---+ Customizing the Context Graph

The [[local view][LocalView.txt]] contains  a   graph  that displays the
target resource in its context. The  graph   is  implemented by the HTML
component context_graph//2, which in turn uses graphviz_graph//2. It can
be customised by defining the following hooks:

  * cliopatria:context_graph/2 generates the context as a graph of
  rdf(S,P,O) triples.  The default implementation is given by
  cpa_browse:context_graph/2.
  * cliopatria:node_shape/3 defines the shape of an individual node.

In addition, graphs may be customized   by  adding certain properties to
their  schema.  To  make  this   work,    the   application   must  load
ontologies/tool/graphviz.ttl. Below is a  Turtle   example  to vizualise
verbs in the output from the Alpino dependency parser.

    ==
    @prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
    @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
    @prefix alpino: <http://www.let.rug.nl/vannoord/alp/Alpino/> .
    @prefix graphviz: <http://www.graphviz.org/> .

    alpino:Verb
        graphviz:shape "box3d" ;
        graphviz:style "filled" ;
        graphviz:fillcolor "#fff48f" ;
        graphviz:hideType true .
    ==

@see	An example for showing the Europeana EDM is given in
	examples/customise/EDM.pl.
@see	http://www.graphviz.org/doc/info/shapes.html defines GraphViz
	supported shapes.