Save metadata in a knowledge graph

[bgajdero]

Save instances of metadata in a knowledge graph.

Knowledge graph schema will be the maturity models.

[bgajdero]

See mapping file to show how to store the knowledge graph.

[LesterLyu]

Design of mapping configuration:

"mappings": {
        "@context": {
            "dcat": "http://www.w3.org/ns/dcat#",
            "skos": "http://www.w3.org/2004/02/skos/core#",
            "rdfs": "http://www.w3.org/2000/01/rdf-schema#",
            "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
            "dct": "http://purl.org/dc/terms/",
            "foaf": "http://xmlns.com/foaf/0.1/"
        },
        "@id": "http://data.urbandatacentre.ca/catalogue/{ckanField.id}",
        "@type": "http://data.urbandatacentre.ca/catalogue",
        "dct:creator": {
            "@id": "http://data.urbandatacetre.ca/{generate_uuid()}",
            "@type": "foaf:Agent",
            "foaf:mbox": "{ckanField.author_email}",
            "foaf:name": "{ckanField.author}"
        },
        "dct:title": {
            "@type": "xsd:string",
            "@value": "{ckanField.title}"
        }
    }

The mappings part follows the JSON-LD Spec. @context stores the namespaces; @id specify the URI of an instance'; @type specify the rdf:type of the value/instance. The text in the curly bracket {} will be evaluated in Python:

• SPARQL query generation from the mappings
  • Update: Delete+Insert query on catalogue update
• Preload ontologies into KG when server starts

  "preload_ontologies": {
      // The graph to use: the file to import
      "http://id.loc.gov/vocabulary/iso639-1": "http://id.loc.gov/vocabulary/iso639-1.json"
  },

• Preload and cache single_select options if it is coming from the KG

  {
    "name": "language",
            "label": "Language",
            "type": "single_select",
            "optionsFromQuery": {
                "text": "label", // The text/label for an option to display in the dropdown
                "value": "s",     // The actual value of an option
                "query": "select * from <http://id.loc.gov/vocabulary/iso639-1> where {?s <http://www.w3.org/2004/02/skos/core#prefLabel> ?label. FILTER (lang(?label) = 'en')}"
            }
  }

• [Interface] Display single_select options from the cache