Cool, it worked fine.
Just curious, I noticed that the named graphs end up embedded in the
required default (nameless) graph (see below).
Any particular reason to do this and not have the default graph empty,
followed by the named graphs?
Cheers,
Hubert
{
"@graph" :
[
{
"@graph" :
[...],
"@id" : "http://example.org/graph1";
},
{
"@graph" :
[...],
"@id" : "http://example.org/graph2";
},
]
}
On Thu, May 22, 2014 at 4:16 AM, Andy Seaborne <[email protected]> wrote:
> On 22/05/14 03:03, Hubert Le Van Gong wrote:
>
>> Greetings,
>>
>> I have a set of N-Quad statements that relate to different graphs. How do
>> I
>> go about exporting all those statements into a single JSON-LD object?
>>
>> For instance, I would expect that something like:
>> <http://one.example/subject3> <http://one.example/predicate3> <
>> http://one.example/object3> <http://example.org/graph3> .
>> _:subject1 <http://an.example/predicate1> "object1" <
>> http://example.org/graph1> .
>> _:subject2 <http://an.example/predicate2> "object2" <
>> http://example.org/graph2> .
>>
>> would end up as the following JSON-LD (disclaimer: I'm not 100% sure this
>> is correct, JSON-LD wise):
>>
>> [
>> {
>> "@context": {
>> "predicate3": "http://one.example/predicate3";
>> },
>> "@id": "http://example.org/graph3";,
>> "@graph":
>> [
>> {
>> "@id": "http://one.example/subject3";,
>> "predicate3": "http://one.example/object3";
>> }
>> ]
>> },
>> {
>> "@context": {
>> "predicate1": "http://an.example/predicate1";
>> },
>> "@id": "http://example.org/graph1";,
>> "@graph":
>> [
>> {
>> "@id": "_:b0",
>> "predicate1": "object1"
>> }
>> ]
>> },
>> {
>> "@context": {
>> "predicate2": "http://an.example/predicate2";
>> },
>> "@id": "http://example.org/graph2";,
>> "@graph":
>> [
>> {
>> "@id": "_:b0",
>> "predicate2": "object2"
>> }
>> ]
>> }
>> ]
>>
>>
>> So far, the approach I took was to load the n-quads using:
>> RDFDataMgr.read(dataset, in, RDFLanguages.NQUADS);
>>
>
>
>
>> and then iterate through the graph names, to get each model with:
>> Model model = dataset.getNamedModel(name);
>>
>> Something like model.write(out, RDFLanguages.strLangJSONLD); works well to
>> convert the data to JSON-LD, however it does not add any graph info
>> (@graph).
>> While I could probably stitch those parts together, I was hoping for a
>> cleaner way to do this.
>>
>
> If you write the whole dataset:
>
> RDFDataMgr.write(System.out, dataset, Lang.JSONLD) ;
>
> all the graphs will come out, named.
>
> If you want to print one graph, with it's name, create a separate dataset,
> put just that graph in it, as a named graph, and print that.
>
> Models don't have names - it's the container (dataset) that gives it it's
> name. It can have several names (be included several times, or in several
> places).
>
> Andy
>
>
>
>> In particular, I tried to create a new model by uniting 2 models at a time
>> but it did not quite work (although I do see @graph added)...
>>
>> Can anyone shed some light on the best approach for this?
>>
>> Cheers,
>> Hubert
>>
>> PS: my apologies if it's already been discussed before but I did not find
>> anything on this particular topic in the list archive.
>>
>>
>
