Ticket #13930: pk_natural_key.diff

django/core/serializers/python.py

@@ -27 +27 @@
         self._current = {}
 
     def end_object(self, obj):
+        if self.use_natural_keys and hasattr(obj, 'natural_key'):
+            pk = obj.natural_key()
+        else:
+            pk = smart_unicode(obj._get_pk_val(), strings_only=True)
+        
         self.objects.append({
             "model"  : smart_unicode(obj._meta),
-            "pk"     : smart_unicode(obj._get_pk_val(), strings_only=True),
+            "pk"     : pk,
             "fields" : self._current
         })
         self._current = None
@@ -82 +87 @@
     for d in object_list:
         # Look up the model and starting build a dict of data for it.
         Model = _get_model(d["model"])
-        data = {Model._meta.pk.attname : Model._meta.pk.to_python(d["pk"])}
+
+        # Handle PK
+        if hasattr(Model._default_manager, 'get_by_natural_key') and hasattr(d["pk"], '__iter__'):
+            try:
+                # If there is an instance for this natural key in the database, use its existing pk
+                obj = Model._default_manager.db_manager(db).get_by_natural_key(*d["pk"])
+                data = {Model._meta.pk.attname : obj.pk}
+            except Model.DoesNotExist:
+                # If there is not, assume that the pk will be generated automatically
+                data = {}
+        else:
+            data = {Model._meta.pk.attname : Model._meta.pk.to_python(d["pk"])}
+            
         m2m_data = {}
 
         # Handle each field