NAME

Class::DBI::Storable - Mixin Storable hooks to freeze and thaw objects

VERSION

Version 0.01

SYNOPSIS

    package My::Class;
    use base 'Class::DBI';
    use Class::DBI::Storable;
  
    package main;
    use Storable qw(freeze thaw dclone);

    my $obj = My::Class->retrieve($id);

    dclone($obj);   # Produces a warning
  

DESCRIPTION

Class::DBI attempts to maintain the the uniqueness of objects in memory. Serializers such as Storable will generally violate this constraint when an object is frozen and thawed.

This mixin module makes your Class::DBI objects serializable with Storable. Only the primary keys are serialized and the objects is thawed using "retrieve" on the appropriate CDBI class.

The Storable hooks carp if there are unsaved changes to the object being frozen or if you attempt to dclone a object. Using dclone on a CDBI object doesn't really make sense.

STORABLE_freeze and STORABLE_attach the only methods. They will be called automatically by Storable.

Are You Sure This Is A Good Idea?

No.

This module exists to try to make Class::DBI and Storable work together acceptably. It's existence is not to be construed as a recommendation of the practice.

DIAGNOSTICS

Storable::dclone($cdbi_object) will emit:

    "Warning, cloning a Class::DBI object of class <class name>"

This is to help catch inadvertent uses of dclone and to discourage it's use. (The warning can be suppressed with the $CloneCarp package variable)

If Storable::freeze is called of an object with unsaved changes then:

    "Warning, freezing <class name> discards unsaved changes"

It also calls the discard_changes method from Class::DBI which may throw an exception. (Suppress the warning with the package variable $FreezeCarp)

DEPENDENCIES

Storable 2.14 or newer

BUGS AND LIMITATIONS

There are no known bugs in this module.

Please report problems to the author directly or via RT

SEE ALSO

Class::DBI in particular "Uniqueness of Objects in Memory", Storable

AUTHOR

Brad Bowman <cpan@bereft.net>

LICENCE AND COPYRIGHT

Copyright (c) 2005 Brad Bowman <cpan@bereft.net>. All rights reserved.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

cpanm Class::DBI::Storable

perl -MCPAN -e shell
install Class::DBI::Storable