Merge pull request kobotoolbox#974 from kobotoolbox/multiple-objects-…

…returned-error

Fixes "AssetSnapshot.MultipleObjectsReturned" error.

kpi/models/asset.py

@@ -141,9 +141,23 @@ def _populate_fields_with_autofields(self, content):
     def _expand_kobo_qs(self, content):
         expand_rank_and_score_in_place(content)
 
+    def _ensure_settings(self, content):
+        # asset.settings should exist already, but
+        # on some legacy forms it might not
+        _settings = content.get('settings', {})
+        if isinstance(_settings, list):
+            if len(_settings) > 0:
+                _settings = _settings[0]
+            else:
+                _settings = {}
+        if not isinstance(_settings, dict):
+            _settings = {}
+        content['settings'] = _settings
+
     def _append(self, content, **sheet_data):
         settings = sheet_data.pop('settings', None)
         if settings:
+            self._ensure_settings(content)
             content['settings'].update(settings)
         for (sht, rows) in sheet_data.items():
             if sht in content:
@@ -503,6 +517,7 @@ def version_id(self):
     def snapshot(self):
         return self._snapshot(regenerate=False)
 
+    @transaction.atomic
     def _snapshot(self, regenerate=True):
         asset_version = self.asset_versions.first()
 
@@ -517,6 +532,12 @@ def _snapshot(self, regenerate=True):
             if regenerate:
                 snapshot.delete()
                 snapshot = False
+        except AssetSnapshot.MultipleObjectsReturned:
+            # how did multiple snapshots get here?
+            snaps = AssetSnapshot.objects.filter(asset=self,
+                                                 asset_version=asset_version)
+            snaps.delete()
+            snapshot = False
         except AssetSnapshot.DoesNotExist:
             snapshot = False
 

kpi/serializers.py

@@ -327,12 +327,9 @@ def create(self, validated_data):
             if not self.context['request'].user.has_perm('view_asset', asset):
                 # The client is not allowed to snapshot this asset
                 raise exceptions.PermissionDenied
-            asset_version = asset.asset_versions.first()
-            try:
-                snapshot = AssetSnapshot.objects.get(asset=asset,
-                                                     asset_version=asset_version)
-            except AssetSnapshot.DoesNotExist as e:
-                snapshot = AssetSnapshot.objects.create(**validated_data)
+            # asset.snapshot pulls , by default, a snapshot for the latest
+            # version.
+            snapshot = asset.snapshot
         elif source:
             # The client provided source directly; no need to copy anything
             # For tidiness, pop off unused fields. `None` avoids KeyError