Middleware ordering importance in Django - Mini Project: Build & Apply

Middleware Ordering Importance in Django

📖 Scenario: You are building a Django web application that needs to process requests and responses through middleware. Middleware are like helpers that do tasks before or after your main code runs. The order of middleware matters because each one can change the request or response for the next.Imagine middleware as a line of workers passing a package. If the order changes, the package might get handled incorrectly.

🎯 Goal: Build a Django settings.py snippet that defines middleware in the correct order. Then add a custom middleware class and place it properly in the list to see how ordering affects behavior.

📋 What You'll Learn

Create a list called MIDDLEWARE with exact middleware names in the correct order

Add a variable CUSTOM_MIDDLEWARE with the path to your custom middleware class

Insert CUSTOM_MIDDLEWARE into MIDDLEWARE at the correct position

Define a simple custom middleware class named CustomMiddleware with __init__ and __call__ methods

💡 Why This Matters

🌍 Real World

Middleware is used in real Django projects to handle security, sessions, authentication, and custom processing of web requests and responses.

💼 Career

Understanding middleware ordering is important for backend developers working with Django to ensure correct application behavior and to implement custom features.

1

Define the initial MIDDLEWARE list

Create a list called MIDDLEWARE with these exact strings in this order: 'django.middleware.security.SecurityMiddleware', 'django.contrib.sessions.middleware.SessionMiddleware', 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', 'django.contrib.auth.middleware.AuthenticationMiddleware'

Django

# Create the MIDDLEWARE list with the given middleware strings
# Your code here

Need a hint?

Remember to use a Python list with the exact middleware strings in the order given.

2

Add a variable for the custom middleware path

Create a variable called CUSTOM_MIDDLEWARE and set it to the string 'myapp.middleware.CustomMiddleware'

Django

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
]

# Define CUSTOM_MIDDLEWARE variable with the middleware path string
# Your code here

Need a hint?

Assign the exact string to CUSTOM_MIDDLEWARE.

3

Insert the custom middleware into MIDDLEWARE list

Insert the CUSTOM_MIDDLEWARE variable into the MIDDLEWARE list right after 'django.middleware.common.CommonMiddleware'

Django

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
]

CUSTOM_MIDDLEWARE = 'myapp.middleware.CustomMiddleware'

# Insert CUSTOM_MIDDLEWARE after 'django.middleware.common.CommonMiddleware'
# Your code here

Need a hint?

Place CUSTOM_MIDDLEWARE right after 'django.middleware.common.CommonMiddleware' in the list.

4

Define the CustomMiddleware class

Define a class called CustomMiddleware with an __init__ method that takes get_response and stores it, and a __call__ method that takes request and returns the result of calling get_response(request)

Django

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    CUSTOM_MIDDLEWARE,
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
]

CUSTOM_MIDDLEWARE = 'myapp.middleware.CustomMiddleware'

# Define the CustomMiddleware class below
# Your code here

Need a hint?

Follow Django middleware pattern: store get_response in __init__ and call it in __call__.