django_simple/directory/views.py

   1 """Copyright Askbot SpA 2014, Licensed under GPLv3 license."""
   2 import os
   3 from django.conf import settings
   4 from django.core.exceptions import PermissionDenied, ImproperlyConfigured
   5 from django.core.urlresolvers import reverse
   6 from django.http import StreamingHttpResponse, Http404, HttpResponseRedirect
   7 from django.shortcuts import render
   8
   9 try:
  10     from django.utils.module_loading import import_string as import_module
  11 except ImportError:
  12     from django.utils.module_loading import import_by_path as import_module
  13
  14 #utils functions
  15 def check_access(request):
  16     """Returns true if user has access to the directory"""
  17     access_mode = getattr(settings, 'DIRECTORY_ACCESS_MODE', 'public')
  18     if access_mode == 'public':
  19         return True
  20     elif access_mode == 'use-perms':
  21         if request.user.is_anonymous():
  22             return False
  23         else:
  24             return request.user.has_perm('directory.read')
  25     elif access_mode == 'custom':
  26         check_perm = settings.DIRECTORY_ACCESS_FUNCTION
  27         if isinstance(check_perm, basestring):
  28             check_perm = import_module(check_perm)
  29         elif not hasattr(check_perm, '__call__'):
  30             raise ImproperlyConfigured('DIRECTORY_ACCESS_FUNCTION must either be a function or python path')
  31         return check_perm(request)
  32     else:
  33         raise ImproperlyConfigured(
  34             "Invalid setting DIRECTORY_ACCESS_MODE: only values "
  35             "'public', 'use-perms', and 'custom' are allowed"
  36         )
  37
  38
  39 def get_file_names(directory):
  40     """Returns list of file names within directory"""
  41     contents = sorted(os.listdir(directory))
  42     files = list()
  43     for item in contents:
  44         if os.path.isfile(os.path.join(directory, item)):
  45             files.append(item)
  46     return files
  47
  48 def read_file_chunkwise(file_obj):
  49     """Reads file in 32Kb chunks"""
  50     while True:
  51         data = file_obj.read(32768)
  52         if not data:
  53             break
  54         yield data
  55
  56
  57 def list_directory(request, dir_name):
  58     """default view - listing of the directory"""
  59     if check_access(request):
  60         directory = dir_name
  61         data = {
  62             'directory_name': os.path.basename(directory),
  63             'directory_files': get_file_names(directory)
  64         }
  65         template = getattr(settings, 'DIRECTORY_TEMPLATE', 'directory/list.html')
  66         return render(request, template, data)
  67
  68     else:
  69         raise PermissionDenied()
  70
  71
  72 def download_file(request, dir_name, file_name):
  73     """allows authorized user to download a given file"""
  74
  75     if os.path.sep in file_name:
  76         raise PermissionDenied()
  77
  78     if check_access(request):
  79         directory = dir_name
  80
  81         #make sure that file exists within current directory
  82         files = get_file_names(directory)
  83         if file_name in files:
  84             file_path = os.path.join(directory, file_name)
  85             response = StreamingHttpResponse(content_type='application/force-download')
  86             response['Content-Disposition'] = 'attachment; filename=%s' % file_name
  87             file_obj = open(os.path.join(directory, file_name))
  88             response.streaming_content = read_file_chunkwise(file_obj)
  89             return response
  90         else:
  91             raise Http404