mediagoblin/federation/decorators.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 from functools import wraps
  17
  18 from mediagoblin.db.models import User
  19 from mediagoblin.decorators import require_active_login
  20 from mediagoblin.tools.response import json_response
  21
  22 def user_has_privilege(privilege_name):
  23     """
  24     Requires that a user have a particular privilege in order to access a page.
  25     In order to require that a user have multiple privileges, use this
  26     decorator twice on the same view. This decorator also makes sure that the
  27     user is not banned, or else it redirects them to the "You are Banned" page.
  28
  29         :param privilege_name       A unicode object that is that represents
  30                                         the privilege object. This object is
  31                                         the name of the privilege, as assigned
  32                                         in the Privilege.privilege_name column
  33     """
  34
  35     def user_has_privilege_decorator(controller):
  36         @wraps(controller)
  37         @require_active_login
  38         def wrapper(request, *args, **kwargs):
  39             user_id = request.user.id
  40             if not request.user.has_privilege(privilege_name):
  41                 error = "User '{0}' needs '{1}' privilege".format(
  42                     request.user.username,
  43                     privilege_name
  44                 )
  45                 return json_response({"error": error}, status=403)
  46
  47             return controller(request, *args, **kwargs)
  48
  49         return wrapper
  50     return user_has_privilege_decorator
  51