Explanation regarding RDF data

[heidivanparys]

Would it be possible to give some explanation regarding the concepts as RDF, both on the structure of the RDF data and on how to retrieve it?

The background for my question: I am trying to map a list of concepts to the corresponding concepts in ISO/TC 211:

It would be great, if I could export my list of concepts as RDF, and have the ISO/TC 211 concepts in RDF too, so the information about all these concepts could be put together and queried.

What is the persistent HTTP-URI of a concept? To give an example: the concept "feature instance" can be viewed via a browser at https://isotc211.geolexica.org/concepts/1431/ At the bottom, there is a link to the RDF representation of that concept:

When I run that Turtle file through SKOS Play, I get the following:

When I change the file to the following:

@base <https://isotc211.geolexica.org/concepts/> .
@prefix : <https://isotc211.geolexica.org/concepts/> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdf-profile: <https://isotc211.geolexica.org/api/rdf-profile#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://isotc211.geolexica.org/concepts/>
  rdf:type owl:Ontology ;
  owl:imports dcterms: ;
  owl:imports </api/rdf-profile> ;
  owl:imports <http://www.w3.org/2004/02/skos/core> ;
.
<1431/>
  rdf:type skos:Concept ;
  dcterms:source "https://www.iso.org/standard/59164.html" ;
  rdf-profile:engOrigin rdf-profile:English ;
  rdf-profile:korOrigin rdf-profile:Korean ;
  rdf-profile:rusOrigin rdf-profile:Russian ;
  rdf-profile:spaOrigin rdf-profile:Spanish ;
  rdf-profile:sweOrigin rdf-profile:Swedish ;
  rdf-profile:termID </api/concepts/1431.ttl> ;
  rdfs:label "feature instance" ;
  skos:notation 1431 ;
  skos:definition "individual of a given feature type having specified feature attribute values"@en ;
  skos:definition "특정 지형지물 속성값을 가진 개별 지형지물 유형"@ko ;
  skos:definition "объект данного типа, имеющий определённые значения атрибутов объекта"@ru ;
  skos:definition "individuo de un tipo de objeto geográfico que tiene especificados valores de atributos de objeto geográfico"@es ;
  skos:definition "förekomst av en viss objekttyp vars attribut har tilldelats värden"@sv ;
  skos:inScheme rdf-profile:GeolexicaConceptScheme ;
  skos:prefLabel "feature instance"@en ;
  skos:prefLabel "지형지물 인스턴스"@ko ;
  skos:prefLabel "экземпляр объекта"@ru ;
  skos:prefLabel "instancia de objeto geográfico"@es ;
  skos:prefLabel "objekt"@sv ;
  dcterms:dateAccepted "2013-12-15" ;
  :status "valid" ;
  :classification "preferred" ;
.
:linked-data-api
  rdf:type dcterms:MediaTypeOrExtent ;
  skos:prefLabel "linked-data-api" ;
.

I get:

In addition: is content negotiation supported? And if yes, how? What URIs to use?

https://isotc211.geolexica.org/concepts/1431/ returns HTML, also when I ask for Turtle (also when I ask for HTML)

curl -I -H "Accept: text/turtle" "https://isotc211.geolexica.org/concepts/1431/"
HTTP/1.1 200 OK
Content-Type: text/html; charset=utf-8
Content-Length: 11750
Connection: keep-alive
Last-Modified: Wed, 12 Aug 2020 22:23:48 GMT
Server: AmazonS3
Date: Tue, 15 Sep 2020 12:59:10 GMT
ETag: "8c9e12f5eb9a2a59619eaf8d2cd7b8fa"
Vary: Accept-Encoding
X-Cache: RefreshHit from cloudfront
Via: 1.1 9e62923882d737ac8cd27f0d1b1c24cf.cloudfront.net (CloudFront)
X-Amz-Cf-Pop: FRA2-C1
X-Amz-Cf-Id: aOjPdD1XUSprMMTsSPsSOYWIstBPaca_zRHofF9UkUlqsIw6ktRf9Q==

https://isotc211.geolexica.org/api/concepts/1431/ returns a 404, when I ask for turtle.

curl -I -H "Accept: text/turtle" "https://isotc211.geolexica.org/api/concepts/1431/"
HTTP/1.1 404 Not Found
Content-Type: text/html; charset=utf-8
Content-Length: 6292
Connection: keep-alive
Last-Modified: Wed, 12 Aug 2020 22:23:39 GMT
Server: AmazonS3
Date: Tue, 15 Sep 2020 12:54:59 GMT
ETag: "592f5b8b19ffb9a29c5f91005b0c0147"
Vary: Accept-Encoding
X-Cache: Error from cloudfront
Via: 1.1 42b60ee17f7593fff72ca1cb725d6c9a.cloudfront.net (CloudFront)
X-Amz-Cf-Pop: FRA2-C1
X-Amz-Cf-Id: JS6JLh9dBPelrSGyD_M1n8g9QI_qG851CWCtq8SlD-rRb5UBCOMUSg==
Age: 144

Only https://isotc211.geolexica.org/api/concepts/1431.ttl seems to return turtle.

curl -I -H "Accept: text/turtle" "https://isotc211.geolexica.org/api/concepts/1431.ttl"
HTTP/1.1 200 OK
Content-Type: text/turtle; charset=utf-8
Content-Length: 2202
Connection: keep-alive
Date: Tue, 15 Sep 2020 12:57:33 GMT
Last-Modified: Wed, 12 Aug 2020 22:25:20 GMT
ETag: "41efeecc3871552355da9cd740ec8311"
Server: AmazonS3
X-Cache: Miss from cloudfront
Via: 1.1 c3b74c81fdcb7942211a6c721efa13fd.cloudfront.net (CloudFront)
X-Amz-Cf-Pop: FRA2-C1
X-Amz-Cf-Id: CJU3-JOCTJ2iwneqBuEjQm8KO6dlitMhqXjJvthelUNlnXaw1OjZyQ==

[ronaldtse]

@heidivanparys thank you for the report.

Currently Geolexica does not support content negotiation. The specific ttl URI must be used to retrieve turtle content.

The other bug encountered via SKOS Play is a known issue (sorry!) -- the identifier for concepts is missing the proper hostname. This is something we need to fix.

[heidivanparys]

Currently Geolexica does not support content negotiation. The specific ttl URI must be used to retrieve turtle content.

Ok. Is there a URI to retrieve all the concepts in turtle format, in one file? I could not find anything at the bottom of https://isotc211.geolexica.org/concepts/, is there a hidden URL or is that functionality not implemented?

[ronaldtse]

@heidivanparys there is no "index" of concepts in turtle, yet. We probably should do that, thanks for asking!

Issue created at geolexica/geolexica-server#139

[heidivanparys]

We probably should do that, thanks for asking!

It would be great to have that, thanks!