-Depending on your task, you'll probably want to make sure to validate the
-user's username and password before you log them in. The easiest way to do so
-is to use the built-in ``authenticate`` and ``login`` functions from within a
+To log a user in, do the following within a view::
- from django.contrib.auth import authenticate, login
- username = request.POST['username']
- password = request.POST['password']
- user = authenticate(username=username, password=password)
+ from django.contrib.auth.models import SESSION_KEY
+ request.session[SESSION_KEY] = some_user.id
-``authenticate`` checks the username and password. If they are valid it
-returns a user object, otherwise it returns ``None``. ``login`` makes it so
-your users don't have send a username and password for every request. Because
-the ``login`` function uses sessions, you'll need to make sure you have
-``SessionMiddleware`` enabled. See the `session documentation`_ for
+Because this uses sessions, you'll need to make sure you have
+``SessionMiddleware`` enabled. See the `session documentation`_ for more
+This assumes ``some_user`` is your ``User`` instance. Depending on your task,
+you'll probably want to make sure to validate the user's username and password.
Limiting access to logged-in users
database. To send messages to anonymous users, use the `session framework`_.
.. _session framework: http://www.djangoproject.com/documentation/sessions/
-Other Authentication Sources
-Django supports other authentication sources as well. You can even use
-multiple sources at the same time.
-The list of backends to use is controlled by the ``AUTHENTICATION_BACKENDS``
-setting. This should be a tuple of python path names. It defaults to
-``('django.contrib.auth.backends.ModelBackend',)``. To add additional backends
-just add them to your settings.py file. Ordering matters, so if the same
-username and password is valid in multiple backends, the first one in the
-list will return a user object, and the remaining ones won't even get a chance.
-Writing an authentication backend
-An authentication backend is a class that implements 2 methods: ``get_user(id)``
-and ``authenticate(**credentials)``. The ``get_user`` method takes an id, which
-could be a username, and database id, whatever, and returns a user object. The
-``authenticate`` method takes credentials as keyword arguments. Many times it
-will just look like this::
- def authenticate(username=None, password=None):
- # check the username/password and return a user
-but it could also authenticate a token like so::
- def authenticate(token=None):
- # check the token and return a user
-Regardless, ``authenticate`` should check the credentials it gets, and if they
-are valid, it should return a user object that matches those credentials.
-The Django admin system is tightly coupled to the Django User object described
-at the beginning of this document. For now, the best way to deal with this is to
-create a Django User object for each user that exists for your backend (i.e.
-in your ldap directory, your external sql database, etc.) You can either
-write a script to do this in advance, or your ``authenticate`` method can do
-it the first time a user logs in. `django.contrib.auth.backends.SettingsBackend`_
-is an example of the latter approach. Note that you don't have to save a user's
-password in the Django User object. Your backend can still check the password
-against an external source, and return a Django User object.
-.. _django.contrib.auth.backends.SettingsBackend: http://code.djangoproject.com/browser/django/branches/magic-removal/django/contrib/auth/backends.py