Query: moose::cookbook::meta::recipe4
OS: osx
Section: 3
Format: Original Unix Latex Style Formatted with HTML and a Horizontal Scroll Bar
Moose::Cookbook::Meta::Recipe4(3) User Contributed Perl Documentation Moose::Cookbook::Meta::Recipe4(3)NAMEMoose::Cookbook::Meta::Recipe4 - Adding a "table" attribute to the metaclassVERSIONversion 2.0205SYNOPSISpackage MyApp::Meta::Class; use Moose; extends 'Moose::Meta::Class'; has table => ( is => 'rw', isa => 'Str', );DESCRIPTIONIn 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 METACLASSThis 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');CONCLUSIONCreating 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 ALSOMoose::Cookbook::Meta::Recipe5 - The "table" attribute implemented as a metaclass trait Moose::Cookbook::Extending::Recipe2 - Acting like Moose.pm and providing sugar Moose-styleAUTHORStevan Little <stevan@iinteractive.com>COPYRIGHT AND LICENSEThis software is copyright (c) 2011 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. perl v5.12.5 2011-09-06 Moose::Cookbook::Meta::Recipe4(3)