Github user afs commented on the issue:
https://github.com/apache/jena/pull/139
Apologies that this has taken so long.
> TODO some documentation. Where should it be added? The best form would be
small sample code.
Examples can go in `jena-arq/src-examples/arq/examples/riot/`. A new
section about JSON-LD output for
https://jena.apache.org/documentation/io/rdf-output.html, and use code links to
apache/jena github, master branch.
Symbols are fine but URI's please! (changing `RIOT.riotIRI` to
"http://jena.apache.org/riot";):
e.g. in JsonLDWriter
```
public static final Symbol JSONLD_CONTEXT =
Symbol.create("JSONLD_CONTEXT");
```
**RDFDataMgr**
The way to set things specially for a writing is to do:
```
WriterDatasetRIOT w =
RDFDataMgr.createDatasetWriter(RDFFormat.JSONLD_COMPACT_FLAT) ;
w.write(System.out, dataset.asDatasetGraph(), null, "http://base";,
RIOT.getContext()) ;
```
rather than add `RDFDataMgr.write(..., Context cxt)`
See
[examples/riot/ExRIOT_2](https://github.com/apache/jena/blob/master/jena-arq/src-examples/arq/examples/riot/ExRIOT_2.java)
for an example for a reader.
If you want, add a new API class specific to JSON output `JsonLdMgr` (to go
in the same package as `RDFDataMgr`) with JSON-LD-specific functions to wrap
common ways to call JSON-LD output.
**Constants**
This could be tidied out with a subclass of `RDFFormatVariant` that carries
JSON-LD information:
```
// From JSON writer
public static enum JSONLD_FORMAT {
COMPACT, FLATTEN, EXPAND, FRAME
}
static class JSONLDFormatVariant extends RDFFormatVariant {
private JSONLD_FORMAT option ;
private boolean prettyJson ;
public JSONLDFormatVariant(String name, boolean prettyJson,
JSONLD_FORMAT option) {
super(name) ;
this.options = option ;
this.prettyJson = prettyJson ;
}
public boolean prettyJson() { return prettyJson ; }
public boolean option(JSONLD_FORMAT fmt) {
for ( JSONLD_FORMAT f : options ) {
if ( fmt == f )
return true ;
}
return false ;
}
}
private static final RDFFormatVariant JSONLD_EXPAND_PRETTY = new
JSONLDFormatVariant("expand pretty", true, JSONLD_FORMAT.EXPAND) ;
private static final RDFFormatVariant JSONLD_EXPAND_FLAT = new
JSONLDFormatVariant("expand flat", false, JSONLD_FORMAT.COMPACT) ;
...
```
then use in JsonLDWriter by casting to and JSONLDFormatVariant
```
JSONLDFormatVariant format = (JSONLDFormatVariant)format ;
```
```
if ( format.option(COMPACT) ) {
...
}
```
**Tests**
I ran the tests for JSONLD but got:
```
10:13:04 WARN JsonLDWriter :: JSONLD_CONTEXT value is not a
String. Assuming a context object expected by JSON-LD JsonLdProcessor.compact
or flatten
10:13:04 INFO TestJsonLDWriter :: Sorry to get this exception
org.apache.jena.riot.RiotException: com.github.jsonldjava.core.JsonLdError:
loading remote context failed: http://schema.org/
at
org.apache.jena.riot.out.JsonLDWriter.serialize(JsonLDWriter.java:218)
at org.apache.jena.riot.out.JsonLDWriter.write(JsonLDWriter.java:123)
at org.apache.jena.riot.out.JsonLDWriter.write(JsonLDWriter.java:129)
at
org.apache.jena.riot.system.RiotLib$WriterAdapter.write(RiotLib.java:376)
at org.apache.jena.riot.RDFDataMgr.write$(RDFDataMgr.java:1232)
...
```
We need to be able to run the tests without assuing that external network
resources are availanle and functioning.
The tests and build should work if there is no extenral connectivity.
**Code organisation**
If you feel there classes, fell free to create a package
org.apache.jena.riot.out.jsonld to put them together.
**Other**
Indentation: spaces, not tabs please.
---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at [email protected] or file a JIRA ticket
with INFRA.
---
