In Django, middleware is a component that sits between the web server and the view that handles a request. It can modify or enhance the request, response or view behavior.
Middleware is used to perform various tasks such as authentication, caching, handling sessions, logging, modifying responses, and much more.
When a request comes into Django, it first goes through all the middleware in the defined order before reaching the view. Similarly, when a response is sent back, it also goes through all the middleware in the reverse order.
Django provides a set of built-in middleware classes that you can use out-of-the-box, and you can also create your own custom middleware to add your own functionality or to override the behavior of the built-in middleware.
To use middleware in Django, you simply need to add the middleware classes to the MIDDLEWARE setting in your project\’s settings.py file.
Let\’s say we want to create a custom middleware that logs the request and response time of each request. We can create a middleware class like this:
import time
class TimingMiddleware:
def __init__(self, get_response):
self.get_response = get_response
def __call__(self, request):
start_time = time.time()
response = self.get_response(request)
end_time = time.time()
total_time = end_time – start_time
print(f\”Request to {request.path} took {total_time:.2f} seconds.\”)
return response
This middleware class has a constructor that takes get_response as a parameter, which is a callable that takes a request and returns a response. The __call__ method is called for each request, and it logs the request path and the total time it took to process the request.
To use this middleware in our Django project, we need to add it to the MIDDLEWARE setting in settings.py:
MIDDLEWARE = [
# other middleware classes…
\’myapp.middleware.TimingMiddleware\’,
]
Now, each time a request is made to our Django application, the TimingMiddleware will log the time it took to process the request.
