X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FMooseX%2FSingleton%2FMeta%2FClass.pm;h=bc929c057edbdfa7203f9e1bf9088116f97a309c;hb=1de95613f2dfae86af1a8f548d66d1de842e7201;hp=447859d5fe8796cbcbd6af37454e34dfd6dd9352;hpb=109b110b1d5969c8ae2ec7a5e5d86066f895d828;p=gitmo%2FMooseX-Singleton.git

diff --git a/lib/MooseX/Singleton/Meta/Class.pm b/lib/MooseX/Singleton/Meta/Class.pm
index 447859d..bc929c0 100644
--- a/lib/MooseX/Singleton/Meta/Class.pm
+++ b/lib/MooseX/Singleton/Meta/Class.pm
@@ -16,5 +16,47 @@ sub initialize {
     );
 };
 
+sub existing_singleton {
+    my ($class) = @_;
+    my $pkg = $class->name;
+
+    no strict 'refs';
+
+    # create exactly one instance
+    if (defined ${"$pkg\::singleton"}) {
+        return ${"$pkg\::singleton"};
+    }
+
+    return;
+}
+
+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;
+};
+
 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
+