package Mouse::Meta::Attribute;
-use strict;
-use warnings;
+use Mouse::Util qw(:meta); # enables strict and warnings
use Carp ();
-use Scalar::Util qw(weaken);
-
-use Mouse::Util qw(:meta);
use Mouse::Meta::TypeConstraint;
-use Mouse::Meta::Method::Accessor;
-
-sub _process_options{
- my($class, $name, $args) = @_;
-
- # taken from Class::MOP::Attribute::new
-
- defined($name)
- or $class->throw_error('You must provide a name for the attribute');
-
- if(!exists $args->{init_arg}){
- $args->{init_arg} = $name;
- }
-
- # 'required' requires eigher 'init_arg', 'builder', or 'default'
- my $can_be_required = defined( $args->{init_arg} );
-
- if(exists $args->{builder}){
- $class->throw_error('builder must be a defined scalar value which is a method name')
- if ref $args->{builder} || !(defined $args->{builder});
-
- $can_be_required++;
- }
- elsif(exists $args->{default}){
- if(ref $args->{default} && ref($args->{default}) ne 'CODE'){
- $class->throw_error("References are not allowed as default values, you must "
- . "wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])");
- }
- $can_be_required++;
- }
-
- if( $args->{required} && !$can_be_required ) {
- $class->throw_error("You cannot have a required attribute ($name) without a default, builder, or an init_arg");
- }
- # taken from Mouse::Meta::Attribute->new and _process_args->
-
- if(exists $args->{is}){
- my $is = $args->{is};
-
- if($is eq 'ro'){
- $args->{reader} ||= $name;
- }
- elsif($is eq 'rw'){
- if(exists $args->{writer}){
- $args->{reader} ||= $name;
- }
- else{
- $args->{accessor} ||= $name;
- }
- }
- elsif($is eq 'bare'){
- # do nothing, but don't complain (later) about missing methods
- }
- else{
- $is = 'undef' if !defined $is;
- $class->throw_error("I do not understand this option (is => $is) on attribute ($name)");
- }
- }
-
- my $tc;
- if(exists $args->{isa}){
- $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_isa_type_constraint($args->{isa});
- }
- elsif(exists $args->{does}){
- $args->{type_constraint} = Mouse::Util::TypeConstraints::find_or_create_does_type_constraint($args->{does});
- }
- $tc = $args->{type_constraint};
-
- if($args->{coerce}){
- defined($tc)
- || $class->throw_error("You cannot have coercion without specifying a type constraint on attribute ($name)");
-
- $args->{weak_ref}
- && $class->throw_error("You cannot have a weak reference to a coerced value on attribute ($name)");
- }
-
- if ($args->{lazy_build}) {
- exists($args->{default})
- && $class->throw_error("You can not use lazy_build and default for the same attribute ($name)");
-
- $args->{lazy} = 1;
- $args->{builder} ||= "_build_${name}";
- if ($name =~ /^_/) {
- $args->{clearer} ||= "_clear${name}";
- $args->{predicate} ||= "_has${name}";
- }
- else {
- $args->{clearer} ||= "clear_${name}";
- $args->{predicate} ||= "has_${name}";
- }
- }
-
- if ($args->{auto_deref}) {
- defined($tc)
- || $class->throw_error("You cannot auto-dereference without specifying a type constraint on attribute ($name)");
-
- ( $tc->is_a_type_of('ArrayRef') || $tc->is_a_type_of('HashRef') )
- || $class->throw_error("You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute ($name)");
- }
+my %valid_options = map { $_ => undef } (
+ 'accessor',
+ 'auto_deref',
+ 'builder',
+ 'clearer',
+ 'coerce',
+ 'default',
+ 'documentation',
+ 'does',
+ 'handles',
+ 'init_arg',
+ 'is',
+ 'isa',
+ 'lazy',
+ 'lazy_build',
+ 'name',
+ 'predicate',
+ 'reader',
+ 'required',
+ 'traits',
+ 'trigger',
+ 'type_constraint',
+ 'weak_ref',
+ 'writer',
+
+ # internally used
+ 'associated_class',
+ 'associated_methods',
+
+ # Moose defines, but Mouse doesn't
+ #'definition_context',
+ #'initializer',
+ #'insertion_order',
+
+ # special case for AttributeHelpers
+ 'provides',
+ 'curries',
+);
+
+our @CARP_NOT = qw(Mouse::Meta::Class);
- if (exists $args->{trigger}) {
- ('CODE' eq ref $args->{trigger})
- || $class->throw_error("Trigger must be a CODE ref on attribute ($name)");
- }
+sub new {
+ my $class = shift;
+ my $name = shift;
- if ($args->{lazy}) {
- (exists $args->{default} || defined $args->{builder})
- || $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it");
- }
+ my $args = $class->Mouse::Object::BUILDARGS(@_);
# XXX: for backward compatibility (with method modifiers)
if($class->can('canonicalize_args') != \&canonicalize_args){
%{$args} = $class->canonicalize_args($name, %{$args});
}
- return;
-}
-sub new {
- my $class = shift;
- my $name = shift;
+ $class->_process_options($name, $args);
- my %args = (@_ == 1) ? %{ $_[0] } : @_;
+ $args->{name} = $name;
- $class->_process_options($name, \%args);
+ # check options
+ # (1) known by core
+ my @bad = grep{ !exists $valid_options{$_} } keys %{$args};
- $args{name} = $name;
+ # (2) known by subclasses
+ if(@bad && $class ne __PACKAGE__){
+ my %valid_attrs = (
+ map { $_ => undef }
+ grep { defined }
+ map { $_->init_arg() }
+ $class->meta->get_all_attributes()
+ );
+ @bad = grep{ !exists $valid_attrs{$_} } @bad;
+ }
- my $instance = bless \%args, $class;
+ # (3) bad options found
+ if(@bad){
+ Carp::carp(
+ "Found unknown argument(s) passed to '$name' attribute constructor in '$class': "
+ . Mouse::Util::english_list(@bad));
+ }
+
+ my $self = bless $args, $class;
# extra attributes
if($class ne __PACKAGE__){
- $class->meta->_initialize_instance($instance,\%args);
+ $class->meta->_initialize_object($self, $args);
}
-# XXX: there is no fast way to check attribute validity
-# my @bad = ...;
-# if(@bad){
-# @bad = sort @bad;
-# Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad");
-# }
-
- return $instance
+ return $self;
}
-# readers
-
-sub name { $_[0]->{name} }
-sub associated_class { $_[0]->{associated_class} }
-
-sub accessor { $_[0]->{accessor} }
-sub reader { $_[0]->{reader} }
-sub writer { $_[0]->{writer} }
-sub predicate { $_[0]->{predicate} }
-sub clearer { $_[0]->{clearer} }
-sub handles { $_[0]->{handles} }
-
-sub _is_metadata { $_[0]->{is} }
-sub is_required { $_[0]->{required} }
-sub default { $_[0]->{default} }
-sub is_lazy { $_[0]->{lazy} }
-sub is_lazy_build { $_[0]->{lazy_build} }
-sub is_weak_ref { $_[0]->{weak_ref} }
-sub init_arg { $_[0]->{init_arg} }
-sub type_constraint { $_[0]->{type_constraint} }
-
-sub trigger { $_[0]->{trigger} }
-sub builder { $_[0]->{builder} }
-sub should_auto_deref { $_[0]->{auto_deref} }
-sub should_coerce { $_[0]->{coerce} }
-
-sub get_read_method { $_[0]->{reader} || $_[0]->{accessor} }
-sub get_write_method { $_[0]->{writer} || $_[0]->{accessor} }
-
-# predicates
-
-sub has_accessor { exists $_[0]->{accessor} }
-sub has_reader { exists $_[0]->{reader} }
-sub has_writer { exists $_[0]->{writer} }
-sub has_predicate { exists $_[0]->{predicate} }
-sub has_clearer { exists $_[0]->{clearer} }
-sub has_handles { exists $_[0]->{handles} }
-
-sub has_default { exists $_[0]->{default} }
-sub has_type_constraint { exists $_[0]->{type_constraint} }
-sub has_trigger { exists $_[0]->{trigger} }
-sub has_builder { exists $_[0]->{builder} }
-
-sub has_read_method { exists $_[0]->{reader} || exists $_[0]->{accessor} }
-sub has_write_method { exists $_[0]->{writer} || exists $_[0]->{accessor} }
-
-sub _create_args {
+sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor }
+sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor }
+
+sub _create_args { # DEPRECATED
$_[0]->{_create_args} = $_[1] if @_ > 1;
$_[0]->{_create_args}
}
-sub accessor_metaclass { 'Mouse::Meta::Method::Accessor' }
-
sub interpolate_class{
- my($class, $name, $args) = @_;
+ my($class, $args) = @_;
if(my $metaclass = delete $args->{metaclass}){
$class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass );
return( $class, @traits );
}
-sub canonicalize_args{
+sub canonicalize_args{ # DEPRECATED
my ($self, $name, %args) = @_;
Carp::cluck("$self->canonicalize_args has been deprecated."
return %args;
}
-sub create {
+sub create { # DEPRECATED
my ($self, $class, $name, %args) = @_;
Carp::cluck("$self->create has been deprecated."
return $self;
}
-sub verify_against_type_constraint {
- my ($self, $value) = @_;
- my $tc = $self->type_constraint;
- return 1 unless $tc;
+sub _coerce_and_verify {
+ my($self, $value, $instance) = @_;
- local $_ = $value;
- return 1 if $tc->check($value);
+ my $type_constraint = $self->{type_constraint};
+ return $value if !defined $type_constraint;
- $self->verify_type_constraint_error($self->name, $value, $tc);
-}
+ if ($self->should_coerce && $type_constraint->has_coercion) {
+ $value = $type_constraint->coerce($value);
+ }
-sub verify_type_constraint_error {
- my($self, $name, $value, $type) = @_;
- $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value));
+ $self->verify_against_type_constraint($value);
+
+ return $value;
}
-sub coerce_constraint { ## my($self, $value) = @_;
- my $type = $_[0]->{type_constraint}
- or return $_[1];
- return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]);
+sub verify_against_type_constraint {
+ my ($self, $value) = @_;
+
+ my $type_constraint = $self->{type_constraint};
+ return 1 if !$type_constraint;
+ return 1 if $type_constraint->check($value);
+
+ $self->_throw_type_constraint_error($value, $type_constraint);
}
-sub _canonicalize_handles {
- my $self = shift;
- my $handles = shift;
+sub _throw_type_constraint_error {
+ my($self, $value, $type) = @_;
- if (ref($handles) eq 'HASH') {
- return %$handles;
- }
- elsif (ref($handles) eq 'ARRAY') {
- return map { $_ => $_ } @$handles;
- }
- else {
- $self->throw_error("Unable to canonicalize the 'handles' option with $handles");
- }
+ $self->throw_error(
+ sprintf q{Attribute (%s) does not pass the type constraint because: %s},
+ $self->name,
+ $type->get_message($value),
+ );
}
sub clone_and_inherit_options{
my $self = shift;
- my $name = shift;
+ my $args = $self->Mouse::Object::BUILDARGS(@_);
+
+ my($attribute_class, @traits) = ref($self)->interpolate_class($args);
+
+ $args->{traits} = \@traits if @traits;
+ # do not inherit the 'handles' attribute
+ foreach my $name(keys %{$self}){
+ if(!exists $args->{$name} && $name ne 'handles'){
+ $args->{$name} = $self->{$name};
+ }
+ }
- return ref($self)->new($name, %{$self}, @_ == 1 ? %{$_[0]} : @_);
+ # remove temporary caches
+ foreach my $attr(keys %{$args}){
+ if($attr =~ /\A _/xms){
+ delete $args->{$attr};
+ }
+ }
+
+ return $attribute_class->new($self->name, $args);
}
-sub clone_parent {
+sub clone_parent { # DEPRECATED
my $self = shift;
my $class = shift;
my $name = shift;
Carp::cluck("$self->clone_parent has been deprecated."
. "Use \$meta->add_attribute and \$attr->install_accessors instead.");
-
- $self->create($class, $name, %args);
+ $self->clone_and_inherited_args($class, $name, %args);
}
-sub get_parent_args {
+sub get_parent_args { # DEPRECATED
my $self = shift;
my $class = shift;
my $name = shift;
$self->throw_error("Could not find an attribute by the name of '$name' to inherit from");
}
+
+sub get_read_method {
+ return $_[0]->reader || $_[0]->accessor
+}
+sub get_write_method {
+ return $_[0]->writer || $_[0]->accessor
+}
+
+sub _get_accessor_method_ref {
+ my($self, $type, $generator) = @_;
+
+ my $metaclass = $self->associated_class
+ || $self->throw_error('No asocciated class for ' . $self->name);
+
+ my $accessor = $self->$type();
+ if($accessor){
+ return $metaclass->get_method_body($accessor);
+ }
+ else{
+ return $self->accessor_metaclass->$generator($self, $metaclass);
+ }
+}
+
+sub get_read_method_ref{
+ my($self) = @_;
+ return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader');
+}
+
+sub get_write_method_ref{
+ my($self) = @_;
+ return $self->{_write_method_ref} ||= $self->_get_accessor_method_ref('get_write_method', '_generate_writer');
+}
+
+sub set_value {
+ my($self, $object, $value) = @_;
+ return $self->get_write_method_ref()->($object, $value);
+}
+
+sub get_value {
+ my($self, $object) = @_;
+ return $self->get_read_method_ref()->($object);
+}
+
+sub has_value {
+ my($self, $object) = @_;
+ my $accessor_ref = $self->{_predicate_ref}
+ ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate');
+
+ return $accessor_ref->($object);
+}
+
+sub clear_value {
+ my($self, $object) = @_;
+ my $accessor_ref = $self->{_crealer_ref}
+ ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer');
+
+ return $accessor_ref->($object);
+}
+
+
+sub associate_method{
+ my ($attribute, $method_name) = @_;
+ $attribute->{associated_methods}++;
+ return;
+}
+
sub install_accessors{
my($attribute) = @_;
- my $metaclass = $attribute->{associated_class};
- my $generator_class = $attribute->accessor_metaclass;
+ my $metaclass = $attribute->associated_class;
+ my $accessor_class = $attribute->accessor_metaclass;
- foreach my $type(qw(accessor reader writer predicate clearer handles)){
+ foreach my $type(qw(accessor reader writer predicate clearer)){
if(exists $attribute->{$type}){
- my $installer = '_install_' . $type;
- $generator_class->$installer($attribute, $attribute->{$type}, $metaclass);
- $attribute->{associated_methods}++;
+ my $generator = '_generate_' . $type;
+ my $code = $accessor_class->$generator($attribute, $metaclass);
+ $metaclass->add_method($attribute->{$type} => $code);
+ $attribute->associate_method($attribute->{$type});
+ }
+ }
+
+ # install delegation
+ if(exists $attribute->{handles}){
+ my %handles = $attribute->_canonicalize_handles($attribute->{handles});
+
+ while(my($handle, $method_to_call) = each %handles){
+ $metaclass->add_method($handle =>
+ $attribute->_make_delegation_method(
+ $handle, $method_to_call));
+
+ $attribute->associate_method($handle);
}
}
if($attribute->can('create') != \&create){
+ # backword compatibility
$attribute->create($metaclass, $attribute->name, %{$attribute});
}
return;
}
+sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' }
+
+sub _canonicalize_handles {
+ my($self, $handles) = @_;
+
+ if (ref($handles) eq 'HASH') {
+ return %$handles;
+ }
+ elsif (ref($handles) eq 'ARRAY') {
+ return map { $_ => $_ } @$handles;
+ }
+ elsif ( ref($handles) eq 'CODE' ) {
+ my $class_or_role = ( $self->{isa} || $self->{does} )
+ || $self->throw_error( "Cannot find delegate metaclass for attribute " . $self->name );
+ return $handles->( $self, Mouse::Meta::Class->initialize("$class_or_role"));
+ }
+ elsif (ref($handles) eq 'Regexp') {
+ my $class_or_role = ($self->{isa} || $self->{does})
+ || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)");
+
+ my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify
+ return map { $_ => $_ }
+ grep { !Mouse::Object->can($_) && $_ =~ $handles }
+ Mouse::Util::is_a_metarole($meta)
+ ? $meta->get_method_list
+ : $meta->get_all_method_names;
+ }
+ else {
+ $self->throw_error("Unable to canonicalize the 'handles' option with $handles");
+ }
+}
+
+sub _make_delegation_method {
+ my($self, $handle, $method_to_call) = @_;
+ return Mouse::Util::load_class($self->delegation_metaclass)
+ ->_generate_delegation($self, $handle, $method_to_call);
+}
+
sub throw_error{
my $self = shift;
}
1;
-
__END__
=head1 NAME
-Mouse::Meta::Attribute - attribute metaclass
+Mouse::Meta::Attribute - The Mouse attribute metaclass
+
+=head1 VERSION
+
+This document describes Mouse version 0.50_03
=head1 METHODS
=over 4
-=item * C<< is => 'ro', 'rw', 'bare' >>
+=item C<< 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
Moose will issue a deprecation warning when this attribute is added to a
metaclass.
-=item * C<< isa => Type >>
+=item C<< 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
be a class name, and that class must do the role specified with
C<does>.
-=item * C<< does => Role >>
+=item C<< does => Role >>
This is short-hand for saying that the attribute's type must be an
object which does the named role.
B<This option is not yet supported.>
-=item * C<< coerce => Bool >>
+=item C<< 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
You can make both this and the C<weak_ref> option true.
-=item * C<< trigger => CodeRef >>
+=item C<< trigger => CodeRef >>
This option accepts a subroutine reference, which will be called after
the attribute is set.
-=item * C<< required => Bool >>
+=item C<< required => Bool >>
An attribute which is required must be provided to the constructor. An
attribute which is required can also have a C<default> or C<builder>,
A required attribute must have a C<default>, C<builder> or a
non-C<undef> C<init_arg>
-=item * C<< lazy => Bool >>
+=item C<< lazy => Bool >>
A lazy attribute must have a C<default> or C<builder>. When an
attribute is lazy, the default value will not be calculated until the
attribute is read.
-=item * C<< weak_ref => Bool >>
+=item C<< weak_ref => Bool >>
If this is true, the attribute's value will be stored as a weak
reference.
-=item * C<< auto_deref => Bool >>
+=item C<< 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 * C<< lazy_build => Bool >>
+=item C<< lazy_build => Bool >>
Setting this to true makes the attribute lazy and provides a number of
default methods.
=back
+=head2 C<< associate_method(MethodName) >>
+
+Associates a method with the attribute. Typically, this is called internally
+when an attribute generates its accessors.
+
+Currently the argument I<MethodName> is ignored in Mouse.
+
=head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >>
Checks that the given value passes this attribute's type constraint. Returns C<true>
=head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >>
-Creates a new attribute in OwnerClass, inheriting options from parent classes.
+Creates a new attribute in the owner class, inheriting options from parent classes.
Accessors and helper methods are installed. Some error checking is done.
+=head2 C<< get_read_method_ref >>
+
+=head2 C<< get_write_method_ref >>
+
+Returns the subroutine reference of a method suitable for reading or
+writing the attribute's value in the associated class. These methods
+always return a subroutine reference, regardless of whether or not the
+attribute is read- or write-only.
+
=head1 SEE ALSO
L<Moose::Meta::Attribute>
+L<Class::MOP::Attribute>
+
=cut
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