Refs #7 - Urlencoded non US-ASCII characters in Content-Disposition header (file name).

CHANGELOG

@@ -8,7 +8,10 @@ future releases, check `milestones`_ and :doc:`/about/vision`.
 1.4 (unreleased)
 ----------------
 
-- Feature #10 - Registered `django-downloadview` on djangopackages.com.
+- Bugfix #7 - Special characters in file names (``Content-Disposition`` header)
+  are urlencoded. An US-ASCII fallback is also provided.
+
+- Feature #10 - `django-downloadview` is registered on djangopackages.com.
 
 
 1.3 (2013-11-08)

django_downloadview/response.py

@@ -2,9 +2,58 @@
 """:py:class:`django.http.HttpResponse` subclasses."""
 import os
 import mimetypes
+import re
+import unicodedata
+import urllib
 
 from django.conf import settings
 from django.http import HttpResponse, StreamingHttpResponse
+from django.utils.encoding import force_str
+
+
+def encode_basename_ascii(value):
+    """Return US-ASCII encoded ``value`` for use in Content-Disposition header.
+
+    >>> encode_basename_ascii(unicode('éà', 'utf-8'))
+    u'ea'
+
+    Spaces are converted to underscores.
+
+    >>> encode_basename_ascii(' ')
+    u'_'
+
+    Text with non US-ASCII characters is expected to be unicode.
+
+    >>> encode_basename_ascii('éà')  # doctest: +ELLIPSIS
+    Traceback (most recent call last):
+        ...
+    UnicodeDecodeError: \'ascii\' codec can\'t decode byte ...
+
+    Of course, ASCII values are not modified.
+
+    >>> encode_basename_ascii('ea')
+    u'ea'
+
+    """
+    ascii_basename = unicode(value)
+    ascii_basename = unicodedata.normalize('NFKD', ascii_basename)
+    ascii_basename = ascii_basename.encode('ascii', 'ignore')
+    ascii_basename = ascii_basename.decode('ascii')
+    ascii_basename = re.sub(r'[\s]', '_', ascii_basename)
+    return ascii_basename
+
+
+def encode_basename_utf8(value):
+    """Return UTF-8 encoded ``value`` for use in Content-Disposition header.
+
+    >>> encode_basename_utf8(u' .txt')
+    '%20.txt'
+
+    >>> encode_basename_utf8(unicode('éà', 'utf-8'))
+    '%C3%A9%C3%A0'
+
+    """
+    return urllib.quote(force_str(value))
 
 
 class DownloadResponse(StreamingHttpResponse):
@@ -86,6 +135,10 @@ class DownloadResponse(StreamingHttpResponse):
         Uses an internal ``_default_headers`` cache.
         Default values are computed if only cache hasn't been set.
 
+        ``Content-Disposition`` header is encoded according to `RFC 5987
+        <http://tools.ietf.org/html/rfc5987>`_. See also
+        http://stackoverflow.com/questions/93551/how-to-encode-the-filename-parameter-of-content-disposition-header-in-http.
+
         """
         try:
             return self._default_headers
@@ -97,8 +150,11 @@ class DownloadResponse(StreamingHttpResponse):
             except (AttributeError, NotImplementedError):
                 pass  # Generated files.
             if self.attachment:
-                headers['Content-Disposition'] = 'attachment; filename=%s' \
-                                                 % self.get_basename()
+                basename = self.get_basename()
+                headers['Content-Disposition'] = \
+                    "attachment; filename={ascii}; filename*=UTF-8''{utf8}" \
+                    .format(ascii=encode_basename_ascii(basename),
+                            utf8=encode_basename_utf8(basename))
             self._default_headers = headers
             return self._default_headers
 

django_downloadview/test.py

@@ -6,6 +6,8 @@ from django.conf import settings
 from django.test.utils import override_settings
 
 from django_downloadview.middlewares import is_download_response
+from django_downloadview.response import (encode_basename_ascii,
+                                          encode_basename_utf8)
 
 
 def setup_view(view, request, *args, **kwargs):
@@ -108,9 +110,24 @@ class DownloadResponseValidator(object):
 
     def assert_basename(self, test_case, response, value):
         """Implies ``attachement is True``."""
-        test_case.assertTrue(
-            response['Content-Disposition'].endswith(
-                'filename={name}'.format(name=value)))
+        ascii_name = encode_basename_ascii(value)
+        utf8_name = encode_basename_utf8(value)
+        if ascii_name == utf8_name:  # Only ASCII characters.
+            check_ascii = True
+            if "filename*=" in response['Content-Disposition']:
+                check_utf8 = True
+        else:
+            check_utf8 = True
+            if "filename=" in response['Content-Disposition']:
+                check_ascii = True
+        if check_ascii:
+            test_case.assertIn('filename={name}'.format(
+                name=ascii_name),
+                response['Content-Disposition'])
+        if check_utf8:
+            test_case.assertIn(
+                "filename*=UTF-8''{name}".format(name=utf8_name),
+                response['Content-Disposition'])
 
     def assert_content_type(self, test_case, response, value):
         test_case.assertEqual(response['Content-Type'], value)

django_downloadview/tests/response.py

@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+"""Unit tests around responses."""
+import unittest
+
+from django_downloadview.response import DownloadResponse
+
+
+class DownloadResponseTestCase(unittest.TestCase):
+    """Tests around :class:`django_downloadviews.response.DownloadResponse`."""
+    def test_content_disposition_encoding(self):
+        """Content-Disposition header is encoded."""
+        response = DownloadResponse('fake file',
+                                    attachment=True,
+                                    basename=u'espacé .txt',)
+        headers = response.default_headers
+        self.assertIn("filename=espace_.txt",
+                      headers['Content-Disposition'])
+        self.assertIn("filename*=UTF-8''espac%C3%A9%20.txt",
+                      headers['Content-Disposition'])