Fixed #15889 -- when trying to access to access a serializer that doe…

…sn't exist, raise a new SerializerDoesNotExist exception. Thanks to Mathieu Agopian for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16104 bcc190cf-cafb-0310-a4f2-bffc1f526a37

AUTHORS

@@ -35,6 +35,7 @@ answer newbie questions, and generally made Django that much better:
 
     Gisle Aas <gisle@aas.no>
     Chris Adams
+    Mathieu Agopian <mathieu.agopian@gmail.com>
     ajs <adi@sieker.info>
     alang@bright-green.com
     A S Alam <aalam@users.sf.net>

django/core/serializers/__init__.py

@@ -18,6 +18,7 @@
 
 from django.conf import settings
 from django.utils import importlib
+from django.core.serializers.base import SerializerDoesNotExist
 
 # Built-in serializers
 BUILTIN_SERIALIZERS = {
@@ -60,11 +61,15 @@ def unregister_serializer(format):
     "Unregister a given serializer. This is not a thread-safe operation."
     if not _serializers:
         _load_serializers()
+    if format not in _serializers:
+        raise SerializerDoesNotExist(format)
     del _serializers[format]
 
 def get_serializer(format):
     if not _serializers:
         _load_serializers()
+    if format not in _serializers:
+        raise SerializerDoesNotExist(format)
     return _serializers[format].Serializer
 
 def get_serializer_formats():
@@ -80,6 +85,8 @@ def get_public_serializer_formats():
 def get_deserializer(format):
     if not _serializers:
         _load_serializers()
+    if format not in _serializers:
+        raise SerializerDoesNotExist(format)
     return _serializers[format].Deserializer
 
 def serialize(format, queryset, **options):

django/core/serializers/base.py

@@ -8,6 +8,10 @@
 from django.utils.encoding import smart_str, smart_unicode
 from django.utils import datetime_safe
 
+class SerializerDoesNotExist(KeyError):
+    """The requested serializer was not found."""
+    pass
+
 class SerializationError(Exception):
     """Something bad happened during serialization."""
     pass

docs/topics/serialization.txt

@@ -38,6 +38,12 @@ This is useful if you want to serialize data directly to a file-like object
     out = open("file.xml", "w")
     xml_serializer.serialize(SomeModel.objects.all(), stream=out)
 
+.. note::
+
+    Calling :func:`~django.core.serializers.get_serializer` with an unknown
+    :ref:`format <serialization-formats>` will raise a
+    :class:`~django.core.serializers.SerializerDoesNotExist` exception.
+
 Subset of fields
 ~~~~~~~~~~~~~~~~
 

tests/regressiontests/serializers_regress/tests.py

@@ -6,7 +6,7 @@
 the serializers. This includes all valid data values, plus
 forward, backwards and self references.
 """
-
+from __future__ import with_statement
 
 import datetime
 import decimal
@@ -17,6 +17,7 @@
 
 from django.conf import settings
 from django.core import serializers, management
+from django.core.serializers import SerializerDoesNotExist
 from django.db import transaction, DEFAULT_DB_ALIAS, connection
 from django.test import TestCase
 from django.utils.functional import curry
@@ -350,7 +351,28 @@ def inherited_compare(testcase, pk, klass, data):
 # Dynamically create serializer tests to ensure that all
 # registered serializers are automatically tested.
 class SerializerTests(TestCase):
-    pass
+    def test_get_unknown_serializer(self):
+        """
+        #15889: get_serializer('nonsense') raises a SerializerDoesNotExist
+        """
+        with self.assertRaises(SerializerDoesNotExist):
+            serializers.get_serializer("nonsense")
+
+        with self.assertRaises(KeyError):
+            serializers.get_serializer("nonsense")
+
+        # SerializerDoesNotExist is instantiated with the nonexistent format
+        with self.assertRaises(SerializerDoesNotExist) as cm:
+            serializers.get_serializer("nonsense")
+        self.assertEqual(cm.exception.args, ("nonsense",))
+
+    def test_unregister_unkown_serializer(self):
+        with self.assertRaises(SerializerDoesNotExist):
+            serializers.unregister_serializer("nonsense")
+
+    def test_get_unkown_deserializer(self):
+        with self.assertRaises(SerializerDoesNotExist):
+            serializers.get_deserializer("nonsense")
 
 def serializerTest(format, self):