This commit is contained in:
132
CPAN/Moose/Cookbook/Legacy/Table_ClassMetaclass.pod
Normal file
132
CPAN/Moose/Cookbook/Legacy/Table_ClassMetaclass.pod
Normal file
@@ -0,0 +1,132 @@
|
||||
# PODNAME: Moose::Cookbook::Legacy::Table_ClassMetaclass
|
||||
# ABSTRACT: Adding a "table" attribute to the metaclass
|
||||
|
||||
__END__
|
||||
|
||||
=pod
|
||||
|
||||
=encoding UTF-8
|
||||
|
||||
=head1 NAME
|
||||
|
||||
Moose::Cookbook::Legacy::Table_ClassMetaclass - Adding a "table" attribute to the metaclass
|
||||
|
||||
=head1 VERSION
|
||||
|
||||
version 2.2207
|
||||
|
||||
=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 AUTHORS
|
||||
|
||||
=over 4
|
||||
|
||||
=item *
|
||||
|
||||
Stevan Little <stevan@cpan.org>
|
||||
|
||||
=item *
|
||||
|
||||
Dave Rolsky <autarch@urth.org>
|
||||
|
||||
=item *
|
||||
|
||||
Jesse Luehrs <doy@cpan.org>
|
||||
|
||||
=item *
|
||||
|
||||
Shawn M Moore <sartak@cpan.org>
|
||||
|
||||
=item *
|
||||
|
||||
יובל קוג'מן (Yuval Kogman) <nothingmuch@woobling.org>
|
||||
|
||||
=item *
|
||||
|
||||
Karen Etheridge <ether@cpan.org>
|
||||
|
||||
=item *
|
||||
|
||||
Florian Ragwitz <rafl@debian.org>
|
||||
|
||||
=item *
|
||||
|
||||
Hans Dieter Pearcey <hdp@cpan.org>
|
||||
|
||||
=item *
|
||||
|
||||
Chris Prather <chris@prather.org>
|
||||
|
||||
=item *
|
||||
|
||||
Matt S Trout <mstrout@cpan.org>
|
||||
|
||||
=back
|
||||
|
||||
=head1 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.
|
||||
|
||||
=cut
|
||||
Reference in New Issue
Block a user