_constraint->coercion->coerce($_[1]);'
- : '')
- . ($self->has_type_constraint ?
- ('(defined $self->type_constraint->check(' . $value_name . '))'
- . '|| confess "Attribute ($attr_name) does not pass the type contraint (" . $self->type_constraint->name . ") with \'' . $value_name . '\'"'
- . 'if defined ' . $value_name . ';')
- : '')
- . '$_[0]->{$attr_name} = ' . $value_name . ';'
- . ($self->is_weak_ref ?
- 'weaken($_[0]->{$attr_name});'
- : '')
- . ($self->has_trigger ?
- '$self->trigger->($_[0], ' . $value_name . ', $self);'
- : '')
- . ' }';
- my $sub = eval $code;
- confess "Could not create writer for '$attr_name' because $@ \n code: $code" if $@;
- return $sub;
+## Slot management
+
+# FIXME:
+# this duplicates too much code from
+# Class::MOP::Attribute, we need to
+# refactor these bits eventually.
+# - SL
+sub _set_initial_slot_value {
+ my ($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 = $self->_coerce_and_verify( shift, $instance );;
+
+ $meta_instance->set_slot_value($instance, $slot_name, $val);
+ };
+
+ 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 = $self->name;
+
+ if ($self->is_required and not @args) {
+ $self->throw_error("Attribute ($attr_name) is required", object => $instance);
+ }
+
+ $value = $self->_coerce_and_verify( $value, $instance );
+
+ my $meta_instance = Class::MOP::Class->initialize(blessed($instance))
+ ->get_meta_instance;
+
+ $meta_instance->set_slot_value($instance, $attr_name, $value);
+
+ if (ref $value && $self->is_weak_ref) {
+ $meta_instance->weaken_slot_value($instance, $attr_name);
+ }
+
+ if ($self->has_trigger) {
+ $self->trigger->($instance, $value);
+ }
+}
+
+sub get_value {
+ my ($self, $instance) = @_;
+
+ if ($self->is_lazy) {
+ unless ($self->has_value($instance)) {
+ my $value;
+ if ($self->has_default) {
+ $value = $self->default($instance);
+ } elsif ( $self->has_builder ) {
+ $value = $self->_call_builder($instance);
+ }
+
+ $value = $self->_coerce_and_verify( $value, $instance );
+
+ $self->set_initial_value($instance, $value);
+ }
+ }
+
+ if ($self->should_auto_deref) {
+
+ my $type_constraint = $self->type_constraint;
+
+ if ($type_constraint->is_a_type_of('ArrayRef')) {
+ my $rv = $self->SUPER::get_value($instance);
+ return unless defined $rv;
+ return wantarray ? @{ $rv } : $rv;
+ }
+ elsif ($type_constraint->is_a_type_of('HashRef')) {
+ my $rv = $self->SUPER::get_value($instance);
+ return unless defined $rv;
+ return wantarray ? %{ $rv } : $rv;
+ }
+ else {
+ $self->throw_error("Can not auto de-reference the type constraint '" . $type_constraint->name . "'", object => $instance, type_constraint => $type_constraint);
+ }
+
+ }
+ else {
+
+ return $self->SUPER::get_value($instance);
+ }
+}
+
+## installing accessors
+
+sub accessor_metaclass { 'Moose::Meta::Method::Accessor' }
+
+sub install_accessors {
+ my $self = shift;
+ $self->SUPER::install_accessors(@_);
+ $self->install_delegation if $self->has_handles;
+ return;
}
-sub generate_reader_method {
- my ($self, $attr_name) = @_;
- my $code = 'sub {'
- . 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;'
- . ($self->is_lazy ?
- '$_[0]->{$attr_name} = ($self->has_default ? $self->default($_[0]) : undef)'
- . 'unless exists $_[0]->{$attr_name};'
- : '')
- . '$_[0]->{$attr_name};'
- . '}';
- my $sub = eval $code;
- confess "Could not create reader for '$attr_name' because $@ \n code: $code" if $@;
- return $sub;
+sub remove_accessors {
+ my $self = shift;
+ $self->SUPER::remove_accessors(@_);
+ $self->remove_delegation if $self->has_handles;
+ return;
}
+sub install_delegation {
+ my $self = shift;
+
+ # NOTE:
+ # Here we canonicalize the 'handles' option
+ # this will sort out any details and always
+ # return an hash of methods which we want
+ # to delagate to, see that method for details
+ my %handles = $self->_canonicalize_handles;
+
+
+ # install the delegation ...
+ my $associated_class = $self->associated_class;
+ foreach my $handle (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);
+
+ # NOTE:
+ # handles is not allowed to delegate
+ # any of these methods, as they will
+ # override the ones in your class, which
+ # is almost certainly not what you want.
+
+ # FIXME warn when $handle was explicitly specified, but not if the source is a regex or something
+ #cluck("Not delegating method '$handle' because it is a core method") and
+ next if $class_name->isa("Moose::Object") and $handle =~ /^BUILD|DEMOLISH$/ || Moose::Object->can($handle);
+
+ my $method = $self->_make_delegation_method($handle, $method_to_call);
+
+ $self->associated_class->add_method($method->name, $method);
+ }
+}
+
+sub remove_delegation {
+ my $self = shift;
+ my %handles = $self->_canonicalize_handles;
+ my $associated_class = $self->associated_class;
+ foreach my $handle (keys %handles) {
+ $self->associated_class->remove_method($handle);
+ }
+}
+
+# private methods to help delegation ...
+
+sub _canonicalize_handles {
+ my $self = shift;
+ my $handles = $self->handles;
+ if (my $handle_type = ref($handles)) {
+ if ($handle_type eq 'HASH') {
+ return %{$handles};
+ }
+ elsif ($handle_type eq 'ARRAY') {
+ return map { $_ => $_ } @{$handles};
+ }
+ elsif ($handle_type eq 'Regexp') {
+ ($self->has_type_constraint)
+ || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)", data => $handles);
+ return map { ($_ => $_) }
+ grep { /$handles/ } $self->_get_delegate_method_list;
+ }
+ elsif ($handle_type eq 'CODE') {
+ return $handles->($self, $self->_find_delegate_metaclass);
+ }
+ else {
+ $self->throw_error("Unable to canonicalize the 'handles' option with $handles", data => $handles);
+ }
+ }
+ else {
+ Class::MOP::load_class($handles);
+ my $role_meta = Class::MOP::class_of($handles);
+
+ (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 { $_ => $_ } (
+ $role_meta->get_method_list,
+ $role_meta->get_required_method_list
+ );
+ }
+}
+
+sub _find_delegate_metaclass {
+ my $self = shift;
+ if (my $class = $self->_isa_metadata) {
+ # we might be dealing with a non-Moose class,
+ # and need to make our own metaclass. if there's
+ # already a metaclass, it will be returned
+ return Moose::Meta::Class->initialize($class);
+ }
+ elsif (my $role = $self->_does_metadata) {
+ return Class::MOP::class_of($role);
+ }
+ else {
+ $self->throw_error("Cannot find delegate metaclass for attribute " . $self->name);
+ }
+}
+
+sub _get_delegate_method_list {
+ my $self = shift;
+ 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' }
+ $meta->get_all_methods;
+ }
+ elsif ($meta->isa('Moose::Meta::Role')) {
+ return $meta->get_method_list;
+ }
+ else {
+ $self->throw_error("Unable to recognize the delegate metaclass '$meta'", data => $meta);
+ }
+}
+
+sub delegation_metaclass { 'Moose::Meta::Method::Delegation' }
+
+sub _make_delegation_method {
+ my ( $self, $handle_name, $method_to_call ) = @_;
+
+ my $method_body;
+
+ $method_body = $method_to_call
+ if 'CODE' eq ref($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,
+ );
+}
+
+sub _coerce_and_verify {
+ my $self = shift;
+ my $val = shift;
+ my $instance = shift;
+
+ return $val unless $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);
+
+ return $val;
+}
+
+sub verify_against_type_constraint {
+ my $self = shift;
+ my $val = shift;
+
+ return 1 if !$self->has_type_constraint;
+
+ my $type_constraint = $self->type_constraint;
+
+ $type_constraint->check($val)
+ || $self->throw_error("Attribute ("
+ . $self->name
+ . ") does not pass the type constraint because: "
+ . $type_constraint->get_message($val), data => $val, @_);
+}
+
+package Moose::Meta::Attribute::Custom::Moose;
+sub register_implementation { 'Moose::Meta::Attribute' }
+
1;
__END__
=head1 DESCRIPTION
-This is a subclass of L<Class::MOP::Attribute> with Moose specific
-extensions.
+This class is a subclass of L<Class::MOP::Attribute> that provides
+additional Moose-specific functionality.
+
+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.
+
+=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(%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' or 'rw'
+
+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.
+
+=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>). If this is true, then coercions will be applied whenever
+this attribute is set.
+
+You can make both this and the C<weak_ref> option true.
+
+=item * trigger => $sub
+
+This option accepts a subroutine reference, which will be called after
+the attribute is set.
+
+=item * required => $bool
-=item B<clone>
+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<initialize_instance_slot>
+A required attribute must have a C<default>, C<builder> or a
+non-C<undef> C<init_arg>
-=item B<generate_accessor_method>
+=item * lazy => $bool
-=item B<generate_writer_method>
+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<generate_reader_method>
+=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 => $bool
+
+Setting this to true makes the attribute lazy and provides a number of
+default methods.
+
+ has 'size' => (
+ is => 'ro',
+ lazy_build => 1,
+ );
+
+is equivalent to this:
+
+ has 'size' => (
+ is => 'ro',
+ lazy => 1,
+ builder => '_build_size',
+ clearer => 'clear_size',
+ predicate => 'has_size',
+ );
+
+=item * documentation
+
+An arbitrary string that can be retrieved later by calling C<<
+$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, 'forty-two') };
+ if($@) {
+ print "Oops: $@\n";
+ }
+
+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>.
+
+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>
+for an example.
+
+=back
+
+=head2 Attribute Accessor generation
+
+=over 4
+
+=item B<< $attr->install_accessors >>
+
+This method overrides the parent to also install delegation methods.
+
+=item B<< $attr->remove_accessors >>
+
+This method overrides the parent to also remove delegation methods.
+
+=item B<< $attr->install_delegation >>
+
+This method adds its delegation methods to the attribute's associated
+class, if it has any to add.
+
+=item B<< $attr->remove_delegation >>
+
+This method remove its delegation methods from the attribute's
+associated class.
+
+=item B<< $attr->accessor_metaclass >>
+
+Returns the accessor metaclass name, which defaults to
+L<Moose::Meta::Method::Accessor>.
+
+=item B<< $attr->delegation_metaclass >>
+
+Returns the delegation metaclass name, which defaults to
+L<Moose::Meta::Method::Delegation>.
=back
=head2 Additional Moose features
-Moose attributes support type-contstraint checking, weak reference
-creation and type coercion.
+These methods are not found in the superclass. They support features
+provided by Moose.
=over 4
-=item B<has_type_constraint>
+=item B<< $attr->does($role) >>
+
+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.
+
+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.
+
+=item B<< Moose::Meta::Class->interpolate_class_and_new($name, %options) >>
+
+This is an alternate constructor that handles the C<metaclass> and
+C<traits> options.
+
+Effectively, this method is a factory that finds or creates the
+appropriate class for the given C<metaclass> and/or C<traits>.
+
+Once it has the appropriate class, it will call C<< $class->new($name,
+%options) >> on that class.
+
+=item B<< $attr->clone_and_inherit_options(%options) >>
+
+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.
+
+One of its main tasks is to make sure that the C<%options> provided
+only includes the options returned by the
+C<legal_options_for_inheritance> method.
+
+=item B<< $attr->legal_options_for_inheritance >>
+
+This returns a whitelist of options that can be overridden in a
+subclass's attribute definition.
+
+This exists to allow a custom metaclass to change or add to the list
+of options which can be changed.
-Returns true if this meta-attribute has a type constraint.
+=item B<< $attr->type_constraint >>
-=item B<type_constraint>
+Returns the L<Moose::Meta::TypeConstraint> object for this attribute,
+if it has one.
-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>.
+=item B<< $attr->has_type_constraint >>
-=item B<is_weak_ref>
+Returns true if this attribute has a type constraint.
-Returns true if this meta-attribute produces a weak reference.
+=item B<< $attr->verify_against_type_constraint($value) >>
-=item B<is_required>
+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 is required to have a value.
+=item B<< $attr->handles >>
-=item B<is_lazy>
+This returns the value of the C<handles> option passed to the
+constructor.
-Returns true if this meta-attribute should be initialized lazily.
+=item B<< $attr->has_handles >>
-NOTE: lazy attributes, B<must> have a C<default> field set.
+Returns true if this attribute performs delegation.
-=item B<should_coerce>
+=item B<< $attr->is_weak_ref >>
-Returns true if this meta-attribute should perform type coercion.
+Returns true if this attribute stores its value as a weak reference.
-=item B<has_trigger>
+=item B<< $attr->is_required >>
-Returns true if this meta-attribute has a trigger set.
+Returns true if this attribute is required to have a value.
-=item B<trigger>
+=item B<< $attr->is_lazy >>
-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.
+Returns true if this attribute is lazy.
+
+=item B<< $attr->is_lazy_build >>
+
+Returns true if the C<lazy_build> option was true when passed to the
+constructor.
+
+=item B<< $attr->should_coerce >>
+
+Returns true if the C<coerce> option passed to the constructor was
+true.
+
+=item B<< $attr->should_auto_deref >>
+
+Returns true if the C<auto_deref> option passed to the constructor was
+true.
+
+=item B<< $attr->trigger >>
+
+This is the subroutine reference that was in the C<trigger> option
+passed to the constructor, if any.
+
+=item B<< $attr->has_trigger >>
+
+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
-All complex software has bugs lurking in it, and this module is no
+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.
Stevan Little E<lt>stevan@iinteractive.comE<gt>
+Yuval Kogman E<lt>nothingmuch@woobling.comE<gt>
+
=head1 COPYRIGHT AND LICENSE
-Copyright 2006 by Infinity Interactive, Inc.
+Copyright 2006-2009 by Infinity Interactive, Inc.
L<http://www.iinteractive.com>
This library is free software; you can redistribute it and/or modify
-it under the same terms as Perl itself.
+it under the same terms as Perl itself.
-=cut
\ No newline at end of file
+=cut
projects / gitmo/Moose.git / blobdiff