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Re: Node.js tool for RDFa -> JSON-LD transformation

From: Niklas Lindström <lindstream@gmail.com>
Date: Sat, 30 Mar 2013 03:16:26 +0100
Message-ID: <CADjV5jfV+HYsHNcfMSd_ZnRaHYrPqFTjnbSPXDQG7ApRrVmHDQ@mail.gmail.com>
To: Manu Sporny <msporny@digitalbazaar.com>
Cc: JSON-LD CG <public-linked-json@w3.org>
Very cool!

As you know, my RDFa implementation in the RDFa-lab (which also runs
on Node and in the browser) [1] directly generates expanded JSON-LD.
I've then used your jsonld.js (with the framing stuff pruned) on that,
e.g. in combination with the Connect algorithm in the lab.

Another thing I've used for a while is RDFLib (Python), combined with
rdflib-jsonld and the "rdfpipe" commandline tool (from RDFExtras) to
do something very similar (rdfpipe can handle most RDF formats in and

    $ curl -L http://w3id.org/payswarm/v1 -o /tmp/payswarm-v1.jsonld
    $ rdfpipe -irdfa http://recipes.payswarm.com/?p=10554

(Something it it goes wrong when fetching the remote context, so I had
to use a local copy. Alas, I haven't had time to work on rdflib-jsonld
for quite some time now.)

And recently (as in 3 hours ago), the Swedish legal information system
I built (in Java/Groovy) [2] was updated to use an up-to-date JSON-LD
context. This system actually consumes legal information published in
RDF/XML or RDFa now (over Atom), and among other things funnel
extracted JSON-LD into ElasticSearch. See e.g. [3] and [4] (but note
that the new context isn't deployed yet).


[1]: https://github.com/niklasl/rdfa-lab
[2]: https://github.com/rinfo/rdl/tree/develop
[3]: http://rinfo.lagrummet.se/publ/sfs/1736:0123_1/konsolidering/1736-01-23
[4]: http://service.lagrummet.se/publ/sfs/1736:0123_1/konsolidering/1736-01-23/data.json

On Sat, Mar 30, 2013 at 2:34 AM, Manu Sporny <msporny@digitalbazaar.com> wrote:
> bcc: RDFa WG, RDF WG
> Dave Lehn and Dave Longley just put together a tool that's pretty rough
> around the edges, but really helpful for those trying to:
>  * Transform RDFa to JSON-LD
>  * Normalize JSON-LD/RDF Datasets to NQuads
>  * Transform JSON-LD to compact, expanded, normalized, or flattened form
> To install the tool, do the following (you will need git, nodejs, and
> npm installed):
> git clone https://github.com/digitalbazaar/jsonld.js.git
> cd jsonld.js
> npm install
> To compact a document on the Web using a JSON-LD context published on
> the Web:
> ./bin/jsonld compact
>   -c "http://w3id.org/payswarm/v1"
>   "http://recipes.payswarm.com/?p=10554"
> That will read in a PaySwarm Asset and Listing in RDFa 1.0 format (using
> Green Turtle by Alex Milowski), convert it to JSON-LD expanded form,
> compact it using the 'http://w3id.org/payswarm/v1' context, and dump it
> out to the console in compacted form.
> ./bin/jsonld normalize -q "http://recipes.payswarm.com/?p=10554"
> That will read in a PaySwarm Asset and Listing in RDFa 1.0 format,
> normalize the data using the RDF Dataset normalization algorithm, and
> then dump the output to normalized NQuads format. The NQuads can then be
> processed via SHA-256, or similar algorithm, to get a deterministic hash
> of the contents of the Dataset.
> The implementation is up-to-date with the RDFa and JSON-LD specs. The
> tool still needs quite a bit of tweaking, but it's a pretty powerful
> demonstration of many of the things this community has been building
> over the past several years.
> -- manu
> --
> Manu Sporny (skype: msporny, twitter: manusporny, G+: +Manu Sporny)
> Founder/CEO - Digital Bazaar, Inc.
> blog: Google Summer of Code 2013: RDFa, JSON-LD, Web Payments
> http://digitalbazaar.com/2013/03/12/gsoc/
Received on Saturday, 30 March 2013 02:17:24 UTC

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