(split from [[Problems_with_graphviz.pm_plug-in]])

[graphviz] generates image URLs relative to the page being rendered, which means the URLs wont work when previewing a graph from the CGI script.

>> Here is an updated patch againt ikiwiki-2.5:

>>> Applied, thanks. --[[Joey]]

    --- IkiWiki/Plugin/graphviz.pm.orig	2007-07-27 11:35:05.000000000 +0200
    +++ IkiWiki/Plugin/graphviz.pm	2007-07-27 11:36:02.000000000 +0200
    @@ -69,7 +69,12 @@ sub render_graph (\%) {
     		}
     	}
     
    -	return "<img src=\"".urlto($dest, $params{page})."\" />\n";
    +	if ($params{preview}) {
    +		return "<img src=\"".urlto($dest, "")."\" />\n";
    +	}
    +	else {
    +		return "<img src=\"".urlto($dest, $params{page})."\" />\n";
    +	}
     }
     
     sub graph (@) {


>> --[[HenrikBrixAndersen]]

>>> Despite this patch I am still experiencing the problem. Normal page source for a graph contains:

    <div id="content">
    <p><img src="./graph-c9fd2a197322feb417bdedbca5e99f5aa65b3f06.png" /></p>
    
    </div>

>>> preview contains

    <div id="preview">
    <p><img src="./demo/diagrams/graph-c9fd2a197322feb417bdedbca5e99f5aa65b3f06.png" /></p>
    
    </div>

>>> I don't quite understand why, this makes sense from the CGI path (in my
>>> case from the root of the site). The browsers appear to be trying to fetch
>>> `/demo/diagrams/demo/diagrams/graph-c9fd2a197322feb417bdedbca5e99f5aa65b3f06.png`
>>> (i.e., prepending the required relpath twice). -- [[Jon]]

>>>> Yeah, that patch may have been right once, but it's wrong now;
>>>> preview mode uses `<base>` to make urls work the same as they would
>>>> when viewing the html page. 
>>>>
>>>> Perhaps this was not noticed for a while while because it only
>>>> shows up if previewing an *unchanged* graph on a page that has already
>>>> been built before. Fixed now. [[done]] --[[Joey]] 
