Compact serialization

[sharpaper]

Is g.serialize() supposed to produce a compacted jsonld document? If I have this graph [node_a]->knows->[blank_node], when I retrieve node_a with rdflib and then serialize with rdflib-jsonld, I obtain this document

{
    "@context": [...],
    "@graph": [
        {
            "name": "Alice"
            "knows": { "id": "_:xxxxx" }
        },
        {
            "id": "_:xxxxx"
        }
    ]
}

whereas I would expect this

{
    "@context": [...],
    "name": "Alice"
    "knows": "_:xxxxx" 
}

Am I doing something wrong?

[jbkoh]

I'd be interested in this issue too. I understand it's easier to assign ids to blank nodes for serialization, but one of the upsides of JSON-LD is the nested format with JSON, which is more human-readable.

[westurner]

See also #52 :

How to use this from the command line with rdfpipe to convert from one format to another (with optional {compaction,}) could be helpfully added to README.rst.

[nicholascar]

The RDFlib maintainers are hoping to see JSON-LD 1.1 support completed soon and then for this package to me merged into the main RDFlib package as a main serializer/parser plugin.

If any of you are interested in completing JSON-LD 1.1 support in order to then take up other issues, such as this one, please let me or the rdflib-dev mailing list know. We have a couple of developers getting ready to look into this but more help will be greatly appreciated.

[westurner]

Is PyLD the only JSON-LD implementation with support for compaction at present? https://github.com/digitalbazaar/pyld/blob/316fbc2c9e25b3cf718b4ee189012a64b91f17e7/tests/runtests.py#L664

I don't think this issue should block the new rdflib major release which will hopefully contain a completed integrated json-ld 1.1 parser/serializer. Looking at https://rdflib.dev/ , JSON-LD [1.1] compaction (and docs for how to specify the serializer format parameter w/ the RDFlib API and the rdfpipe CLI [#52]) would probably entail a minor version bump to e.g. 6.1.0?

[nicholascar]

I don't think this issue should block the new rdflib major release

Agreed. We discussed just bringing rdflib-jsonld into main rdflib right now but I think it sensible to prove the 1.1 support and then do that, since the support is part-way implemented already. Then we retain the Issues/PRs and commit history that added the 1.1 support here for historical record but port over all issues such as this to the main rdflib Issues tracker.

[sblack-usu]

This is something I have interest in as well. Has there been any movement on supporting compact serialization of json-ld?

[westurner]

From google/yamlfmt#125 ; it's called JSON-LD Framing :

reframe/compact/expand the underlying JSON-LD graph

• https://json-ld.org/playground/ has {Expanded, Compacted, Flattened, Framed,} JSON-LD 'compactions'(?)
  • Compact serialization RDFLib/rdflib-jsonld#93
  • https://www.w3.org/TR/json-ld11-framing/#framing-0

    The following sections describe algorithms for framing JSON-LD documents. Framing is the process of taking a JSON-LD document, which expresses a graph of information, and applying a specific graph layout (called a Frame).