1 package DBIx::Class::IntrospectableM2M;
5 use base 'DBIx::Class';
7 our $VERSION = '0.001000';
9 #namespace pollution. sadface.
10 __PACKAGE__->mk_classdata( _m2m_metadata => {} );
14 my ($meth_name, $link, $far_side) = @_;
15 my $store = $class->_m2m_metadata;
16 warn("You are overwritting another relationship's metadata")
17 if exists $store->{$meth_name};
20 accessor => $meth_name,
21 relation => $link, #"link" table or imediate relation
22 foreign_relation => $far_side, #'far' table or foreign relation
23 (@_ > 3 ? (attrs => $_[3]) : ()), #only store if exist
24 rs_method => "${meth_name}_rs", #for completeness..
25 add_method => "add_to_${meth_name}",
26 set_method => "set_${meth_name}",
27 remove_method => "remove_from_${meth_name}",
30 #inheritable data workaround
31 $class->_m2m_metadata({ $meth_name => $attrs, %$store});
32 $class->next::method(@_);
41 DBIx::Class::IntrospectableM2M - Introspect many-to-many shortcuts
45 In your L<DBIx::Class> Result class
46 (sometimes erroneously referred to as the 'table' class):
48 __PACKAGE__->load_components(qw/IntrospectableM2M ... Core/);
50 #Digest encoder with hex format and SHA-1 algorithm
51 __PACKAGE__->many_to_many(roles => user_roles => 'role);
53 When you want to introspect this data
55 my $metadata = $result_class->_m2m_metadata->{roles};
56 # $metadata->{accessor} method name e.g. 'roles'
57 # $metadata->{relation} maping relation e.g. 'user_roles'
58 # $metadata->{foreign_relation} far-side relation e.g. 'role
59 # $metadata->{attrs} relationship attributes, if any
60 # Convenience methods created by DBIx::Class
61 # $metadata->{rs_method} 'roles_rs'
62 # $metadata->{add_method} 'add_to_roles',
63 # $metadata->{set_method} 'set_roles',
64 # $metadata->{remove_method} 'remove_from_roles'
66 B<Note:> The component needs to be loaded I<before> Core.
70 Because the many-to-many relationships are not real relationships, they can not
71 be introspected with DBIx::Class. Many-to-many relationships are actually just
72 a collection of convenience methods installed to bridge two relationships.
73 This L<DBIx::Class> component can be used to store all relevant information
74 about these non-relationships so they can later be introspected and examined.
80 Extended to store all relevant information in the C<_m2m_metadata> HASH ref.
84 Accessor to a HASH ref where the keys are the names of m2m relationships and
85 the value is a HASH ref as described in the SYNOPSIS.
89 Guillermo Roditi (groditi) E<lt>groditi@cpan.orgE<gt>
91 =head1 COPYRIGHT AND LICENSE
93 Copyright (C) 2008 by Guillermo Roditi
95 This library is free software; you can redistribute it and/or modify
96 it under the same terms as Perl itself.