initial dcat:CatalogRecord implementation

ckanext/dcat/processors.py

@@ -13,7 +13,7 @@
 
 import ckan.plugins as p
 
-from ckanext.dcat.utils import catalog_uri, dataset_uri, url_to_rdflib_format, DCAT_EXPOSE_SUBCATALOGS
+from ckanext.dcat.utils import catalog_uri, dataset_uri, catalog_record_uri, url_to_rdflib_format, DCAT_EXPOSE_SUBCATALOGS
 from ckanext.dcat.profiles import DCAT, DCT, FOAF
 from ckanext.dcat.exceptions import RDFProfileException, RDFParserException
 
@@ -264,6 +264,24 @@ def graph_from_dataset(self, dataset_dict):
 
         return dataset_ref
 
+    def graph_from_catalog_record(self, dataset_dict, dataset_ref, catalog_ref):
+        '''
+        Creates a graph for the catalog record using the loaded profiles
+
+        The class RDFLib graph (accessible via `serializer.g`) will be updated
+        by the loaded profiles.
+
+        Returns the reference to the catalog record, which will be an rdflib URIRef.
+        '''
+
+        catalog_record_ref = URIRef(catalog_record_uri(dataset_dict))
+
+        for profile_class in self._profiles:
+            profile = profile_class(self.g, compatibility_mode=self.compatibility_mode)
+            profile.graph_from_catalog_record(dataset_dict, dataset_ref, catalog_record_ref)
+
+        return catalog_record_ref
+
     def graph_from_catalog(self, catalog_dict=None):
         '''
         Creates a graph for the catalog (CKAN site) using the loaded profiles
@@ -356,6 +374,9 @@ def serialize_catalog(self, catalog_dict=None, dataset_dicts=None,
         if dataset_dicts:
             for dataset_dict in dataset_dicts:
                 dataset_ref = self.graph_from_dataset(dataset_dict)
+                catalog_record_ref = self.graph_from_catalog_record(dataset_dict, dataset_ref, catalog_ref)
+                if self.g.triples((catalog_record_ref, RDF.type, DCAT.CatalogRecord)):
+                    self.g.add((catalog_ref, DCAT.record, catalog_record_ref))
 
                 cat_ref = self._add_source_catalog(catalog_ref, dataset_dict, dataset_ref)
                 if not cat_ref:

ckanext/dcat/profiles/base.py

@@ -1305,6 +1305,21 @@ def _extract_catalog_dict(self, catalog_ref):
         )
         return out
 
+    def graph_from_catalog_record(self, dataset_dict, dataset_ref, catalog_record_ref):
+        """
+        Creates an RDF graph for the catalog record
+
+        The class RDFLib graph (accessible via `self.g`) should be updated on
+        this method
+
+        `dataset_dict` is a dict with the dataset metadata like the one
+        returned by `package_show`. `dataset_ref` is an rdflib URIRef object
+        that must be used to reference the dataset when working with the graph.
+        `catalog_record_ref` is an rdflib URIRef object
+        that must be used to reference the catalog record when working with the graph.
+        """
+        pass
+
     def graph_from_catalog(self, catalog_dict, catalog_ref):
         """
         Creates an RDF graph for the whole catalog (site)

ckanext/dcat/profiles/dcat_us_3.py

@@ -62,6 +62,10 @@ def graph_from_catalog(self, catalog_dict, catalog_ref):
 
         self._graph_from_catalog_base(catalog_dict, catalog_ref)
 
+    def graph_from_catalog_record(self, dataset_dict, dataset_ref, catalog_record_ref):
+
+        self._graph_from_catalog_record_base(dataset_dict, dataset_ref, catalog_record_ref)
+
     def _data_dictionary_parse(self, data_dict, subject):
 
         g = self.g

ckanext/dcat/profiles/euro_dcat_ap.py

@@ -31,6 +31,10 @@ def graph_from_catalog(self, catalog_dict, catalog_ref):
 
         self._graph_from_catalog_base(catalog_dict, catalog_ref)
 
+    def graph_from_catalog_record(self, dataset_dict, dataset_ref, catalog_record_ref):
+
+        self._graph_from_catalog_record_base(dataset_dict, dataset_ref, catalog_record_ref)
+
     def _graph_from_dataset_v1_only(self, dataset_dict, dataset_ref):
         """
         CKAN -> DCAT v1 specific properties (not applied to higher versions)

ckanext/dcat/profiles/euro_dcat_ap_2.py

@@ -57,6 +57,10 @@ def graph_from_catalog(self, catalog_dict, catalog_ref):
 
         self._graph_from_catalog_base(catalog_dict, catalog_ref)
 
+    def graph_from_catalog_record(self, dataset_dict, dataset_ref, catalog_record_ref):
+
+        self._graph_from_catalog_record_base(dataset_dict, dataset_ref, catalog_record_ref)
+
     def _parse_dataset_v2(self, dataset_dict, dataset_ref):
         """
         DCAT -> CKAN properties carried forward to higher DCAT-AP versions

ckanext/dcat/profiles/euro_dcat_ap_3.py

@@ -49,6 +49,10 @@ def graph_from_catalog(self, catalog_dict, catalog_ref):
 
         self._graph_from_catalog_base(catalog_dict, catalog_ref)
 
+    def graph_from_catalog_record(self, dataset_dict, dataset_ref, catalog_record_ref):
+
+        self._graph_from_catalog_record_base(dataset_dict, dataset_ref, catalog_record_ref)
+
     def _graph_from_dataset_v3(self, dataset_dict, dataset_ref):
 
         dataset_series = False

ckanext/dcat/profiles/euro_dcat_ap_base.py

@@ -779,3 +779,18 @@ def _graph_from_catalog_base(self, catalog_dict, catalog_ref):
         modified = self._last_catalog_modification()
         if modified:
             self._add_date_triple(catalog_ref, DCT.modified, modified)
+
+    def _graph_from_catalog_record_base(self, dataset_dict, dataset_ref, catalog_record_ref):
+        g = self.g
+
+        for prefix, namespace in namespaces.items():
+            g.bind(prefix, namespace)
+
+        g.add((catalog_record_ref, RDF.type, DCAT.CatalogRecord))
+        g.add((catalog_record_ref, FOAF.primaryTopic, dataset_ref))
+        # NOTE: _graph_from_dataset_base sets dct:modified for dcat:Dataset with metadata_modified too
+        # This might be semanctically incorrect, as this should pertain to the content of the dataset according to MobilityDCAT's interpretation of DCAT-AP2
+        items =[
+            ('metadata_modified', DCT.modified, None, Literal),
+        ]
+        self._add_date_triples_from_dict(dataset_dict, catalog_record_ref, items)

ckanext/dcat/utils.py

@@ -166,6 +166,24 @@ def dataset_uri(dataset_dict):
 
     return uri
 
+def catalog_record_uri(dataset_dict):
+    '''
+    Returns an URI for the catalog record
+
+    This will be used to uniquely reference the catalog record on the RDF
+    serializations.
+
+    Returns a string with the catalog record URI.
+    '''
+    if dataset_dict.get('id'):
+        uri = '{0}/catalog-record/{1}'.format(catalog_uri().rstrip('/'),
+                                       dataset_dict['id'])
+    else:
+        uri = '{0}/catalog-record/{1}'.format(catalog_uri().rstrip('/'),
+                                       str(uuid.uuid4()))
+        log.warning('Using a random id for catalog record URI')
+
+    return uri
 
 def resource_uri(resource_dict):
     '''