| Moose::Cookbook::Legacy::Table_ClassMetaclass - phpMan
Moose::Cookbook::Legacy::Table_UsersContributedMoose::Cookbook::Legacy::Table_ClassMetaclass(3pm)
NAME
Moose::Cookbook::Legacy::Table_ClassMetaclass - Adding a "table" attribute to the
metaclass
VERSION
version 2.1213
SYNOPSIS
package MyApp::Meta::Class;
use Moose;
extends 'Moose::Meta::Class';
has table => (
is => 'rw',
isa => 'Str',
);
DESCRIPTION
WARNING: Subclassing metaclasses (as opposed to providing metaclass traits) is strongly
discouraged. This recipe is provided solely for reference when encountering older code
that does this.
In this recipe, we'll create a new metaclass which has a "table" attribute. This metaclass
is for classes associated with a DBMS table, as one might do for an ORM.
In this example, the table name is just a string, but in a real ORM the table might be an
object describing the table.
THE METACLASS
This really is as simple as the recipe "SYNOPSIS" shows. The trick is getting your classes
to use this metaclass, and providing some sort of sugar for declaring the table. This is
covered in Moose::Cookbook::Extending::Recipe2, which shows how to make a module like
"Moose.pm" itself, with sugar like "has_table()".
Using this Metaclass in Practice
Accessing this new "table" attribute is quite simple. Given a class named "MyApp::User",
we could simply write the following:
my $table = MyApp::User->meta->table;
As long as "MyApp::User" has arranged to use "MyApp::Meta::Class" as its metaclass, this
method call just works. If we want to be more careful, we can check the metaclass's class:
$table = MyApp::User->meta->table
if MyApp::User->meta->isa('MyApp::Meta::Class');
CONCLUSION
Creating custom metaclass is trivial. Using it is a little harder, and is covered in other
recipes. We will also talk about applying traits to a class metaclass, which is a more
flexible and cooperative implementation.
SEE ALSO
Moose::Cookbook::Meta::Recipe5 - The "table" attribute implemented as a metaclass trait
Moose::Cookbook::Extending::Recipe2 - Acting like Moose.pm and providing sugar Moose-style
AUTHORS
· Stevan Little <stevan.little AT iinteractive.com>
· Dave Rolsky <autarch AT urth.org>
· Jesse Luehrs <doy AT tozt.net>
· Shawn M Moore <code AT sartak.org>
· XXXX XXX'XX (Yuval Kogman) <nothingmuch AT woobling.org>
· Karen Etheridge <ether AT cpan.org>
· Florian Ragwitz <rafl AT debian.org>
· Hans Dieter Pearcey <hdp AT weftsoar.net>
· Chris Prather <chris AT prather.org>
· Matt S Trout <mst AT shadowcat.uk>
COPYRIGHT AND LICENSE
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.
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