NAME

       Graph::Writer::XML - write out directed graph as XML

SYNOPSIS

           use Graph;
           use Graph::Writer::XML;

           $graph = Graph->new();
           # add edges and nodes to the graph

           $writer = Graph::Writer::XML->new();
           $writer->write_graph($graph, 'mygraph.xml');

DESCRIPTION

       Graph::Writer::XML is a class for writing out a directed graph in a simple XML format.
       The graph must be an instance of the Graph class, which is actually a set of classes
       developed by Jarkko Hietaniemi.

       The XML format is designed to support the Graph classes: it can be used to represent a
       single graph with a collection of nodes, and edges between those nodes.  The graph, nodes,
       and edges can all have attributes specified, where an attribute is a (name,value) pair,
       with the value being scalar.

METHODS

   new()
       Constructor - generate a new writer instance.

           $writer = Graph::Writer::XML->new();

       This doesn't take any arguments.

   write_graph()
       Write a specific graph to a named file:

           $writer->write_graph($graph, $file);

       The $file argument can either be a filename, or a filehandle for a previously opened file.

KNOWN BUGS

       Attribute values must be scalar. If they're not, well, you're on your own.

SEE ALSO

       XML::Writer
           The perl module used to actually write out the XML.  It handles entities etc.

       Graph
           Jarkko Hietaniemi's modules for representing directed graphs, available from CPAN
           under modules/by-module/Graph/

       Algorithms in Perl
           The O'Reilly book which has a chapter on directed graphs, which is based around
           Jarkko's modules.

       Graph::Writer
           The base-class for Graph::Writer::XML

AUTHOR

       Neil Bowers <neil@bowers.com>

COPYRIGHT

       Copyright (c) 2001-2012, Neil Bowers. All rights reserved.  Copyright (c) 2001, Canon
       Research Centre Europe. All rights reserved.

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