package MooseX::Singleton;
-use Moose::Role;
-our $VERSION = 0.02;
+use Moose 0.82 ();
+use Moose::Exporter;
+use MooseX::Singleton::Role::Object;
+use MooseX::Singleton::Role::Meta::Class;
+use MooseX::Singleton::Role::Meta::Instance;
-override new => sub {
- my ($class) = @_;
+our $VERSION = '0.21';
+$VERSION = eval $VERSION;
- no strict 'refs';
+Moose::Exporter->setup_import_methods( also => 'Moose' );
- # create our instance if we don't already have one
- if (!defined ${"$class\::singleton"}) {
- ${"$class\::singleton"} = super;
- }
+sub init_meta {
+ shift;
+ my %p = @_;
- return ${"$class\::singleton"};
-};
+ Moose->init_meta(%p);
-# instance really is the same as new. any ideas for a better implementation?
-sub instance {
- shift->new(@_);
+ my $caller = $p{for_class};
+
+ Moose::Util::MetaRole::apply_metaclass_roles(
+ for_class => $caller,
+ metaclass_roles => ['MooseX::Singleton::Role::Meta::Class'],
+ instance_metaclass_roles =>
+ ['MooseX::Singleton::Role::Meta::Instance'],
+ constructor_class_roles =>
+ ['MooseX::Singleton::Role::Meta::Method::Constructor'],
+ );
+
+ Moose::Util::MetaRole::apply_base_class_roles(
+ for_class => $caller,
+ roles =>
+ ['MooseX::Singleton::Role::Object'],
+ );
+
+ return $caller->meta();
}
+
1;
+__END__
+
+=pod
+
+=head1 NAME
+
+MooseX::Singleton - turn your Moose class into a singleton
+
+=head1 SYNOPSIS
+
+ package MyApp;
+ use MooseX::Singleton;
+
+ has env => (
+ is => 'rw',
+ isa => 'HashRef[Str]',
+ default => sub { \%ENV },
+ );
+
+ package main;
+
+ delete MyApp->env->{PATH};
+ my $instance = MyApp->instance;
+ my $same = MyApp->instance;
+
+=head1 DESCRIPTION
+
+A singleton is a class that has only one instance in an application.
+C<MooseX::Singleton> lets you easily upgrade (or downgrade, as it were) your
+L<Moose> class to a singleton.
+
+All you should need to do to transform your class is to change C<use Moose> to
+C<use MooseX::Singleton>. This module uses a new class metaclass and instance
+metaclass, so if you're doing metamagic you may not be able to use this.
+
+C<MooseX::Singleton> gives your class an C<instance> method that can be used to
+get a handle on the singleton. It's actually just an alias for C<new>.
+
+Alternatively, C<< YourPackage->method >> should just work. This includes
+accessors.
+
+If you need to reset your class's singleton object for some reason (e.g.
+tests), you can call C<< YourPackage->_clear_instance >>.
+
+=head1 TODO
+
+=over
+
+=item Always more tests and doc
+
+=item Fix speed boost
+
+C<instance> invokes C<new> every time C<< Package->method >> is called, which
+incurs a nontrivial runtime cost. I've implemented a short-circuit for this
+case, which does eliminate nearly all of the runtime cost. However, it's ugly
+and should be fixed in a more elegant way.
+
+=back
+
+=head1 BUGS
+
+All complex software has bugs lurking in it, and this module is no
+exception. If you find a bug please either email me, or add the bug
+to cpan-RT.
+
+=head1 AUTHORS
+
+Shawn M Moore E<lt>sartak@gmail.comE<gt>
+
+Dave Rolsky E<lt>autarch@urth.orgE<gt>
+
+=head1 SOME CODE STOLEN FROM
+
+Anders Nor Berle E<lt>debolaz@gmail.comE<gt>
+
+=head1 AND PATCHES FROM
+
+Ricardo SIGNES E<lt>rjbs@cpan.orgE<gt>
+
+=head1 COPYRIGHT AND LICENSE
+
+Copyright 2007, 2008 Infinity Interactive
+
+This program is free software; you can redistribute it and/or modify it under
+the same terms as Perl itself.
+
+=cut
+