Access Mixins
=============

These mixins all control a user's access to a given view. Since many of them extend the ``AccessMixin``, the following are common attributes:

::

    login_url = settings.LOGIN_URL
    raise_exception = False
    redirect_field_name = REDIRECT_FIELD_NAME
    redirect_unauthenticated_users = False

The ``raise_exception`` attribute allows for these scenarios, in case a
permission is denied:

    * ``False`` (default): redirects to the provided login view.
    * ``True``: raises a ``PermissionDenied`` exception.
    * A subclass of ``Exception``: raises this exception.
    * A callable: gets called with the ``request`` argument.
      The function has to return a ``HttpResponse`` or
      ``StreamingHttpResponse`` (Django 1.5+), otherwise a ``PermissionDenied``
      exception gets raised.

This gets done in ``handle_no_permission``, which can be overridden itself.

.. contents::

.. _LoginRequiredMixin:

LoginRequiredMixin
------------------

This mixin is rather simple and is generally the first inherited class in any view. If you don't have an authenticated user, there's no need to go any further. If you've used Django before you are probably familiar with the ``login_required`` decorator.  This mixin replicates the decorator's functionality.

    .. note::
        As of version 1.0, the LoginRequiredMixin has been rewritten to behave like the rest of the ``access`` mixins. It now accepts ``login_url``, ``redirect_field_name``
        and ``raise_exception``.

    .. note::

        This should be the left-most mixin of a view, except when combined with :ref:`CsrfExemptMixin` - which in that case should be the left-most mixin.

::

    from django.views.generic import TemplateView

    from braces.views import LoginRequiredMixin


    class SomeSecretView(LoginRequiredMixin, TemplateView):
        template_name = "path/to/template.html"

        #optional
        login_url = "/signup/"
        redirect_field_name = "hollaback"
        raise_exception = True

        def get(self, request):
            return self.render_to_response({})

An optional class attribute of ``redirect_unauthenticated_users`` can be set to ``True`` if you are using another ``access`` mixin with ``raise_exception`` set to ``True``. This will redirect to the login page if the user is not authenticated, but raises an exception if they are but do not have the required access defined by the other mixins. This defaults to ``False``.

.. _PermissionRequiredMixin:

PermissionRequiredMixin
-----------------------

This mixin was originally written by `Daniel Sokolowski`_ (`code here`_), but this version eliminates an unneeded render if the permissions check fails.

Rather than overloading the dispatch method manually on every view that needs to check for the existence of a permission, use this mixin and set the ``permission_required`` class attribute on your view. If you don't specify ``permission_required`` on your view, an ``ImproperlyConfigured`` exception is raised reminding you that you haven't set it.

The one limitation of this mixin is that it can **only** accept a single permission. If you need multiple permissions use :ref:`MultiplePermissionsRequiredMixin`.

In normal use of this mixin, :ref:`LoginRequiredMixin` comes first, then the ``PermissionRequiredMixin``. If the user isn't an authenticated user, there is no point in checking for any permissions.

    .. note::
        If you are using Django's built in auth system, ``superusers`` automatically have all permissions in your system.

::

    from django.views import TemplateView

    from braces import views


    class SomeProtectedView(views.LoginRequiredMixin,
                            views.PermissionRequiredMixin,
                            TemplateView):

        permission_required = "auth.change_user"
        template_name = "path/to/template.html"

The ``PermissionRequiredMixin`` also offers a ``check_permssions`` method that should be overridden if you need custom permissions checking.


.. _MultiplePermissionsRequiredMixin:

MultiplePermissionsRequiredMixin
--------------------------------

The ``MultiplePermissionsRequiredMixin`` is a more powerful version of the :ref:`PermissionRequiredMixin`.  This view mixin can handle multiple permissions by setting the mandatory ``permissions`` attribute as a dict with the keys ``any`` and/or ``all`` to a list or tuple of permissions.  The ``all`` key requires the ``request.user`` to have **all** of the specified permissions. The ``any`` key requires the ``request.user`` to have **at least one** of the specified permissions. If you only need to check a single permission, the :ref:`PermissionRequiredMixin` is a better choice.

    .. note::
        If you are using Django's built in auth system, ``superusers`` automatically have all permissions in your system.

::

    from django.views import TemplateView

    from braces import views


    class SomeProtectedView(views.LoginRequiredMixin,
                            views.MultiplePermissionsRequiredMixin,
                            TemplateView):

        #required
        permissions = {
            "all": ("blog.add_post", "blog.change_post"),
            "any": ("blog.delete_post", "user.change_user")
        }

The ``MultiplePermissionsRequiredMixin`` also offers a ``check_permssions`` method that should be overridden if you need custom permissions checking.


.. _GroupRequiredMixin:

GroupRequiredMixin
------------------

.. versionadded:: 1.2

The ``GroupRequiredMixin`` ensures that the requesting user is in the group or groups specified. This view mixin can handle multiple groups by setting the mandatory ``group_required`` attribute as a list or tuple.

    .. note::
        The mixin assumes you're using Django's default Group model and that your user model provides ``groups`` as a ManyToMany relationship.
        If this **is not** the case, you'll need to override ``check_membership`` in the mixin to handle your custom set up.

Standard Django Usage
^^^^^^^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import GroupRequiredMixin


    class SomeProtectedView(GroupRequiredMixin, TemplateView):

        #required
        group_required = u"editors"

Multiple Groups Possible Usage
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import GroupRequiredMixin


    class SomeProtectedView(GroupRequiredMixin, TemplateView):

        #required
        group_required = [u"editors", u"admins"]


Custom Group Usage
^^^^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import GroupRequiredMixin


    class SomeProtectedView(GroupRequiredMixin, TemplateView):

        #required
        group_required = u"editors"

        def check_membership(self, group):
            ...
            # Check some other system for group membership
            if user_in_group:
                return True
            else:
                return False


Dynamically Build Groups
^^^^^^^^^^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import GroupRequiredMixin


    class SomeProtectedView(GroupRequiredMixin, TemplateView):
        def get_group_required(self):
            # Get group or groups however you wish
            group = 'secret_group'
            return group

.. _UserPassesTestMixin:

UserPassesTestMixin
-------------------

.. versionadded:: 1.3.0

Mixin that reimplements the `user_passes_test`_ decorator. This is helpful for much more complicated cases than checking if user ``is_superuser`` (for example if their email is from a specific domain).

::

    from django.views import TemplateView

    from braces.views import UserPassesTestMixin


    class SomeUserPassView(UserPassesTestMixin, TemplateView):
        def test_func(self, user):
            return (user.is_staff and not user.is_superuser
                    and user.email.endswith(u"mydomain.com"))


.. _SuperuserRequiredMixin:

SuperuserRequiredMixin
----------------------

Another permission-based mixin. This is specifically for requiring a user to be a superuser. Comes in handy for tools that only privileged users should have access to.

::

    from django.views import TemplateView

    from braces import views


    class SomeSuperuserView(views.LoginRequiredMixin,
                            views.SuperuserRequiredMixin,
                            TemplateView):

        template_name = u"path/to/template.html"


.. _AnonymousRequiredMixin:

AnonymousRequiredMixin
----------------------

.. versionadded:: 1.4.0

Mixin that will redirect authenticated users to a different view. The default redirect is to
Django's `settings.LOGIN_REDIRECT_URL`_.


Static Examples
^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import AnonymousRequiredMixin


    class SomeView(AnonymousRequiredMixin, TemplateView):
        authenticated_redirect_url = u"/send/away/"


::

    from django.core.urlresolvers import reverse_lazy
    from django.views import TemplateView

    from braces.views import AnonymousRequiredMixin


    class SomeLazyView(AnonymousRequiredMixin, TemplateView):
        authenticated_redirect_url = reverse_lazy(u"view_url")


Dynamic Example
^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import AnonymousRequiredMixin


    class SomeView(AnonymousRequiredMixin, TemplateView):
        """ Redirect based on user level """
        def get_authenticated_redirect_url(self):
            if self.request.user.is_superuser:
                return u"/admin/"
            return u"/somewhere/else/"


.. _StaffuserRequiredMixin:

StaffuserRequiredMixin
----------------------

Similar to :ref:`SuperuserRequiredMixin`, this mixin allows you to require a user with ``is_staff`` set to ``True``.

::

    from django.views import TemplateView

    from braces import views


    class SomeStaffuserView(views.LoginRequiredMixin,
                            views.StaffuserRequiredMixin,
                            TemplateView):

        template_name = u"path/to/template.html"


.. _SSLRequiredMixin

SSLRequiredMixin
----------------

.. versionadded:: 1.8.0

Simple view mixin that requires the incoming request to be secure by checking
Django's `request.is_secure()` method. By default the mixin will return a
permanent (301) redirect to the https verison of the current url. Optionally
you can set `raise_exception=True` and a 404 will be raised.

Standard Django Usage
^^^^^^^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import SSLRequiredMixin


    class SomeSecureView(SSLRequiredMixin, TemplateView):
        """ Redirects from http -> https """
        template_name = "path/to/template.html"

Standard Django Usage
^^^^^^^^^^^^^^^^^^^^^

::

    from django.views import TemplateView

    from braces.views import SSLRequiredMixin


    class SomeSecureView(SSLRequiredMixin, TemplateView):
        """ http request would raise 404. https renders view """
        raise_exception = True
        template_name = "path/to/template.html"


.. _RecentLoginRequiredMixin:

RecentLoginRequiredMixin
------------------------

.. versionadded:: 1.8.0

This mixin requires a user to have logged in within a certain number of seconds. This is to prevent stale sessions or to create a session time-out, as is often used for financial applications and the like. This mixin includes the functionality of `LoginRequiredMixin`_, so you don't need to use both on the same view.


::

    from django.views.generic import TemplateView

    from braces.views import RecentLoginRequiredMixin


    class SomeSecretView(RecentLoginRequiredMixin, TemplateView):
        max_last_login_delta = 600  # Require a login within the last 10 minutes
        template_name = "path/to/template.html"


.. _Daniel Sokolowski: https://github.com/danols
.. _code here: https://github.com/lukaszb/django-guardian/issues/48
.. _user_passes_test: https://docs.djangoproject.com/en/1.6/topics/auth/default/#django.contrib.auth.decorators.user_passes_test
.. _settings.LOGIN_REDIRECT_URL: https://docs.djangoproject.com/en/1.6/ref/settings/#login-redirect-url
