[export gexf] void attributes are not exported #985

Hi,

I have encountered some issues when I exported my graph in the format gexf. My previous structure, which I imported, of data is an gexf graph. I use gephi toolkit to spatialize the graph and add nodes color . Some of attributes values' are void. As in this exemple :

After spatialization and other actions on my graph, i export it in a format gexf. And when I look at the structure of my new file, I noticed that the attributes which have void values are not in. As in the exemple, this is the gexf exported :

-> There are attribute 4/5 and 7 which are missing.

I found where does the issue come from. It's in the code of gephi-toolkit, in the class "ExporterGEXF.java".

Especially in the method

In this method, all nodes are iterated and for each node all attributes are iterated. Next, the current attribute is tested : if it is not null, we write the attribute in the xml file. If not, the attribute null is ignored.

I am not going re compil the gephi toolkit, so i will replace all null attributes by a space (string).

==> Now my question is, is it possible to enable this behavior to let all attributes even if they are null ?