On Tue, Oct 26, 2021 at 11:52 AM Andy Seaborne <a...@apache.org> wrote:
>
>
> On 26/10/2021 09:40, Martynas Jusevičius wrote:
> > Hi,
> >
> > I'm implementing a Reader that extracts <script
> > type="application/ld+json"> from HTML and then uses JsonLDReader to
> > parse that data.
> >
> > I've got a few questions in the process:
> >
> > 1. How does one obtain the default ParserProfile and ErrorHandler?
> > Currently I'm using
> >
> > ParserProfile profile =
> > RiotLib.profile(HtmlJsonLDReaderFactory.HTML, null,
> > ErrorHandlerFactory.getDefaultErrorHandler());
>
> Use
>
> RDFParser.create()... parse(stream);
>
> then don't call .factory() .errorHandler() on the RDFParserBuilder and
> the defaults will be used.
I'm doing some hacking because currently I'm stuck with 3.16.0 which
does not support JsonLDReader.JSONLD_OPTIONS.
So I can't propery initialize RDFParser for JSON-LD. For now I've
copied the JsonLDReader class from 3.17.0 which has JSONLD_OPTIONS.
> > but internally the method it calls are all deprecated.
> >
> > 2. Can multiple StreamRDF be combined into one?
>
> A single StreamRDF can be reused unless it documents otherwise. A graph
> sink can be used multiple times.
>
> > There might be
> > multiple <script> elements and the reader should merge the data from
> > them. I attempted
> >
> > public void read(Reader in, String baseURI, Lang lang, StreamRDF
> > output, Context context)
> > {
> > ...
> > for (Element element : jsonLdElements)
> > {
> > String jsonLd = element.data();
> > getJsonLDReader().read(new StringReader(jsonLd), baseURI,
> > JSONLD.getContentType(), output, context);
> > }
> > }
> >
> > but only the first element gets read,
>
> > I guess because
> > getJsonLDReader().read() calls output.start()/output.finish().
>
> Unlikely - .start/.finish can be called multiple times (unless the
> StreamRDF explicitly documents otherwise - a graph sink can be used
> multiple times.
Right. It seems to work, I think I looked at the wrong examples when I
wrote this -- sorry about that.
The code can be found here:
https://github.com/AtomGraph/LinkedDataHub/blob/develop/src/main/java/com/atomgraph/linkeddatahub/io/HtmlJsonLDReader.java
