[Django] #34174: async process_exception being called as sync from async view/middleware
Django
-------------------------------------+-------------------------------------
Reporter: Gabriel | Owner: nobody
Rado |
Type: | Status: new
Cleanup/optimization |
Component: | Version: 4.1
Documentation | Keywords: middleware async
Severity: Normal | process_exception
Triage Stage: | Has patch: 0
Unreviewed |
Needs documentation: 0 | Needs tests: 0
Patch needs improvement: 0 | Easy pickings: 0
UI/UX: 0 |
-------------------------------------+-------------------------------------
following this bold part of the
docs[https://docs.djangoproject.com/en/4.1/topics/http/middleware
/#asynchronous-support]:
process_view, process_template_response and process_exception methods, if
they are provided, **should also be adapted to match the sync/async
mode**. However, Django will individually adapt them as required if you do
not, at an additional performance penalty.
I' using this middleware to parse errors from sync and async views:
{{{
@sync_and_async_middleware
def custom_error(get_response):
if asyncio.iscoroutinefunction(get_response):
async def middleware(request):
response = await get_response(request)
return response
async def _process_exception(request, exception):
return my_custom_process_exception(exception)
else:
def middleware(request):
response = get_response(request)
return response
def _process_exception(request, exception):
return my_custom_process_exception(exception)
middleware.process_exception = _process_exception
return middleware
}}}
and I'm getting "ValueError: The view my_view.view_func didn't return an
HttpResponse object. It returned an unawaited coroutine instead. You may
need to add an 'await' into your view." from
here[https://github.com/django/django/blob/main/django/core/handlers/base.py#L257]
i thought that with an async middleware + async view, all my hooks
(process_view, process_template_response and process_exception) should be
also async, but it appears that is mandatory to use sync process_exception
with async capable middlewares. if this is intended, could the official
docs be changed to expose this mandatory behavior?
--
Ticket URL: <https://code.djangoproject.com/ticket/34174>
Django <https://code.djangoproject.com/>
The Web framework for perfectionists with deadlines.
Django
-------------------------------------+-------------------------------------
Type: | Status: new
Cleanup/optimization |
Component: Documentation | Version: 4.1
Severity: Normal | Resolution:
Keywords: middleware async | Triage Stage:
process_exception | Unreviewed
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Old description:
New description:
following this bold part from
[https://docs.djangoproject.com/en/4.1/topics/http/middleware
/#asynchronous-support]:
> process_view, process_template_response and process_exception methods,
if they are provided, **should also be adapted to match the sync/async
mode**. However, Django will individually adapt them as required if you do
not, at an additional performance penalty.
I'm using this middleware to parse errors from sync and async views:
{{{
@sync_and_async_middleware
def custom_error(get_response):
if asyncio.iscoroutinefunction(get_response):
async def middleware(request):
response = await get_response(request)
return response
async def _process_exception(request, exception):
return my_custom_process_exception(exception)
else:
def middleware(request):
response = get_response(request)
return response
def _process_exception(request, exception):
return my_custom_process_exception(exception)
middleware.process_exception = _process_exception
return middleware
}}}
and I'm getting "ValueError: The view my_view.view_func didn't return an
HttpResponse object. It returned an unawaited coroutine instead. You may
need to add an 'await' into your view." from
[https://github.com/django/django/blob/main/django/core/handlers/base.py#L257]
i thought that with an async middleware + async view, all my hooks
(process_view, process_template_response and process_exception) should be
also async, but it appears that is mandatory to use sync process_exception
with async capable middlewares. if this is intended, could the official
docs be changed to expose this mandatory behavior?
--
--
Ticket URL: <https://code.djangoproject.com/ticket/34174#comment:1>
Django
-------------------------------------+-------------------------------------
Reporter: Gabriel Rado | Owner: nobody
Type: | Status: new
Cleanup/optimization |
Component: Documentation | Version: 4.1
Severity: Normal | Resolution:
process_exception |
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* stage: Unreviewed => Accepted
Comment:
Hi Gabriel. OK, seems right, are you happy to suggest a docs adjustment?
(… but if you could add a test to demonstrate what you're seeing
explicitly, that would be good too.) Thanks.
--
Ticket URL: <https://code.djangoproject.com/ticket/34174#comment:2>
Django
-------------------------------------+-------------------------------------
Type: | Rado
Cleanup/optimization | Status: assigned
Component: Documentation | Version: 4.1
Severity: Normal | Resolution:
Keywords: middleware async | Triage Stage: Accepted
process_exception |
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
* owner: nobody => Gabriel Rado
* status: new => assigned
--
Ticket URL: <https://code.djangoproject.com/ticket/34174#comment:3>
Django
-------------------------------------+-------------------------------------
Reporter: Gabriel Rado | Owner: Gabriel
Type: | Rado
Component: Documentation | Version: 4.1
Severity: Normal | Resolution: invalid
Keywords: middleware async | Triage Stage: Accepted
process_exception |
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Changes (by Gabriel Rado):
* status: assigned => closed
* resolution: => invalid
Comment:
i tried to create a test to demonstrate this behavior and every try was
successfull. thinking the problem could be another point of my project and
not django itself, i'll close this ticket
--
Ticket URL: <https://code.djangoproject.com/ticket/34174#comment:4>
Django
-------------------------------------+-------------------------------------
Reporter: Gabriel Rado | Owner: Gabriel
Type: | Rado
Cleanup/optimization | Status: closed
Component: Documentation | Version: 4.1
Severity: Normal | Resolution: invalid
Keywords: middleware async | Triage Stage: Accepted
process_exception |
Has patch: 0 | Needs documentation: 0
Needs tests: 0 | Patch needs improvement: 0
Easy pickings: 0 | UI/UX: 0
-------------------------------------+-------------------------------------
Comment (by Carlton Gibson):
OK, thanks for the follow-up. Do reopen if you're able to reduce it to an
issue in Django.
--
Ticket URL: <https://code.djangoproject.com/ticket/34174#comment:5>