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;
use Mouse::Meta::TypeConstraint;
-use Mouse::Meta::Method::Accessor;
+
+#use Mouse::Meta::Method::Accessor;
+use Mouse::Meta::Method::Delegation;
sub _process_options{
my($class, $name, $args) = @_;
+ # XXX: for backward compatibility (with method modifiers)
+ if($class->can('canonicalize_args') != \&canonicalize_args){
+ %{$args} = $class->canonicalize_args($name, %{$args});
+ }
+
# taken from Class::MOP::Attribute::new
defined($name)
my $can_be_required = defined( $args->{init_arg} );
if(exists $args->{builder}){
+ # XXX:
+ # Moose refuses a CODE ref builder, but Mouse doesn't for backward compatibility
+ # This feature will be changed in a future. (gfx)
$class->throw_error('builder must be a defined scalar value which is a method name')
- if ref $args->{builder} || !(defined $args->{builder});
+ #if ref $args->{builder} || !defined $args->{builder};
+ if !defined $args->{builder};
$can_be_required++;
}
|| $class->throw_error("You cannot have lazy attribute ($name) without specifying a default value for it");
}
- # XXX: for backward compatibility (with method modifiers)
- if($class->can('canonicalize_args') != \&canonicalize_args){
- %{$args} = $class->canonicalize_args($name, %{$args});
- }
return;
}
$args{name} = $name;
- my $instance = bless \%args, $class;
+ 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
# Carp::cluck("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad");
# }
- return $instance
+ return $self;
}
-sub does {
- my ($self, $role_name) = @_;
- my $meta = Mouse::Meta::Class->initialize(ref($self) || $self);
-
- (defined $role_name)
- || $meta->throw_error("You must supply a role name to does()");
-
- return $meta->does_role($role_name);
-};
-
-# readers
+sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor }
+sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor }
-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 _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."
- . "Use \$self->_process_options instead.");
+ . "Use \$self->_process_options instead.")
+ if Mouse::Util::_MOUSE_VERBOSE;
return %args;
}
-sub create {
+sub create { # DEPRECATED
my ($self, $class, $name, %args) = @_;
Carp::cluck("$self->create has been deprecated."
- . "Use \$meta->add_attribute and \$attr->install_accessors instead.");
+ . "Use \$meta->add_attribute and \$attr->install_accessors instead.")
+ if Mouse::Util::_MOUSE_VERBOSE;
# noop
return $self;
}
+sub _coerce_and_verify {
+ my($self, $value, $instance) = @_;
+
+ my $type_constraint = $self->{type_constraint};
+ return $value if !defined $type_constraint;
+
+ if ($self->should_coerce && $type_constraint->has_coercion) {
+ $value = $type_constraint->coerce($value);
+ }
+
+ $self->verify_against_type_constraint($value);
+
+ return $value;
+}
+
sub verify_against_type_constraint {
my ($self, $value) = @_;
- my $tc = $self->type_constraint;
- return 1 unless $tc;
- local $_ = $value;
- return 1 if $tc->check($value);
+ my $type_constraint = $self->{type_constraint};
+ return 1 if !$type_constraint;
+ return 1 if $type_constraint->check($value);
- $self->verify_type_constraint_error($self->name, $value, $tc);
+ $self->verify_type_constraint_error($self->name, $value, $type_constraint);
}
sub verify_type_constraint_error {
my($self, $name, $value, $type) = @_;
- $self->throw_error("Attribute ($name) does not pass the type constraint because: " . $type->get_message($value));
+ $self->throw_error("Attribute ($name) does not pass the type constraint because: "
+ . $type->get_message($value));
}
-sub coerce_constraint { ## my($self, $value) = @_;
+sub coerce_constraint { # DEPRECATED
my $type = $_[0]->{type_constraint}
or return $_[1];
- return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $_[0]->type_constraint, $_[1]);
-}
-sub _canonicalize_handles {
- my $self = shift;
- my $handles = shift;
+ Carp::cluck("coerce_constraint() has been deprecated, which was an internal utility anyway");
- if (ref($handles) eq 'HASH') {
- return %$handles;
- }
- elsif (ref($handles) eq 'ARRAY') {
- return map { $_ => $_ } @$handles;
- }
- else {
- $self->throw_error("Unable to canonicalize the 'handles' option with $handles");
- }
+ return Mouse::Util::TypeConstraints->typecast_constraints($_[0]->associated_class->name, $type, $_[1]);
}
sub clone_and_inherit_options{
- my $self = shift;
- my $name = shift;
+ my($self, %args) = @_;
+
+ my($attribute_class, @traits) = ref($self)->interpolate_class(\%args);
- return ref($self)->new($name, %{$self}, @_ == 1 ? %{$_[0]} : @_);
+ $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 $attribute_class->new($self->name, %args);
}
-sub clone_parent {
+sub clone_parent { # DEPRECATED
my $self = shift;
my $class = shift;
my $name = shift;
my %args = ($self->get_parent_args($class, $name), @_);
Carp::cluck("$self->clone_parent has been deprecated."
- . "Use \$meta->add_attribute and \$attr->install_accessors instead.");
+ . "Use \$meta->add_attribute and \$attr->install_accessors instead.")
+ if Mouse::Util::_MOUSE_VERBOSE;
-
- $self->create($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 $predicate_ref = $self->{_predicate_ref}
+ ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate');
+
+ return $predicate_ref->($object);
+}
+
+sub clear_value {
+ my($self, $object) = @_;
+ my $predicate_ref = $self->{_crealer_ref}
+ ||= $self->_get_accessor_method_ref('clearer', '_generate_clearer');
+
+ return $predicate_ref->($object);
+}
+
+
+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 '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 $handles");
+ }
+}
+
+sub associate_method{
+ my ($attribute, $method_name) = @_;
+ $attribute->{associated_methods}++;
+ return;
+}
+
+sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' }
+
sub install_accessors{
my($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 $delegation_class = $attribute->delegation_metaclass;
+ my %handles = $attribute->_canonicalize_handles($attribute->{handles});
+ my $reader = $attribute->get_read_method_ref;
+
+ while(my($handle_name, $method_to_call) = each %handles){
+ my $code = $delegation_class->_generate_delegation($attribute, $metaclass,
+ $reader, $handle_name, $method_to_call);
+
+ $metaclass->add_method($handle_name => $code);
+ $attribute->associate_method($handle_name);
}
}
if($attribute->can('create') != \&create){
+ # backword compatibility
$attribute->create($metaclass, $attribute->name, %{$attribute});
}
}
1;
-
__END__
=head1 NAME
-Mouse::Meta::Attribute - attribute metaclass
+Mouse::Meta::Attribute - The Mouse attribute metaclass
+
+=head1 VERSION
+
+This document describes Mouse version 0.44
=head1 METHODS
-=head2 new %args -> Mouse::Meta::Attribute
+=head2 C<< new(%options) -> Mouse::Meta::Attribute >>
Instantiates a new Mouse::Meta::Attribute. Does nothing else.
-=head2 create OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
+It adds the following options to the constructor:
-Creates a new attribute in OwnerClass. Accessors and helper methods are
-installed. Some error checking is done.
+=over 4
-=head2 name -> AttributeName
+=item C<< is => 'ro', 'rw', 'bare' >>
-=head2 associated_class -> OwnerClass
+This provides a shorthand for specifying the C<reader>, C<writer>, or
+C<accessor> names. If the attribute is read-only ('ro') then it will
+have a C<reader> method with the same attribute as the name.
-=head2 is_required -> Bool
+If it is read-write ('rw') then it will have an C<accessor> method
+with the same name. If you provide an explicit C<writer> for a
+read-write attribute, then you will have a C<reader> with the same
+name as the attribute, and a C<writer> with the name you provided.
-=head2 default -> Item
+Use 'bare' when you are deliberately not installing any methods
+(accessor, reader, etc.) associated with this attribute; otherwise,
+Moose will issue a deprecation warning when this attribute is added to a
+metaclass.
-=head2 has_default -> Bool
+=item C<< isa => Type >>
-=head2 is_lazy -> Bool
+This option accepts a type. The type can be a string, which should be
+a type name. If the type name is unknown, it is assumed to be a class
+name.
-=head2 predicate -> MethodName | Undef
+This option can also accept a L<Moose::Meta::TypeConstraint> object.
-=head2 has_predicate -> Bool
+If you I<also> provide a C<does> option, then your C<isa> option must
+be a class name, and that class must do the role specified with
+C<does>.
-=head2 clearer -> MethodName | Undef
+=item C<< does => Role >>
-=head2 has_clearer -> Bool
+This is short-hand for saying that the attribute's type must be an
+object which does the named role.
-=head2 handles -> { LocalName => RemoteName }
+B<This option is not yet supported.>
-=head2 has_handles -> Bool
+=item C<< coerce => Bool >>
-=head2 is_weak_ref -> Bool
+This option is only valid for objects with a type constraint
+(C<isa>). If this is true, then coercions will be applied whenever
+this attribute is set.
-=head2 init_arg -> Str
+You can make both this and the C<weak_ref> option true.
-=head2 type_constraint -> Str
+=item C<< trigger => CodeRef >>
-=head2 has_type_constraint -> Bool
+This option accepts a subroutine reference, which will be called after
+the attribute is set.
-=head2 trigger => CODE | Undef
+=item C<< required => Bool >>
-=head2 has_trigger -> Bool
+An attribute which is required must be provided to the constructor. An
+attribute which is required can also have a C<default> or C<builder>,
+which will satisfy its required-ness.
-=head2 builder => MethodName | Undef
+A required attribute must have a C<default>, C<builder> or a
+non-C<undef> C<init_arg>
-=head2 has_builder -> Bool
+=item C<< lazy => Bool >>
-=head2 is_lazy_build => Bool
+A lazy attribute must have a C<default> or C<builder>. When an
+attribute is lazy, the default value will not be calculated until the
+attribute is read.
-=head2 should_auto_deref -> Bool
+=item C<< weak_ref => Bool >>
-Informational methods.
+If this is true, the attribute's value will be stored as a weak
+reference.
-=head2 verify_against_type_constraint Item -> 1 | ERROR
+=item C<< auto_deref => Bool >>
-Checks that the given value passes this attribute's type constraint. Returns 1
-on success, otherwise C<confess>es.
+If this is true, then the reader will dereference the value when it is
+called. The attribute must have a type constraint which defines the
+attribute as an array or hash reference.
+
+=item C<< lazy_build => Bool >>
+
+Setting this to true makes the attribute lazy and provides a number of
+default methods.
+
+ has 'size' => (
+ is => 'ro',
+ lazy_build => 1,
+ );
+
+is equivalent to this:
+
+ has 'size' => (
+ is => 'ro',
+ lazy => 1,
+ builder => '_build_size',
+ clearer => 'clear_size',
+ predicate => 'has_size',
+ );
-=head2 canonicalize_args Name, %args -> %args
+=back
-Canonicalizes some arguments to create. In particular, C<lazy_build> is
-canonicalized into C<lazy>, C<builder>, etc.
+=head2 C<< associate_method(MethodName) >>
-=head2 validate_args Name, \%args -> 1 | ERROR
+Associates a method with the attribute. Typically, this is called internally
+when an attribute generates its accessors.
-Checks that the arguments to create the attribute (ie those specified by
-C<has>) are valid.
+Currently the argument I<MethodName> is ignored in Mouse.
-=head2 clone_parent OwnerClass, AttributeName, %args -> Mouse::Meta::Attribute
+=head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >>
-Creates a new attribute in OwnerClass, inheriting options from parent classes.
+Checks that the given value passes this attribute's type constraint. Returns C<true>
+on success, otherwise C<confess>es.
+
+=head2 C<< clone_and_inherit_options(options) -> Mouse::Meta::Attribute >>
+
+Creates a new attribute in the owner class, inheriting options from parent classes.
Accessors and helper methods are installed. Some error checking is done.
-=head2 get_parent_args OwnerClass, AttributeName -> Hash
+=head2 C<< get_read_method_ref >>
+
+=head2 C<< get_write_method_ref >>
+
+Returns the subroutine reference of a method suitable for reading or
+writing the attribute's value in the associated class. These methods
+always return a subroutine reference, regardless of whether or not the
+attribute is read- or write-only.
+
+=head1 SEE ALSO
+
+L<Moose::Meta::Attribute>
-Returns the options that the parent class of C<OwnerClass> used for attribute
-C<AttributeName>.
+L<Class::MOP::Attribute>
=cut