HTML-like labels supported

[lenntt]

graphviz doc says: http://www.graphviz.org/doc/info/shapes.html#html

When using this in ruby-graphviz, so setting an edge.label to something like "<some <b>label</b>>" I just get a "some label" without the markup.

Am I doing something wrong or is this not supported in the current version? I see some note in the changelog of version 1.0.0 regarding to html labels, but i cant figure out how to use it. Is there an example around?

[lenntt]

Could anyone verify whether I'm doing something wrong or whether this is not supported at the moment?

[glejeune]

See sample55.rb

[lenntt]

Thanks, i'm definitely going to try it out

[lenntt]

I've verified the example builds, but graphviz seems to ignore the HTML labels. In order to show that, I've changed the example a little bit: One node with markup, one node without, so we should see a difference in the output of both.

  n1 = g.add_nodes( "N1", :label => 'node 1')
  n2 = g.add_nodes( "N2", :label => '<<b>node 2</b>>')

gives me this when outputted to svg (tested with latest released gem, 1.0.9 and latest graphviz available for my system: 2.26.3-10ubuntu1):

<svg width="116pt" height="157pt" viewBox="0.00 0.00 116.00 157.00" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
<g id="graph1" class="graph" transform="scale(1 1) rotate(0) translate(4 153)">
<title>G</title>
<polygon fill="white" stroke="white" points="-4,5 -4,-153 113,-153 113,5 -4,5"></polygon>
<text text-anchor="start" x="8.5" y="-8.73333" font-family="Times Roman,serif" font-size="14.00">This</text>
<text text-anchor="start" x="37.5" y="-8.73333" font-family="Times Roman,serif" font-size="14.00"> is </text>
<text text-anchor="start" x="57.5" y="-8.73333" font-family="Times Roman,serif" font-size="14.00">a</text>
<text text-anchor="start" x="66.5" y="-8.73333" font-family="Times Roman,serif" font-size="14.00"> </text>
<text text-anchor="start" x="71.5" y="-8.73333" font-family="Times Roman,serif" font-size="14.00">test</text>
<!-- N1 -->
<g id="node1" class="node"><title>N1</title>
<ellipse fill="none" stroke="black" cx="54" cy="-130" rx="44.7575" ry="18.3848"></ellipse>
<text text-anchor="middle" x="54" y="-126.4" font-family="Times Roman,serif" font-size="14.00">node 1</text>
</g>
<!-- N2 -->
<g id="node2" class="node"><title>N2</title>
<ellipse fill="none" stroke="black" cx="54" cy="-41" rx="42.2463" ry="18"></ellipse>
<text text-anchor="start" x="30" y="-38.2333" font-family="Times Roman,serif" font-size="14.00">node 2</text>
</g>
<!-- N1&#45;&#45;N2 -->
<g id="edge2" class="edge"><title>N1--N2</title>
<path fill="none" stroke="black" d="M54,-111.125C54,-95.8177 54,-74.3731 54,-59.2387"></path>
<text text-anchor="start" x="54.5" y="-82.2333" font-family="Times Roman,serif" font-size="14.00">edge</text>
</g>
</g>
</svg>

Note that the example behaves correctly, because it renders a png. This functionality is working only under svg rendering. http://www.graphviz.org/doc/info/shapes.html#html

[glejeune]

I think it is a problem with your graphviz version. Indeed, with GV 2.31, everything looks good. Could you test with 2.30 or 2.31 ?

[lenntt]

I've verified it indeed was a problem with my graphviz version. I'm now using 2.31.20130522.0446-1 (from ppa:gviz-adm/graphviz-dev) and it works as expected. Thanks