On 01/12/2020 19:02, Jean-Marc Vanel wrote:
Empty maps are obtained by calling getPrefixMapping() ,
either with a graph from a SPARQL query, or from the Union Graph.
Perfect timing!
JENA-2006 (in-progress as of 2020-12-01 - PR went in today.
adds Dataset.getPrefixMapping() and DatsetGraph.prefixes()
For a TDB database, all graphs will have the same prefix map, including
the union graph.
Currently - 3.17.0 - the dataset prefixes (i.e. as used for output) are
held with the default graph. While the code supports additonal prefix
sets, they are accssible without going into the implementation.
JENA-2006 changes all that.
From a SPARQL query, only possible prefix mappings are from the query, not
the database.
They are on the default graph, if there are any from TriG.
Same thing with
PrefixMappingUtils.calcInUsePrefixMapping(graph)
There is a class called DatasetPrefixesTDB , but it seems a low level
implementation class.
Some code comments imply that a prefixes map is not maintained
permanently ...
Not yet tested with 3.17.0 .
No change.
Andy
Jean-Marc Vanel
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