1 package MooseX::Singleton;
5 use MooseX::Singleton::Role::Object;
6 use MooseX::Singleton::Role::Meta::Class;
7 use MooseX::Singleton::Role::Meta::Instance;
10 $VERSION = eval $VERSION;
12 Moose::Exporter->setup_import_methods( also => 'Moose' );
20 my $caller = $p{for_class};
22 Moose::Util::MetaRole::apply_metaclass_roles(
24 metaclass_roles => ['MooseX::Singleton::Role::Meta::Class'],
25 instance_metaclass_roles =>
26 ['MooseX::Singleton::Role::Meta::Instance'],
27 constructor_class_roles =>
28 ['MooseX::Singleton::Role::Meta::Method::Constructor'],
31 Moose::Util::MetaRole::apply_base_class_roles(
34 ['MooseX::Singleton::Role::Object'],
37 return $caller->meta();
49 MooseX::Singleton - turn your Moose class into a singleton
54 use MooseX::Singleton;
58 isa => 'HashRef[Str]',
59 default => sub { \%ENV },
64 delete MyApp->env->{PATH};
65 my $instance = MyApp->instance;
66 my $same = MyApp->instance;
70 A singleton is a class that has only one instance in an application.
71 C<MooseX::Singleton> lets you easily upgrade (or downgrade, as it were) your
72 L<Moose> class to a singleton.
74 All you should need to do to transform your class is to change C<use Moose> to
75 C<use MooseX::Singleton>. This module uses a new class metaclass and instance
76 metaclass, so if you're doing metamagic you may not be able to use this.
78 C<MooseX::Singleton> gives your class an C<instance> method that can be used to
79 get a handle on the singleton. It's actually just an alias for C<new>.
81 Alternatively, C<< YourPackage->method >> should just work. This includes
84 If you need to reset your class's singleton object for some reason (e.g.
85 tests), you can call C<< YourPackage->_clear_instance >>.
91 =item Always more tests and doc
95 C<instance> invokes C<new> every time C<< Package->method >> is called, which
96 incurs a nontrivial runtime cost. I've implemented a short-circuit for this
97 case, which does eliminate nearly all of the runtime cost. However, it's ugly
98 and should be fixed in a more elegant way.
104 All complex software has bugs lurking in it, and this module is no
105 exception. If you find a bug please either email me, or add the bug
110 Shawn M Moore E<lt>sartak@gmail.comE<gt>
112 Dave Rolsky E<lt>autarch@urth.orgE<gt>
114 =head1 SOME CODE STOLEN FROM
116 Anders Nor Berle E<lt>debolaz@gmail.comE<gt>
118 =head1 AND PATCHES FROM
120 Ricardo SIGNES E<lt>rjbs@cpan.orgE<gt>
122 =head1 COPYRIGHT AND LICENSE
124 Copyright 2007, 2008 Infinity Interactive
126 This program is free software; you can redistribute it and/or modify it under
127 the same terms as Perl itself.