Implement customizable exception handler

rest_framework/handlers.py

@@ -0,0 +1,43 @@
+"""Default handlers, configurable in settings"""
+
+from rest_framework.response import Response
+from rest_framework import exceptions
+from rest_framework import status
+from django.core.exceptions import PermissionDenied
+from django.http import Http404
+
+
+def handle_exception(view_instance, exc):
+    """
+    Default exception handler for APIView.
+
+    Handle any exception that occurs, by returning an appropriate response,
+    or re-raising the error.
+    """
+    if isinstance(exc, exceptions.Throttled):
+        # Throttle wait header
+        view_instance.headers['X-Throttle-Wait-Seconds'] = '%d' % exc.wait
+
+    if isinstance(exc, (exceptions.NotAuthenticated,
+                        exceptions.AuthenticationFailed)):
+        # WWW-Authenticate header for 401 responses, else coerce to 403
+        auth_header = view_instance.get_authenticate_header(
+            view_instance.request)
+
+        if auth_header:
+            view_instance.headers['WWW-Authenticate'] = auth_header
+        else:
+            exc.status_code = status.HTTP_403_FORBIDDEN
+
+    if isinstance(exc, exceptions.APIException):
+        return Response(exc.data, status=exc.status_code,
+                        exception=True)
+    elif isinstance(exc, Http404):
+        return Response({'detail': 'Not found'},
+                        status=status.HTTP_404_NOT_FOUND,
+                        exception=True)
+    elif isinstance(exc, PermissionDenied):
+        return Response({'detail': 'Permission denied'},
+                        status=status.HTTP_403_FORBIDDEN,
+                        exception=True)
+    raise

rest_framework/settings.py

@@ -59,6 +59,9 @@ DEFAULTS = {
         'rest_framework.pagination.PaginationSerializer',
     'DEFAULT_FILTER_BACKENDS': (),
 
+    # Exception handling
+    'DEFAULT_EXCEPTION_HANDLER': 'rest_framework.handlers.handle_exception',
+
     # Throttling
     'DEFAULT_THROTTLE_RATES': {
         'user': None,
@@ -117,6 +120,7 @@ IMPORT_STRINGS = (
     'FILTER_BACKEND',
     'UNAUTHENTICATED_USER',
     'UNAUTHENTICATED_TOKEN',
+    'DEFAULT_EXCEPTION_HANDLER',
 )
 
 

rest_framework/tests/test_generics.py

@@ -343,7 +343,7 @@ class TestInstanceView(TestCase):
         self.assertIn('text', response.data)
         self.assertEqual(
             response.data['text'],
-            [u'Ensure this value has at most 100 characters (it has 120).'])
+            ['Ensure this value has at most 100 characters (it has 120).'])
 
     def test_put_to_deleted_instance(self):
         """

rest_framework/views.py

@@ -5,8 +5,7 @@ from __future__ import unicode_literals
 
 import warnings
 
-from django.core.exceptions import PermissionDenied
-from django.http import Http404, HttpResponse
+from django.http import HttpResponse
 from django.utils.datastructures import SortedDict
 from django.views.decorators.csrf import csrf_exempt
 from rest_framework import status, exceptions
@@ -26,6 +25,7 @@ class APIView(View):
     throttle_classes = api_settings.DEFAULT_THROTTLE_CLASSES
     permission_classes = api_settings.DEFAULT_PERMISSION_CLASSES
     content_negotiation_class = api_settings.DEFAULT_CONTENT_NEGOTIATION_CLASS
+    handle_exception = api_settings.DEFAULT_EXCEPTION_HANDLER
 
     @classmethod
     def as_view(cls, **initkwargs):
@@ -265,38 +265,6 @@ class APIView(View):
 
         return response
 
-    def handle_exception(self, exc):
-        """
-        Handle any exception that occurs, by returning an appropriate response,
-        or re-raising the error.
-        """
-        if isinstance(exc, exceptions.Throttled):
-            # Throttle wait header
-            self.headers['X-Throttle-Wait-Seconds'] = '%d' % exc.wait
-
-        if isinstance(exc, (exceptions.NotAuthenticated,
-                            exceptions.AuthenticationFailed)):
-            # WWW-Authenticate header for 401 responses, else coerce to 403
-            auth_header = self.get_authenticate_header(self.request)
-
-            if auth_header:
-                self.headers['WWW-Authenticate'] = auth_header
-            else:
-                exc.status_code = status.HTTP_403_FORBIDDEN
-
-        if isinstance(exc, exceptions.APIException):
-            return Response(exc.data, status=exc.status_code,
-                            exception=True)
-        elif isinstance(exc, Http404):
-            return Response({'detail': 'Not found'},
-                            status=status.HTTP_404_NOT_FOUND,
-                            exception=True)
-        elif isinstance(exc, PermissionDenied):
-            return Response({'detail': 'Permission denied'},
-                            status=status.HTTP_403_FORBIDDEN,
-                            exception=True)
-        raise
-
     # Note: session based authentication is explicitly CSRF validated,
     # all other authentication is CSRF exempt.
     @csrf_exempt