What is Middleware?

Middleware is a framework of hooks into Django’s request/response processing. It allows you to process requests globally before they reach the view or after the view has processed them.

Middleware Features:

• Request Processing: Modify or inspect requests before they reach the view.
• Response Processing: Modify or inspect responses before they are sent to the client.
• Exception Handling: Handle exceptions globally.

Common Middleware Examples:

• AuthenticationMiddleware: Manages user sessions.
• SessionMiddleware: Manages sessions across requests.
• XFrameOptionsMiddleware: Protects against clickjacking by setting X-Frame-Options headers.

Custom Middleware Example:

Here’s how to create custom middleware that logs request details.

1. Create the Middleware: Create a new Python file for the middleware (e.g., myapp/middleware.py):

   class LogRequestMiddleware:
       def __init__(self, get_response):
           self.get_response = get_response
   
       def __call__(self, request):
           print(f"Request URL: {request.path}")
           response = self.get_response(request)
           return response
   

2. Add Middleware to Settings: Add your middleware to the MIDDLEWARE list in settings.py:

   MIDDLEWARE = [
       # Other middleware classes
       'myapp.middleware.LogRequestMiddleware',  # Add your custom middleware
   ]
   

Customizing Middleware

You can use middleware to:

• Modify requests or responses (e.g., add headers, check user authentication).
• Implement caching logic.
• Handle exceptions globally.