NAME
DBIx::Class::Graph - Represent a graph in a relational database using DBIC
SYNOPSIS
package MySchema::Graph;
use strict;
use warnings;
use base 'DBIx::Class';
__PACKAGE__->load_components("Graph", "Core");
__PACKAGE__->table("client_groups");
__PACKAGE__->add_columns("id", "name", "parent_id");
__PACKAGE__->connect_graph(predecessor => "parent_id");
# predecessor can also be a relationship
my $g = $rs->get_graph;
my @children = $g->successors($rs->get_vertex($id));
# do other cool stuff like calculating distances etc.DESCRIPTION
This module allows to create and interact with a directed graph. It will take care of storing the information in a relational database. It uses Graph for calculations. This module extends the DBIx::Class::ResultSet. Some methods are added to the resultset, some to the row objects.
Important: This is a developer release! It works fine for simple layouts (see tests) but does not yet work if you use relationships to address the parents/childs. =head1 METHODS
connect_graph(@opt)
The first argument is the relation to the next vertex. Possible values: "predecessor" and "successor"
The name of the relation to the next vertex is defined by the second argument.
RESULTSET METHODS
get_vertex($id)
finds a vertex by searching the underlying resultset for $id in the primary key column (only single primary keys are supported). It's not as smart as the original "find" in DBIx::Class::ResultSet because it looks on the primary key(s) for $id only.
ADDITIONAL GRAPH METHODS
Graph lacks some useful methods
all_successors($v)
Returns all successors of a vertex $v. It's a recusive method. It avoids infinite loops.
all_predecessors($v)
Returns all predecessors of a vertex $v. It's a recusive method. It avoids infinite loops.
FAQ
How do I sort the nodes?
Simply sort the resultset
$rs->search(undef, {order_by => "title ASC"})->get_graph;CAVEATS
Integrity
It might be possible that some database actions are not recognized by the graph object and thus do not represent the correct status of the graph. To make sure you are working with the correct graph object reload it after editing the graph.
Multigraph
you should ommit creating multigraphs. Most graph algorithms expect a simple graph and may break if they get a multigraph.
Speed
you should consider caching the output of your scripts since retrieving and creating a Graph is not very fast.
SEE ALSO
Mention other useful documentation such as the documentation of related modules or operating system documentation (such as man pages in UNIX), or any relevant external documentation such as RFCs or standards.
I am also avaiable on the DBIx::Class mailinglist
TODO
Allow mulle oulle
und so weiter
BUGS
See "CAVEATS"
AUTHOR
Moritz Onken, <onken@houseofdesign.de>
COPYRIGHT AND LICENSE
Copyright (C) 2008 by Moritz Onken
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.8 or, at your option, any later version of Perl 5 you may have available.