Django's CsrfViewMiddleware fails in conjunction with response generated by middleware - django

Question

My Django application is using a middleware stack containing the CsrfViewMiddleware and an own middleware:
MIDDLEWARE_CLASSES = (
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.middleware.transaction.TransactionMiddleware',
'myapp.OwnMiddleware'
)
The basic idea is that if an URL can't be found, i.e. no view function is being found, this error is caught by OwnMiddleware.process_response() which returns an own response if the HTTP status is 404 (and some other conditions are being met).
This works fine, with a single problem: Because no view function is called when an invalid URL (according to URLconf) is provided, CsrfViewMiddleware.process_view() is never called, and thus no CSRF cookie is generated.
Therefore the whole CSRF system does not work and the CSRF token is still set to "NOTPROVIDED" in OwnMiddleware.process_response (which means that {% csrf_token %} generates an empty string instead of the usual hidden form field).
What is the best way to solve this problem, i.e. have OwnMiddleware catch 404s and return another (non-404) response, while still being able to use the CSRF token in these responses?
Thanks in advance.

Answer 1

You can manually run something like:
CsrfViewMiddleware.process_view(request, lambda: your_response, [], {})
P.S. I think it's better to use handler404 to catch 404's