Ticket #11882: 11882.diff

docs/ref/contrib/admin/index.txt

@@ -818 +818 @@
             return super(MyModelAdmin, self).formfield_for_foreignkey(db_field, request, **kwargs)
 
 This uses the ``HttpRequest`` instance to filter the ``Car`` foreign key field
-to only the cars owned by the ``User`` instance.
+to only display the cars owned by the ``User`` instance.
 
+.. method:: ModelAdmin.formfield_for_manytomany(self, db_field, request, **kwargs)
+
+.. versionadded:: 1.1
+
+Like the ``formfield_for_foreignkey`` method, the ``formfield_for_manytomany`` 
+method can be overridden to change the default formfield for a many to many
+field. For example, if an owner can own multiple cars and cars can belong
+to multiple owners -- a many to many relationship -- you could filter the 
+``Car`` foreign key field to only display the cars owned by the ``User``::
+
+    class MyModelAdmin(admin.ModelAdmin):
+        def formfield_for_manytomany(self, db_field, request, **kwargs):
+            if db_field.name == "cars":
+                kwargs["queryset"] = Car.objects.filter(owner=request.user)
+                return db_field.formfield(**kwargs)
+            return super(MyModelAdmin, self).formfield_for_manytomany(db_field, request, **kwargs)
+
 Other methods
 ~~~~~~~~~~~~~