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package Moose::Cookbook::Meta::Table_ClassMetaclass; # ABSTRACT: Adding a "table" attribute to the metaclass =pod =head1 NAME Moose::Cookbook::Meta::Table_ClassMetaclass - Adding a "table" attribute to the metaclass =head1 VERSION version 2.0604 =head1 SYNOPSIS package MyApp::Meta::Class; use Moose; extends 'Moose::Meta::Class'; has table => ( is => 'rw', isa => 'Str', ); =head1 DESCRIPTION B<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. =head1 THE METACLASS This really is as simple as the recipe L</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 L<Moose::Cookbook::Extending::Recipe2>, which shows how to make a module like C<Moose.pm> itself, with sugar like C<has_table()>. =head2 Using this Metaclass in Practice Accessing this new C<table> attribute is quite simple. Given a class named C<MyApp::User>, we could simply write the following: my $table = MyApp::User->meta->table; As long as C<MyApp::User> has arranged to use C<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'); =head1 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. =head1 SEE ALSO L<Moose::Cookbook::Meta::Recipe5> - The "table" attribute implemented as a metaclass trait L<Moose::Cookbook::Extending::Recipe2> - Acting like Moose.pm and providing sugar Moose-style =head1 AUTHOR Moose is maintained by the Moose Cabal, along with the help of many contributors. See L<Moose/CABAL> and L<Moose/CONTRIBUTORS> for details. =head1 COPYRIGHT AND LICENSE This software is copyright (c) 2012 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. =cut __END__