DBIx::Class::DeleteAction - Define delete triggers
# Actor DBIC class
package Your::Schema::Actor;
use strict;
use warnings;
use base 'DBIx::Class';
__PACKAGE__->load_components("DeleteAction","PK","Core");
__PACKAGE__->table("actor");
__PACKAGE__->add_columns(qw/id name/);
__PACKAGE__->set_primary_key('id');
__PACKAGE__->has_many(
'actorroles' => 'MyDB::Schema::ActorRole',
{ 'foreign.actor' => 'self.id' },
{ delete_action => 'delete' }
);
# Actor Role DBIC class
package Your::Schema::ActorRole;
use strict;
use warnings;
use base 'DBIx::Class';
__PACKAGE__->load_components("DeleteAction","PK","Core");
__PACKAGE__->table("actor_role");
__PACKAGE__->add_columns(qw/id name actor production/);
__PACKAGE__->set_primary_key('id');
__PACKAGE__->belongs_to(
'actor' => 'MyDB::Schema::Actor',
{ 'foreign.id' => 'self.actor' },
{ delete_action =>
sub {
my ($self,$params) = @_;
# Do something special
}
}
);
__PACKAGE__->belongs_to(
'production' => 'MyDB::Schema::Production',
{ 'foreign.id' => 'self.production' },
{ delete_action => 'deny' }
);
# Somewhere else
$schema->txn_do(sub {
$actor->delete();
});
# Deletes all related actorroles only if they don't have a production
# Finally deletes the actor itself
$schema->txn_do(sub {
$actor_role->delete();
});
# Calls custom subroutine on actor
# Denies deletion if a production is related
With this DBIx::Class component you can specify actions that should be triggered on a row delete. A delete action is specified by adding the 'delete_action' key to the optional attribute HASH reference when specifing a new relation (see DBIx::Class::Relationship).
The following delete actions are supported:
Set all columns in related rows pointing to this record to NULL. Only works on 'has_many' relationships.
Delete all related records one by one. This can trigger further delete actions.
Delete all related records in a single step. This does not trigger further delete actions.
Only works on 'has_many' relationships.
Deny deletion if this record is being referenced from other rows.
Executes the code referece on delete. The current DBIx::Class::Row object and the name of the relation are passed to the code reference.
Execute a method with the given name. The method will be called on the current DBIx::Class::Row object and will be passed the name of the relation.
Do nothing
If you set the delete_action to execute a method or a code reference the method will be called with the following parameters:
The DBIx::Class::Row object the delete action has been called upon.
A hashref of named parameters
The name of the relationship that is currently being processed.
The related object(s) for the given object and relationship.
Depending on the type of the relationship this can either be a DBIx::Class::Row or a DBIx::Class::ResultSet object.
An arraryref with object identifiers which have already been processed. If you want to call another delete method from your code you MUST pass on this variable so that we can ensure that each object/row is handled only once.
Any other values that you pass to 'delete'.
$object->delete(); OR $object->delete(HASHREF);
This method overdrives the DBIx::Class::Row delete method. You can add arbitrary data as HASHREF which will be passed to your custom delete handles.
Make sure that you ALWAYS call delete always from within a TRANSACTION block.
If you call delete from within a custom delete handler always pass on the seen parameter.
Note that the delete method in DBIx::Class::ResultSet will not run DeleteAction triggers. See delete_all if you need triggers to run.
Any database-level cascade, restrict or trigger will be performed AFTER a DBIx-Class-DeleteAction based trigger.
Always use transactions, or else you might end up with inconsistent data.
Please report any bugs or feature requests to bug-dbix-class-deleteaction@rt.cpan.org, or through the web interface at http://rt.cpan.org/Public/Bug/Report.html?Queue=DBIx::Class::DeleteAction. I will be notified, and then you'll automatically be notified of progress on your report as I make changes.
Maroš Kollár
CPAN ID: MAROS
maros [at] k-1.com
L<http://www.revdev.at>
This module was written for Revdev http://www.revdev.at, a nice litte software company I run with Koki and Domm (http://search.cpan.org/~domm/).
DBIx::Class::DeleteAction is Copyright (c) 2008 Maroš Kollár - http://www.revdev.at
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
The full text of the license can be found in the LICENSE file included with this module.
