Get an attributes value from within the attribute - perl

Question

In the Moose Extension I'm writing I'm trying to access the attributes value from within the attribute, without going through the accessor, but I can't seem to get this right.
I'm trying to be able to write this code
{
package Test;
use Moose;
use MooseX::RemoteName; #provides magic
has attr0 => (
isa => 'Bool',
is => 'ro',
default => sub { 1 },
serializer => sub {
my $s = shift;
return $s->get_value( $s ) ? 'Y' : 'N';
},
);
has attr1 => (
isa => 'Str',
is => 'ro',
)
}
so that I can then do (from my test)
my $t0 = Test->new({ attr1 => 'foo' });
isa_ok my $attr0 = $t0->meta->get_attribute('attr0'), 'Class::MOP::Attribute';
is $attr0->serialized, 'Y', 'remote_name serializes';
isa_ok my $attr1 = $t0->meta->get_attribute('attr1'), 'Class::MOP::Attribute';
is $attr1->serialized, 'foo', 'remote_name serializes'; # undef
This is what I'm trying in the extension
has serializer => (
isa => 'CodeRef',
is => 'ro',
lazy => 1,
default => sub {
return sub {
my $arg = shift;
return $arg->get_value( $arg->associated_class );
}
},
);
sub serialized {
my $self = shift;
my $coderef = $self->serializer;
return &$coderef( $self );
}

Answer 1

my problems appear to be two fold, my anonymous subroutines weren't done right, and I needed to pass the instance of the object to the anonymous subroutine.
This seems to be working in my Moose Extension
has serializer => (
predicate => 'has_serializer',
traits => ['Code'],
is => 'ro',
default => sub {
return sub {
my ( $self, $instance ) = #_;
return $self->get_value( $instance );
}
},
handles => {
serializing => 'execute_method',
},
);
sub serialized {
my ( $self, $instance ) = #_;
return $self->serializing( $instance );
}
which then allows me to write the following (slightly different)
package Test;
use Moose;
use MooseX::RemoteName;
has attr0 => (
isa => 'Bool',
is => 'ro',
lazy => 1,
default => sub { 1 },
serializer => sub {
my ( $attr, $instance ) = #_;
return $attr->get_value( $instance ) ? 'Y' : 'N';
},
);
which will pass this test without issue
subtest t0 => sub {
my $t = Test->new;
is $t->attr0, 1, 'attr0 is 1';
isa_ok my $attr0 = $t->meta->get_attribute('attr0'), 'Class::MOP::Attribute';
is $attr0->serialized( $t ), 'Y', 'attr0 serializes';
isa_ok $t, 'Test';
};
I think I can live passing the instance in, though I'm not entirely sure why get_value needs that.