philo/middleware.py

   1 from django.conf import settings
   2 from django.contrib.sites.models import Site
   3 from django.http import Http404
   4 from philo.models import Node, View
   5
   6
   7 class LazyNode(object):
   8         def __get__(self, request, obj_type=None):
   9                 if not hasattr(request, '_cached_node_path'):
  10                         return None
  11
  12                 if not hasattr(request, '_found_node'):
  13                         try:
  14                                 current_site = Site.objects.get_current()
  15                         except Site.DoesNotExist:
  16                                 current_site = None
  17
  18                         path = request._cached_node_path
  19                         trailing_slash = False
  20                         if path[-1] == '/':
  21                                 trailing_slash = True
  22
  23                         try:
  24                                 node, subpath = Node.objects.get_with_path(path, root=getattr(current_site, 'root_node', None), absolute_result=False)
  25                         except Node.DoesNotExist:
  26                                 node = None
  27                         else:
  28                                 if subpath is None:
  29                                         subpath = ""
  30                                 subpath = "/" + subpath
  31
  32                                 if not node.handles_subpath(subpath):
  33                                         node = None
  34                                 else:
  35                                         if trailing_slash and subpath[-1] != "/":
  36                                                 subpath += "/"
  37
  38                                         node.subpath = subpath
  39
  40                         request._found_node = node
  41
  42                 return request._found_node
  43
  44
  45 class RequestNodeMiddleware(object):
  46         """Middleware to process the request's path and attach the closest ancestor node."""
  47         def process_request(self, request):
  48                 request.__class__.node = LazyNode()
  49
  50         def process_view(self, request, view_func, view_args, view_kwargs):
  51                 try:
  52                         request._cached_node_path = view_kwargs['path']
  53                 except KeyError:
  54                         pass
  55
  56         def process_exception(self, request, exception):
  57                 if settings.DEBUG or not hasattr(request, 'node') or not request.node:
  58                         return
  59
  60                 if isinstance(exception, Http404):
  61                         error_view = request.node.attributes.get('Http404', None)
  62                 else:
  63                         error_view = request.node.attributes.get('Http500', None)
  64
  65                 if error_view is None or not isinstance(error_view, View):
  66                         # Should this be duck-typing? Perhaps even no testing?
  67                         return
  68
  69                 extra_context = {'exception': exception}
  70                 return error_view.render_to_response(request, extra_context)