mygpo/api/__init__.py

   1 from datetime import datetime
   2
   3 from django.core.exceptions import ObjectDoesNotExist
   4 from django.http import HttpResponseBadRequest, HttpResponseNotFound
   5 from django.views.decorators.csrf import csrf_exempt
   6 from django.views.decorators.cache import never_cache
   7 from django.utils.decorators import method_decorator
   8 from django.views import View
   9
  10 from mygpo.utils import parse_request_body
  11 from mygpo.api.exceptions import ParameterMissing
  12 from mygpo.decorators import cors_origin
  13 from mygpo.api.basic_auth import require_valid_user, check_username
  14
  15
  16 import logging
  17 logger = logging.getLogger(__name__)
  18
  19
  20 class RequestException(Exception):
  21     """ Raised if the request is malfored or otherwise invalid """
  22
  23
  24 class APIView(View):
  25
  26     @method_decorator(csrf_exempt)
  27     @method_decorator(require_valid_user)
  28     @method_decorator(check_username)
  29     @method_decorator(never_cache)
  30     @method_decorator(cors_origin())
  31     def dispatch(self, *args, **kwargs):
  32         """ Dispatches request and does generic error handling """
  33         try:
  34             return super(APIView, self).dispatch(*args, **kwargs)
  35
  36         except ObjectDoesNotExist as e:
  37             return HttpResponseNotFound(str(e))
  38
  39         except (RequestException, ParameterMissing) as e:
  40             return HttpResponseBadRequest(str(e))
  41
  42     def parsed_body(self, request):
  43         """ Returns the object parsed from the JSON request body """
  44
  45         if not request.body:
  46             raise RequestException('POST data must not be empty')
  47
  48         try:
  49             # TODO: implementation of parse_request_body can be moved here
  50             # after all views using it have been refactored
  51             return parse_request_body(request)
  52         except (UnicodeDecodeError, ValueError) as e:
  53             msg = 'Could not decode request body for user {}: {}'.format(
  54                 request.user.username,
  55                 request.body.decode('ascii', errors='replace'))
  56             logger.warn(msg, exc_info=True)
  57             raise RequestException(msg)
  58
  59     def get_since(self, request):
  60         """ Returns parsed "since" GET parameter """
  61         since_ = request.GET.get('since', None)
  62
  63         if since_ is None:
  64             raise RequestException("parameter 'since' missing")
  65
  66         try:
  67             since_ = int(since_)
  68             since = datetime.fromtimestamp(since_)
  69         except ValueError:
  70             raise RequestException("'since' is not a valid timestamp")
  71
  72         if since_ < 0:
  73             raise RequestException("'since' must be a non-negative number")
  74
  75         return since