Add "query-path" API endpoint

Merges #34
Closes #31

Rename querypair endpoint to `query-metapaths`

Update continuous deployment conda env update
Refs #35

Author: dhimmel

.circleci/deploy.sh

@@ -10,7 +10,8 @@ git pull
 
 # Update conda env if needed
 if [ -n "$ENV_DIFF" ]; then
-    conda update --file $ENV_FILE
+    source ~/miniconda/etc/profile.d/conda.sh
+    conda env update --file $ENV_FILE
 fi
 
 # Restart Gunicorn daemon

dj_hetmech/urls.py

@@ -23,5 +23,6 @@
 urlpatterns = [
     path('v1/', views.api_root),
     path('v1/', include(router.urls)),
-    path('v1/querypair/', views.QueryPairView.as_view(), name="query-pair"),
+    path('v1/query-metapaths/', views.QueryMetapathsView.as_view(), name="query-metapaths"),
+    path('v1/query-paths/', views.QueryPathsView.as_view(), name="query-paths"),
 ]

dj_hetmech_app/models.py

@@ -41,6 +41,10 @@ class Meta:
         # https://stackoverflow.com/a/42676612/4651668
         unique_together = ('metanode', 'identifier')
 
+    def get_cast_identifier(self):
+        import builtins
+        caster = getattr(builtins, self.identifier_type)
+        return caster(self.identifier)
 
 class Metapath(models.Model):
     abbreviation = models.CharField(primary_key=True, max_length=20)

dj_hetmech_app/views.py

@@ -14,7 +14,8 @@
 def api_root(request):
     return Response({
         'nodes': reverse('node-list', request=request),
-        'querypair': reverse('query-pair',  request=request),
+        'query-metapaths': reverse('query-metapaths',  request=request),
+        'query-paths': reverse('query-paths',  request=request),
     })
 
 
@@ -42,7 +43,7 @@ def get_queryset(self):
         return queryset
 
 
-class QueryPairView(APIView):
+class QueryMetapathsView(APIView):
     http_method_names = ['get']
 
     def polish_pathcounts(self, source_id, target_id, pathcounts_data):
@@ -130,3 +131,61 @@ def get(self, request):
         )
 
         return Response(data)
+
+
+class QueryPathsView(APIView):
+    http_method_names = ['get']
+
+    def get(self, request):
+        # Validate "source" parameter
+        source_id = request.query_params.get('source', None)
+        if source_id is None:
+            return Response(
+                {'error': 'source parameter not found in URL'},
+                status=status.HTTP_400_BAD_REQUEST
+            )
+        try:
+            source_node = Node.objects.get(pk=source_id)
+        except:
+            return Response(
+                {'error': 'source node not found in database'},
+                status=status.HTTP_404_NOT_FOUND
+            )
+        source_identifier = source_node.get_cast_identifier()
+
+        # Validate "target" parameter
+        target_id = request.query_params.get('target', None)
+        if target_id is None:
+            return Response(
+                {'error': 'target parameter not found in URL'},
+                status=status.HTTP_400_BAD_REQUEST
+            )
+        try:
+            target_node = Node.objects.get(pk=target_id)
+        except:
+            return Response(
+                {'error': 'target node not found in database'},
+                status=status.HTTP_404_NOT_FOUND
+            )
+        target_identifier = target_node.get_cast_identifier()
+
+        # Validate "metapath"
+        metapath = request.query_params.get('metapath', None)
+        if metapath is None:
+            return Response(
+                {'error': 'metapth parameter not found in URL'},
+                status=status.HTTP_400_BAD_REQUEST
+            )
+
+        # TODO: test metapath is a valid metapath abbreviation
+
+        max_paths = request.query_params.get('max-paths', '100')
+        max_paths = int(max_paths)
+        if max_paths < 0:
+            max_paths = None
+
+        from .utils.paths import get_paths
+        from .utils import get_hetionet_metagraph
+        metagraph = get_hetionet_metagraph()
+        output = get_paths(metagraph, metapath, source_identifier, target_identifier, limit=max_paths)
+        return Response(output)