Problems with GraphViz module

punkish has asked for the wisdom of the Perl Monks concerning the following question:

I am trying to generate graphs of my wiki -- incoming pages (I keep track of trackbacks), and outgoing pages from the current page. Using GraphViz, I can do this quite easily. However, I have two problems with running GraphViz module (and/or the GraphViz program) via the web on Win32 with ActiveState.

the program runs fine on command line, and generates an image map and the image (except, it insists on assigning "test" to both map id and map name!), but it hangs when run via the web. Generates a 0kb image, and just hangs. Perl and circo.exe both peg the CPU and memory. Read GraphViz , apache, but that doesn't seem to apply to me (although the problem described there is identical to mine). That monk is using Debian, I am using Win32. I added a SetEnv HOME /tmp/ setting to httpd.conf, but that doesn't help. Read Generating clickable graphs, and added a Path var to my cgi, but that doesn't help. What is going on here?
Update: added sample code on Anonymonk's castigation --
```
use GraphViz;

my $g = GraphViz->new(
  directed => 1, 
  layout => 'circo', 
  ratio => 'compress', 
  width => 6,
  height => 6, 
  node => {shape => 'ellipse'},
);

..
add nodes and edges
..

my $image = 'foo';

open OUT_FILE, ">$image.png" or die $!;
binmode (OUT_FILE);
$g->as_png(\*OUT_FILE);
close OUT_FILE;

my $cmap  = $g->as_cmapx;

print <<END;
Content-Type: text/html\n\n

<html>
  <head>
    <title>test</title>
    $cmap
  </head>
  <body>
    <img src="$image.png" border="0" usemap="#test">
  </body>
</html>

END
[download]
```
The pngs produced by GraphViz are butt-ugly. SVG creates nice output, but can't do image maps, and outputting PostScript and then running Ghostview on it is way too complicated. Any other solutions?

Any suggestions? Or suggested replacement for GraphViz for this? There are a number of Java network viz libs out there, but I want to stay away from Java as much as possible.

--

when small people start casting long shadows, it is time to go to bed

Comment on Problems with GraphViz module Download Code

Replies are listed 'Best First'.
Re: Problems with GraphViz module by jeteve (Pilgrim) on Sep 18, 2006 at 11:13 UTC
Hi. GraphViz needs a HOME environment variable to work properly. Do a SetEnv HOME /tmp/ within you CGI environment and it should work fine after that. You can produce SVG and attach links to your node with GraphViz. GraphViz will output clickable SVG, so no need for an image map !! See this node -- Nice photos of naked perl sources here !	[reply]
Re^2: Problems with GraphViz module by jeteve (Pilgrim) on Sep 18, 2006 at 11:18 UTC
Ooops, I haven't see that you had already found this node. Sorry.. -- Nice photos of naked perl sources here !	[reply]
Re: Problems with GraphViz module by Util (Priest) on Sep 18, 2006 at 06:12 UTC
Are you sure that SVG can't do image maps? This works for me, producing clickable links: `echo 'graph G { node [URL="http://search.cpan.org" ] CPAN; node [URL="http://www.perlmonks.org"] PerlMonks; CPAN -- PerlMonks; } ' \| dot -Tsvg > PM_573377.svg` [download]	[reply] [d/l]
Re: Problems with GraphViz module by Anonymous Monk on Sep 17, 2006 at 11:17 UTC
Show your code (How (Not) To Ask A Question).	[reply]