TMSS-261: action/url to retreive all subtasks for a scheduling unit

SAS/TMSS/backend/src/tmss/tmssapp/viewsets/specification.py

@@ -730,6 +730,18 @@ class SchedulingUnitBlueprintViewSet(LOFARViewSet):
         # result is list of dict so thats why
         return JsonResponse(result, safe=False)
 
+    @swagger_auto_schema(responses={200: "All Subtasks in this SchedulingUnitBlueprint",
+                                    403: 'forbidden'},
+                         operation_description="Get all subtasks for this scheduling_unit")
+    @action(methods=['get'], detail=True, url_name="subtasks", name="all subtasks in this scheduling_unit")
+    def subtasks(self, request, pk=None):
+        subtasks = models.Subtask.objects.all().filter(task_blueprint__scheduling_unit_blueprint_id=pk). \
+                                                select_related('state', 'specifications_template', 'specifications_template__type', 'cluster', 'created_or_updated_by_user').all()
+
+        # return a response with the new serialized scheduling_unit_blueprint (with references to the created task_blueprint(s) and (scheduled) subtasks)
+        return Response(serializers.SubtaskSerializer(subtasks, many=True, context={'request':request}).data,
+                        status=status.HTTP_200_OK)
+
 
 class SchedulingUnitBlueprintExtendedViewSet(SchedulingUnitBlueprintViewSet):
     serializer_class = serializers.SchedulingUnitBlueprintExtendedSerializer