KiokuDB::TypeMap::Entry::Callback - Callback based inflation/deflation of objects


        entries => {
            'My::Class' => KiokuDB::TypeMap::Entry::Callback->new(
                expand => "new", # My::Class->new(%$self)
                collapse => sub {
                    my $self = shift;
                    return %$self; # provide args to 'new' in this example
                id => sub { "foo" }, # 'id' callback is optional


This KiokuDB::TypeMap entry provides callback based inflation/deflation.

The major limitation of this method is that it cannot be used for self referential structures. This is because the object being inflated is only constructed after all of its arguments are.

For the overwhelming majority of the use cases this is good enough though.



A method name or code reference invoked on the object during collapsing.

This is evaluated in list context, and the list of values it returns will be collapsed by the KiokuDB::Collapser and then stored.


A method name or code reference invoked on the class of the object during loading.

The arguments are as returned by the collapse callback.


An optional method name or code reference invoked to get an ID for the object.

If one is not provided the default (UUID based) generation is used.


A boolean denoting whether or not the object should be collapsed with no ID, and serialized as part of its parent object.

This is useful for value like objects, for whom the reference address makes no difference (such as URI objects).