-#!/usr/bin/env perl
package Mouse::Meta::Attribute;
-use strict;
-use warnings;
-
-use Carp 'confess';
-use Scalar::Util 'blessed';
+use Mouse::Util qw(:meta); # enables strict and warnings
+
+use Carp ();
+
+use Mouse::Meta::TypeConstraint;
+
+my %valid_options = map { $_ => undef } (
+ 'accessor',
+ 'auto_deref',
+ 'builder',
+ 'clearer',
+ 'coerce',
+ 'default',
+ 'documentation',
+ 'does',
+ 'handles',
+ 'init_arg',
+ 'is',
+ 'isa',
+ 'lazy',
+ 'lazy_build',
+ 'name',
+ 'predicate',
+ 'reader',
+ 'required',
+ 'traits',
+ 'trigger',
+ 'type_constraint',
+ 'weak_ref',
+ 'writer',
+
+ # internally used
+ 'associated_class',
+ 'associated_methods',
+
+ # Moose defines, but Mouse doesn't
+ #'definition_context',
+ #'initializer',
+ #'insertion_order',
+
+ # special case for AttributeHelpers
+ 'provides',
+ 'curries',
+);
sub new {
my $class = shift;
- my %args = @_;
+ my $name = shift;
- $args{init_arg} = $args{name}
- unless exists $args{init_arg};
- $args{is} ||= '';
+ my $args = $class->Mouse::Object::BUILDARGS(@_);
- bless \%args, $class;
-}
+ # XXX: for backward compatibility (with method modifiers)
+ if($class->can('canonicalize_args') != \&canonicalize_args){
+ %{$args} = $class->canonicalize_args($name, %{$args});
+ }
-sub name { $_[0]->{name} }
-sub class { $_[0]->{class} }
-sub _is_metadata { $_[0]->{is} }
-sub is_required { $_[0]->{required} }
-sub default { $_[0]->{default} }
-sub is_lazy { $_[0]->{lazy} }
-sub predicate { $_[0]->{predicate} }
-sub clearer { $_[0]->{clearer} }
-sub handles { $_[0]->{handles} }
-sub is_weak_ref { $_[0]->{weak_ref} }
-sub init_arg { $_[0]->{init_arg} }
-sub type_constraint { $_[0]->{type_constraint} }
-sub trigger { $_[0]->{trigger} }
-sub builder { $_[0]->{builder} }
-sub should_auto_deref { $_[0]->{auto_deref} }
-
-sub has_default { exists $_[0]->{default} }
-sub has_predicate { exists $_[0]->{predicate} }
-sub has_clearer { exists $_[0]->{clearer} }
-sub has_handles { exists $_[0]->{handles} }
-sub has_type_constraint { exists $_[0]->{type_constraint} }
-sub has_trigger { exists $_[0]->{trigger} }
-sub has_builder { exists $_[0]->{builder} }
-
-sub generate_accessor {
- my $attribute = shift;
-
- my $name = $attribute->name;
- my $key = $name;
- my $default = $attribute->default;
- my $trigger = $attribute->trigger;
- my $type = $attribute->type_constraint;
- my $constraint = $attribute->find_type_constraint;
- my $builder = $attribute->builder;
-
- my $accessor = 'sub {
- my $self = shift;';
-
- if ($attribute->_is_metadata eq 'rw') {
- $accessor .= 'if (@_) {
- local $_ = $_[0];';
-
- if ($constraint) {
- $accessor .= 'do {
- my $display = defined($_) ? overload::StrVal($_) : "undef";
- Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display") unless $constraint->();
- };'
- }
+ $class->_process_options($name, $args);
- $accessor .= '$self->{$key} = $_;';
+ $args->{name} = $name;
- if ($attribute->is_weak_ref) {
- $accessor .= 'Scalar::Util::weaken($self->{$key}) if ref($self->{$key});';
- }
+ # check options
+ # (1) known by core
+ my @bad = grep{ !exists $valid_options{$_} } keys %{$args};
- if ($trigger) {
- $accessor .= '$trigger->($self, $_, $attribute);';
- }
+ # (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;
+ }
- $accessor .= '}';
+ # (3) bad options found
+ if(@bad){
+ @bad = sort @bad;
+ local $Carp::Internal{'Mouse'} = 1;
+ local $Carp::Internal{'Mouse::Meta::Class'} = 1;
+ Carp::carp("Found unknown argument(s) passed to '$name' attribute constructor in '$class': @bad");
}
- else {
- $accessor .= 'confess "Cannot assign a value to a read-only accessor" if @_;';
+
+ my $self = bless $args, $class;
+
+ # extra attributes
+ if($class ne __PACKAGE__){
+ $class->meta->_initialize_object($self, $args);
}
- if ($attribute->is_lazy) {
- $accessor .= '$self->{$key} = ';
+ return $self;
+}
+
+sub has_read_method { $_[0]->has_reader || $_[0]->has_accessor }
+sub has_write_method { $_[0]->has_writer || $_[0]->has_accessor }
- $accessor .= $attribute->has_builder
- ? '$self->$builder'
- : ref($default) eq 'CODE'
- ? '$default->($self)'
- : '$default';
+sub _create_args { # DEPRECATED
+ $_[0]->{_create_args} = $_[1] if @_ > 1;
+ $_[0]->{_create_args}
+}
+
+sub interpolate_class{
+ my($class, $args) = @_;
- $accessor .= ' if !exists($self->{$key});';
+ if(my $metaclass = delete $args->{metaclass}){
+ $class = Mouse::Util::resolve_metaclass_alias( Attribute => $metaclass );
}
- if ($attribute->should_auto_deref) {
- if ($attribute->type_constraint eq 'ArrayRef') {
- $accessor .= 'if (wantarray) {
- return @{ $self->{$key} || [] };
- }';
+ my @traits;
+ if(my $traits_ref = delete $args->{traits}){
+
+ for (my $i = 0; $i < @{$traits_ref}; $i++) {
+ my $trait = Mouse::Util::resolve_metaclass_alias(Attribute => $traits_ref->[$i], trait => 1);
+
+ next if $class->does($trait);
+
+ push @traits, $trait;
+
+ # are there options?
+ push @traits, $traits_ref->[++$i]
+ if ref($traits_ref->[$i+1]);
}
- else {
- $accessor .= 'if (wantarray) {
- return %{ $self->{$key} || {} };
- }';
+
+ if (@traits) {
+ $class = Mouse::Meta::Class->create_anon_class(
+ superclasses => [ $class ],
+ roles => \@traits,
+ cache => 1,
+ )->name;
}
}
- $accessor .= 'return $self->{$key};
- }';
+ return( $class, @traits );
+}
+
+sub canonicalize_args{ # DEPRECATED
+ my ($self, $name, %args) = @_;
- return eval $accessor;
+ Carp::cluck("$self->canonicalize_args has been deprecated."
+ . "Use \$self->_process_options instead.");
+
+ return %args;
}
-sub generate_predicate {
- my $attribute = shift;
- my $key = $attribute->name;
+sub create { # DEPRECATED
+ my ($self, $class, $name, %args) = @_;
- my $predicate = 'sub { exists($_[0]->{$key}) }';
+ Carp::cluck("$self->create has been deprecated."
+ . "Use \$meta->add_attribute and \$attr->install_accessors instead.");
- return eval $predicate;
+ # noop
+ return $self;
}
-sub generate_clearer {
- my $attribute = shift;
- my $key = $attribute->name;
+sub _coerce_and_verify {
+ my($self, $value, $instance) = @_;
- my $predicate = 'sub { delete($_[0]->{$key}) }';
+ my $type_constraint = $self->{type_constraint};
+ return $value if !defined $type_constraint;
- return eval $predicate;
+ if ($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 $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 generate_handles {
- my $attribute = shift;
- my $reader = $attribute->name;
- my %handles = $attribute->_canonicalize_handles($attribute->handles);
+sub _throw_type_constraint_error {
+ my($self, $value, $type) = @_;
- my %method_map;
+ $self->throw_error(
+ sprintf q{Attribute (%s) does not pass the type constraint because: %s},
+ $self->name,
+ $type->get_message($value),
+ );
+}
+
+sub clone_and_inherit_options{
+ my $self = shift;
+ my $args = $self->Mouse::Object::BUILDARGS(@_);
- for my $local_method (keys %handles) {
- my $remote_method = $handles{$local_method};
+ my($attribute_class, @traits) = ref($self)->interpolate_class($args);
- my $method = 'sub {
- my $self = shift;
- $self->$reader->$remote_method(@_)
- }';
+ $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};
+ }
+ }
- $method_map{$local_method} = eval $method;
+ # remove temporary caches
+ foreach my $attr(keys %{$args}){
+ if($attr =~ /\A _/xms){
+ delete $args->{$attr};
+ }
}
- return \%method_map;
+ return $attribute_class->new($self->name, $args);
}
-sub create {
- my ($self, $class, $name, %args) = @_;
+sub clone_parent { # DEPRECATED
+ my $self = shift;
+ my $class = shift;
+ my $name = shift;
+ my %args = ($self->get_parent_args($class, $name), @_);
- confess "You cannot have lazy attribute ($name) without specifying a default value for it"
- if $args{lazy} && !exists($args{default}) && !exists($args{builder});
+ Carp::cluck("$self->clone_parent has been deprecated."
+ . "Use \$meta->add_attribute and \$attr->install_accessors instead.");
- confess "References are not allowed as default values, you must wrap the default of '$name' in a CODE reference (ex: sub { [] } and not [])"
- if ref($args{default})
- && ref($args{default}) ne 'CODE';
+ $self->clone_and_inherited_args($class, $name, %args);
+}
- confess "You cannot auto-dereference without specifying a type constraint on attribute $name"
- if $args{auto_deref} && !exists($args{isa});
+sub get_parent_args { # DEPRECATED
+ my $self = shift;
+ my $class = shift;
+ my $name = shift;
- confess "You cannot auto-dereference anything other than a ArrayRef or HashRef on attribute $name"
- if $args{auto_deref}
- && $args{isa} ne 'ArrayRef'
- && $args{isa} ne 'HashRef';
+ for my $super ($class->linearized_isa) {
+ my $super_attr = $super->can("meta") && $super->meta->get_attribute($name)
+ or next;
+ return %{ $super_attr->_create_args };
+ }
- $args{type_constraint} = delete $args{isa}
- if exists $args{isa};
+ $self->throw_error("Could not find an attribute by the name of '$name' to inherit from");
+}
- my $attribute = $self->new(%args, name => $name, class => $class);
- my $meta = $class->meta;
- $meta->add_attribute($attribute);
+sub get_read_method {
+ return $_[0]->reader || $_[0]->accessor
+}
+sub get_write_method {
+ return $_[0]->writer || $_[0]->accessor
+}
- # install an accessor
- if ($attribute->_is_metadata eq 'rw' || $attribute->_is_metadata eq 'ro') {
- my $accessor = $attribute->generate_accessor;
- no strict 'refs';
- *{ $class . '::' . $name } = $accessor;
- }
+sub _get_accessor_method_ref {
+ my($self, $type, $generator) = @_;
- for my $method (qw/predicate clearer/) {
- my $predicate = "has_$method";
- if ($attribute->$predicate) {
- my $generator = "generate_$method";
- my $coderef = $attribute->$generator;
- no strict 'refs';
- *{ $class . '::' . $attribute->$method } = $coderef;
- }
- }
+ my $metaclass = $self->associated_class
+ || $self->throw_error('No asocciated class for ' . $self->name);
- if ($attribute->has_handles) {
- my $method_map = $attribute->generate_handles;
- for my $method_name (keys %$method_map) {
- no strict 'refs';
- *{ $class . '::' . $method_name } = $method_map->{$method_name};
- }
+ my $accessor = $self->$type();
+ if($accessor){
+ return $metaclass->get_method_body($accessor);
+ }
+ else{
+ return $self->accessor_metaclass->$generator($self, $metaclass);
}
+}
- return $attribute;
+sub get_read_method_ref{
+ my($self) = @_;
+ return $self->{_read_method_ref} ||= $self->_get_accessor_method_ref('get_read_method', '_generate_reader');
}
-sub find_type_constraint {
- my $self = shift;
- my $type = $self->type_constraint;
+sub get_write_method_ref{
+ my($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);
+}
- return unless $type;
+sub get_value {
+ my($self, $object) = @_;
+ return $self->get_read_method_ref()->($object);
+}
- my $checker = Mouse::TypeRegistry->optimized_constraints->{$type};
- return $checker if $checker;
+sub has_value {
+ my($self, $object) = @_;
+ my $accessor_ref = $self->{_predicate_ref}
+ ||= $self->_get_accessor_method_ref('predicate', '_generate_predicate');
- return sub { blessed($_) && blessed($_) eq $type };
+ 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 verify_type_constraint {
- my $self = shift;
- local $_ = shift;
- my $type = $self->type_constraint
- or return 1;
- my $constraint = $self->find_type_constraint;
+sub associate_method{
+ my ($attribute, $method_name) = @_;
+ $attribute->{associated_methods}++;
+ return;
+}
+
+sub install_accessors{
+ my($attribute) = @_;
+
+ my $metaclass = $attribute->associated_class;
+ my $accessor_class = $attribute->accessor_metaclass;
+
+ foreach my $type(qw(accessor reader writer predicate clearer)){
+ if(exists $attribute->{$type}){
+ my $generator = '_generate_' . $type;
+ my $code = $accessor_class->$generator($attribute, $metaclass);
+ $metaclass->add_method($attribute->{$type} => $code);
+ $attribute->associate_method($attribute->{$type});
+ }
+ }
+
+ # 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);
+ }
+ }
- return 1 if $constraint->($_);
+ if($attribute->can('create') != \&create){
+ # backword compatibility
+ $attribute->create($metaclass, $attribute->name, %{$attribute});
+ }
- my $name = $self->name;
- my $display = defined($_) ? overload::StrVal($_) : 'undef';
- Carp::confess("Attribute ($name) does not pass the type constraint because: Validation failed for \'$type\' failed with value $display");
+ return;
}
+sub delegation_metaclass() { 'Mouse::Meta::Method::Delegation' }
+
sub _canonicalize_handles {
- my $self = shift;
- my $handles = shift;
+ my($self, $handles) = @_;
if (ref($handles) eq 'HASH') {
return %$handles;
elsif (ref($handles) eq 'ARRAY') {
return map { $_ => $_ } @$handles;
}
+ elsif ( ref($handles) eq 'CODE' ) {
+ my $class_or_role = ( $self->{isa} || $self->{does} )
+ || $self->throw_error( "Cannot find delegate metaclass for attribute " . $self->name );
+ return $handles->( $self, Mouse::Meta::Class->initialize("$class_or_role"));
+ }
+ elsif (ref($handles) eq 'Regexp') {
+ my $class_or_role = ($self->{isa} || $self->{does})
+ || $self->throw_error("Cannot delegate methods based on a Regexp without a type constraint (isa)");
+
+ my $meta = Mouse::Meta::Class->initialize("$class_or_role"); # "" for stringify
+ return map { $_ => $_ }
+ grep { !Mouse::Object->can($_) && $_ =~ $handles }
+ Mouse::Util::is_a_metarole($meta)
+ ? $meta->get_method_list
+ : $meta->get_all_method_names;
+ }
else {
- confess "Unable to canonicalize the 'handles' option with $handles";
+ $self->throw_error("Unable to canonicalize the 'handles' option with $handles");
}
}
-1;
+sub _make_delegation_method {
+ my($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;
+
+ my $metaclass = (ref $self && $self->associated_class) || 'Mouse::Meta::Class';
+ $metaclass->throw_error(@_, depth => 1);
+}
+
+1;
__END__
=head1 NAME
-Mouse::Meta::Attribute - attribute metaclass
+Mouse::Meta::Attribute - The Mouse attribute metaclass
+
+=head1 VERSION
+
+This document describes Mouse version 0.50_03
=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:
+
+=over 4
+
+=item C<< is => 'ro', 'rw', 'bare' >>
-Creates a new attribute in OwnerClass. Accessors and helper methods are
-installed. Some error checking is done.
+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 name -> AttributeName
+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 class -> OwnerClass
+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 is_required -> Bool
+=item C<< isa => Type >>
-=head2 default -> Item
+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 has_default -> Bool
+This option can also accept a L<Moose::Meta::TypeConstraint> object.
-=head2 is_lazy -> 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 predicate -> MethodName | Undef
+=item C<< does => Role >>
-=head2 has_predicate -> Bool
+This is short-hand for saying that the attribute's type must be an
+object which does the named role.
-=head2 clearer -> MethodName | Undef
+B<This option is not yet supported.>
-=head2 has_clearer -> Bool
+=item C<< coerce => Bool >>
-=head2 handles -> { LocalName => RemoteName }
+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 has_handles -> Bool
+You can make both this and the C<weak_ref> option true.
-=head2 is_weak_ref -> Bool
+=item C<< trigger => CodeRef >>
-=head2 init_arg -> Str
+This option accepts a subroutine reference, which will be called after
+the attribute is set.
-=head2 type_constraint -> Str
+=item C<< required => Bool >>
-=head2 has_type_constraint -> 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 trigger => CODE | Undef
+A required attribute must have a C<default>, C<builder> or a
+non-C<undef> C<init_arg>
-=head2 has_trigger -> Bool
+=item C<< lazy => Bool >>
-=head2 builder => MethodName | Undef
+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 has_builder -> Bool
+=item C<< weak_ref => Bool >>
-=head2 should_auto_deref -> Bool
+If this is true, the attribute's value will be stored as a weak
+reference.
-Informational methods.
+=item C<< auto_deref => Bool >>
-=head2 generate_accessor -> CODE
+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.
-Creates a new code reference for the attribute's accessor.
+=item C<< lazy_build => Bool >>
-=head2 generate_predicate -> CODE
+Setting this to true makes the attribute lazy and provides a number of
+default methods.
-Creates a new code reference for the attribute's predicate.
+ has 'size' => (
+ is => 'ro',
+ lazy_build => 1,
+ );
-=head2 generate_clearer -> CODE
+is equivalent to this:
-Creates a new code reference for the attribute's clearer.
+ has 'size' => (
+ is => 'ro',
+ lazy => 1,
+ builder => '_build_size',
+ clearer => 'clear_size',
+ predicate => 'has_size',
+ );
-=head2 generate_handles -> { MethodName => CODE }
+=back
-Creates a new code reference for each of the attribute's handles methods.
+=head2 C<< associate_method(MethodName) >>
-=head2 find_type_constraint -> CODE
+Associates a method with the attribute. Typically, this is called internally
+when an attribute generates its accessors.
-Returns a code reference which can be used to check that a given value passes
-this attribute's type constraint;
+Currently the argument I<MethodName> is ignored in Mouse.
-=head2 verify_type_constraint Item -> 1 | ERROR
+=head2 C<< verify_against_type_constraint(Item) -> TRUE | ERROR >>
-Checks that the given value passes this attribute's type constraint. Returns 1
+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 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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