Added filter backend config to api views.

This fixes the aggregationlayer filter option on the api.

Author: yellowcap

raster_aggregation/views.py

@@ -20,6 +20,7 @@ class AggregationAreaViewSet(viewsets.ReadOnlyModelViewSet):
     Regular aggregation Area model view endpoint.
     """
     serializer_class = AggregationAreaSimplifiedSerializer
+    filter_backends = (filters.DjangoFilterBackend, )
     filter_fields = ('aggregationlayer', )
 
     def get_queryset(self):
@@ -61,6 +62,7 @@ class AggregationAreaValueViewSet(viewsets.ReadOnlyModelViewSet):
     Regular aggregation Area model view endpoint.
     """
     serializer_class = AggregationAreaValueSerializer
+    filter_backends = (filters.DjangoFilterBackend, )
     filter_fields = ('aggregationlayer', )
 
     def initial(self, request, *args, **kwargs):

tests/test_aggregation_api.py

@@ -144,6 +144,25 @@ def test_value_count_for_raster_with_missing_tile(self):
         # Assert all data values are empty
         self.assertEqual(result, [{}, {}])
 
+    def test_filter_by_layer(self):
+        url = reverse('aggregationareavalue-list')
+
+        # Setup request with fromula that will multiply the rasterlayer by itself
+        response = self.client.get(url + '?layers=a={0}&formula=a&zoom=4&aggregationlayer={1}'.format(
+            self.rasterlayer.id,
+            self.agglayer.id,
+        ))
+
+        count = len(json.loads(response.content.strip().decode()))
+        self.assertEqual(count, self.agglayer.aggregationarea_set.count())
+
+        response = self.client.get(url + '?layers=a={0}&formula=a&zoom=4&aggregationlayer={1}'.format(
+            self.rasterlayer.id,
+            1234,  # Not existing agglayer id.
+        ))
+        count = len(json.loads(response.content.strip().decode()))
+        self.assertEqual(0, count)
+
     def test_aggregation_null_values(self):
         response = self.client.get(
             self.url + '?layers=a={0}&formula=99*(a==NULL)%2B2*(~a==2)'.format(self.rasterlayer.id)