# Movable Type (r) Open Source (C) 2001-2008 Six Apart, Ltd.
# This program is distributed under the terms of the
# GNU General Public License, version 2.
#
# $Id: PluginData.pm 2287 2008-05-08 22:18:31Z bchoate $

package MT::PluginData;
use strict;

use MT::Serialize;

use MT::Blog;
use base qw( MT::Object );

__PACKAGE__->install_properties ({
    column_defs => {
        'id' => 'integer not null auto_increment',
        'plugin' => 'string(50) not null',
        'key' => 'string(255) not null',
        'data' => 'blob',
    },
    indexes => {
        plugin => 1,
        key => 1,
    },
    child_of => 'MT::Blog',
    datasource => 'plugindata',
    primary_key => 'id',
});

sub class_label {
    MT->translate("Plugin Data");
}

sub remove {
    my $pd = shift;
    return $pd->SUPER::remove(@_) if ref($pd);

    # class method call - might have blog_id parameter
    my ($terms, $args) = @_;
    $pd->SUPER::remove(@_) unless $terms && exists($terms->{blog_id});

    my $blog_ids = delete $terms->{blog_id};
    if ( 'ARRAY' ne ref($blog_ids) ) {
        $blog_ids = [ $blog_ids ];
    }

    my @keys = map { "configuration:blog:$_" } @$blog_ids;
    $terms->{key} = \@keys;
    $pd->SUPER::remove($terms, $args);
}

{
    my $ser;
    sub data {
        my $self = shift;
        $ser ||= MT::Serialize->new('MT');  # force MT serialization for plugins
        if (@_) {
            my $data = shift;
            if (ref($data)) {
                $self->column('data', $ser->serialize( \$data ));
            } else {
                $self->column('data', $data);
            }
            $data;
        } else {
            my $data = $self->column('data');
            return undef unless defined $data;
            if (substr($data, 0, 4) eq 'SERG') {
                my $thawed = $ser->unserialize( $data );
                defined $thawed ? $$thawed : undef;
            } else {
                # signature is not a match, so the data must be stored
                # using Storable...
                require Storable;
                my $thawed = eval { Storable::thaw( $data ) };
                if ($@ =~ m/byte order/i) {
                    $Storable::interwork_56_64bit = 1;
                    $thawed = eval { Storable::thaw( $data ) };
                }
                return undef if $@;
                return $thawed;
            }
        }
    }
}

1;
__END__

=head1 NAME

MT::PluginData - Arbitrary data storage for Movable Type plugins

=head1 SYNOPSIS

    use MT::PluginData;
    my $data = MT::PluginData->new;
    $data->plugin('my-plugin');
    $data->key('unique-key');
    $data->data($big_data_structure);
    $data->save or die $data->errstr;

    ## ... later ...

    my $data = MT::PluginData->load({ plugin => 'my-plugin',
                                      key    => 'unique-key' });
    my $big_data_structure = $data->data;

=head1 DESCRIPTION

I<MT::PluginData> is a data storage mechanism for Movable Type plugins. It
uses the same backend datasource as the rest of the Movable Type system:
Berkeley DB, MySQL, etc. Plugins can use this class to store arbitrary
data structures in the database, keyed on a string specific to the plugin
and a key, just like a big associate array. Data structures are serialized
using I<Storable>.

=head1 USAGE

As a subclass of I<MT::Object>, I<MT::PluginData> inherits all of the
data-management and -storage methods from that class; thus you should look
at the I<MT::Object> documentation for details about creating a new object,
loading an existing object, saving an object, etc.

=head1 DATA ACCESS METHODS

The I<MT::PluginData> object holds the following pieces of data. These fields
can be accessed and set using the standard data access methods described in
the I<MT::Object> documentation.

=over 4

=item * id

The numeric ID of the record.

=item * plugin

A unique name identifying the plugin.

=item * key

A key--like the key in an associative array--that, with the I<plugin>
column, uniquely identifies this record.

=item * data

The data structure that is being stored. When setting the value for this
column, the value provided must be a reference. For example, the following
will die with an error:

    $data->data('string');

You must use

    $data->data(\'string');

instead.

=back

=head1 DATA LOOKUP

In addition to numeric ID lookup, you can look up or sort records by any
combination of the following fields. See the I<load> documentation in
I<MT::Object> for more information.

=over 4

=item * plugin

=item * key

=back

=head1 AUTHOR & COPYRIGHTS

Please see the I<MT> manpage for author, copyright, and license information.

=cut
