From d662ef554015a3508ff8100c73b370728156a02c Mon Sep 17 00:00:00 2001
From: Malcolm Tredinnick <malcolm.tredinnick@gmail.com>
Date: Mon, 8 Dec 2008 08:15:37 +0000
Subject: [PATCH] The first step in fixing a group of problems related to
 outputting a proper "value" for a field that is a relation to another model.

This part adds the utility method on Model that should help in general.Also
cleans up the slightly ugly mess from r8957.


git-svn-id: http://code.djangoproject.com/svn/django/trunk@9601 bcc190cf-cafb-0310-a4f2-bffc1f526a37
---
 django/db/models/base.py    | 10 ++++++++++
 django/db/models/options.py |  1 +
 django/forms/models.py      |  8 +-------
 3 files changed, 12 insertions(+), 7 deletions(-)

diff --git a/django/db/models/base.py b/django/db/models/base.py
index bf6588d7fe..a561b80979 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -296,6 +296,16 @@ class Model(object):
 
     pk = property(_get_pk_val, _set_pk_val)
 
+    def serializable_value(self, field_name):
+        """
+        Returns the value of the field name for this instance. If the field
+        is a foreign key, returns the id value, instead of the object.
+        Used to serialize a field's value (in the serializer, or form output,
+        for example).
+        """
+        field = self._meta.get_field_by_name(field_name)[0]
+        return getattr(self, field.attname)
+
     def save(self, force_insert=False, force_update=False):
         """
         Saves the current instance. Override this in a subclass if you want to
diff --git a/django/db/models/options.py b/django/db/models/options.py
index 6e0d6b5082..5d8a7b7104 100644
--- a/django/db/models/options.py
+++ b/django/db/models/options.py
@@ -448,3 +448,4 @@ class Options(object):
             #        objects.append(opts)
             self._ordered_objects = objects
         return self._ordered_objects
+
diff --git a/django/forms/models.py b/django/forms/models.py
index 65f20ad303..81a7439331 100644
--- a/django/forms/models.py
+++ b/django/forms/models.py
@@ -624,13 +624,7 @@ class ModelChoiceIterator(object):
 
     def choice(self, obj):
         if self.field.to_field_name:
-            # FIXME: The try..except shouldn't be necessary here. But this is
-            # going in just before 1.0, so I want to be careful. Will check it
-            # out later.
-            try:
-                key = getattr(obj, self.field.to_field_name).pk
-            except AttributeError:
-                key = getattr(obj, self.field.to_field_name)
+            key = obj.serializable_value(self.field.to_field_name)
         else:
             key = obj.pk
         return (key, self.field.label_from_instance(obj))