Fixed #13584 -- Optionally allow empty files with django.forms.FileField. Thanks for the patch erickr and closedbracket.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@16090 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/forms/fields.py

@@ -450,6 +450,7 @@ class FileField(Field):
 
     def __init__(self, *args, **kwargs):
         self.max_length = kwargs.pop('max_length', None)
+        self.allow_empty_file = kwargs.pop('allow_empty_file', False)
         super(FileField, self).__init__(*args, **kwargs)
 
     def to_python(self, data):
@@ -468,7 +469,7 @@ class FileField(Field):
             raise ValidationError(self.error_messages['max_length'] % error_values)
         if not file_name:
             raise ValidationError(self.error_messages['invalid'])
-        if not file_size:
+        if not self.allow_empty_file and not file_size:
             raise ValidationError(self.error_messages['empty'])
 
         return data

docs/ref/forms/fields.txt

@@ -503,10 +503,15 @@ given length.
     * Empty value: ``None``
     * Normalizes to: An ``UploadedFile`` object that wraps the file content
       and file name into a single object.
-    * Validates that non-empty file data has been bound to the form.
+    * Can validate that non-empty file data has been bound to the form.
     * Error message keys: ``required``, ``invalid``, ``missing``, ``empty``,
       ``max_length``
 
+Has two optional arguments for validation, ''max_length'' and 
+''allow_empty_file''. If provided, these ensure that the file name is at 
+most the given length, and that validation will succeed even if the file 
+content is empty.
+
 To learn more about the ``UploadedFile`` object, see the :doc:`file uploads
 documentation </topics/http/file-uploads>`.
 

tests/regressiontests/forms/tests/fields.py

@@ -506,6 +506,11 @@ class FieldsTests(TestCase):
         self.assertEqual('files/test2.pdf', f.clean(None, 'files/test2.pdf'))
         self.assertEqual(SimpleUploadedFile, type(f.clean(SimpleUploadedFile('name', 'Some File Content'))))
 
+    def test_filefield_3(self):
+        f = FileField(allow_empty_file=True)
+        self.assertEqual(SimpleUploadedFile,
+                         type(f.clean(SimpleUploadedFile('name', ''))))
+
     # URLField ##################################################################
 
     def test_urlfield_1(self):