This document discusses Django middleware, including available hooks, things to know when writing middleware, and an example benchmark middleware. It provides references for further documentation on Django middleware.

1. DJANGO
MIDDLEWARE
Creating a custom
@andreagrandi
Andrea Grandi

2. DJANGO ARCHITECTURE

3. AVAILABLE HOOKS
• process_request(request)
• process_view(
request, view_func, view_args, view_kwargs)
• process_exception(request, response)
• process_template_response(request, response)
• process_response(request, response)
(during a request)
(during a response)

4. THINGS TO KNOW WHEN YOU WRITE A MIDDLEWARE
• You need to write a class that just inherit from object
• The order in settings.py is important: middlewares are processed from top to
bottom during a request and from bottom to top during a response.
• You don’t need to implement all the available methods of a middleware. For
example you can just implement process_request and
process_template_response
• If you implement process_request and you decide to return an HttpResponse,
all the other middlewares, views etc… will be ignored and only your response
will be returned

5. EXAMPLE: BENCHMARKMIDDLEWARE
from datetime import datetime
class BenchmarkMiddleware(object):
def process_request(self, request):
request._request_time = datetime.now()
def process_template_response(self, request, response):
response_time = request._request_time - datetime.now()
response.context_data['response_time'] = abs(response_time)
return response

6. REFERENCES
Complete example:
https://github.com/andreagrandi/benchmark-middleware-example
Documentation:
• https://docs.djangoproject.com/en/1.8/topics/http/middleware/
• http://agiliq.com/blog/2015/07/understanding-django-middlewares/
• http://code.runnable.com/UrSGolK00ygpAAAQ/creating-a-custom-
middleware-for-python-and-django

7. Thanks!