[Lds] ideas/recommendations for JSON-LD serializations

Adrian Pohl pohl at hbz-nrw.de
Mi Apr 25 14:42:47 CEST 2018

Hello Thomas,

we are happy you like the possibility of getting dumps and updates via 
lobid and we will let you know when we have implemented this for GND.

Re. your question:

On 4/25/18 12:46 PM, Thomas Gängler wrote:

> Albeit, this still lefts a general question, why is HBZ doing/offering 
> services that should be offered by DNB itself? ;)

I don't agree with the underlying assumption of your question. GND as 
well as ZDB are cooperative projects with a lot of institutions 
(including the hbz and its member libraries) involved. The DNB is 
responsible for maintaining the Pica system the cataloging is happening 
in but as far as I know there is no agreement or whatsoever that makes 
DNB responsible for providing the GND in different Linked Data 
serializations as dumps and with regular updates.

Anyway, it is great that they developed the GND ontology and provide 
Linked Data  under CC0 so everyone is allowed to create services on top 
of it. So lobid-gnd might be a case of unexpected cool thinks people 
will do if you provide open data. ;-)

With respect to the ZDB data, our offer of a dump plus updates is just a 
side effect of us publishing the hbz union catalogue as linked open data 
with the complete ZDB being a subset of the catalogue. Other people use 
the dump function to get other subsets e.g. all the titles that have 
holdings in libraries in  a specific town...

> PS: @Jana: in [1] is the code from HBZ guys, where a rather generic 
> N-Triples to nested JSON-LD records converter is included - I guess, 
> this is probably what you are looking for, or?

For lobid-gnd we use another approach utilizing the JSON-LD [framing] 
mechanism that enables the selection of a root element for a 
hierarchical JSON-LD document and the embedding of information for 
referenced nodes (@embed and @always). We even make use of JSON-LD 1.1 
features here. See this [example] in the JSON-LD playground where the 
input is the JSON-LD from [DNB] which is processed with the @context 
from lobid.org and a minimal JSON-LD frame and already looks much 
better. (I don't understand why the @graph is still there, it shouldn't 
in the dev playground which is based on JSON-LD 1.1.)

All the best

[framing] https://json-ld.org/spec/latest/json-ld-framing/
[example] http://tinyurl.com/y7m2o9md
[DNB] https://d-nb.info/gnd/102609478X/about/lds.jsonld

> [1] 
> https://github.com/hbz/lobid-resources/tree/master/src/main/java/de/hbz/lobid/helper 

Adrian Pohl
hbz - Hochschulbibliothekszentrum des Landes NRW
Jülicher Straße 6
50674 Köln
Telefon +49-221-40075-235

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