mygpo/decorators.py

   1 # -*- coding: utf-8 -*-
   2 #
   3 # gPodder - A media aggregator and podcast client
   4 # Copyright (c) 2005-2009 Thomas Perl and the gPodder Team
   5 #
   6 # gPodder is free software; you can redistribute it and/or modify
   7 # it under the terms of the GNU General Public License as published by
   8 # the Free Software Foundation; either version 3 of the License, or
   9 # (at your option) any later version.
  10 #
  11 # gPodder is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 # GNU General Public License for more details.
  15 #
  16 # You should have received a copy of the GNU General Public License
  17 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18 #
  19
  20 from django.shortcuts import render_to_response, get_object_or_404
  21 from django.template import RequestContext
  22 from mygpo.web.models import SecurityToken
  23 from django.contrib.auth.models import User
  24 from django.http import HttpResponseForbidden, HttpResponseNotAllowed
  25 import random
  26 import string
  27 import gc
  28
  29 def requires_token(object, action, denied_template=None):
  30     """
  31     returns a decorator that checks if the security token in the 'token' GET
  32     parameter matches the requires token for the resource. The resource is indicated by
  33     * the username parameter passed to the decorated function
  34     * object and action passed to this method
  35
  36     The decorated method is returned, if
  37     * no token is required for the resource
  38     * the token in the 'token' GET parameter matches the required token
  39
  40     If the passed token does not match
  41     * the denied_template is rendered and returned if given
  42     * HttpResponseForbidden is returned, if denied_template is not given
  43     """
  44     def decorator(fn):
  45         def tmp(request, username, *args, **kwargs):
  46
  47             user = get_object_or_404(User, username=username)
  48             token, c = SecurityToken.objects.get_or_create(user=user, object=object, action=action,
  49                         defaults = {'token': "".join(random.sample(string.letters+string.digits, 32))})
  50
  51             u_token = request.GET.get('token', '')
  52
  53             if token.token == '' or token.token == u_token:
  54                 return fn(request, username, *args, **kwargs)
  55
  56             else:
  57                 if denied_template:
  58                     return render_to_response(denied_template, {
  59                         'other_user': user
  60                         }, context_instance=RequestContext(request))
  61
  62                 else:
  63                     return HttpResponseForbidden()
  64
  65         return tmp
  66     return decorator
  67
  68
  69 def manual_gc(view):
  70     def tmp(*args, **kwargs):
  71         res = view(*args, **kwargs)
  72         gc.collect()
  73         return res
  74
  75     return tmp
  76
  77
  78 def allowed_methods(methods):
  79     def decorator(fn):
  80         def tmp(request, *args, **kwargs):
  81             if request.method in methods:
  82                 return fn(request, *args, **kwargs)
  83             else:
  84                 return HttpResponseNotAllowed(methods)
  85
  86         return tmp
  87
  88     return decorator
  89