File Coverage

blib/lib/Graph/Writer/XML.pm

Criterion	Covered	Total	%
statement	39	53	73.5
branch	2	4	50.0
condition			n/a
subroutine	7	7	100.0
pod			n/a
total	48	64	75.0

#
# Graph::Writer::XML - write a directed graph out as XML
#
package Graph::Writer::XML;
$Graph::Writer::XML::VERSION = '2.09';
use 5.006;
use strict;
use warnings;

use parent 'Graph::Writer';
use XML::Writer;


#=======================================================================
#
# _write_graph() - perform the writing of the graph
#
# This is invoked from the public write_graph() method,
# and is where the actual writing of the graph happens.
#
# Basically we start a graph element then:
#	[] dump out any attributes of the graph
#	[] dump out all vertices, with any attributes of each vertex
#	[] dump out all edges, with any attributes of each edge
# And then close the graph element. Ta da!
#
#=======================================================================
sub _write_graph
{
    my $self  = shift;
    my $graph = shift;
    my $FILE  = shift;

    my $v;
    my $from;
    my $to;
    my $aref;
    my $xmlwriter;


    $xmlwriter = XML::Writer->new(OUTPUT      => $FILE,
                                  DATA_MODE   => 1,
                                  DATA_INDENT => 2);
    $xmlwriter->setOutput($FILE);

    $xmlwriter->startTag('graph');

    #-------------------------------------------------------------------
    # dump out attributes of the graph, if it has any
    #-------------------------------------------------------------------
    $aref = $graph->get_graph_attributes();
    foreach my $attr (keys %{ $aref })
    {
	$xmlwriter->emptyTag('attribute',
				'name' => $attr,
				'value' => $aref->{$attr});
    }

    #-------------------------------------------------------------------
    # dump out vertices of the graph, including any attributes
    #-------------------------------------------------------------------
    foreach $v (sort $graph->vertices)
    {
	$aref = $graph->get_vertex_attributes($v);

	if (keys(%{ $aref }) > 0)
	{
	    $xmlwriter->startTag('node', 'id' => $v);

	    foreach my $attr (keys %{ $aref })
	    {
		$xmlwriter->emptyTag('attribute',
					'name' => $attr,
					'value' => $aref->{$attr});
	    }

	    $xmlwriter->endTag('node');
	}
	else
	{
	    $xmlwriter->emptyTag('node', 'id' => $v);
	}
    }

    #-------------------------------------------------------------------
    # dump out edges of the graph, including any attributes
    #-------------------------------------------------------------------
    foreach my $edge (sort _by_vertex $graph->edges)
    {
	($from, $to) = @$edge;
	$aref = $graph->get_edge_attributes($from, $to);
	if (keys(%{ $aref }) > 0)
	{
	    $xmlwriter->startTag('edge', 'from' => $from, 'to' => $to);

	    foreach my $attr (keys %{ $aref })
	    {
		$xmlwriter->emptyTag('attribute',
					'name' => $attr,
					'value' => $aref->{$attr});
	    }

	    $xmlwriter->endTag('edge');
	}
	else
	{
	    $xmlwriter->emptyTag('edge', 'from' => $from, 'to' => $to);
	}
    }

    $xmlwriter->endTag('graph');
    $xmlwriter->end();

    return 1;
}

sub _by_vertex
{
    return $a->[0].$a->[1] cmp $b->[0].$b->[1];
}

1;

__END__