package MooseX::Singleton::Meta::Class;
use Moose;
use MooseX::Singleton::Meta::Instance;
+use MooseX::Singleton::Meta::Method::Constructor;
extends 'Moose::Meta::Class';
my $class = shift;
my $pkg = shift;
- $class->SUPER::initialize(
+ my $self = $class->SUPER::initialize(
$pkg,
instance_metaclass => 'MooseX::Singleton::Meta::Instance',
+ constructor_class => 'MooseX::Singleton::Meta::Method::Constructor',
@_,
);
+
+ return $self;
+}
+
+sub existing_singleton {
+ my ($class) = @_;
+ my $pkg = $class->name;
+
+ no strict 'refs';
+
+ # create exactly one instance
+ if (defined ${"$pkg\::singleton"}) {
+ return ${"$pkg\::singleton"};
+ }
+
+ return;
+}
+
+sub clear_singleton {
+ my ($class) = @_;
+ my $pkg = $class->name;
+ no strict 'refs';
+ undef ${"$pkg\::singleton"};
+}
+
+override _construct_instance => sub {
+ my ($class) = @_;
+
+ # create exactly one instance
+ my $existing = $class->existing_singleton;
+ return $existing if $existing;
+
+ my $pkg = $class->name;
+ no strict 'refs';
+ return ${"$pkg\::singleton"} = super;
};
+no Moose;
+
1;
+__END__
+
+=pod
+
+=head1 NAME
+
+MooseX::Singleton::Meta::Class
+
+=head1 DESCRIPTION
+
+This metaclass is where the forcing of one instance occurs. The first call to
+C<construct_instance> is run normally (and then cached). Subsequent calls will
+return the cached version.
+
+=cut
+