oracular (3) Moose::Cookbook::Meta::WhyMeta.3pm.gz

Provided by: libmoose-perl_2.2207-1build2_amd64 bug

NAME

       Moose::Cookbook::Meta::WhyMeta - Welcome to the meta world (Why Go Meta?)

VERSION

       version 2.2207

SUMMARY

       You might want to read Moose::Manual::MOP if you haven't done so yet.

       If you've ever thought "Moose is great, but I wish it did X differently", then you've gone meta. The meta
       recipes demonstrate how to change and extend the way Moose works by extending and overriding how the meta
       classes (Moose::Meta::Class, Moose::Meta::Attribute, etc) work.

       The metaclass API is a set of classes that describe classes, roles, attributes, etc. The metaclass API
       lets you ask questions about a class, like "what attributes does it have?", or "what roles does the class
       do?"

       The metaclass system also lets you make changes to a class, for example by adding new methods or
       attributes.

       The interface presented by Moose.pm ("has", "with", "extends") is just a thin layer of syntactic sugar
       over the underlying metaclass system.

       By extending and changing how this metaclass system works, you can create your own Moose variant.

   Examples
       Let's say that you want to add additional properties to attributes. Specifically, we want to add a
       "label" property to each attribute, so we can write "My::Class->meta()->get_attribute('size')->label()".
       The first recipe shows how to do this using an attribute trait.

       You might also want to add additional properties to your metaclass. For example, if you were writing an
       ORM based on Moose, you could associate a table name with each class via the class's metaclass object,
       letting you write "My::Class->meta()->table_name()".

SEE ALSO

       Many of the MooseX modules on CPAN implement metaclass extensions. A couple good examples include
       MooseX::Aliases and MooseX::UndefTolerant. For a more complex example see Fey::ORM or
       Bread::Board::Declare.

AUTHORS

       •   Stevan Little <stevan@cpan.org>

       •   Dave Rolsky <autarch@urth.org>

       •   Jesse Luehrs <doy@cpan.org>

       •   Shawn M Moore <sartak@cpan.org>

       •   יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>

       •   Karen Etheridge <ether@cpan.org>

       •   Florian Ragwitz <rafl@debian.org>

       •   Hans Dieter Pearcey <hdp@cpan.org>

       •   Chris Prather <chris@prather.org>

       •   Matt S Trout <mstrout@cpan.org>

       This software is copyright (c) 2006 by Infinity Interactive, Inc.

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