You can’t really win this. You simply must make a declaration of the authorization requirements. Where else would you put this declaration except right by the view function?

Consider replacing your view functions with callable objects.

class LoginViewFunction( object ):
    def __call__( self, request, *args, **kw ):
        p1 = self.login( request, *args, **kw )
        if p1 is not None:
            return p1
        return self.view( request, *args, **kw )
    def login( self, request )
        if not request.user.is_authenticated():
            return HttpResponseRedirect('/login/?next=%s' % request.path)
    def view( self, request, *args, **kw ):
        raise NotImplementedError

You then make your view functions subclasses of LoginViewFunction.

class MyRealView( LoginViewFunction ):
    def view( self, request, *args, **kw ):
        .... the real work ...

my_real_view = MyRealView()  

It doesn’t save any lines of code. And it doesn’t help the “we forgot” problem. All you can do is examine the code to be sure that the view functions are objects. Of the right class.

But even then, you’ll never really know that every view function is correct without a unit test suite.

It’s hard to change the built-in assumptions in Django without reworking the way url’s are handed off to view functions.

Instead of mucking about in Django internals, here’s an audit you can use. Simply check each view function.

import os
import re

def view_modules( root ):
    for path, dirs, files in os.walk( root ):
        for d in dirs[:]:
            if d.startswith("."):
                dirs.remove(d)
        for f in files:
            name, ext = os.path.splitext(f)
            if ext == ".py":
                if name == "views":
                    yield os.path.join( path, f )

def def_lines( root ):
    def_pat= re.compile( "n(S.*)n+(^defs+.*:$)", re.MULTILINE )
    for v in view_modules( root ):
        with open(v,"r") as source:
            text= source.read()
            for p in def_pat.findall( text ):
                yield p

def report( root ):
    for decorator, definition in def_lines( root ):
        print decorator, definition

Run this and examine the output for defs without appropriate decorators.

There is an alternative to putting a decorator on each view function. You can also put the login_required() decorator in the urls.py file.
While this is still a manual task, at least you have it all in one place, which makes it easier to audit.

e.g.,

    from my_views import home_view

    urlpatterns = patterns('',
        # "Home":
        (r'^$', login_required(home_view), dict(template_name='my_site/home.html', items_per_page=20)),
    )

Note that view functions are named and imported directly, not as strings.

Also note that this works with any callable view object, including classes.

Inspired by Ber’s answer I wrote a little snippet that replaces the patterns function, by wrapping all of the URL callbacks with the login_required decorator. This works in Django 1.6.

def login_required_patterns(*args, **kw):
    for pattern in patterns(*args, **kw):
        # This is a property that should return a callable, even if a string view name is given.
        callback = pattern.callback

        # No property setter is provided, so this will have to do.
        pattern._callback = login_required(callback)

        yield pattern

Using it works like this (the call to list is required because of the yield).

urlpatterns = list(login_required_patterns('', url(r'^$', home_view)))

Here is a middleware solution for django 1.10+

The middlewares in have to be written in a new way in django 1.10+.

Code

import re

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


class RequireLoginMiddleware(object):

    def __init__(self, get_response):
         # One-time configuration and initialization.
        self.get_response = get_response

        self.required = tuple(re.compile(url)
                              for url in settings.LOGIN_REQUIRED_URLS)
        self.exceptions = tuple(re.compile(url)
                                for url in settings.LOGIN_REQUIRED_URLS_EXCEPTIONS)

    def __call__(self, request):

        response = self.get_response(request)
        return response

    def process_view(self, request, view_func, view_args, view_kwargs):

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

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

        # Requests matching a restricted URL pattern are returned
        # wrapped with the login_required decorator
        for url in self.required:
            if url.match(request.path):
                return login_required(view_func)(request, *view_args, **view_kwargs)

        # Explicitly return None for all non-matching requests
        return None

Installation

1. Copy the code into your project folder, and save as middleware.py

2. Add to MIDDLEWARE

   MIDDLEWARE = [
   …
   ‘.middleware.RequireLoginMiddleware’, # Require login
   ]

3. Add to your settings.py:

LOGIN_REQUIRED_URLS = (
    r'(.*)',
)
LOGIN_REQUIRED_URLS_EXCEPTIONS = (
    r'/admin(.*)$',
)
LOGIN_URL = '/admin'

Sources:

1. This answer by Daniel Naab

2. Django Middleware tutorial by Max Goodridge

3. Django Middleware Docs

Would be possible to have a single starting point for all the urls in a sort of include and that decorate it using this packages https://github.com/vorujack/decorate_url.

In Django 2.1, we can decorate all methods in a class with:

from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import TemplateView

@method_decorator(login_required, name='dispatch')
class ProtectedView(TemplateView):
    template_name = 'secret.html'

UPDATE:
I have also found the following to work:

from django.contrib.auth.mixins import LoginRequiredMixin
from django.views.generic import TemplateView

class ProtectedView(LoginRequiredMixin, TemplateView):
    template_name = 'secret.html'

and set LOGIN_URL = '/accounts/login/' in your settings.py

There’s an app that provides a plug-and-play solution to this:

https://github.com/mgrouchy/django-stronghold

pip install django-stronghold

# settings.py

INSTALLED_APPS = (
    #...
    'stronghold',
)

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

As of Django 3+, you can change the default like the followings:

Step 1: Create a new file anything.py in your yourapp directory and write the following:

import re
from django.conf import settings
from django.contrib.auth.decorators import login_required

//for registering a class as middleware you at least __init__() and __call__()
//for this case we additionally need process_view() which will be automatically called by Django before rendering a view/template

class ClassName(object):
    
    //need for one time initialization, here response is a function which will be called to get response from view/template
    def __init__(self, response):
        self.get_response = response
        self.required = tuple(re.compile(url) for url in settings.AUTH_URLS)
        self.exceptions = tuple(re.compile(url)for url in settings.NO_AUTH_URLS)

    def __call__(self, request):
        //any code written here will be called before requesting response
        response = self.get_response(request)
        //any code written here will be called after response
        return response

    //this is called before requesting response
    def process_view(self, request, view_func, view_args, view_kwargs):
        //if authenticated return no exception
        if request.user.is_authenticated:
            return None
                
        //default case, no exception
        return login_required(view_func)(request, *view_args, **view_kwargs)

Step 2: Add this anything.py to Middleware[] in project/settings.py like followings

MIDDLEWARE = [
    // your previous middleware
    'yourapp.anything.ClassName',
]

This is the answer for Newer versions of Django. It works pretty well!

https://pypi.org/project/django-login-required-middleware/

works with:

• Python: 3.6, 3.7, 3.8
• Django: 1.11, 2.0, 2.1, 2.2, 3.x