Django middleware component that wraps the login_required decorator around all URL patterns be default, with exceptions. Can also require user to belong to a group ("admin" in this gist) or be adapted if using the Django admin app.

LoginRequiredMiddleware.py

"""
Middleware component that wraps the login_required decorator around all URL patterns be default, with exceptions.
Define PUBLIC_URLS and ADMIN_URLS using regex in settings.py, where:
PUBLIC_URLS do not require user to be logged in.     
ADMIN_URLS require user to be in admin group.
Source: http://stackoverflow.com/a/2164224/720054
"""

# settings.py
PUBLIC_URLS = (
    r'/accounts/register/(.*)$',
    r'/accounts/activate/(.*)$',
    r'/accounts/password/reset/(.*)$',
    r'/accounts/login/(.*)$',
    r'/api/(.*)$',
)

ADMIN_URLS = (
    r'/admin/(.*)$',
)

MIDDLEWARE_CLASSES = (
    # Other middleware...
    'middleware.LoginRequiredMiddleware',
)

# middleware.py
import re

from django.conf import settings
from django.contrib.auth.decorators import login_required, user_passes_test

class LoginRequiredMiddleware(object):    
    def __init__(self):
        self.admin = tuple(re.compile(url) for url in settings.ADMIN_URLS)
        self.public = tuple(re.compile(url) for url in settings.PUBLIC_URLS)

    def process_view(self, request, view_func, view_args, view_kwargs):        
        # No need to process URLs if user is admin
        if request.user.groups.filter(name="admin").exists():
            return None
        
        # Requests matching an admin URL pattern are returned wrapped with the user_passes_test decorator
        for url in self.admin:
            if url.match(request.path):
                return user_passes_test(lambda u: u.groups.filter(name="admin").exists())(view_func)(request, *view_args, **view_kwargs)

        # No need to process remaining URLs if user already logged in
        if request.user.is_authenticated():
            return None

        # An exception match (public) should immediately return None
        for url in self.public:
            if url.match(request.path):
                return None

        # Require login for all non-matching requests
        return login_required(view_func)(request, *view_args, **view_kwargs)