aspect::library::singleton(3pm) [debian man page]

Aspect::Library::Singleton(3pm) 			User Contributed Perl Documentation			   Aspect::Library::Singleton(3pm)

NAME

       Aspect::Library::Singleton - A singleton aspect

SYNOPSIS

	 use Aspect;
	 use Aspect::Singleton;

	 aspect Singleton => 'Foo::new';

	 my $f1 = Foo->new;
	 my $f2 = Foo->new;

	 # Both $f1 and $f2 refer to the same object

DESCRIPTION

       A reusable aspect that forces singleton behavior on a constructor. The constructor is defined by a pointcut spec: a string. regexp, or code
       ref.

       It is slightly different from "Class::Singleton" (http://search.cpan.org/~abw/Class-Singleton/Singleton.pm
       <http://search.cpan.org/~abw/Class-Singleton/Singleton.pm>):

       o   No specific name requirement on the constructor for the external interface, or for the implementation ("Class::Singleton" requires
	   clients use "instance()", and that subclasses override "_new_instance()"). With aspects, you can change the cardinality of your objects
	   without changing the clients, or the objects themselves.

       o   No need to inherit from anything- use pointcuts to specify the constructors you want to memoize. Instead of pulling singleton behavior
	   from a base class, you are pushing it in, using the aspect.

       o   No package variable or method is added to the callers namespace

       Note that this is just a special case of memoizing.

AUTHORS

       Adam Kennedy <adamk@cpan.org>

       Marcel Gruenauer <marcel@cpan.org>

       Ran Eilam <eilara@cpan.org>

COPYRIGHT

       Copyright 2001 by Marcel Gruenauer

       Some parts copyright 2009 - 2012 Adam Kennedy.

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.14.2							    2012-02-01					   Aspect::Library::Singleton(3pm)

MooseX::Singleton(3)					User Contributed Perl Documentation				      MooseX::Singleton(3)

NAME

       MooseX::Singleton - turn your Moose class into a singleton

VERSION

       version 0.29

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;

DESCRIPTION

       A singleton is a class that has only one instance in an application.  "MooseX::Singleton" lets you easily upgrade (or downgrade, as it
       were) your Moose class to a singleton.

       All you should need to do to transform your class is to change "use Moose" to "use MooseX::Singleton". This module uses metaclass roles to
       do its magic, so it should cooperate with most other "MooseX" modules.

METHODS

       A singleton class will have the following additional methods:

   Singleton->instance
       This returns the singleton instance for the given package. This method does not accept any arguments. If the instance does not yet exist,
       it is created with its defaults values. This means that if your singleton requires arguments, calling "instance" will die if the object has
       not already been initialized.

   Singleton->initialize(%args)
       This method can be called only once per class. It explicitly initializes the singleton object with the given arguments.

   Singleton->_clear_instance
       This clears the existing singleton instance for the class. Obviously, this is meant for use only inside the class itself.

   Singleton->new
       This method currently works like a hybrid of "initialize" and "instance". However, calling "new" directly will probably be deprecated in a
       future release. Instead, call "initialize" or "instance" as appropriate.

BUGS

       Please report any bugs or feature requests to "bug-moosex-singleton@rt.cpan.org", or through the web interface at <http://rt.cpan.org>. We
       will be notified, and then you'll automatically be notified of progress on your bug as we make changes.

SOME CODE STOLEN FROM

       Anders Nor Berle <debolaz@gmail.com>

AND PATCHES FROM

       Ricardo SIGNES <rjbs@cpan.org>

AUTHOR

       Shawn M Moore <sartak@gmail.com>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2011 by Shawn M Moore.

       This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.

perl v5.18.2							    2011-12-08						      MooseX::Singleton(3)