feat: Add support for DCAT creator field in dataset metadata

- Added fields to store creator details (name, email, URL, and identifier) in the DCAT profile.
- Implemented functionality to serialize and deserialize creator information similar to the publisher.
- Updated RDF generation logic to include creator fields in the output graph.
- Enhanced unit tests to verify proper handling and serialization of creator metadata.

ckanext/dcat/tests/profiles/base/test_base_profile.py

@@ -660,7 +660,7 @@ def test_publisher_foaf(self):
 
         p = RDFProfile(g)
 
-        publisher = p._publisher(URIRef('http://example.org'), DCT.publisher)
+        publisher = p._agent_details(URIRef('http://example.org'), DCT.publisher)
 
         assert publisher['uri'] == 'http://orgs.vocab.org/some-org'
         assert publisher['name'] == 'Publishing Organization for dataset 1'
@@ -688,7 +688,7 @@ def test_publisher_ref(self):
 
         p = RDFProfile(g)
 
-        publisher = p._publisher(URIRef('http://example.org'), DCT.publisher)
+        publisher = p._agent_details(URIRef('http://example.org'), DCT.publisher)
 
         assert publisher['uri'] == 'http://orgs.vocab.org/some-org'
 

examples/ckan/ckan_dataset.json

@@ -8,6 +8,8 @@
             {"key": "guid", "value": "9df8df51-63db-37a8-e044-0003ba9b0d98"},
             {"key": "dcat_publisher_name", "value": "Geological Society"},
             {"key": "dcat_publisher_email", "value": "info@gs.org"},
+            {"key": "dcat_creator_name", "value": "John Doe"},
+            {"key": "dcat_creator_email", "value": "johndoe@example.com"},
             {"key": "language", "value": "en,es,ca"}
     ],
     "resources": [{"id": "b1e0b666-b7f4-44c1-9b16-56c78e86b66a",

examples/ckan/dataset.json

@@ -11,9 +11,15 @@
         "name": "Geological Society",
         "mbox": "info@gs.org"
     },
-    "distribution": [{"accessURL": "http://www.bgs.ac.uk/gbase/geochemcd/home.html",
-                       "byteSize": null,
-                       "description": "Resource locator",
-                       "format": "text/html",
-                       "title": ""}]
+    "creator": {
+        "name": "John Doe",
+        "mbox": "johndoe@example.com"
+    },
+    "distribution": [{
+        "accessURL": "http://www.bgs.ac.uk/gbase/geochemcd/home.html",
+        "byteSize": null,
+        "description": "Resource locator",
+        "format": "text/html",
+        "title": ""
+    }]
 }

examples/ckan/full_ckan_dataset.json

@@ -1,6 +1,6 @@
 {
-    "author": null,
-    "author_email": null,
+    "author": "John Doe",
+    "author_email": "johndoe@example.com",
     "extras": [
         {
             "__extras": {