Book Image

Django 4 By Example - Fourth Edition

By : Antonio Melé
4.7 (3)
Book Image

Django 4 By Example - Fourth Edition

4.7 (3)
By: Antonio Melé

Overview of this book

Django 4 By Example is the 4th edition of the best-selling franchise that helps you build web apps. This book will walk you through the creation of real-world applications, solving common problems, and implementing best practices using a step-by-step approach. You'll cover a wide range of web app development topics as you build four different apps: A blog application: Create data models, views, and URLs and implement an admin site for your blog. Create sitemaps and RSS feeds and implement a full-text search engine with PostgreSQL. A social website: Implement authentication with Facebook, Twitter, and Google. Create user profiles, image thumbnails, a bookmarklet, and an activity stream. Implement a user follower system and add infinite scroll pagination to your website. An e-commerce application: Build a product catalog, a shopping cart, and asynchronous tasks with Celery and RabbitMQ. Process payments with Stripe and manage payment notifications via webhooks. Build a product recommendation engine with Redis. Create PDF invoices and export orders to CSV. An e-learning platform: Create a content management system to manage polymorphic content. Cache content with Memcached and Redis. Build and consume a RESTful API. Implement a real-time chat using WebSockets with ASGI. Create a production environment using NGINX, uWSGI and Daphne with Docker Compose. This is a practical book that will have you creating web apps quickly.
Table of Contents (20 chapters)
18
Other Books You May Enjoy
19
Index

Creating a custom middleware

You already know the MIDDLEWARE setting, which contains the middleware for your project. You can think of it as a low-level plugin system, allowing you to implement hooks that get executed in the request/response process. Each middleware is responsible for some specific action that will be executed for all HTTP requests or responses.

Avoid adding expensive processing to middleware, since they are executed in every single request.

When an HTTP request is received, middleware is executed in order of appearance in the MIDDLEWARE setting. When an HTTP response has been generated by Django, the response passes through all middleware back in reverse order.

A middleware can be written as a function, as follows:

def my_middleware(get_response):
    def middleware(request):
        # Code executed for each request before
        # the view (and later middleware) are called.
        response = get_response(request)
        # Code executed for each...