From 0d109c90a74bc575efa6d497a6501aef2b837983 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sat, 13 Dec 2014 18:18:00 -0400
Subject: [PATCH 1/8] Add context to exception handler #2236

Same context as renderers which include: the view,
args, kwargs, and request.

This provides enough contextual information to the
exception handlers to handle errors better.

In a use case like #1671, a custom handler
would allow Sentry to log the request properly.
---
 rest_framework/views.py | 5 +++--
 tests/test_views.py     | 7 ++++++-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index bc870417f..07e713939 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -46,7 +46,7 @@ def get_view_description(view_cls, html=False):
     return description
 
 
-def exception_handler(exc):
+def exception_handler(exc, context=None):
     """
     Returns the response that should be used for any given exception.
 
@@ -369,7 +369,8 @@ class APIView(View):
             else:
                 exc.status_code = status.HTTP_403_FORBIDDEN
 
-        response = self.settings.EXCEPTION_HANDLER(exc)
+        context = self.get_renderer_context()
+        response = self.settings.EXCEPTION_HANDLER(exc, context)
 
         if response is None:
             raise
diff --git a/tests/test_views.py b/tests/test_views.py
index 77b113ee5..e9b75f065 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -121,7 +121,12 @@ class TestCustomExceptionHandler(TestCase):
     def setUp(self):
         self.DEFAULT_HANDLER = api_settings.EXCEPTION_HANDLER
 
-        def exception_handler(exc):
+        def exception_handler(exc, context=None):
+            self.assertTrue('args' in context)
+            self.assertTrue('kwargs' in context)
+            self.assertTrue('request' in context)
+            self.assertTrue('view' in context)
+
             return Response('Error!', status=status.HTTP_400_BAD_REQUEST)
 
         api_settings.EXCEPTION_HANDLER = exception_handler

From e8c0766568cb20a5357c5e6823283f0c187b35b8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sat, 13 Dec 2014 20:54:35 -0400
Subject: [PATCH 2/8] Support handlers with and without context

---
 rest_framework/views.py | 10 ++++++++--
 tests/test_views.py     | 27 +++++++++++++++++++++------
 2 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index 07e713939..3ece66e68 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -2,6 +2,7 @@
 Provides an APIView class that is the base of all views in REST framework.
 """
 from __future__ import unicode_literals
+import inspect
 
 from django.core.exceptions import PermissionDenied
 from django.http import Http404
@@ -369,8 +370,13 @@ class APIView(View):
             else:
                 exc.status_code = status.HTTP_403_FORBIDDEN
 
-        context = self.get_renderer_context()
-        response = self.settings.EXCEPTION_HANDLER(exc, context)
+        exception_handler = self.settings.EXCEPTION_HANDLER
+
+        if 'context' in inspect.getargspec(exception_handler).args:
+            context = self.get_renderer_context()
+            response = exception_handler(exc, context)
+        else:
+            response = exception_handler(exc)
 
         if response is None:
             raise
diff --git a/tests/test_views.py b/tests/test_views.py
index e9b75f065..9952248fc 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -6,6 +6,7 @@ from django.test import TestCase
 from rest_framework import status
 from rest_framework.decorators import api_view
 from rest_framework.response import Response
+from rest_framework.request import Request
 from rest_framework.settings import api_settings
 from rest_framework.test import APIRequestFactory
 from rest_framework.views import APIView
@@ -121,12 +122,7 @@ class TestCustomExceptionHandler(TestCase):
     def setUp(self):
         self.DEFAULT_HANDLER = api_settings.EXCEPTION_HANDLER
 
-        def exception_handler(exc, context=None):
-            self.assertTrue('args' in context)
-            self.assertTrue('kwargs' in context)
-            self.assertTrue('request' in context)
-            self.assertTrue('view' in context)
-
+        def exception_handler(exc):
             return Response('Error!', status=status.HTTP_400_BAD_REQUEST)
 
         api_settings.EXCEPTION_HANDLER = exception_handler
@@ -151,3 +147,22 @@ class TestCustomExceptionHandler(TestCase):
         expected = 'Error!'
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
         self.assertEqual(response.data, expected)
+
+    def test_context_exception_handler(self):
+        def exception_handler(exc, context=None):
+            self.assertEqual(context['args'], ())
+            self.assertEqual(context['kwargs'], {})
+            self.assertTrue(isinstance(context['request'], Request))
+            self.assertTrue(isinstance(context['view'], ErrorView))
+
+            return Response('Error!', status=status.HTTP_400_BAD_REQUEST)
+
+        api_settings.EXCEPTION_HANDLER = exception_handler
+
+        view = ErrorView.as_view()
+
+        request = factory.get('/', content_type='application/json')
+        response = view(request)
+        expected = 'Error!'
+        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
+        self.assertEqual(response.data, expected)

From 3f85b476fa2ddb8a205c03cea6684fca257dbd02 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sun, 14 Dec 2014 10:15:13 -0400
Subject: [PATCH 3/8] Remove test

---
 tests/test_views.py | 20 --------------------
 1 file changed, 20 deletions(-)

diff --git a/tests/test_views.py b/tests/test_views.py
index 9952248fc..77b113ee5 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -6,7 +6,6 @@ from django.test import TestCase
 from rest_framework import status
 from rest_framework.decorators import api_view
 from rest_framework.response import Response
-from rest_framework.request import Request
 from rest_framework.settings import api_settings
 from rest_framework.test import APIRequestFactory
 from rest_framework.views import APIView
@@ -147,22 +146,3 @@ class TestCustomExceptionHandler(TestCase):
         expected = 'Error!'
         self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
         self.assertEqual(response.data, expected)
-
-    def test_context_exception_handler(self):
-        def exception_handler(exc, context=None):
-            self.assertEqual(context['args'], ())
-            self.assertEqual(context['kwargs'], {})
-            self.assertTrue(isinstance(context['request'], Request))
-            self.assertTrue(isinstance(context['view'], ErrorView))
-
-            return Response('Error!', status=status.HTTP_400_BAD_REQUEST)
-
-        api_settings.EXCEPTION_HANDLER = exception_handler
-
-        view = ErrorView.as_view()
-
-        request = factory.get('/', content_type='application/json')
-        response = view(request)
-        expected = 'Error!'
-        self.assertEqual(response.status_code, status.HTTP_400_BAD_REQUEST)
-        self.assertEqual(response.data, expected)

From 478c8d724b846b370c897548f8ee89f1128e12c9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sun, 14 Dec 2014 10:16:52 -0400
Subject: [PATCH 4/8] Update docs

---
 docs/api-guide/exceptions.md | 4 ++--
 docs/api-guide/settings.md   | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/docs/api-guide/exceptions.md b/docs/api-guide/exceptions.md
index 467ad9709..31a8431bc 100644
--- a/docs/api-guide/exceptions.md
+++ b/docs/api-guide/exceptions.md
@@ -51,10 +51,10 @@ In order to alter the style of the response, you could write the following custo
 
     from rest_framework.views import exception_handler
 
-    def custom_exception_handler(exc):
+    def custom_exception_handler(exc, context):
         # Call REST framework's default exception handler first,
         # to get the standard error response.
-        response = exception_handler(exc)
+        response = exception_handler(exc, context)
 
         # Now add the HTTP status code to the response.
         if response is not None:
diff --git a/docs/api-guide/settings.md b/docs/api-guide/settings.md
index 9005511b7..2c4f84237 100644
--- a/docs/api-guide/settings.md
+++ b/docs/api-guide/settings.md
@@ -393,7 +393,7 @@ This setting can be changed to support error responses other than the default `{
 
 This should be a function with the following signature:
 
-    exception_handler(exc)
+    exception_handler(exc, context)
 
 * `exc`: The exception.
 

From fd003fcefaee964e744ded0aec1ae76715889378 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sun, 14 Dec 2014 15:03:20 -0400
Subject: [PATCH 5/8] Add pending deprecation warning message

---
 rest_framework/views.py | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index 3ece66e68..37889d1b4 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -3,6 +3,7 @@ Provides an APIView class that is the base of all views in REST framework.
 """
 from __future__ import unicode_literals
 import inspect
+import warnings
 
 from django.core.exceptions import PermissionDenied
 from django.http import Http404
@@ -370,13 +371,16 @@ class APIView(View):
             else:
                 exc.status_code = status.HTTP_403_FORBIDDEN
 
-        exception_handler = self.settings.EXCEPTION_HANDLER
-
-        if 'context' in inspect.getargspec(exception_handler).args:
-            context = self.get_renderer_context()
-            response = exception_handler(exc, context)
+        if len(inspect.getargspec(self.settings.EXCEPTION_HANDLER).args) == 1:
+            warnings.warn(
+                'The `exception_handler(exc)` call signature is deprecated. '
+                'Use `exception_handler(exc, context) instead.',
+                PendingDeprecationWarning
+            )
+            response = self.settings.EXCEPTION_HANDLER(exc)
         else:
-            response = exception_handler(exc)
+            context = self.get_renderer_context()
+            response = self.settings.EXCEPTION_HANDLER(exc, context)
 
         if response is None:
             raise

From 89e9fc98d6e7407e6f7715fa2680df7c94221105 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sun, 14 Dec 2014 15:20:44 -0400
Subject: [PATCH 6/8] Reuse exception_handler variable throughout

---
 rest_framework/views.py | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index 37889d1b4..c2e19bf42 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -371,16 +371,18 @@ class APIView(View):
             else:
                 exc.status_code = status.HTTP_403_FORBIDDEN
 
-        if len(inspect.getargspec(self.settings.EXCEPTION_HANDLER).args) == 1:
+        exception_handler = self.settings.EXCEPTION_HANDLER
+
+        if len(inspect.getargspec(exception_handler).args) == 1:
             warnings.warn(
                 'The `exception_handler(exc)` call signature is deprecated. '
                 'Use `exception_handler(exc, context) instead.',
                 PendingDeprecationWarning
             )
-            response = self.settings.EXCEPTION_HANDLER(exc)
+            response = exception_handler(exc)
         else:
             context = self.get_renderer_context()
-            response = self.settings.EXCEPTION_HANDLER(exc, context)
+            response = exception_handler(exc, context)
 
         if response is None:
             raise

From 26c223a34f7e0cc21d37c6302e53d547dae252dd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sun, 14 Dec 2014 16:43:58 -0400
Subject: [PATCH 7/8] Add get_exception_handler_context()

---
 rest_framework/views.py | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index c2e19bf42..80a13a1a9 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -186,6 +186,18 @@ class APIView(View):
             'request': getattr(self, 'request', None)
         }
 
+    def get_exception_handler_context(self):
+        """
+        Returns a dict that is passed through to EXCEPTION_HANDLER,
+        as the `context` argument.
+        """
+        return {
+            'view': self,
+            'args': getattr(self, 'args', ()),
+            'kwargs': getattr(self, 'kwargs', {}),
+            'request': getattr(self, 'request', None)
+        }
+
     def get_view_name(self):
         """
         Return the view name, as used in OPTIONS responses and in the
@@ -381,7 +393,7 @@ class APIView(View):
             )
             response = exception_handler(exc)
         else:
-            context = self.get_renderer_context()
+            context = self.get_exception_handler_context()
             response = exception_handler(exc, context)
 
         if response is None:

From 4ebd8770b94ecb8fe8fb41fe8daa4309b33b9952 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Padilla?= <jpadilla@webapplicate.com>
Date: Sun, 14 Dec 2014 20:47:33 -0400
Subject: [PATCH 8/8] Update excepteion_handler signature

---
 rest_framework/views.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index 80a13a1a9..b39724c2f 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -48,7 +48,7 @@ def get_view_description(view_cls, html=False):
     return description
 
 
-def exception_handler(exc, context=None):
+def exception_handler(exc, context):
     """
     Returns the response that should be used for any given exception.