integrate shows strange behavior when JSON-LD is used

[TBoonX]

Command:

java -jar $PATH_RPT integrate -o=local_licenses.jsonld --out-format=jsonld datasources.n3 get_licenses.rq

Version: 1.9.1

datasources.n3:

<http://dalicc.net/dependencygraph/dg_default/>
        <http://www.w3.org/1999/02/22-rdf-syntax-ns#type>  <https://vocab.eccenca.com/di/Dataset> .

<https://coypu.org/datasource/COY%20Ontology%20%2F%20CoyPu%20Schema> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://www.w3.org/ns/dcat#Dataset>.
<https://coypu.org/datasource/COY%20Ontology%20%2F%20CoyPu%20Schema> <http://purl.org/dc/terms/title> "COY Ontology / CoyPu Schema".
<https://coypu.org/datasource/COY%20Ontology%20%2F%20CoyPu%20Schema> <http://purl.org/dc/terms/language> "http://id.loc.gov/vocabulary/iso639-1/en".
<https://coypu.org/datasource/COY%20Ontology%20%2F%20CoyPu%20Schema> <http://purl.org/dc/terms/license> <http://dalicc.net/licenselibrary/CC-BY_v4>.

get_licenses.rq:

PREFIX dcterms: <http://purl.org/dc/terms/>
PREFIX odrl: <http://www.w3.org/ns/odrl/2/>
construct { ?license a odrl:Set . }
 WHERE {
   SELECT distinct ?license WHERE {
     ?ds a <http://www.w3.org/ns/dcat#Dataset> ;
     dcterms:license ?license .
   }

}

It shows an RDF result in the terminal, but writes [] into the jsonld file. With other formats it works.

[Aklakan]

One part of the issue seems to be that there is no streaming json ld writer in jena. The code is adapted that the request for formats for which no streaming writer exists now fall back to non-streaming serialization.

A useful improvement now would be writing out a log message whether streaming or non-streaming is used - not yet sure about how to handle this; e.g. the sink could either expose a flag or a more general set of capabilities.

[Aklakan]

A release candidate with the jsonld fix (and the latest jenax plugins) has been created at https://github.com/SmartDataAnalytics/RdfProcessingToolkit/releases/tag/v1.9.2-rc1

[TBoonX]

Works with RC1.

[Aklakan]

A couple of minor issues:

• Using --out-format json (instead of --out-format jsonld) only writes out an empty json array [] (which might be easily mistaken for a blank node). The reason is that the json format is only internally used if the --jq switch is present . This is somewhat confusing.
• Conversely, using --jq and --out-file unexpectedly requires to specify --out-format json