use strict;
use Carp 'confess';
use Scalar::Util 'blessed', 'weaken';
our $VERSION = '0.94';
$VERSION = eval $VERSION;
our $AUTHORITY = 'cpan:STEVAN';
sub new {
my $class = shift;
my %options = @_;
(exists $options{attribute})
|| confess "You must supply an attribute to construct with";
(exists $options{accessor_type})
|| confess "You must supply an accessor_type to construct with";
(blessed($options{attribute}) && $options{attribute}->isa('Class::MOP::Attribute'))
|| confess "You must supply an attribute which is a 'Class::MOP::Attribute' instance";
($options{package_name} && $options{name})
|| confess "You must supply the package_name and name parameters $Class::MOP::Method::UPGRADE_ERROR_TEXT";
my $self = $class->_new(\%options);
# we don't want this creating
# a cycle in the code, if not
# needed
weaken($self->{'attribute'});
$self->_initialize_body;
return $self;
}
sub _new {
my $class = shift;
return Class::MOP::Class->initialize($class)->new_object(@_)
if $class ne __PACKAGE__;
my $params = @_ == 1 ? $_[0] : {@_};
return bless {
# inherited from Class::MOP::Method
body => $params->{body},
associated_metaclass => $params->{associated_metaclass},
package_name => $params->{package_name},
name => $params->{name},
original_method => $params->{original_method},
# inherit from Class::MOP::Generated
is_inline => $params->{is_inline} || 0,
definition_context => $params->{definition_context},
# defined in this class
attribute => $params->{attribute},
accessor_type => $params->{accessor_type},
} => $class;
}
## accessors
sub associated_attribute { (shift)->{'attribute'} }
sub accessor_type { (shift)->{'accessor_type'} }
## factory
sub _initialize_body {
my $self = shift;
my $method_name = join "_" => (
'_generate',
$self->accessor_type,
'method',
($self->is_inline ? 'inline' : ())
);
$self->{'body'} = $self->$method_name();
}
## generators
sub _generate_accessor_method {
my $attr = (shift)->associated_attribute;
return sub {
$attr->set_value($_[0], $_[1]) if scalar(@_) == 2;
$attr->get_value($_[0]);
};
}
sub _generate_reader_method {
my $attr = (shift)->associated_attribute;
return sub {
confess "Cannot assign a value to a read-only accessor" if @_ > 1;
$attr->get_value($_[0]);
};
}
sub _generate_writer_method {
my $attr = (shift)->associated_attribute;
return sub {
$attr->set_value($_[0], $_[1]);
};
}
sub _generate_predicate_method {
my $attr = (shift)->associated_attribute;
return sub {
$attr->has_value($_[0])
};
}
sub _generate_clearer_method {
my $attr = (shift)->associated_attribute;
return sub {
$attr->clear_value($_[0])
};
}
## Inline methods
sub _generate_accessor_method_inline {
my $self = shift;
my $attr = $self->associated_attribute;
my $attr_name = $attr->name;
my $meta_instance = $attr->associated_class->instance_metaclass;
my ( $code, $e ) = $self->_eval_closure(
{},
'sub {'
. $meta_instance->inline_set_slot_value('$_[0]', $attr_name, '$_[1]')
. ' if scalar(@_) == 2; '
. $meta_instance->inline_get_slot_value('$_[0]', $attr_name)
. '}'
);
confess "Could not generate inline accessor because : $e" if $e;
return $code;
}
sub _generate_reader_method_inline {
my $self = shift;
my $attr = $self->associated_attribute;
my $attr_name = $attr->name;
my $meta_instance = $attr->associated_class->instance_metaclass;
my ( $code, $e ) = $self->_eval_closure(
{},
'sub {'
. 'confess "Cannot assign a value to a read-only accessor" if @_ > 1;'
. $meta_instance->inline_get_slot_value('$_[0]', $attr_name)
. '}'
);
confess "Could not generate inline reader because : $e" if $e;
return $code;
}
sub _generate_writer_method_inline {
my $self = shift;
my $attr = $self->associated_attribute;
my $attr_name = $attr->name;
my $meta_instance = $attr->associated_class->instance_metaclass;
my ( $code, $e ) = $self->_eval_closure(
{},
'sub {'
. $meta_instance->inline_set_slot_value('$_[0]', $attr_name, '$_[1]')
. '}'
);
confess "Could not generate inline writer because : $e" if $e;
return $code;
}
sub _generate_predicate_method_inline {
my $self = shift;
my $attr = $self->associated_attribute;
my $attr_name = $attr->name;
my $meta_instance = $attr->associated_class->instance_metaclass;
my ( $code, $e ) = $self->_eval_closure(
{},
'sub {'
. $meta_instance->inline_is_slot_initialized('$_[0]', $attr_name)
. '}'
);
confess "Could not generate inline predicate because : $e" if $e;
return $code;
}
sub _generate_clearer_method_inline {
my $self = shift;
my $attr = $self->associated_attribute;
my $attr_name = $attr->name;
my $meta_instance = $attr->associated_class->instance_metaclass;
my ( $code, $e ) = $self->_eval_closure(
{},
'sub {'
. $meta_instance->inline_deinitialize_slot('$_[0]', $attr_name)
. '}'
);
confess "Could not generate inline clearer because : $e" if $e;
return $code;
}
1;
__END__
=pod
=head1 NAME
Class::MOP::Method::Accessor - Method Meta Object for accessors
=head1 SYNOPSIS
use Class::MOP::Method::Accessor;
my $reader = Class::MOP::Method::Accessor->new(
attribute => $attribute,
is_inline => 1,
accessor_type => 'reader',
);
$reader->body->execute($instance); # call the reader method
=head1 DESCRIPTION
This is a subclass of <Class::MOP::Method> which is used by
C<Class::MOP::Attribute> to generate accessor code. It handles
generation of readers, writers, predicates and clearers. For each type
of method, it can either create a subroutine reference, or actually
inline code by generating a string and C<eval>'ing it.
=head1 METHODS
=over 4
=item B<< Class::MOP::Method::Accessor->new(%options) >>
This returns a new C<Class::MOP::Method::Accessor> based on the
C<%options> provided.
=over 4
=item * attribute
This is the C<Class::MOP::Attribute> for which accessors are being
generated. This option is required.
=item * accessor_type
This is a string which should be one of "reader", "writer",
"accessor", "predicate", or "clearer". This is the type of method
being generated. This option is required.
=item * is_inline
This indicates whether or not the accessor should be inlined. This
defaults to false.
=item * name
The method name (without a package name). This is required.
=item * package_name
The package name for the method. This is required.
=back
=item B<< $metamethod->accessor_type >>
Returns the accessor type which was passed to C<new>.
=item B<< $metamethod->is_inline >>
Returns a boolean indicating whether or not the accessor is inlined.
=item B<< $metamethod->associated_attribute >>
This returns the L<Class::MOP::Attribute> object which was passed to
C<new>.
=item B<< $metamethod->body >>
The method itself is I<generated> when the accessor object is
constructed.
=back
=head1 AUTHORS
Stevan Little E<lt>stevan@iinteractive.comE<gt>
=head1 COPYRIGHT AND LICENSE
Copyright 2006-2009 by Infinity Interactive, Inc.
This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.
=cut