@amiedes: @entantoencuanto will be looking at some of these things this week.

Issue updated with link to DCAT-AP in EU site https://joinup.ec.europa.eu/solution/dcat-application-profile-data-portals-europe

I've inspected the DCAT of datos.madrid.es. And I think we can generate similar data by adding some extra attributes to both custom fields and vocabularies terms. For example, a dataset appears in the catalog in this way:

<dct:identifier>···</dct:identifier>
<dct:title xml:lang="es">···</dct:title>
<dct:description xml:lang="es">···</dct:description>
<dcat:theme rdf:resource="http://···"/>
<dct:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">···</dct:issued>
<dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">···</dct:modified>
<dc:language>···</dc:language>
<dct:publisher rdf:resource="http://···"/>
<dct:license rdf:resource="https://···l"/>
<dcat:distribution>
  <dcat:Distribution>
    <dcat:accessURL rdf:datatype="http://www.w3.org/2001/XMLSchema#anyURI"></dcat:accessURL>
    <dcat:mediaType>···</dcat:mediaType>
    <dcat:byteSize>···</dcat:byteSize>
  </dcat:Distribution>
</dcat:distribution>

For the custom fields:

• Each one can have an additional attribute rdf_decorator which knows how to represent the resource in DCAT format as string. For example, if the description internally is stored as:

{
    "es": "Parques Nacionales",
    "en": "National Parks"
}

once decorated this information can be included as:

<dct:title xml:lang="es">Parques Nacionales</dct:title>
<dct:title xml:lang="es">National Parks</dct:title>

For the vocabulary terms:

• A vocabulary term should include an extra attribute with associated metadata. For example, if there is a custom field of type vocabulary named theme, internally is stored as:

{
    "theme": [1]
}

The 1 is the id of a vocabulary term which includes a meta:

{
    "rdf:resource": "http://datos.gob.es/kos/sector-publico/sector/medio-ambiente"
}

With a vocabulary decorator with source for the custom field the result would be:

<dcat:theme rdf:resource="http://datos.gob.es/kos/sector-publico/sector/medio-ambiente"/>

Other type of vocabulary fields may use different decorators with an output like this (in this case it's a vocabulary field with multiple selection allowed):

<dcat:keyword xml:lang="es">Medio Ambiente</dcat:keyword>
<dcat:keyword xml:lang="es">Impacto ambiental</dcat:keyword>

== WIP ==

before to create a filled rdf dcat it is necessary map some values in any part of application.

Also I'd confirm my thought of a Catalog is dependant of a site (in any way) and a site only have a catalog

dcat:Catalog

values possibly related with a site:

dcat:Dataset

of course there another associated to a dataset that probably should be added as custom fields

dcat:Distribution

a distribution belongs to dataset and it is a specific representation of a dataset like csv, xml ...

dcat:DataService (UNUSED BY NOW)

a data service: is a collection of operations through an interface (ex API) to access to one or more datasets

WIP

For creator I'd just use site_name

@stbnrivas please use https://www.itb.ec.europa.eu/shacl/dcat-ap/upload or other validator to validate the XML.

RDF validator
DCAT validator

DCAT-AP VALIDATOR (not use, we are implement DCAT)