app/django/contrib/auth/backends.py
author Sverre Rabbelier <srabbelier@gmail.com>
Mon, 10 Nov 2008 00:42:41 +0000
changeset 461 fca6a8b5ae34
parent 323 ff1a9aa48cfd
permissions -rw-r--r--
Partially use the new user code The 'edit self' is not working fully yet, the 'lookup' code is not working at all, as such, only 'create', 'edit', 'list', and 'delete' make use of the generic code.

try:
    set
except NameError:
    from sets import Set as set # Python 2.3 fallback

from django.db import connection
from django.contrib.auth.models import User


class ModelBackend(object):
    """
    Authenticates against django.contrib.auth.models.User.
    """
    # TODO: Model, login attribute name and password attribute name should be
    # configurable.
    def authenticate(self, username=None, password=None):
        try:
            user = User.objects.get(username=username)
            if user.check_password(password):
                return user
        except User.DoesNotExist:
            return None

    def get_group_permissions(self, user_obj):
        """
        Returns a set of permission strings that this user has through his/her
        groups.
        """
        if not hasattr(user_obj, '_group_perm_cache'):
            cursor = connection.cursor()
            # The SQL below works out to the following, after DB quoting:
            # cursor.execute("""
            #     SELECT ct."app_label", p."codename"
            #     FROM "auth_permission" p, "auth_group_permissions" gp, "auth_user_groups" ug, "django_content_type" ct
            #     WHERE p."id" = gp."permission_id"
            #         AND gp."group_id" = ug."group_id"
            #         AND ct."id" = p."content_type_id"
            #         AND ug."user_id" = %s, [self.id])
            qn = connection.ops.quote_name
            sql = """
                SELECT ct.%s, p.%s
                FROM %s p, %s gp, %s ug, %s ct
                WHERE p.%s = gp.%s
                    AND gp.%s = ug.%s
                    AND ct.%s = p.%s
                    AND ug.%s = %%s""" % (
                qn('app_label'), qn('codename'),
                qn('auth_permission'), qn('auth_group_permissions'),
                qn('auth_user_groups'), qn('django_content_type'),
                qn('id'), qn('permission_id'),
                qn('group_id'), qn('group_id'),
                qn('id'), qn('content_type_id'),
                qn('user_id'),)
            cursor.execute(sql, [user_obj.id])
            user_obj._group_perm_cache = set(["%s.%s" % (row[0], row[1]) for row in cursor.fetchall()])
        return user_obj._group_perm_cache

    def get_all_permissions(self, user_obj):
        if not hasattr(user_obj, '_perm_cache'):
            user_obj._perm_cache = set([u"%s.%s" % (p.content_type.app_label, p.codename) for p in user_obj.user_permissions.select_related()])
            user_obj._perm_cache.update(self.get_group_permissions(user_obj))
        return user_obj._perm_cache

    def has_perm(self, user_obj, perm):
        return perm in self.get_all_permissions(user_obj)

    def has_module_perms(self, user_obj, app_label):
        """
        Returns True if user_obj has any permissions in the given app_label.
        """
        for perm in self.get_all_permissions(user_obj):
            if perm[:perm.index('.')] == app_label:
                return True
        return False

    def get_user(self, user_id):
        try:
            return User.objects.get(pk=user_id)
        except User.DoesNotExist:
            return None