Map Aardvark.dct_spatial_sm to Locations@kind="Place Name" (#146)

* Map Aardvark.dct_spatial_sm to Locations@kind="Place Name"

Why these changes are being introduced:
* Support place names for location-based searching

How this addresses that need:
* Add global Transformer method to create Location objects from spatial subjects

Side effects of this change:
* None

Relevant ticket(s):
* https://mitlibraries.atlassian.net/browse/GDT-217

tests/sources/test_transformer.py

@@ -46,6 +46,30 @@ def test_create_dates_and_locations_from_publishers_success():
     }
 
 
+def test_create_locations_from_spatial_subjects():
+    fields = {
+        "subjects": [
+            timdex.Subject(
+                value=["Some city, Some country"], kind="Dublin Core; Spatial"
+            ),
+            timdex.Subject(value=["City 1", "City 2"], kind="Dublin Core; Spatial"),
+        ]
+    }
+    assert Transformer.create_locations_from_spatial_subjects(fields) == {
+        "subjects": [
+            timdex.Subject(
+                value=["Some city, Some country"], kind="Dublin Core; Spatial"
+            ),
+            timdex.Subject(value=["City 1", "City 2"], kind="Dublin Core; Spatial"),
+        ],
+        "locations": [
+            timdex.Location(value="Some city, Some country", kind="Place Name"),
+            timdex.Location(value="City 1", kind="Place Name"),
+            timdex.Location(value="City 2", kind="Place Name"),
+        ],
+    }
+
+
 def test_xmltransformer_initializes_with_expected_attributes(oai_pmh_records):
     transformer = XMLTransformer("cool-repo", oai_pmh_records)
     assert transformer.source == "cool-repo"

transmogrifier/sources/transformer.py

@@ -253,6 +253,7 @@ def _transform(
         }
 
         fields = self.create_dates_and_locations_from_publishers(fields)
+        fields = self.create_locations_from_spatial_subjects(fields)
 
         # If citation field was not present, generate citation from other fields
         if fields.get("citation") is None:
@@ -392,3 +393,27 @@ def create_dates_and_locations_from_publishers(fields: dict) -> dict:
                 if publisher_location not in fields.setdefault("locations", []):
                     fields["locations"].append(publisher_location)
         return fields
+
+    @final
+    @staticmethod
+    def create_locations_from_spatial_subjects(fields: dict) -> dict:
+        """Add Location objects for spatial subjects.
+
+        Args:
+           fields: A dict of fields representing a TIMDEX record.
+        """
+        if fields.get("subjects") is None:
+            return fields
+
+        spatial_subjects = [
+            subject
+            for subject in fields.get("subjects", [])  # defaults to empty list
+            if subject.kind == "Dublin Core; Spatial" and subject.value is not None
+        ]
+
+        for subject in spatial_subjects:
+            for place_name in subject.value:
+                subject_location = timdex.Location(value=place_name, kind="Place Name")
+                if subject_location not in fields.setdefault("locations", []):
+                    fields["locations"].append(subject_location)
+        return fields