2 files changed, 8 insertions, 4 deletions
diff --git a/web-server/opendc/models/model.py b/web-server/opendc/models/model.py
index 2b8eb4dc..1935638f 100644
--- a/web-server/opendc/models/model.py
+++ b/web-server/opendc/models/model.py
@@ -21,6 +21,10 @@ class Model:
     def __init__(self, obj):
         self.obj = obj
 
+    def get_id(self):
+        """Returns the ID of the enclosed object."""
+        return self.obj['_id']
+
     def check_exists(self):
         """Raises an error if the enclosed object does not exist."""
         if self.obj is None:
@@ -36,8 +40,8 @@ class Model:
 
     def update(self):
         """Updates the enclosed object and updates the internal reference to the newly inserted object."""
-        self.obj = DB.update(self.obj['_id'], self.obj, self.collection_name)
+        self.obj = DB.update(self.get_id(), self.obj, self.collection_name)
 
     def delete(self):
         """Deletes the enclosed object in the database."""
-        DB.delete_one({'_id': self.obj['_id']}, self.collection_name)
+        DB.delete_one({'_id': self.get_id()}, self.collection_name)
diff --git a/web-server/opendc/models/simulation.py b/web-server/opendc/models/simulation.py
index bf19368c..dbe1e800 100644
--- a/web-server/opendc/models/simulation.py
+++ b/web-server/opendc/models/simulation.py
@@ -18,7 +18,7 @@ class Simulation(Model):
         """
         user = User.from_google_id(google_id)
         authorizations = list(
-            filter(lambda x: str(x['simulationId']) == str(self.obj['_id']), user.obj['authorizations']))
+            filter(lambda x: str(x['simulationId']) == str(self.get_id()), user.obj['authorizations']))
         if len(authorizations) == 0 or (edit_access and authorizations[0]['authorizationLevel'] == 'VIEW'):
             raise ClientError(Response(403, "Forbidden from retrieving simulation."))
 
@@ -26,6 +26,6 @@ class Simulation(Model):
         """Get all user IDs having access to this simulation."""
         return [
             user['_id'] for user in DB.fetch_all({'authorizations': {
-                'simulationId': self.obj['_id']
+                'simulationId': self.get_id()
             }}, User.collection_name)
         ]