[Boost-users] read_graphml: read more than 1 graph from the same graphml file

Subject: [Boost-users] read_graphml: read more than 1 graph from the same graphml file
From: Bartha Attila (abartha_at_[hidden])
Date: 2012-11-12 13:20:23

Hello !

Is there a way a to read more than one graph from a .graphml file using read_graphml ?
Here's what I tried:
-open an input stream to the graphml file;
-call a function to read the graph from the file (the function uses read_graphml) and print the graph to stdout;

-call the same function again, hoping that the second graph from the file will be read;
-close the file input stream.

If I call the function once, it works fine and returns the first graph defined in the graphml file.
If I call the function the twice, I get the following runtime exception:
 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector<boost::property_tree::ptree_bad_path> >'
 what():  No such node (graphml)


The graphml file looks like this :

<graphml ....header stuff... >
<key id= ...key definitions...>

  <graph id="TestSite1" edgedefault="undirected">
    <node id="node0"> <data key="map">map1</data> <data key="x">5.0</data> <data key="y">1.0</data> </node>
    <node id="node1"> <data key="map">map1</data> <data key="x">5.0</data> <data key="y">4.0</data> </node>    <edge source="node0" target="node1"/>

  </graph>
  <graph id="TestSite2" edgedefault="undirected">
    <node id="node0"> <data key="map">map3</data> 
<data key="x">6.0</data> <data 
key="y">2.0</data> </node>
    <node id="node1"> <data key="map">map4</data> 
<data key="x">7.0</data> <data 
key="y">9.0</data> </node>    <edge source="node0" target="node1"/>

  </graph></graphml>

I can correctly get the data of TestSite1 graph if I call the function once.
How can I get the TestSite2 graph from the same file, or, for that matter, how can I get one specific graph (ex TestSiteN) ? 

Thanx for any help,
-attoparsec-