Class::DBI::Cascade::None(3pm)				User Contributed Perl Documentation			    Class::DBI::Cascade::None(3pm)

NAME

       Class::DBI::Cascade::None - Do nothing upon deletion

DESCRIPTION

       This is a Cascading Delete strategy that will do nothing, leaving orphaned records behind.

       It is the base class for most ofther Cascade strategies, and so provides several important methods:

CONSTRUCTOR

   new
	       my $strategy = Cascade::Class->new($Relationship);

       This must be instantiated with a Class::DBI::Relationship object.

METHODS

   foreign_for
	       my $iterator = $strategy->foreign_for($obj);

       This will return all the objects which are foreign to $obj across the relationship. It's a normal Class::DBI search you can get the results
       either as a list or as an iterator.

   cascade
	       $strategy->cascade($obj);

       Cascade across the related objects to $obj.

WRITING NEW STRATEGIES

       Creating a Cascade strategy should be fairly simple. You usually just need to inherit from here, and then supply a cascade() method that
       does the required thing with the results from foreign_for().

       So, for example, Cascade::Delete is implemented simply as:

	       package Class::DBI::Cascade::Delete;

	       use base 'Class::DBI::Cascade::None';

	       sub cascade {
		       my ($self, $obj) = @_;
		       $self->foreign_for($obj)->delete_all;
	       }

perl v5.12.4							    2005-09-14					    Class::DBI::Cascade::None(3pm)